WorldWideScience

Sample records for based multistage modeling

  1. Biologically based multistage modeling of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    William Hazelton; Suresh Moolgavkar; E. Georg Luebeck

    2005-08-30

    This past year we have made substantial progress in modeling the contribution of homeostatic regulation to low-dose radiation effects and carcinogenesis. We have worked to refine and apply our multistage carcinogenesis models to explicitly incorporate cell cycle states, simple and complex damage, checkpoint delay, slow and fast repair, differentiation, and apoptosis to study the effects of low-dose ionizing radiation in mouse intestinal crypts, as well as in other tissues. We have one paper accepted for publication in ''Advances in Space Research'', and another manuscript in preparation describing this work. I also wrote a chapter describing our combined cell-cycle and multistage carcinogenesis model that will be published in a book on stochastic carcinogenesis models edited by Wei-Yuan Tan. In addition, we organized and held a workshop on ''Biologically Based Modeling of Human Health Effects of Low dose Ionizing Radiation'', July 28-29, 2005 at Fred Hutchinson Cancer Research Center in Seattle, Washington. We had over 20 participants, including Mary Helen Barcellos-Hoff as keynote speaker, talks by most of the low-dose modelers in the DOE low-dose program, experimentalists including Les Redpath (and Mary Helen), Noelle Metting from DOE, and Tony Brooks. It appears that homeostatic regulation may be central to understanding low-dose radiation phenomena. The primary effects of ionizing radiation (IR) are cell killing, delayed cell cycling, and induction of mutations. However, homeostatic regulation causes cells that are killed or damaged by IR to eventually be replaced. Cells with an initiating mutation may have a replacement advantage, leading to clonal expansion of these initiated cells. Thus we have focused particularly on modeling effects that disturb homeostatic regulation as early steps in the carcinogenic process. There are two primary considerations that support our focus on homeostatic regulation. First, a number of

  2. An Inventory-Theory-Based Inexact Multistage Stochastic Programming Model for Water Resources Management

    OpenAIRE

    M. Q. Suo; Li, Y. P.; Huang, G. H.; Fan, Y. R.; Li, Z

    2013-01-01

    An inventory-theory-based inexact multistage stochastic programming (IB-IMSP) method is developed for planning water resources systems under uncertainty. The IB-IMSP is based on inexact multistage stochastic programming and inventory theory. The IB-IMSP cannot only effectively handle system uncertainties represented as probability density functions and discrete intervals but also efficiently reflect dynamic features of system conditions under different flow levels within a multistage context....

  3. An Inventory-Theory-Based Inexact Multistage Stochastic Programming Model for Water Resources Management

    Directory of Open Access Journals (Sweden)

    M. Q. Suo

    2013-01-01

    Full Text Available An inventory-theory-based inexact multistage stochastic programming (IB-IMSP method is developed for planning water resources systems under uncertainty. The IB-IMSP is based on inexact multistage stochastic programming and inventory theory. The IB-IMSP cannot only effectively handle system uncertainties represented as probability density functions and discrete intervals but also efficiently reflect dynamic features of system conditions under different flow levels within a multistage context. Moreover, it can provide reasonable transferring schemes (i.e., the amount and batch of transferring as well as the corresponding transferring period associated with various flow scenarios for solving water shortage problems. The applicability of the proposed IB-IMSP is demonstrated by a case study of planning water resources management. The solutions obtained are helpful for decision makers in not only identifying different transferring schemes when the promised water is not met, but also making decisions of water allocation associated with different economic objectives.

  4. Improved quality prediction model for multistage machining process based on geometric constraint equation

    Science.gov (United States)

    Zhu, Limin; He, Gaiyun; Song, Zhanjie

    2016-03-01

    Product variation reduction is critical to improve process efficiency and product quality, especially for multistage machining process (MMP). However, due to the variation accumulation and propagation, it becomes quite difficult to predict and reduce product variation for MMP. While the method of statistical process control can be used to control product quality, it is used mainly to monitor the process change rather than to analyze the cause of product variation. In this paper, based on a differential description of the contact kinematics of locators and part surfaces, and the geometric constraints equation defined by the locating scheme, an improved analytical variation propagation model for MMP is presented. In which the influence of both locator position and machining error on part quality is considered while, in traditional model, it usually focuses on datum error and fixture error. Coordinate transformation theory is used to reflect the generation and transmission laws of error in the establishment of the model. The concept of deviation matrix is heavily applied to establish an explicit mapping between the geometric deviation of part and the process error sources. In each machining stage, the part deviation is formulized as three separated components corresponding to three different kinds of error sources, which can be further applied to fault identification and design optimization for complicated machining process. An example part for MMP is given out to validate the effectiveness of the methodology. The experiment results show that the model prediction and the actual measurement match well. This paper provides a method to predict part deviation under the influence of fixture error, datum error and machining error, and it enriches the way of quality prediction for MMP.

  5. Pricing convertible bonds based on a multi-stage compound-option model

    Science.gov (United States)

    Gong, Pu; He, Zhiwei; Zhu, Song-Ping

    2006-07-01

    In this paper, we introduce the concept of multi-stage compound options to the valuation of convertible bonds (CBs). Rather than evaluating a nested high-dimensional integral that has arisen from the valuation of multi-stage compound options, we found that adopting the finite difference method (FDM) to solve the Black-Scholes equation for each stage actually resulted in a better numerical efficiency. By comparing our results with those obtained by solving the Black-Scholes equation directly, we can show that the new approach does provide an approximation approach for the valuation of CBs and demonstrate that it offers a great potential for a further extension to CBs with more complex structures such as those with call and/or put provisions.

  6. Mathematical modeling on multi-stage series crushing ratio distribution based on fuzzy physical programming

    Institute of Scientific and Technical Information of China (English)

    Yu-Long QI; Chen-Chen CAI; Ping-Zhen LANG

    2013-01-01

    Double-layer,multi-roller plate crusher is a new device,that uses a multi-stage series crushing style to break particles,with the crushing ratio distribution directly influencing the machine's performance.Three crushing ratios of 2.25,2.15 and 2.0 1,used for fuzzy physical programming,were determined.The comparison of the optimized result between the double-layer multi-roller plate crusher and a high pressure roll grinder showed that the double-layer multi-roller plate crusher had a better performance,reducing crushing force and wear.

  7. Double differential cross-section calculations based on a Monte Carlo formulation of the multistage preequilibrium model

    International Nuclear Information System (INIS)

    Nuclear data libraries are widely used in reactor design, shielding, and activation analyses. In many instances there is either a complete lack of paucity of data; therefore nuclear reaction models must supplement and augment experimental data. Theoretical nuclear models, therefore, go hand in hand with data in creating the best nuclear data libraries possible. The intranuclear cascade model (INC), the first and classical approach to describing the preequilibrium regime, follows coordinate-space, particle trajectories within the nucleus by means of the Monte Carlo algorithm in which numerical simulation of the scattering process is based on experimental nucleon-nucleon scattering cross sections. Angular distributions are calculated but the emission at back angles can underpredict data by a few orders of magnitude. The multistage preequilibrium exciton model (MPM) has been implemented in LAHET, the Los Alamos National Laboratory version of the high-energy transport code, in order to correct this defect. Preequilibrium models are statistical, but employ an analytical solution technique. First, the MPM does not completely replace the INC, even at low-incident energies. It is possible that augmenting the MPM with a nuclear surface model, which provides greater particle emission at the tail of the spectra, may allow MPM to replace INC for these cases. Second, a more physical interfacing scheme between MPM and the Bertini model INC is being sought that would employ an excitation energy dependence. This would augment the present ISABEL INC counting scheme that follows the number of excitons created

  8. Multi-stage separations based on dielectrophoresis

    Science.gov (United States)

    Mariella, Jr., Raymond P.

    2004-07-13

    A system utilizing multi-stage traps based on dielectrophoresis. Traps with electrodes arranged transverse to the flow and traps with electrodes arranged parallel to the flow with combinations of direct current and alternating voltage are used to trap, concentrate, separate, and/or purify target particles.

  9. Heterogeneity in multistage carcinogenesis and mixture modeling

    Directory of Open Access Journals (Sweden)

    Morgenthaler Stephan

    2008-07-01

    Full Text Available Abstract Carcinogenesis is commonly described as a multistage process, in which stem cells are transformed into cancer cells via a series of mutations. In this article, we consider extensions of the multistage carcinogenesis model by mixture modeling. This approach allows us to describe population heterogeneity in a biologically meaningful way. We focus on finite mixture models, for which we prove identifiability. These models are applied to human lung cancer data from several birth cohorts. Maximum likelihood estimation does not perform well in this application due to the heavy censoring in our data. We thus use analytic graduation instead. Very good fits are achieved for models that combine a small high risk group with a large group that is quasi immune.

  10. Thermal modelling of the multi-stage heating system with variable boundary conditions in the wafer based precision glass moulding process

    DEFF Research Database (Denmark)

    Sarhadi, Ali; Hattel, Jesper Henri; Hansen, Hans Nørgaard;

    2012-01-01

    of the multi-stage heating system in a wafer based glass moulding process. In order to investigate the importance of the radiation from the interior and surface of the glass, a simple finite volume code is developed to model one dimensional radiation–conduction heat transfer in the glass wafer for an...... different pressures. Finally, the three-dimensional modelling of the multi-stage heating system in the wafer based glass moulding process is simulated with the FEM software ABAQUS for a particular industrial application for mobile phone camera lenses to obtain the temperature distribution in the glass wafer...... of the heating system in the glass moulding process considering detailed heating mechanisms therefore plays an important part in optimizing the heating system and the subsequent pressing stage in the lens manufacturing process.The current paper deals with three-dimensional transient thermal modelling...

  11. Sequential maneuvering decisions based on multi-stage influence diagram in air combat

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A multi-stage influence diagram is used to model the pilot's sequential decision making in one on one air combat.The model based on the multi-stage influence diagram graphically describes the elements of decision process,and contains a point-mass model for the dynamics of an aircraft and takes into account the decision maker's Dreferences under uncertain conditions.Considering an active opponent,the opponent's maneuvers can be modeled stochastically.The solution of multistage influence diagram Can be obtained by converting the multistage influence diagram into a two-level optimization problem.The simulation results show the model is effective.

  12. Ramsey Stochastic Model via Multistage Stochastic Programming

    Czech Academy of Sciences Publication Activity Database

    Kaňková, Vlasta

    Vol. Part II. České Budějovice: University of South Bohemia in České Budějovice, Faculty of Economy , 2010 - (Houda, M.; Friebelová, J.), s. 328-333 ISBN 978-80-7394-218-2. [28th International Conference on Mathematical Methods in Economics 2010. České Budějovice (CZ), 08.09.2010-10.09.2010] R&D Projects: GA ČR GAP402/10/0956; GA ČR(CZ) GA402/08/0107; GA ČR GAP402/10/1610 Institutional research plan: CEZ:AV0Z10750506 Keywords : Ramsey stochastic model * Multistage stochastic programming * Confidence intervals * Autoregressive sequences * Stability * Empirical estimates Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2010/E/kankova-ramsey stochastic model via multistage stochastic programming.pdf

  13. Recent developments in the multistage modeling of cohort data for carcinogenic risk assessment.

    OpenAIRE

    Mazumdar, S; Redmond, C K; Costantino, J P; Patwardhan, R N; Zhou, S. Y.

    1991-01-01

    The modeling of cohort data based on the Armitage-Doll multistage model of the carcinogenic process has gained popular acceptance as a methodology for quantitative risk assessment for estimating the dose-related relationships between different occupational and environmental carcinogenic exposures and cancer mortality. The multistage model can be used for extrapolation to low doses relevant for setting environmental standards and also provides information regarding whether more than one stage ...

  14. Mechanical and mathematical models of multi-stage horizontal fracturing strings and their application

    OpenAIRE

    Zhanghua Lian; Ying Zhang; Xu Zhao; Shidong Ding; Tiejun Lin

    2015-01-01

    Multi-stage SRV fracturing in horizontal wells is a new technology developed at home and abroad in recent years to effectively develop shale gas or low-permeability reservoirs, but on the other hand makes the mechanical environment of fracturing strings more complicated at the same time. In view of this, based on the loading features of tubing strings during the multi-stage fracturing of a horizontal well, mechanical models were established for three working cases of multiple packer setting, ...

  15. A Quasi-One-Dimensional CFD Model for Multistage Turbomachines

    Institute of Scientific and Technical Information of China (English)

    Olivier Léonard; Olivier Adam

    2008-01-01

    The objective of this paper is to present a fast and reliable CFD model that is able to simulate stationary and transient operations of multistage compressors and turbines. This analysis tool is based on an adapted version of the Euler equations solved by a time-marching, finite-volume method. The Euler equations have been extended by including source terms expressing the blade-flow interactions. These source terms are determined using the velocity triangles and a row-by-row representation of the blading at mid-span. The losses and deviations undergone by the fluid across each blade row are supplied by correlations. The resulting flow solver is a performance prediction tool based only on the machine geometry, offering the possibility of exploring the entire characteristic map of a multistage compressor or turbine. Its efficiency in terms of CPU time makes it possible to couple it to an optimization algorithm or to a gas turbine performance tool. Different test-cases are presented for which the calculated characteristic maps are compared to experimental ones.

  16. Axial flow, multi-stage turbine and compressor models

    International Nuclear Information System (INIS)

    Design models of multi-stage, axial-flow turbine and compressor are developed for high temperature nuclear reactor power plants with Closed Brayton Cycle for energy conversion. The models are based on a mean-line through-flow analysis for free-vortex flow, account for the profile, secondary, end wall, trailing edge and tip clearance losses in the cascades, and calculate the geometrical parameters of the blade cascades. The effects of the mean-stage work coefficient, flow coefficient and stage reaction on the design and performance of helium turbine and compressor are investigated. The results compare favorably with those reported for 6 stages helium turbine and 20 stages helium compressor. Also presented and discussed are the results of parametric analyses of a 530-MW helium turbine, and a 251-MW helium compressor.

  17. Robust modified GA based multi-stage fuzzy LFC

    International Nuclear Information System (INIS)

    In this paper, a robust genetic algorithm (GA) based multi-stage fuzzy (MSF) controller is proposed for solution of the load frequency control (LFC) problem in a restructured power system that operates under deregulation based on the bilateral policy scheme. In this strategy, the control signal is tuned online from the knowledge base and the fuzzy inference, which request fewer sources and has two rule base sets. In the proposed method, for achieving the desired level of robust performance, exact tuning of the membership functions is very important. Thus, to reduce the design effort and find a better fuzzy system control, membership functions are designed automatically by modified genetic algorithms. The classical genetic algorithms are powerful search techniques to find the global optimal area. However, the global optimum value is not guaranteed using this method, and the speed of the algorithm's convergence is extremely reduced too. To overcome this drawback, a modified genetic algorithm is being used to tune the membership functions of the proposed MSF controller. The effectiveness of the proposed method is demonstrated on a three area restructured power system with possible contracted scenarios under large load demand and area disturbances in comparison with the multi-stage fuzzy and classical fuzzy PID controllers through FD and ITAE performance indices. The results evaluation shows that the proposed control strategy achieves good robust performance for a wide range of system parameters and load changes in the presence of system nonlinearities and is superior to the other controllers. Moreover, this newly developed control strategy has a simple structure, does not require an accurate model of the plant and is fairly easy to implement, which can be useful for the real world complex power systems

  18. A NOVEL METHOD FOR MULTISTAGE SCENARIO GENERATION BASED ON CLUSTER ANALYSIS

    OpenAIRE

    XIAODONG JI; XIUJUAN ZHAO; XIULI CHAO

    2006-01-01

    Based on cluster analysis, a novel method is introduced in this paper to generate multistage scenarios. A linear programming model is proposed to exclude the arbitrage opportunity by appending a scenario to the generated scenario set. By means of a cited stochastic linear goal programming portfolio model, a case is given to exhibit the virtues of this scenario generation approach.

  19. A multistage model of hospital bed requirements.

    OpenAIRE

    Pendergast, J F; Vogel, W B

    1988-01-01

    This article presents a model for projecting future hospital bed requirements, based on clinical judgment and basic probability theory. Clinical judgment is used to define various categories of care, including a category for patients who are inappropriately hospitalized, for a large teaching hospital with a heavy indigent and psychiatric workload. Survey results and discharge abstract data are then used to calculate expected discharges and patient days for each clinical category. These expect...

  20. Multistage Effort and the Equity Structure of Venture Investment Based on Reciprocity Motivation

    Directory of Open Access Journals (Sweden)

    Chuan Ding

    2015-01-01

    Full Text Available For venture capitals, it is a long process from an entry to its exit. In this paper, the activity of venture investment will be divided into multistages. And, according to the effort level entrepreneurs will choose, the venture capitalists will provide an equity structure at the very beginning. As a benchmark for comparison, we will establish two game models on multistage investment under perfect rationality: a cooperative game model and a noncooperative one. Further, as a cause of pervasive psychological preference behavior, reciprocity motivation will influence the behavior of the decision-makers. Given this situation, Rabin’s reciprocity motivation theory will be applied to the multistage game model of the venture investment, and multistage behavior game model will be established as well, based on the reciprocity motivation. By looking into the theoretical derivations and simulation studies, we find that if venture capitalists and entrepreneurs both have reciprocity preferences, their utility would have been Pareto improvement compared with those under perfect rationality.

  1. Mechanical and mathematical models of multi-stage horizontal fracturing strings and their application

    Directory of Open Access Journals (Sweden)

    Zhanghua Lian

    2015-03-01

    Full Text Available Multi-stage SRV fracturing in horizontal wells is a new technology developed at home and abroad in recent years to effectively develop shale gas or low-permeability reservoirs, but on the other hand makes the mechanical environment of fracturing strings more complicated at the same time. In view of this, based on the loading features of tubing strings during the multi-stage fracturing of a horizontal well, mechanical models were established for three working cases of multiple packer setting, open differential-pressure sliding sleeve, and open ball-injection sliding sleeve under a hold-down packer. Moreover, mathematical models were respectively built for the above three cases. According to the Lame formula and Von Mises stress calculation formula for the thick-walled cylinder in the theory of elastic mechanics, a mathematical model was also established to calculate the equivalent stress for tubing string safety evaluation when the fracturing string was under the combined action of inner pressure, external squeezing force and axial stress, and another mathematical model was built for the mechanical strength and safety evaluation of multi-stage fracturing strings. In addition, a practical software was developed for the mechanical safety evaluation of horizontal well multi-stage fracturing strings according to the mathematical model developed for the mechanical calculation of the multi-packer string in horizontal wells. The research results were applied and verified in a gas well of Tahe Oilfield in the Tarim Basin with excellent effects, providing a theoretical basis and a simple and reliable technical means for optimal design and safety evaluation of safe operational parameters of multi-stage fracturing strings in horizontal wells.

  2. Discontinuous transition of a multistage independent cascade model on networks

    International Nuclear Information System (INIS)

    We propose a multistage version of the independent cascade model, which we call a multistage independent cascade (MIC) model, on networks. This model is parameterized by two probabilities: the probability T1 that a node adopting a fad increases the awareness of a neighboring susceptible node and the probability T2 that an adopter directly causes a susceptible node to adopt the fad. We formulate a tree approximation for the MIC model on an uncorrelated network with an arbitrary degree distribution pk. Applied on a random regular network with degree k = 6, this model exhibits a rich phase diagram, including continuous and discontinuous transition lines for fad percolation and a continuous transition line for the percolation of susceptible nodes. In particular, the percolation transition of fads is discontinuous (continuous) when T1 is larger (smaller) than a certain value. A similar discontinuous transition is observed in random graphs and scale-free networks. Furthermore, assigning a finite fraction of initial adopters dramatically changes the phase boundaries. (paper)

  3. Wetness measurements in a model multistage low pressure steam turbine

    International Nuclear Information System (INIS)

    Comprehensive measurement of wetness losses, exhaust fog droplet diameters, wetness and coarse water content have been taken in a model multistage LP steam turbine over a wide range of flow conditions. It was found that for conventional condensing turbine exhaust wetness fractions of approximately 0.10, the measured wetness loss factor was in reasonable agreement with the Baumann value. Comparison of exhaust wetness fractions derived from dynamometer power and five-hole probe radial traverse measurements, with those found independently from the Central Electricity Research Laboratories optical probe traverses, generally showed agreement to within approximately ±0.01. (author)

  4. Modelling of losses in multi-stage axial compressors with subsonic conditions / William James Swift

    OpenAIRE

    Swift, William James

    2003-01-01

    The need was identified to develop an analytical performance prediction code for subsonic multistage axial compressors that can be included in network analysis software. It was found that performance calculations based on an elementary one-dimensional meanline prediction method could achieve remarkable accuracy, provided that sound models are used for the losses, deviation and the onset of rotating stall. Consequently, this study focuses on gaining more expertise on the modelli...

  5. A multistage differential transformation method for approximate solution of Hantavirus infection model

    Science.gov (United States)

    Gökdoğan, Ahmet; Merdan, Mehmet; Yildirim, Ahmet

    2012-01-01

    The goal of this study is presented a reliable algorithm based on the standard differential transformation method (DTM), which is called the multi-stage differential transformation method (MsDTM) for solving Hantavirus infection model. The results obtanied by using MsDTM are compared to those obtained by using the Runge-Kutta method (R-K-method). The proposed technique is a hopeful tool to solving for a long time intervals in this kind of systems.

  6. A Predictive Model of Multi-Stage Production Planning for Fixed Time Orders

    Directory of Open Access Journals (Sweden)

    Kozłowski Edward

    2014-09-01

    Full Text Available The traditional production planning model based upon a deterministic approach is well described in the literature. Due to the uncertain nature of manufacturing processes, such model can however incorrectly represent actual situations on the shop floor. This study develops a mathematical modeling framework for generating production plans in a multistage manufacturing process. The devised model takes into account the stochastic model for predicting the occurrence of faulty products. The aim of the control model is to determine the number of products which should be manufactured in each planning period to minimize both manufacturing costs and potential financial penalties for failing to fulfill the order completely.

  7. Research on Three-Dimensional Unsteady Turbulent Flow in Multistage Centrifugal Pump and Performance Prediction Based on CFD

    OpenAIRE

    Zhi-jian Wang; Jian-she Zheng; Lu-lu Li; Shuai Luo

    2013-01-01

    The three-dimensional flow physical model of any stage of the 20BZ4 multistage centrifugal pump is built which includes inlet region, impeller flow region, guide-vane flow region and exit region. The three-dimensional unsteady turbulent flow numerical model is created based on Navier-Stoke solver and standard k-ε turbulent equations. The method of multireference frame (MRF) and SIMPLE algorithm are used to simulate the flow in multistage centrifugal pump based on FLUENT software. The distribu...

  8. Mean squared error properties of the kernel-based multi-stage median predictor for time series

    NARCIS (Netherlands)

    J.G. de Gooijer; A. Gannoun; D. Zerom Godefay

    2002-01-01

    We propose a kernel-based multi-stage conditional median predictor for -mixing time series of Markovian structure. Mean squared error properties of single-stage and multi-stage conditional medians are derived and discussed.

  9. Multi-stage Stochastic Programming Models in Production Planning

    Directory of Open Access Journals (Sweden)

    Abas Esmaeili

    2013-10-01

    Full Text Available Production planing is a key area of operations management. An important methodology for production planing is mathematical programming. Traditonal mathematical programming models for production planing are deterministic, and canot provide robust production plans in the presence of uncertainty. As such, deterministic planing models may yield unsatisfactory decisions. Stochastic programming, an active branch of mathematical programming dealing with optimization problems involving uncertain data, has sen several sucesful aplications in production planing. Unlike alternative aproaches to decision making under uncertainty, such as Markov decision proceses, stochastic programming requires few asumptions on the underlying stochastic proceses and alows for modeling of complicated decision structures. On the other hand, stochastic programming asumes finite number of stages and exogenous uncertainties. With recent increase in computational power and algorithmic developments, the limitations of stochastic programming arising from computational dificulties have ben relieved to a large extent. Nowadays, god production planing is a considered as one of the reason for improvement in production and many studies have ben conducted in order to identify the models of production planing. The main purpose of this research is to study multi-stage stochastic programming models in production planing.

  10. Discontinuous Transition of a Multistage Independent Cascade Model on Networks

    CERN Document Server

    Hasegawa, Takehisa

    2012-01-01

    We study a multistage independent cascade (MIC) model in complex networks. This model is parameterized by two probabilities: T1 is the probability that a node adopting a fad increases the awareness of a neighboring susceptible node until it abandons the fad, and T2 is the probability that an adopter directly causes a susceptible node to adopt the fad. We formulate a framework of tree approximation for the MIC model on an uncorrelated network with an arbitrary given degree distribution. As an application, we study this model on a random regular network with degree k=6 to show that it has a rich phase diagram including continuous and discontinuous transition lines for the percolation of fads as well as a continuous transition line for the percolation of susceptible nodes. In particular, the percolation transition of fads is discontinuous (continuous) when T1 is larger (smaller) than a certain value. Furthermore, the phase boundaries drastically change by assigning a finite fraction of initial adopters. We discu...

  11. Preference Integration and Optimization of Multistage Weighted Voting System Based on Ordinal Preference

    OpenAIRE

    Yu-ke Chen; Yan Zou; Zhe Chen

    2014-01-01

    Multistage voting is a common voting form through which the winners are selected. By virtue of weighted multistage voting rules, in this paper, we establish a weighted voting model by analyzing the correlation between individual preference and group preference. The weights of voters in each voting stage are adjusted through preference deviation degrees between individual preferences and group preference, and the ranking among candidates in each stage is determined according to weighted Borda ...

  12. Multistage Development of Müller-Achenbach model for Shape Memory Alloy

    Directory of Open Access Journals (Sweden)

    Simin A. Oshkovr

    2008-01-01

    Full Text Available This research focused on the conceptual development of constitutive Müller-Achenbach model and proceeds to construct a model based on phase transition under changing temperature and load for variants of martensite in shape memory alloy CuAlNi (Copper-aluminum-nickel. Problem statement: Motivation of this research is rare information of a variant of martensite phase (M++ and prediction of the shape recovery of shape memory alloy in this stage of transformation. Approach: The mathematical equations proposed a prediction of stability of Austenite phases and extend it to multistage martensitic phase transformation. These phase transformations occurred by loading on the material. Equations described free energy landscape in CuAlNi shape memory alloys at low (260K and high temperature (440K. The model evaluated the free energy due to the phase transformation between the austenite and multistage martensitic structures. Results: Results for M++ phase showed decrease in temperature from 440K to 260K presented decrease in stress approximately from 1 kN to 0.4kN and free energy from 5 kJ/kg to 0.1 kJ/kg. Equations have been solved and plotted by software programmed in MATLAB. Conclusions/Recommendations: The model which has derived focused on homogeneous shape memory alloys, but future performance requirements will most likely be met with heterogeneous materials. Therefore, simulation models for heterogeneous materials must be developed.

  13. On use of the multistage dose-response model for assessing laboratory animal carcinogenicity

    OpenAIRE

    Nitcheva, Daniella; Piegorsch, Walter W.; West, R. Webster

    2007-01-01

    We explore how well a statistical multistage model describes dose-response patterns in laboratory animal carcinogenicity experiments from a large database of quantal response data. The data are collected from the U.S. EPA’s publicly available IRIS data warehouse and examined statistically to determine how often higher-order values in the multistage predictor yield significant improvements in explanatory power over lower-order values. Our results suggest that the addition of a second-order par...

  14. Reduced models of multi-stage cyclic structures using cyclic symmetry reduction and component mode synthesis

    Science.gov (United States)

    Tran, Duc-Minh

    2014-10-01

    Reduced models of multi-stage cyclic structures such as bladed-disk assemblies are developed by using the multi-stage cyclic symmetry reduction and/or component mode synthesis methods. The multi-stage cyclic symmetry reduction consists in writing the equations of the bladed disks, the inter-disk structures, the inter-disk constraints and the whole multi-stage coupled system in terms of the traveling wave coordinates for all the phase indexes of the reference sectors and for all the bladed disks. Several reduced coupled systems are then solved by selecting at each time only one or a few phase indexes for each bladed disk and by applying the cyclic symmetry boundary conditions. On the other hand, component mode synthesis methods are used either independently or in combination with the multi-stage cyclic symmetry reduction to obtain reduced models of the multi-stage structure. Two of them are particularly efficient, that are firstly component mode synthesis methods with interface modes applied on the bladed disks and secondly component mode synthesis methods with traveling wave coordinates applied on the reference sectors.

  15. Modeling multistage decision processes with Reflexive Game Theory

    OpenAIRE

    Tarasenko, Sergey

    2012-01-01

    This paper introduces application of Reflexive Game Theory to the matter of multistage decision making processes. The idea behind is that each decision making session has certain parameters like "when the session is taking place", "who are the group members to make decision", "how group members influence on each other", etc. This study illustrates the consecutive or sequential decision making process, which consist of two stages. During the stage 1 decisions about the parameters of the ultima...

  16. A multistage FE updating procedure for damage identification in large-scale structures based on multiobjective evolutionary optimization

    OpenAIRE

    Ruiz Perea, Antonio; Perera Velamazán, Ricardo

    2008-01-01

    This study aims to develop a multistage scheme for damage detection for large structures based on experimental modal data and on finite element (FE) model updating methods applied on simple FE models. In the first stage, occurrence and approximate location of damage is performed by using damage functions in order to decrease the number of parameters to be updated. The goal in the second stage is to identify the specific damaged members and damage extent by considering only the members belongi...

  17. Multistage Stochastic Programming and its Applications in Energy Systems Modeling and Optimization

    Science.gov (United States)

    Golari, Mehdi

    considering the integration of renewable energy resources into production planning of energy-intensive manufacturing industries. Recently, a growing number of manufacturing companies are considering renewable energies to meet their energy requirements to move towards green manufacturing as well as decreasing their energy costs. However, the intermittent nature of renewable energies imposes several difficulties in long term planning of how to efficiently exploit renewables. In this study, we propose a scheme for manufacturing companies to use onsite and grid renewable energies provided by their own investments and energy utilities as well as conventional grid energy to satisfy their energy requirements. We propose a multistage stochastic programming model and study an efficient solution method to solve this problem. We examine the proposed framework on a test case simulated based on a real-world semiconductor company. Moreover, we evaluate long-term profitability of such scheme via so called value of multistage stochastic programming.

  18. Multistage principal component analysis based method for abdominal ECG decomposition

    International Nuclear Information System (INIS)

    Reflection of fetal heart electrical activity is present in registered abdominal ECG signals. However this signal component has noticeably less energy than concurrent signals, especially maternal ECG. Therefore traditionally recommended independent component analysis, fails to separate these two ECG signals. Multistage principal component analysis (PCA) is proposed for step-by-step extraction of abdominal ECG signal components. Truncated representation and subsequent subtraction of cardio cycles of maternal ECG are the first steps. The energy of fetal ECG component then becomes comparable or even exceeds energy of other components in the remaining signal. Second stage PCA concentrates energy of the sought signal in one principal component assuring its maximal amplitude regardless to the orientation of the fetus in multilead recordings. Third stage PCA is performed on signal excerpts representing detected fetal heart beats in aim to perform their truncated representation reconstructing their shape for further analysis. The algorithm was tested with PhysioNet Challenge 2013 signals and signals recorded in the Department of Obstetrics and Gynecology, Lithuanian University of Health Sciences. Results of our method in PhysioNet Challenge 2013 on open data set were: average score: 341.503 bpm2 and 32.81 ms. (paper)

  19. A Multi-Stage Optimization Model With Minimum Energy Consumption-Wireless Mesh Networks

    Directory of Open Access Journals (Sweden)

    S. Krishnakumar

    2012-09-01

    Full Text Available Optimization models related with routing, bandwidth utilization and power consumption are developed in the wireless mesh computing environment using the operations research techniques such as maximal flow model, transshipment model and minimax optimizing algorithm. The Path creation algorithm is used to find the multiple paths from source to destination.A multi-stage optimization model is developed by combining the multi-path optimization model, optimization model in capacity utilization and energy optimization model and minimax optimizing algorithm. The input to the multi-stage optimization model is a network with many source and destination. The optimal solution obtained from this model is a minimum energy consuming path from source to destination along with the maximum data rate over each link. The performance is evaluated by comparing the data rate values of superimposed algorithm and minimax optimizing algorithm. The main advantage of this model is the reduction of traffic congestion in the network.

  20. A semi-analytical modelling of multistage bunch compression with collective effects

    Energy Technology Data Exchange (ETDEWEB)

    Zagorodnov, Igor; Dohlus, Martin

    2010-07-15

    In this paper we introduce an analytical solution (up to the third order) for a multistage bunch compression and acceleration system without collective effects. The solution for the system with collective effects is found by an iterative procedure based on this analytical result. The developed formalism is applied to the FLASH facility at DESY. Analytical estimations of RF tolerances are given. (orig.)

  1. Wavelet-based Gaussian-mixture hidden Markov model for the detection of multistage seizure dynamics: A proof-of-concept study

    Directory of Open Access Journals (Sweden)

    Carlen Peter L

    2011-04-01

    Full Text Available Abstract Background Epilepsy is a common neurological disorder characterized by recurrent electrophysiological activities, known as seizures. Without the appropriate detection strategies, these seizure episodes can dramatically affect the quality of life for those afflicted. The rationale of this study is to develop an unsupervised algorithm for the detection of seizure states so that it may be implemented along with potential intervention strategies. Methods Hidden Markov model (HMM was developed to interpret the state transitions of the in vitro rat hippocampal slice local field potentials (LFPs during seizure episodes. It can be used to estimate the probability of state transitions and the corresponding characteristics of each state. Wavelet features were clustered and used to differentiate the electrophysiological characteristics at each corresponding HMM states. Using unsupervised training method, the HMM and the clustering parameters were obtained simultaneously. The HMM states were then assigned to the electrophysiological data using expert guided technique. Minimum redundancy maximum relevance (mRMR analysis and Akaike Information Criterion (AICc were applied to reduce the effect of over-fitting. The sensitivity, specificity and optimality index of chronic seizure detection were compared for various HMM topologies. The ability of distinguishing early and late tonic firing patterns prior to chronic seizures were also evaluated. Results Significant improvement in state detection performance was achieved when additional wavelet coefficient rates of change information were used as features. The final HMM topology obtained using mRMR and AICc was able to detect non-ictal (interictal, early and late tonic firing, chronic seizures and postictal activities. A mean sensitivity of 95.7%, mean specificity of 98.9% and optimality index of 0.995 in the detection of chronic seizures was achieved. The detection of early and late tonic firing was

  2. Multistage models of carcinogenesis and their implications for dose-response models and risk projections

    International Nuclear Information System (INIS)

    Multistage models are used to both describe the biological steps in developing a cancer and as a mathematical description of the relationship of exposure to tumor incidence. With the rapid development of molecular biology the stages of tumor development are becoming understood. Specifically, the effect and role of proto-oncogenes and suppressor genes are exciting developments in the field of carcinogenesis. Mathematically the field has moved from the original Armitage-Doll multistage model to the more current cell kinetic models. These latter models attempt to describe both the rate of cell mutation and the birth-death process involved in clonal expansion. This then allows modeling of both initiation and promotion or cellular proliferation. The field of radiation carcinogenesis has a considerable body of data and knowledge. Unfortunately, relatively little work has been done with the cell kinetic models as to estimation of tumor incidence. This may be due to the newness of kinetic models in general. The field holds promise and it is essential if we are to develop better human risk estimates from exposure to ionizing radiation. (author)

  3. A Multistage Control Mechanism for Group-Based Machine-Type Communications in an LTE System

    Directory of Open Access Journals (Sweden)

    Wen-Chien Hung

    2013-01-01

    Full Text Available When machine-type communication (MTC devices perform the long-term evolution (LTE attach procedure without bit rate limitations, they may produce congestion in the core network. To prevent this congestion, the LTE standard suggests using group-based policing to regulate the maximum bit rate of all traffic generated by a group of MTC devices. However, previous studies on the access point name-aggregate maximum bit rate based on group-based policing are relatively limited. This study proposes a multistage control (MSC mechanism to process the operations of maximum bit rate allocation based on resource-use information. For performance evaluation, this study uses a Markov chain with to analyze MTC application in a 3GPP network. Traffic flow simulations in an LTE system indicate that the MSC mechanism is an effective bandwidth allocation method in an LTE system with MTC devices. Experimental results show that the MSC mechanism achieves a throughput 22.5% higher than that of the LTE standard model using the group-based policing, and it achieves a lower delay time and greater long-term fairness as well.

  4. Vibration based condition monitoring of a multistage epicyclic gearbox in lifting cranes

    Science.gov (United States)

    Assaad, Bassel; Eltabach, Mario; Antoni, Jérôme

    2014-01-01

    This paper proposes a model-based technique for detecting wear in a multistage planetary gearbox used by lifting cranes. The proposed method establishes a vibration signal model which deals with cyclostationary and autoregressive models. First-order cyclostationarity is addressed by the analysis of the time synchronous average (TSA) of the angular resampled vibration signal. Then an autoregressive model (AR) is applied to the TSA part in order to extract a residual signal containing pertinent fault signatures. The paper also explores a number of methods commonly used in vibration monitoring of planetary gearboxes, in order to make comparisons. In the experimental part of this study, these techniques are applied to accelerated lifetime test bench data for the lifting winch. After processing raw signals recorded with an accelerometer mounted on the outside of the gearbox, a number of condition indicators (CIs) are derived from the TSA signal, the residual autoregressive signal and other signals derived using standard signal processing methods. The goal is to check the evolution of the CIs during the accelerated lifetime test (ALT). Clarity and fluctuation level of the historical trends are finally considered as a criteria for comparing between the extracted CIs.

  5. Multi-stage genetic fuzzy systems based on the iterative rule learning approach

    OpenAIRE

    González Muñoz, Antonio; Herrera Triguero, Francisco

    1997-01-01

    Genetic algorithms (GAs) represent a class of adaptive search techniques inspired by natural evolution mechanisms. The search properties of GAs make them suitable to be used in machine learning processes and for developing fuzzy systems, the so-called genetic fuzzy systems (GFSs). In this contribution, we discuss genetics-based machine learning processes presenting the iterative rule learning approach, and a special kind of GFS, a multi-stage GFS based on the iterative rule...

  6. Multi-stage phase retrieval algorithm based upon the gyrator transform

    OpenAIRE

    Rodrigo, José A.; Duadi, H.; Alieva, Tatiana; Zalevsky, Z.

    2010-01-01

    The gyrator transform is a useful tool for optical information processing applications. In this work we propose a multi-stage phase retrieval approach based on this operation as well as on the well-known Gerchberg-Saxton algorithm. It results in an iterative algorithm able to retrieve the phase information using several measurements of the gyrator transform power spectrum. The viability and performance of the proposed algorithm is demonstrated by means of several numerical simulations and exp...

  7. Lung cancer from radon and smoking: a multistage model for the WISMUT uranium miners

    International Nuclear Information System (INIS)

    Full text: In the world's third-largest uranium-mining province located in areas of Saxony and Thuringia in the former German Democratic Republic, the WISMUT Company conducted extensive uranium mining starting in 1946. Up to 1990, when mining activities were discontinued, most of the 400,000 employees had been exposed to uranium ore dust and radon and its progeny. It is well established that, besides smoking, such exposures are associated with an increased risk of lung cancer. From about 130,000 known miners a huge cohort of 59,000 miners has been formed and in an epidemiological analysis lung cancer risks have been evaluated (Grosche et al., 2006). We will present an alternative approach using a biologically-based multistage carcinogenesis model quantifying the lung-cancer risk related to both the exposure to radon and smoking habits. This mechanistic technique allows for extrapolation to the low exposures that are important for present-day radiation protection purposes and the transfer of risk across populations. The model is applied to a sub-cohort of about 35,000 persons who were employed at WISMUT after 1955, with known annual exposures estimated from the job-exposure matrix (Lehmann et al., 2004). Unfortunately, detailed information on smoking is missing for most miners. However, this information has been retrieved in two case-control studies, one of which was nested in the cohort while the other was not (Brueske-Hohlfeld et al., 2006). For these studies, the relevant smoking parameters are assembled in so-called smoking spectra that are next projected onto the entire cohort using a Monte-Carlo sampling method. Individual smoking habits that are randomly assigned to the cohort members, together with the information on annual exposure to radon, is used as an input for the multistage model. Model parameters related to radon and tobacco exposure are fitted with a maximum-likelihood technique. We will show results of the observed and expected lung

  8. Material modeling for multistage tube hydroforming process simulation

    Science.gov (United States)

    Saboori, Mehdi

    The Aerospace industries of the 21st century demand the use of cutting edge materials and manufacturing technology. New manufacturing methods such as hydroforming are relatively new and are being used to produce commercial vehicles. This process allows for part consolidation and reducing the number of parts in an assembly compared to conventional methods such as stamping, press forming and welding of multiple components. Hydroforming in particular, provides an endless opportunity to achieve multiple crosssectional shapes in a single tube. A single tube can be pre-bent and subsequently hydroformed to create an entire component assembly instead of welding many smaller sheet metal sections together. The knowledge of tube hydroforming for aerospace materials is not well developed yet, thus new methods are required to predict and study the formability, and the critical forming limits for aerospace materials. In order to have a better understanding of the formability and the mechanical properties of aerospace materials, a novel online measurement approach based on free expansion test is developed using a 3D automated deformation measurement system (AramisRTM) to extract the coordinates of the bulge profile during the test. These coordinates are used to calculate the circumferential and longitudinal curvatures, which are utilized to determine the effective stresses and effective strains at different stages of the tube hydroforming process. In the second step, two different methods, a weighted average method and a new hardening function are utilized to define accurately the true stress-strain curve for post-necking regime of different aerospace alloys, such as inconel 718 (IN 718), stainless steel 321 (SS 321) and titanium (Ti6Al4V). The flow curves are employed in the simulation of the dome height test, which is utilized for generating the forming limit diagrams (FLDs). Then, the effect of stress triaxiality, the stress concentration factor and the effective plastic

  9. An integrated multi-stage supply chain inventory model with imperfect production process

    OpenAIRE

    Soumita Kundu; Tripti Chakrabarti

    2015-01-01

    This paper deals with an integrated multi-stage supply chain inventory model with the objective of cost minimization by synchronizing the replenishment decisions for procurement, production and delivery activities. The supply chain structure examined here consists of a single manufacturer with multi-buyer where manufacturer orders a fixed quantity of raw material from outside suppliers, processes the materials and delivers the finished products in unequal shipments to each customer. In this p...

  10. Using multistage models to describe radiation-induced leukaemia

    International Nuclear Information System (INIS)

    The Armitage-Doll model of carcinogenesis is fitted to data on leukaemia mortality among the Japanese atomic bomb survivors with the DS86 dosimetry and on leukaemia incidence in the International Radiation Study of Cervical Cancer patients. Two different forms of model are fitted: the first postulates up to two radiation-affected stages and the second additionally allows for the presence at birth of a non-trivial population of cells which have already accumulated the first of the mutations leading to malignancy. Among models of the first form, a model with two adjacent radiation-affected stages appears to fit the data better than other models of the first form, including both models with two affected stages in any order and models with only one affected stage. The best fitting model predicts a linear-quadratic dose-response and reductions of relative risk with increasing time after exposure and age at exposure, in agreement with what has previously been observed in the Japanese and cervical cancer data. However, on the whole it does not provide an adequate fit to either dataset. The second form of model appears to provide a rather better fit, but the optimal models have biologically implausible parameters (the number of initiated cells at birth is negative) so that this model must also be regarded as providing an unsatisfactory description of the data. (author)

  11. Immunogenic multistage recombinant protein vaccine confers partial protection against experimental toxoplasmosis mimicking natural infection in murine model

    Directory of Open Access Journals (Sweden)

    Yaprak Gedik

    2016-01-01

    To generate a protective vaccine against toxoplasmosis, multistage vaccines and usage of challenging models mimicking natural route of infection are critical cornerstones. In this study, we generated a BAG1 and GRA1 multistage vaccine that induced strong immune response in which the protection was not at anticipated level. In addition, the murine model was orally challenged with tissue cysts to mimic natural route of infection.

  12. Multi-stage Stochastic Programming Models in Production Planning

    OpenAIRE

    Abas Esmaeili; Ahmad Jafarnejad; Fariborz Jolai

    2013-01-01

    Production planing is a key area of operations management. An important methodology for production planing is mathematical programming. Traditonal mathematical programming models for production planing are deterministic, and canot provide robust production plans in the presence of uncertainty. As such, deterministic planing models may yield unsatisfactory decisions. Stochastic programming, an active branch of mathematical programming dealing with optimization problems involving uncertain d...

  13. Research on Three-Dimensional Unsteady Turbulent Flow in Multistage Centrifugal Pump and Performance Prediction Based on CFD

    Directory of Open Access Journals (Sweden)

    Zhi-jian Wang

    2013-01-01

    Full Text Available The three-dimensional flow physical model of any stage of the 20BZ4 multistage centrifugal pump is built which includes inlet region, impeller flow region, guide-vane flow region and exit region. The three-dimensional unsteady turbulent flow numerical model is created based on Navier-Stoke solver and standard k-ε turbulent equations. The method of multireference frame (MRF and SIMPLE algorithm are used to simulate the flow in multistage centrifugal pump based on FLUENT software. The distributions of relative velocity, absolute velocity, static pressure, and total pressure in guide vanes and impellers under design condition are analyzed. The simulation results show that the flow in impeller is mostly uniform, without eddy, backflow, and separation flow, and jet-wake phenomenon appears only along individual blades. There is secondary flow at blade end and exit of guide vane. Due to the different blade numbers of guide vane and impeller, the total pressure distribution is asymmetric. This paper also simulates the flow under different working conditions to predict the hydraulic performances of centrifugal pump and external characteristics including flow-lift, flow-shaft power, and flow-efficiency are attained. The simulation results are compared with the experimental results, and because of the mechanical losses and volume loss ignored, there is a little difference between them.

  14. Biotransformation of polyphenols in a dynamic multistage gastrointestinal model.

    Science.gov (United States)

    Sadeghi Ekbatan, Shima; Sleno, Lekha; Sabally, Kebba; Khairallah, Joelle; Azadi, Behnam; Rodes, Laetitia; Prakash, Satya; Donnelly, Danielle J; Kubow, Stan

    2016-08-01

    A multi-reactor gastrointestinal model was used to digest a mixture of pure polyphenol compounds, including non-flavonoid phenolic acids (chlorogenic acid, caffeic acid, ferulic acid) and a flavonoid (rutin) to identify phenolic metabolites and short chain fatty acids (SCFAs) and compare relative antioxidant capacities following a 24h digestion. Biotransformation of these polyphenols occurred in the colonic compartments generating phenylpropionic, benzoic, phenylacetic and cinnamic acids. Total SCFAs increased in all colonic vessels with a rise in the proportion of propionic to acetic acid. Antioxidant capacity increased significantly in all compartments, but first in the stomach, small intestine and ascending colon. After 24h, the colonic vessels without parent polyphenols, but containing new metabolites, had antioxidant capacities similar to the stomach and small intestine, containing parent compounds. Biotransformation of pure polyphenols resulted in different phenolic metabolite and SCFAs profiles in each colonic segment, with important health implications for these colonic compartments. PMID:26988524

  15. Lab-testing, predicting, and modeling multi-stage activated carbon adsorption of organic micro-pollutants from treated wastewater.

    Science.gov (United States)

    Zietzschmann, F; Altmann, J; Hannemann, C; Jekel, M

    2015-10-15

    Multi-stage reuse of powdered activated carbon (PAC) is often applied in practice for a more efficient exploitation of the PAC capacity to remove organic micro-pollutants (OMP). However, the adsorption mechanisms in multi-stage PAC reuse are rarely investigated, as large-scale experiments do not allow for systematic tests. In this study, a laboratory method for the separation of PAC/water suspensions and the subsequent reuse of the PAC and the water was developed. The method was tested on wastewater treatment plant (WWTP) effluent in a setup with up to 7 PAC reuse stages. The tests show that the overall OMP removal from WWTP effluent can be increased when reusing PAC. The reason is that a repeated adsorption in multi-stage PAC reuse results in similar equilibrium concentrations as a single-stage adsorption. Thus, a single relationship between solid and liquid phase OMP concentrations appears valid throughout all stages. This also means that the adsorption efficiency of multi-stage PAC reuse setups can be estimated from the data of a single-stage setup. Furthermore, the overall OMP removals in multi-stage setups coincide with the overall UV254 removals, and for each respective OMP one relationship to UV254 removal is valid throughout all stages. The results were modeled by a simple modification of the equivalent background compound model (EBCM) which was also used to simulate the additional OMP removals in multi-stage setups with up to 50 reuse stages. PMID:26117373

  16. Direction of Arrival Estimation Based on the Multistage Nested Wiener Filter

    OpenAIRE

    Xiaodong He; Bin Tang

    2015-01-01

    A novel direction of arrival (DOA) estimation technique based on data level and order recursive Multistage Nested Wiener Filters (MSNWF) which is used in adaptive beamforming for subarray signal is proposed in this paper. The two subarrays using the same array geometry are used to form a signal whose phase relative to the reference signal is a function of the DOA. The DOA is estimated by calculating the phase-shift between the reference signal and its phase-shifted version. The performance of...

  17. Forestry inventory based on multistage sampling with probability proportional to size

    Science.gov (United States)

    Lee, D. C. L.; Hernandez, P., Jr.; Shimabukuro, Y. E.

    1983-01-01

    A multistage sampling technique, with probability proportional to size, is developed for a forest volume inventory using remote sensing data. The LANDSAT data, Panchromatic aerial photographs, and field data are collected. Based on age and homogeneity, pine and eucalyptus classes are identified. Selection of tertiary sampling units is made through aerial photographs to minimize field work. The sampling errors for eucalyptus and pine ranged from 8.34 to 21.89 percent and from 7.18 to 8.60 percent, respectively.

  18. Reduction of multi-stage disk models: Application to an industrial rotor

    OpenAIRE

    Sternchüss, Arnaud,; Balmes, Etienne; Jean, Pierrick; Lombard, Jean Pierre

    2009-01-01

    The present study deals with the reduction of models of multi-stage bladed disk assemblies. The proposed method relies on the substructuring of the rotor into sectors. The bladed disks are coupled by intermediate rings which remove the problem of incompatible meshes. The sectors are represented by super-elements whose kinematic subspaces are spanned by a set of cyclic modeshapes and a set of normal modes when their left and right interfaces are fixed. The first step is to compute the cyclic m...

  19. A Multi-Stage Wear Model for Grid-to-Rod Fretting of Nuclear Fuel Rods

    Energy Technology Data Exchange (ETDEWEB)

    Blau, Peter Julian [ORNL

    2014-01-01

    The wear of fuel rod cladding against the supporting structures in the cores of pressurized water nuclear reactors (PWRs) is an important and potentially costly tribological issue. Grid-to-rod fretting (GTRF), as it is known, involves not only time-varying contact conditions, but also elevated temperatures, flowing hot water, aqueous tribo-corrosion, and the embrittling effects of neutron fluences. The multi-stage, closed-form analytical model described in this paper relies on published out-of-reactor wear and corrosion data and a set of simplifying assumptions to portray the conversion of frictional work into wear depth. The cladding material of interest is a zirconium-based alloy called Zircaloy-4, and the grid support is made of a harder and more wear-resistant material. Focus is on the wear of the cladding. The model involves an incubation stage, a surface oxide wear stage, and a base alloy wear stage. The wear coefficient, which is a measure of the efficiency of conversion of frictional work into wear damage, can change to reflect the evolving metallurgical condition of the alloy. Wear coefficients for Zircaloy-4 and for a polyphase zirconia layer were back-calculated for a range of times required to wear to a critical depth. Inputs for the model, like the friction coefficient, are taken from the tribology literature in lieu of in-reactor tribological data. Concepts of classical fretting were used as a basis, but are modified to enable the model to accommodate the complexities of the PWR environment. Factors like grid spring relaxation, pre-oxidation of the cladding, multiple oxide phases, gap formation, impact, and hydrogen embrittlement are part of the problem definition but uncertainties in their relative roles limits the ability to validate the model. Sample calculations of wear depth versus time in the cladding illustrate how GTRF wear might occur in a discontinuous fashion during months-long reactor operating cycles. A means to account for grid/rod gaps

  20. Real-time video fusion based on multistage hashing and hybrid transformation with depth adjustment

    Science.gov (United States)

    Zhao, Hongjian; Xia, Shixiong; Yao, Rui; Niu, Qiang; Zhou, Yong

    2015-11-01

    Concatenating multicamera videos with differing centers of projection into a single panoramic video is a critical technology of many important applications. We propose a real-time video fusion approach to create wide field-of-view video. To provide a fast and accurate video registration method, we propose multistage hashing to find matched feature-point pairs from coarse to fine. In the first stage of multistage hashing, a short compact binary code is learned from all feature points, and then we calculate the Hamming distance between each two points to find the candidate-matched points. In the second stage, a long binary code is obtained by remapping the candidate points for fine matching. To tackle the distortion and scene depth variation of multiview frames in videos, we build hybrid transformation with depth adjustment. The depth compensation between two adjacent frames extends into multiple frames in an iterative model for successive video frames. We conduct several experiments with different dynamic scenes and camera numbers to verify the performance of the proposed real-time video fusion approach.

  1. Modeling Humans as Reinforcement Learners: How to Predict Human Behavior in Multi-Stage Games

    Science.gov (United States)

    Lee, Ritchie; Wolpert, David H.; Backhaus, Scott; Bent, Russell; Bono, James; Tracey, Brendan

    2011-01-01

    This paper introduces a novel framework for modeling interacting humans in a multi-stage game environment by combining concepts from game theory and reinforcement learning. The proposed model has the following desirable characteristics: (1) Bounded rational players, (2) strategic (i.e., players account for one anothers reward functions), and (3) is computationally feasible even on moderately large real-world systems. To do this we extend level-K reasoning to policy space to, for the first time, be able to handle multiple time steps. This allows us to decompose the problem into a series of smaller ones where we can apply standard reinforcement learning algorithms. We investigate these ideas in a cyber-battle scenario over a smart power grid and discuss the relationship between the behavior predicted by our model and what one might expect of real human defenders and attackers.

  2. A multi-stage approach for damage detection in structural systems based on flexibility

    Science.gov (United States)

    Grande, E.; Imbimbo, M.

    2016-08-01

    The paper proposes a fusion approach for damage detection in structural applications in the case of multiple damage locations and three-dimensional systems. Based on the Dempster-Shafer evidence theory, a multi-stage approach is proposed with the mode shapes assumed as primary sources and local decisions based on a flexibility method. The proposed approach has been applied to two case studies, a a fixed end beam analyzed in other papers and a three dimensional structures codified in a Benchmark problem. Both the case studies have shown the ability and the efficiency of the proposed approach to detect damage also in the case of multiple damage, limited number of identified parameters and noise measurements.

  3. SOLAR ABSORBING COOLING SYSTEMS BASED ON MULTISTAGE HEAT-MASS-TRANSFER DEVICES

    Directory of Open Access Journals (Sweden)

    Doroshenko A.V.

    2014-08-01

    Full Text Available The article presents the worked out schematics for the alternative refrigeration systems and of air-conditioning systems, based on the use of absorbing cycle and of the sunny energy for the regeneration (renewals of absorbent solution. We use here the cascade principle of construction of all heat-mass-transfer apparatus with variation of both the temperature level and the growth of absorbent concentration on the cascade stages. The heat-mass-transfer equipment as a part of the drying and cooling units is standardized and is executed by means of multistage monoblock compositions from poly-meric materials. The preliminary analysis of possibilities of the sunny systems in application to the tasks of cooling of environment and air-conditioning systems is carried out.

  4. Multi-Stage Optimization Based Automatic Voltage Control Systems Considering Wind Power Forecasting Errors

    DEFF Research Database (Denmark)

    Qin, Nan; Bak, Claus Leth; Abildgaard, Hans;

    2016-01-01

    This paper proposes an automatic voltage control (AVC) system for power systems with limited continuous voltage control capability. The objective is to minimize the operational cost over a period, which consists of the power loss in the grid, the shunt switching cost, the transformer tap change...... cost and the generator reactive power output cost. The problem is formulated in a multi-stage optimal reactive power flow (MORPF) framework, solved by the nonlinear programming techniques via a rolling process. The voltage uncertainty caused by wind power forecasting errors is considered in the optimal...... electricity control center, where study cases based on the western Danish power system demonstrate the superiority of the proposed AVC system in term of the cost minimization. Monte Carlo simulations are carried out to verify the proposed method on the robustness improvements....

  5. An integrated multi-stage supply chain inventory model with imperfect production process

    Directory of Open Access Journals (Sweden)

    Soumita Kundu

    2015-09-01

    Full Text Available This paper deals with an integrated multi-stage supply chain inventory model with the objective of cost minimization by synchronizing the replenishment decisions for procurement, production and delivery activities. The supply chain structure examined here consists of a single manufacturer with multi-buyer where manufacturer orders a fixed quantity of raw material from outside suppliers, processes the materials and delivers the finished products in unequal shipments to each customer. In this paper, we consider an imperfect production system, which produces defective items randomly and assumes that all defective items could be reworked. A simple algorithm is developed to obtain an optimal production policy, which minimizes the expected average total cost of the integrated production-inventory system.

  6. Mathematical models for process commonality under quality and resources breakdown in multistage production

    Institute of Scientific and Technical Information of China (English)

    Mohammed Abdul WAZED; Shamsuddin AHMED; Yusoff Bin NUKMANt

    2011-01-01

    It is essential to manage customers' diverse desires and to keep manufacturing costs as low as possible for survival in competition and eventually in production.Sharing resources in manufacturing for different products is a vital method of accomplishing this goal.The advantages of using a common process in production are stated in the literature.However,the mathematical models as well as simulation or conceptual models are not sufficient.The main objective of this paper is to develop mathematical models for multiproduct and multistage production under quality and breakdown uncertainties.The idea of the process commonality is incorporated in the proposed models.The models are validated by primary data collected from a Malaysian company and comparison of the timely requirement schedules of earlier MRP Ⅱ and the proposed models under stable and perfect production environments.An appreciable convergence of the outcomes is observed.However,the proposed models are carrying additional information about the available locations of the parts in a time frame.After validation,the effects of process commonality on cost,capacity and the requirement schedule under uncertainties are examined.It is observed that the use of common processes in manufacturing is always better than the non-commonality scenario in terms of production cost.However,the increase in capacity requirement for commonality designs is higher for an ideal system,while it is less when the system suffers from breakdowns and a quality problem.

  7. A simple multistage closed-(box+reservoir model of chemical evolution

    Directory of Open Access Journals (Sweden)

    Caimmi R.

    2011-01-01

    Full Text Available Simple closed-box (CB models of chemical evolution are extended on two respects, namely (i simple closed-(box+reservoir (CBR models allowing gas outflow from the box into the reservoir (Hartwick 1976 or gas inflow into the box from the reservoir (Caimmi 2007 with rate proportional to the star formation rate, and (ii simple multistage closed-(box+reservoir (MCBR models allowing different stages of evolution characterized by different inflow or outflow rates. The theoretical differential oxygen abundance distribution (TDOD predicted by the model maintains close to a continuous broken straight line. An application is made where a fictitious sample is built up from two distinct samples of halo stars and taken as representative of the inner Galactic halo. The related empirical differential oxygen abundance distribution (EDOD is represented, to an acceptable extent, as a continuous broken line for two viable [O/H]-[Fe/H] empirical relations. The slopes and the intercepts of the regression lines are determined, and then used as input parameters to MCBR models. Within the errors (-+σ, regression line slopes correspond to a large inflow during the earlier stage of evolution and to low or moderate outflow during the subsequent stages. A possible inner halo - outer (metal-poor bulge connection is also briefly discussed. Quantitative results cannot be considered for applications to the inner Galactic halo, unless selection effects and disk contamination are removed from halo samples, and discrepancies between different oxygen abundance determination methods are explained.

  8. A scenario tree-based decomposition for solving multistage stochastic programs. With application in energy production

    Energy Technology Data Exchange (ETDEWEB)

    Mahlke, Debora

    2011-07-01

    This thesis is concerned with the development and implementation of an optimization method for the solution of multistage stochastic mixed-integer programs arising in energy production. Motivated by the strong increase in electricity produced from wind energy, we investigate the question of how energy storages may contribute to integrate the strongly fluctuating wind power into the electric power network. In order to study the economics of energy storages, we consider a power generation system which consists of conventional power plants, different types of energy storages, and an offshore wind park which supplies a region of certain dimension with electrical energy. On this basis, we aim at optimizing the commitment of the facilities over several days minimizing the overall costs. We formulate the problem as a mixed-integer optimization program concentrating on the combinatorial and stochastic aspects. The nonlinearities arising from partial load efficiencies of the units are approximated by piece-wise linear functions. In order to account for the uncertainty regarding the fluctuations of the available wind power and of the prices for electricity purchased on the spot market, we describe the affected data via a scenario tree. Altogether, we obtain a stochastic multistage mixed-integer problem (SMIP) of high complexity whose solution is algorithmically and computationally challenging. The main focus of this thesis is on the development of a scenario tree-based decomposition approach combined with a branch-and-bound method (SD-BB) for solution of the SMIP described above. This novel method relies on the decomposition of the original formulation into several subproblems based on the splitting of the scenario tree into subtrees. Using a branch-and-bound framework which we extend by Lagrangian relaxation, we can solve the problem to global optimality. In order to support the solution process, we investigate the polyhedral substructure which results from the description

  9. An e-quality control model for multistage machining processes of workpieces

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To track and control the changes of process quality attributes in multistage machining processes(MMPs),an e-quality control(e-QC) model is proposed.The e-QC model is defined as a quality information service node with e-formalizing technology,whose input/output and intermediate process(that is IPO) are known to other nodes,and its implemention in MMPs is provided.In order to establish the e-QC model,a measuring network is constructed to acquire the original quality data,and the changes of process quality attributes are monitored and diagnosed by the integrated quality analysis tools attached to the e-QC,which can be tracked by information template network in real time.Furthermore,a hierarchical control method is adopted to coordinate e-QCs,in which the quality loss and adjusting cost are used to quantify the opportunities for e-QCs to improve process quality.At last,a prototype is developed to verify the proposed methods.

  10. An e-quality control model for multistage machining processes of workpieces

    Institute of Scientific and Technical Information of China (English)

    LIU DaoYu; JIANG PingYu; ZHANG YingFeng

    2008-01-01

    To track and control the changes of process quality attributes in multistage ma-chining processes (MMPs), an e-quality control (e-QC) model is proposed. The e-QC model is defined as a quality information service node with e-formalizing technology, whose input/output and intermediate process (that is IPO) are known to other nodes, and its implemention in MMPs is provided. In order to establish the e-QC model, a measuring network is constructed to acquire the original quality data, and the changes of process quality attributes are monitored and diagnosed by the integrated quality analysis tools attached to the e-QC, which can be tracked by in-formation template network in real time. Furthermore, a hierarchical control method is adopted to coordinate e-QCs, in which the quality loss and adjusting cost are used to quantify the opportunities for e-QCs to improve process quality. At last, a prototype is developed to verify the proposed methods.

  11. Multi-Stage Feature Selection by Using Genetic Algorithms for Fault Diagnosis in Gearboxes Based on Vibration Signal

    Directory of Open Access Journals (Sweden)

    Mariela Cerrada

    2015-09-01

    Full Text Available There are growing demands for condition-based monitoring of gearboxes, and techniques to improve the reliability, effectiveness and accuracy for fault diagnosis are considered valuable contributions. Feature selection is still an important aspect in machine learning-based diagnosis in order to reach good performance in the diagnosis system. The main aim of this research is to propose a multi-stage feature selection mechanism for selecting the best set of condition parameters on the time, frequency and time-frequency domains, which are extracted from vibration signals for fault diagnosis purposes in gearboxes. The selection is based on genetic algorithms, proposing in each stage a new subset of the best features regarding the classifier performance in a supervised environment. The selected features are augmented at each stage and used as input for a neural network classifier in the next step, while a new subset of feature candidates is treated by the selection process. As a result, the inherent exploration and exploitation of the genetic algorithms for finding the best solutions of the selection problem are locally focused. The Sensors 2015, 15 23904 approach is tested on a dataset from a real test bed with several fault classes under different running conditions of load and velocity. The model performance for diagnosis is over 98%.

  12. A multistage framework for reliability-based distribution expansion planning considering distributed generations by a self-adaptive global-based harmony search algorithm

    International Nuclear Information System (INIS)

    In this paper, the authors present a new multistage framework for reliability-based Distribution Expansion Planning (DEP) in which expansion options are a reinforcement and/or installation of substations, feeders, and Distributed Generations (DGs). The proposed framework takes into account not only costs associated with investment, maintenance, and operation, but also expected customer interruption cost in the optimization as four problem objectives. At the same time, operational restrictions, Kirchhoff's laws, radial structure limitation, voltage limits, and capital expenditure budget restriction are considered as problem constraints. The proposed model is a non-convex optimization problem having a non-linear, mixed-integer nature. Hence, a hybrid Self-adaptive Global-based Harmony Search Algorithm (SGHSA) and Optimal Power Flow (OPF) were used and followed by a fuzzy satisfying method in order to obtain the final optimal solution. The SGHSA is a recently developed optimization algorithm which imitates the music improvisation process. In this process, the harmonists improvise their instrument pitches, searching for the perfect state of harmony. The planning methodology was demonstrated on the 27-node, 13.8-kV test system in order to demonstrate the feasibility and capability of the proposed model. Simulation results illustrated the sufficiency and profitableness of the newly developed framework, when compared with other methods. - Highlights: • A new multistage framework is presented for reliability-based DEP problem. • In this paper, DGs are considered as an expansion option to increase the flexibility of the proposed model. • In this paper, effective factors of DEP problem are incorporated as a multi-objective model. • In this paper, three new algorithms HSA, IHSA and SGHSA are proposed. • Results obtained by the proposed SGHSA algorithm are better than others

  13. A design methodology for a magnetorheological fluid damper based on a multi-stage radial flow mode

    Science.gov (United States)

    Liao, C. R.; Zhao, D. X.; Xie, L.; Liu, Q.

    2012-08-01

    In this paper, a magnetorheological (MR) fluid damper based on a multi-stage radial flow mode is put forward, compared with traditional ones with annular damping channel which are of low magnetic field utilization and high energy consumption. The equivalent magnetic circuit model is derived, along with the relation between the magnetic induction at the working gap and the exciting current in the field coils. The finite-element software ANYSY is used to analyze the distribution of the magnetic field in the MR valve. The flow differential equation for a MR fluid in radial flow is theoretically set up, and the numerical solution is validated by means of the Herschel-Bulkley constitutive model. A MR damper was designed and fabricated in Chongqing University in accordance with the technical requirements of a railway vehicle anti-yaw damper, and the force-displacement characteristic of the damper was tested with J95-I type shock absorber test-bed. The results show that the experimental damping forces are in good agreement with the analytical ones, and the methodology is believed to help predict the damping force of a MR damper.

  14. A design methodology for a magnetorheological fluid damper based on a multi-stage radial flow mode

    International Nuclear Information System (INIS)

    In this paper, a magnetorheological (MR) fluid damper based on a multi-stage radial flow mode is put forward, compared with traditional ones with annular damping channel which are of low magnetic field utilization and high energy consumption. The equivalent magnetic circuit model is derived, along with the relation between the magnetic induction at the working gap and the exciting current in the field coils. The finite-element software ANYSY is used to analyze the distribution of the magnetic field in the MR valve. The flow differential equation for a MR fluid in radial flow is theoretically set up, and the numerical solution is validated by means of the Herschel–Bulkley constitutive model. A MR damper was designed and fabricated in Chongqing University in accordance with the technical requirements of a railway vehicle anti-yaw damper, and the force–displacement characteristic of the damper was tested with J95-I type shock absorber test-bed. The results show that the experimental damping forces are in good agreement with the analytical ones, and the methodology is believed to help predict the damping force of a MR damper. (paper)

  15. Transient Analysis of Multistage Degraded Systems with Partial Repairs of General Distribution Modeled by Erlang-k Distribution

    OpenAIRE

    Moustafa Magdi S.

    2006-01-01

    The paper presents a model of multistage degraded system subjected to random failures and partial repairs. A transient analysis is performed and transient probabilities are calculated to find the availability, the means of life time and operational life time. In the paper, constant state dependent transition rates for the degradation process as well as failure process are considered. On the other hand the partial repairs follow general distributions. This paper extends previous systems that c...

  16. Intelligent Search Method Based ACO Techniques for a Multistage Decision Problem EDP/LFP

    Directory of Open Access Journals (Sweden)

    Mostefa RAHLI

    2006-07-01

    Full Text Available The implementation of a numerical library of calculation based optimization in electrical supply networks area is in the centre of the current research orientations, thus, our project in a form given is centred on the development of platform NMSS1. It's a software environment which will preserve many efforts as regards calculations of charge, smoothing curves, losses calculation and economic planning of the generated powers [23].The operational research [17] in a hand and the industrial practice in the other, prove that the means and processes of simulation reached a level of very appreciable reliability and mathematical confidence [4, 5, 14]. It is of this expert observation that many processes make confidence to the results of simulation.The handicaps of this approach or methodology are that it makes base its judgments and handling on simplified assumptions and constraints whose influence was deliberately neglected to be added to the cost to spend [14].By juxtaposing the methods of simulation with artificial intelligence techniques, gathering set of numerical methods acquires an optimal reliability whose assurance can not leave doubt.Software environment NMSS [23] can be a in the field of the rallying techniques of simulation and electric network calculation via a graphic interface. In the same software integrate an AI capability via a module expert system.Our problem is a multistage case where are completely dependant and can't be performed separately.For a multistage problem [21, 22], the results obtained from a credible (large size problem calculation, makes the following question: Could choice of numerical methods set make the calculation of a complete problem using more than two treatments levels, a total error which will be the weakest one possible? It is well-known according to algorithmic policy; each treatment can be characterized by a function called mathematical complexity. This complexity is in fact a coast (a weight overloading

  17. Multi-stage kernel-based conditional quantile prediction in time series

    NARCIS (Netherlands)

    J.G. de Gooijer; A. Gannoun; D. Zerom Godefay

    2001-01-01

    We present a multi-stage conditional quantile predictor for time series of Markovian structure. It is proved that at any quantile level p \\in (0,1), the asymptotic mean squared error (MSE) of the new predictor is smaller than the single-stage conditional quantile predictor. A simulation study confir

  18. Optimization of Unbalanced Multi-stage Logistics Systems Based on Prüfer Number and Effective Capacity Coding

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Unbalanced multi-stage logistics systems are optimized using an improved genetic algorithm based on the Prüfer number and the effective capacity coding. The improved decoding procedure uses the node capacity of the logistics system as an important factor, which influences the decoding procedure. As a result, any Prüfer number produced stochastically can be decoded to a feasible logistics pattern, which matchs the node capacities of the logistics system. With effective capacity coding, an unbalanced logistics system can be converted to a set of balanced systems. The effective capacity coding was combined with the Prüfer number to construct the chromosome for the new method to search the whole solution space of the unbalanced multi-stage logistics system. Simulation results show that the new method finds a better solution with less computational time than st-GA. Although using a little more memory, the new method is still an efficient and robust method for optimizing unbalanced multi-stage logistics systems.

  19. A risk-based interactive multi-stage stochastic programming approach for water resources planning under dual uncertainties

    Science.gov (United States)

    Wang, Y. Y.; Huang, G. H.; Wang, S.; Li, W.; Guan, P. B.

    2016-08-01

    In this study, a risk-based interactive multi-stage stochastic programming (RIMSP) approach is proposed through incorporating the fractile criterion method and chance-constrained programming within a multi-stage decision-making framework. RIMSP is able to deal with dual uncertainties expressed as random boundary intervals that exist in the objective function and constraints. Moreover, RIMSP is capable of reflecting dynamics of uncertainties, as well as the trade-off between the total net benefit and the associated risk. A water allocation problem is used to illustrate applicability of the proposed methodology. A set of decision alternatives with different combinations of risk levels applied to the objective function and constraints can be generated for planning the water resources allocation system. The results can help decision makers examine potential interactions between risks related to the stochastic objective function and constraints. Furthermore, a number of solutions can be obtained under different water policy scenarios, which are useful for decision makers to formulate an appropriate policy under uncertainty. The performance of RIMSP is analyzed and compared with an inexact multi-stage stochastic programming (IMSP) method. Results of comparison experiment indicate that RIMSP is able to provide more robust water management alternatives with less system risks in comparison with IMSP.

  20. Nonlinear model predictive control of a multistage evaporator system using recurrent neural networks

    NARCIS (Netherlands)

    Atuonwu, J.C.; Cao, Y.; Rangaiah, G.P.; Tade, M.O.

    2011-01-01

    The use of multistage evaporators, motivated by the energy economy from reusing the flashed steam is common in a wide range of process industries. Such evaporators however present several control problems which manifest in the form of strong interactions among the many process variables, significant

  1. Research on Efficiency of R&D Activity of Gansu Based on the Multi-stage VRS Model of DEA Method%甘肃省R&D活动效率研究

    Institute of Scientific and Technical Information of China (English)

    张爱宁; 玄兆辉; 马巧丽

    2012-01-01

    Based on VRS model of data envelopment analysis and the data of the second investigation of R&D Resources, the paper puts forward the measuring method for efficiency of R&D activity to calculate the efficiency of R&D activity of Cansu provinces in 2009. Meanwhile, the paper analyzes the DEA validity, pure technical efficiency and scale efficiency of various regions. In order to reach a better efficiency, it makes a further study on the reasons of low-efficiency of R&D activity and how to adjust the combination between inputs and outputs correctly in some areas.%本文基于数据包络分析的VRS模型原理提出了R&D活动效率的测算方法,运用第二次R&D资源清查资料对甘肃省2009年各市州的R&D活动效率进行了测算,分析了各地区R&D活动的DEA有效性、纯技术效率、规模效益情况,并就部分地区R&D活动效率低的原因及如何调整其投入产出项的组合,从而达到较高的效率进行了深入研究.

  2. Multistage stochastic optimization

    CERN Document Server

    Pflug, Georg Ch

    2014-01-01

    Multistage stochastic optimization problems appear in many ways in finance, insurance, energy production and trading, logistics and transportation, among other areas. They describe decision situations under uncertainty and with a longer planning horizon. This book contains a comprehensive treatment of today’s state of the art in multistage stochastic optimization.  It covers the mathematical backgrounds of approximation theory as well as numerous practical algorithms and examples for the generation and handling of scenario trees. A special emphasis is put on estimation and bounding of the modeling error using novel distance concepts, on time consistency and the role of model ambiguity in the decision process. An extensive treatment of examples from electricity production, asset liability management and inventory control concludes the book

  3. On multistage homotopy-perturbation method applied to nonlinear biochemical reaction model

    International Nuclear Information System (INIS)

    The total time evolution of the reactant concentrations in the basic enzyme-substrate reaction is simulated by an adaptation of the standard analytic homotopy-perturbation method (HPM). The standard HPM is converted into a hybrid numeric-analytic method called the multistage HPM (MHPM). The numerical results obtained from the MHPM and the classical fourth-order Runge-Kutta (RK4) method are in complete agreement

  4. Accounting for rotation in a multi-stage cyclo-symmetric model - a case study

    OpenAIRE

    Balmes, Etienne; Bucher, Izhak

    2010-01-01

    Rotating structures typically have stages with cyclo-symmetric geometries that are periodic by rotation. The spatial Fourier transform of fields at periodic positions leads to multiple uncoupled low cost problems for each Fourier harmonic. Real rotors are assemblies of stages that have different number of sectors. This motivated the extension of cyclo-symmetry to multistage assemblies. The resulting methodology gives access to low cost predictions of full rotor dynamics. The present paper summ...

  5. A new model of water-lubricated rubber bearings for vibration analysis of flexible multistage rotor systems

    Science.gov (United States)

    Liu, Shibing; Yang, Bingen

    2015-08-01

    Flexible multistage rotating systems that are supported or guided by long water-lubricated rubber bearings (WLRBs) have a variety of engineering applications. Vibration analysis of this type of machinery for performance and duality requires accurate modeling of WLRBs and related rotor-bearing assemblies. This work presents a new model of WLRBs, with attention given to the determination of bearing dynamic coefficients. Due to its large length-to-diameter ratio, a WLRB cannot be described by conventional pointwise bearing models with good fidelity. The bearing model proposed in this paper considers spatially distributed bearing forces. For the first time in the literature, the current study addresses the issue of mixed lubrication in the operation of WLRBs, which involves interactions of shaft vibration, elastic deformation of rubber material and fluid film pressure, and validates the WLRB model in experiments. Additionally, with the new bearing model, vibration analysis of WLRB-supported flexible multistage rotating systems is performed through use of a distributed transfer function method, which delivers accurate and closed-form analytical solutions of steady-state responses without discretization.

  6. Multi area and multistage expansion-planning of electricity supply with sustainable energy development criteria: a multi objective model

    Energy Technology Data Exchange (ETDEWEB)

    Unsihuay-Vila, Clodomiro; Marangon-Lima, J.W.; Souza, A.C Zambroni de [Universidade Federal de Itajuba (UNIFEI), MG (Brazil)], emails: clodomirounsihuayvila @gmail.com, marangon@unifei.edu.br, zambroni@unifei.edu.br; Perez-Arriaga, I.J. [Universidad Pontificia Comillas, Madrid (Spain)], email: ipa@mit.edu

    2010-07-01

    A novel multi objective, multi area and multistage model to long-term expansion-planning of integrated generation and transmission corridors incorporating sustainable energy developing is presented in this paper. The proposed MESEDES model is a multi-regional multi-objective and 'bottom-up' energy model which considers the electricity generation/transmission value-chain, i.e., power generation alternatives including renewable, nuclear and traditional thermal generation along with transmission corridors. The model decides the optimal location and timing of the electricity generation/transmission abroad the multistage planning horizon. The MESEDES model considers three objectives belonging to sustainable energy development criteria such as: a) the minimization of investments and operation costs of : power generation, transmission corridors, energy efficiency (demand side management (DSM) programs) considering CO2 capture technologies; b) minimization of Life Cycle Greenhouse Gas Emissions (LC GHG); c) maximization of the diversification of electricity generation mix. The proposed model consider aspects of the carbon abatement policy under the CDM - Clean Development Mechanism or European Union Greenhouse Gas Emission Trading Scheme. A case study is used to illustrate the proposed framework. (author)

  7. Health and human rights in Chin State, Western Burma: a population-based assessment using multistaged household cluster sampling.

    Directory of Open Access Journals (Sweden)

    Richard Sollom

    Full Text Available BACKGROUND: The Chin State of Burma (also known as Myanmar is an isolated ethnic minority area with poor health outcomes and reports of food insecurity and human rights violations. We report on a population-based assessment of health and human rights in Chin State. We sought to quantify reported human rights violations in Chin State and associations between these reported violations and health status at the household level. METHODS AND FINDINGS: Multistaged household cluster sampling was done. Heads of household were interviewed on demographics, access to health care, health status, food insecurity, forced displacement, forced labor, and other human rights violations during the preceding 12 months. Ratios of the prevalence of household hunger comparing exposed and unexposed to each reported violation were estimated using binomial regression, and 95% confidence intervals (CIs were constructed. Multivariate models were done to adjust for possible confounders. Overall, 91.9% of households (95% CI 89.7%-94.1% reported forced labor in the past 12 months. Forty-three percent of households met FANTA-2 (Food and Nutrition Technical Assistance II project definitions for moderate to severe household hunger. Common violations reported were food theft, livestock theft or killing, forced displacement, beatings and torture, detentions, disappearances, and religious and ethnic persecution. Self reporting of multiple rights abuses was independently associated with household hunger. CONCLUSIONS: Our findings indicate widespread self-reports of human rights violations. The nature and extent of these violations may warrant investigation by the United Nations or International Criminal Court. Please see later in the article for the Editors' Summary.

  8. Verification of KAERI-DySCo for a dynamic simulation of VHTR-based SI hydrogen production facilities 1: sulfuric acid multistage distillation column module

    International Nuclear Information System (INIS)

    KAERI has developed the dynamic code (KAERI-DySCo) to analyze the start-up behaviors of the SI process components. This study focuses on the verification of a simulation module for the sulfuric acid multi-stage distillation column in the KAERI-DySCo. In agreement with the steady state values measured experimentally by KIST, it has been finally confirmed that the SAMDC, which is one of the simulation modules in KAERI-DySCo for the dynamic simulation code of VHTR-based SI hydrogen production facilities, is a feasible simulation module for calculating the start-up dynamic behavior of a sulfuric acid multistage distillation column

  9. Validation of multi-stage telephone-based identification of cognitive impairment and dementia

    Directory of Open Access Journals (Sweden)

    Chui Helena

    2005-04-01

    Full Text Available Abstract Background Many types of research on dementia and cognitive impairment require large sample sizes. Detailed in-person assessment using batteries of neuropyschologic testing is expensive. This study evaluates whether a brief telephone cognitive assessment strategy can reliably classify cognitive status when compared to an in-person "gold-standard" clinical assessment. Methods The gold standard assessment of cognitive status was conducted at the University of Southern California Alzheimer Disease Research Center (USC ADRC. It involved an examination of patients with a memory complaint by a neurologist or psychiatrist specializing in cognitive disorders and administration of a battery of neuropsychologic tests. The method being evaluated was a multi-staged assessment using the Telephone Interview of Cognitive Status-modified (TICSm with patients and the Telephone Dementia Questionnaire (TDQ with a proxy. Elderly male and female patients who had received the gold standard in-person assessment were asked to also undergo the telephone assessment. The unweighted kappa statistic was calculated to compare the gold standard and the multistage telephone assessment methods. Sensitivity for classification with dementia and specificity for classification as normal were also calculated. Results Of 50 patients who underwent the gold standard assessment and were referred for telephone assessment, 38 (76% completed the TICS. The mean age was 78.1 years and 26 (68% were female. When comparing the gold standard assessment and the telephone method for classifying subjects as having dementia or no dementia, the sensitivity of the telephone method was 0.83 (95% confidence interval 0.36, 1.00, the specificity was 1.00 (95% confidence interval 0.89,1.00. Kappa was 0.89 (95% confidence interval 0.69, 1.000. Considering a gold-standard assessment of age-associated memory impairment as cognitive impairment, the sensitivity of the telephone approach is 0.38 (95

  10. Endogenous Econometric Models and Multi-Stage Estimation in High-Dimensional Settings: Theory and Applications

    OpenAIRE

    Zhu, Ying

    2015-01-01

    Econometric models based on observational data are often endogenous due to measurement error, autocorrelated errors, simultaneity and omitted variables, non-random sampling, self-selection, etc. Parameter estimates of these models without corrective measures may be inconsistent. The potential high-dimensional feature of these models (where the dimension of the parameters of interests is comparable to or even larger than the sample size) further complicates the statistical estimation and infer...

  11. Multistage Three-Way Decisions of Spam SMS Filtering Model%多阶段三支决策垃圾短信过滤模型

    Institute of Scientific and Technical Information of China (English)

    李建林; 黄顺亮

    2014-01-01

    提出了一种多阶段三支决策垃圾短信过滤模型。该模型使用不同的信息粒度对短信进行表示,运用序列决策(即多阶段、多步骤决策),在不同的决策阶段基于不同的信息粒度分别进行三支决策,有效地避免了当信息粒度太大或信息量不足时进行不合理的决策,对于不能满足当前决策条件的信息,可以通过补充足够的粒度信息作进一步的决策。最后通过实验证明了该模型的合理性和有效性。%This paper proposes a multistage three-way decisions of spam SMS (short messaging service) filtering model. By using different granularity information to express the SMS, with the sequence decisions (i.e., multistage, multiple steps in decision-making), at different decision-making stages, based on different information granularity respectively three-way decision-making, those can avoid to make irrational decisions when the message size is too big or insufficient information. If the information does not meet the current decision-making conditions, this model can add enough granularity information before making a further decision. Finally, the experimental results prove the rationality and validity of the model.

  12. Empirical vs. Expected IRT-Based Reliability Estimation in Computerized Multistage Testing (MST)

    Science.gov (United States)

    Zhang, Yanwei; Breithaupt, Krista; Tessema, Aster; Chuah, David

    2006-01-01

    Two IRT-based procedures to estimate test reliability for a certification exam that used both adaptive (via a MST model) and non-adaptive design were considered in this study. Both procedures rely on calibrated item parameters to estimate error variance. In terms of score variance, one procedure (Method 1) uses the empirical ability distribution…

  13. Multi-stage Modeling of Lüders Elongation and Work-Hardening Behaviors of Ferrite Steels Under Tension

    Science.gov (United States)

    Zhang, Zhongyang; Liao, Yiliang

    2016-04-01

    For structural and engineering steels, accurate modeling of stress-strain relation of ferrite phase is of particular importance, since the modeling results could benefit new material system design and process-microstructure-property analysis. Several modeling efforts have been made to achieve this target. However, few efforts have been put on the Lüders elongation behavior of ferrite. As a result, the modeling results from proposed models do not match well with experimental data, particularly at a relatively low-strain range. Furthermore, without the consideration of yield point elongation due to the formation of Lüders bands, additional calibration parameters are required to capture the stress level of stress-strain curves. In this work, a multi-stage model is developed to predict the stress-strain relation of ferrite phase steel under room temperature tension. This model is capable of capturing the grain size effect on both Lüders elongation and work-hardening behaviors of ferrite. The modeling results are extensively validated by experimental data.

  14. Improved Heuristics for Multi-Stage Requirements Planning Systems

    OpenAIRE

    Joseph D. Blackburn; Robert A. Millen

    1982-01-01

    Most of the recent studies of heuristic lot-sizing techniques for multi-stage material requirements planning systems have investigated the problem in the context of a single stage. In this paper, the multi-stage problem is first modeled analytically to indicate the potential errors inherent in the commonly proposed single-pass, stage-by-stage approaches (e.g., Wagner-Whitin). Then, based on this analysis, several simple cost modifications are suggested to improve the global optimality of thes...

  15. Task I: A Computational Model for Short Wavelength Stall Inception and Development In Multi-Stage Compressors

    Science.gov (United States)

    Suder, Kenneth (Technical Monitor); Tan, Choon-Sooi

    2003-01-01

    A computational model is presented for simulating axial compressor stall inception and development via disturbances with length scales on the order of several (typically about three) blade pitches. The model was designed for multi-stage compressors in which stall is initiated by these short wavelength disturbances, also referred to as spikes. The inception process described is fundamentally nonlinear, in contrast to the essentially linear behavior seen in so-called modal stall inception . The model was able to capture the following experimentally observed phenomena: (1) development of rotating stall via short wavelength disturbances, (2) formation and evolution of localized short wavelength stall cells in the first stage of a mismatched compressor, (3) the switch from long to short wavelength stall inception resulting from the re-staggering of the inlet guide vane, (4) the occurrence of rotating stall inception on the negatively sloped portion of the compressor characteristic. Parametric investigations indicated that (1) short wavelength disturbances were supported by the rotor blade row, (2) the disturbance strength was attenuated within the stators, and (3) the reduction of inter-blade row gaps can suppress the growth of short wavelength disturbances. It is argued that each local component group (rotor plus neighboring stators) has its own instability point (i.e. conditions at which disturbances are sustained) for short wavelength disturbances, with the instability point for the compressor set by the most unstable component group.

  16. A new model to predict multi-stage pyrolysis of flammable materials in standard fire tests

    International Nuclear Information System (INIS)

    Test procedures to assess material flammability are focused on radiative heating of the examined material followed by ignition of volatiles produced by pyrolysis. In this work, a new model (Pyropolis) for predicting thermal degradation of polymer materials exposed to the external heat flux is presented. Composite materials of interest consist of a matrix polymer and a (glass or carbonized) fiber. If temperature is sufficiently high, the matrix polymer degrades thereby producing solid and/or gaseous components. Solid decomposition products may exhibit a considerable size change, which is a notable feature of intumescent materials also considered in this work. The model incorporates multi-step decomposition mechanism including two reactions in anaerobic conditions and four reactions in oxidative atmosphere. Kinetic data could be derived from TGA, DSC and PCFC/MCC measurements, which are processed by either simplified (peak value based) or comprehensive (non-linear optimization) approach suitable for both n-th order and autocatalytic reactions. The model is validated by comparing predictions of gasification rates for to two distinct types of non-charring (PS) and charring intumescent (PC) polymers. Reasonable agreement has been obtained with the measured mass loss rates, which are proportional to the heat release rates if volatiles are ignited.

  17. SOLAR ABSORBING COOLING SYSTEMS BASED ON MULTISTAGE HEAT-MASS-TRANSFER DEVICES

    OpenAIRE

    Doroshenko A.V.; Ludnitsky K.V.

    2014-01-01

    The article presents the worked out schematics for the alternative refrigeration systems and of air-conditioning systems, based on the use of absorbing cycle and of the sunny energy for the regeneration (renewals) of absorbent solution. We use here the cascade principle of construction of all heat-mass-transfer apparatus with variation of both the temperature level and the growth of absorbent concentration on the cascade stages. The heat-mass-transfer equipment as a part of the drying and coo...

  18. SOLAR MULTI-STAGE ABSORPTION REFRIGERATION SYSTEMS BASED ON FILM TYPE HEAT-MASS EXCHANGE APPARATUSES

    OpenAIRE

    Дорошенко, О.В.; Антонова, А.Р.; Людницький, К.В.

    2015-01-01

    The paper presents the developed circuit solutions for alternative refrigeration systems based on the of heat-absorption cycle and solar energy utilization for regeneration (recovery) of the absorbent solution. Cascade principle of heat-mass exchange apparatuses construction was applied, of drying and cooling loops with varying of  temperature level and increasing  of absorbent concentration on the cascade steps. Film type heat and mass transfer equipment, which is the part of the drying and ...

  19. A multi-stage model for fundamental functional properties in primary visual cortex.

    Directory of Open Access Journals (Sweden)

    Nastaran Hesam Shariati

    Full Text Available Many neurons in mammalian primary visual cortex have properties such as sharp tuning for contour orientation, strong selectivity for motion direction, and insensitivity to stimulus polarity, that are not shared with their sub-cortical counterparts. Successful models have been developed for a number of these properties but in one case, direction selectivity, there is no consensus about underlying mechanisms. We here define a model that accounts for many of the empirical observations concerning direction selectivity. The model describes a single column of cat primary visual cortex and comprises a series of processing stages. Each neuron in the first cortical stage receives input from a small number of on-centre and off-centre relay cells in the lateral geniculate nucleus. Consistent with recent physiological evidence, the off-centre inputs to cortex precede the on-centre inputs by a small (∼4 ms interval, and it is this difference that confers direction selectivity on model neurons. We show that the resulting model successfully matches the following empirical data: the proportion of cells that are direction selective; tilted spatiotemporal receptive fields; phase advance in the response to a stationary contrast-reversing grating stepped across the receptive field. The model also accounts for several other fundamental properties. Receptive fields have elongated subregions, orientation selectivity is strong, and the distribution of orientation tuning bandwidth across neurons is similar to that seen in the laboratory. Finally, neurons in the first stage have properties corresponding to simple cells, and more complex-like cells emerge in later stages. The results therefore show that a simple feed-forward model can account for a number of the fundamental properties of primary visual cortex.

  20. Randomly Wired Multistage Networks

    OpenAIRE

    Maggs, Bruce M.

    1993-01-01

    Randomly wired multistage networks have recently been shown to outperform traditional multistage networks in three respects. First, they have fast deterministic packet-switching and circuit-switching algorithms for routing permutations. Second, they are nonblocking, and there are on-line algorithms for establishing new connections in them, even if many requests for connections are made simultaneously. Finally, and perhaps most importantly, they are highly fault tolerant.

  1. Wind power integration studies using a multi-stage stochastic electricity system model

    DEFF Research Database (Denmark)

    Meibom, Peter; Barth, R.; Brand, H.; Weber, C.

    A large share of integrated wind power causes technical and financial impacts on the operation of the existing electricity system due to the fluctuating behaviour and unpredictability of wind power. The presented stochastic electricity market model optimises the unit commitment considering four k...

  2. Characterization of kerogen from Timahdit shale (Y-layer) based on multistage alkaline permanganate degradation

    Energy Technology Data Exchange (ETDEWEB)

    Ambles, A.; Halim, M.; Jacquesy, J.-C.; Vitorovic, D.; Ziyad, M. (Universite de Poitiers, Poitiers (France). Lab. de Chimie)

    1994-01-01

    A 15-step alkaline permanganate degradation of kerogen from Moroccan Timahdit Oil Shale (Y-layer) was carried out. Oxidation products were obtained in a good yield (64 wt% based on initial kerogen). Detailed g.c. and g.c.-m.s. analyses of ether- and water-soluble acids and products of further controlled permanganate degradation of precipitated acids served as a basis for the quantitative estimation of the contributions of various types of products and for comparison with other kerogens. Taking into account the dominant aliphatic (44.2%) and aromatic (34.8%) nature of the acidic oxidation products, the existence of an aliphatic cross-linked nucleus mixed with cross-linked aromatic units in the Timahdit-Y shale kerogen is postulated. These findings were corroborated by FT-i.r. and [sup 13]C CP-MAS n.m.r. analyses. Saturated hydrocarbons were also found in the oxidation products; they were probably trapped in the kerogen matrix. 34 refs., 7 figs., 4 tabs.

  3. Split-plot designs for multistage experimentation

    DEFF Research Database (Denmark)

    Kulahci, Murat; Tyssedal, John

    2016-01-01

    at the same time will be more efficient. However, there have been only a few attempts in the literature to provide an adequate and easy-to-use approach for this problem. In this paper, we present a novel methodology for constructing two-level split-plot and multistage experiments. The methodology is based...... be accommodated in each stage. Furthermore, split-plot designs for multistage experiments with good projective properties are also provided....

  4. Model reduction applied to multi-stage assemblies of bladed disks

    OpenAIRE

    Sternchüss, Arnaud; Balmes, Etienne; Jean, Pierrick; Lombard, Jean Pierre

    2008-01-01

    This paper deals with model reduction of assemblies of bladed disks. Some considerations about the use of the Fourier theory to describe the dynamics of assemblies of geometrically periodic structures are first recalled. This allows to define a set of spatially mono-harmonic solutions that are used to build the kinematic subspaces in a subsequent reduction process. The main characteristics of this sector substructuring technique are then presented and discussed. Finally, the proposed methodol...

  5. Solving multistage stochastic programming models of portfolio selection with outstanding liabilities

    Energy Technology Data Exchange (ETDEWEB)

    Edirisinghe, C. [Univ. of Tennessee, Knoxville, TN (United States)

    1994-12-31

    Models for portfolio selection in the presence of an outstanding liability have received significant attention, for example, models for pricing options. The problem may be described briefly as follows: given a set of risky securities (and a riskless security such as a bond), and given a set of cash flows, i.e., outstanding liability, to be met at some future date, determine an initial portfolio and a dynamic trading strategy for the underlying securities such that the initial cost of the portfolio is within a prescribed wealth level and the expected cash surpluses arising from trading is maximized. While the trading strategy should be self-financing, there may also be other restrictions such as leverage and short-sale constraints. Usually the treatment is limited to binomial evolution of uncertainty (of stock price), with possible extensions for developing computational bounds for multinomial generalizations. Posing as stochastic programming models of decision making, we investigate alternative efficient solution procedures under continuous evolution of uncertainty, for discrete time economies. We point out an important moment problem arising in the portfolio selection problem, the solution (or bounds) on which provides the basis for developing efficient computational algorithms. While the underlying stochastic program may be computationally tedious even for a modest number of trading opportunities (i.e., time periods), the derived algorithms may used to solve problems whose sizes are beyond those considered within stochastic optimization.

  6. Age Effects and Temporal Trends in HPV-Related and HPV-Unrelated Oral Cancer in the United States: A Multistage Carcinogenesis Modeling Analysis.

    Directory of Open Access Journals (Sweden)

    Andrew F Brouwer

    Full Text Available Differences in prognosis in HPV-positive and HPV-negative oral (oropharyngeal and oral cavity squamous cell carcinomas (OSCCs and increasing incidence of HPV-related cancers have spurred interest in demographic and temporal trends in OSCC incidence. We leverage multistage clonal expansion (MSCE models coupled with age-period-cohort (APC epidemiological models to analyze OSCC data in the SEER cancer registry (1973-2012. MSCE models are based on the initiation-promotion-malignant conversion paradigm in carcinogenesis and allow for interpretation of trends in terms of biological mechanisms. APC models seek to differentiate between the temporal effects of age, period, and birth cohort on cancer risk. Previous studies have looked at the effect of period and cohort on tumor initiation, and we extend this to compare model fits of period and cohort effects on each of tumor initiation, promotion, and malignant conversion rates. HPV-related, HPV-unrelated except oral tongue, and HPV-unrelated oral tongue sites are best described by placing period and cohort effects on the initiation rate. HPV-related and non-oral-tongue HPV-unrelated cancers have similar promotion rates, suggesting similar tumorigenesis dynamics once initiated. Estimates of promotion rates at oral tongue sites are lower, corresponding to a longer sojourn time; this finding is consistent with the hypothesis of an etiology distinct from HPV or alcohol and tobacco use. Finally, for the three subsite groups, men have higher initiation rates than women of the same race, and black people have higher promotion than white people of the same sex. These differences explain part of the racial and sex differences in OSCC incidence.

  7. Age Effects and Temporal Trends in HPV-Related and HPV-Unrelated Oral Cancer in the United States: A Multistage Carcinogenesis Modeling Analysis.

    Science.gov (United States)

    Brouwer, Andrew F; Eisenberg, Marisa C; Meza, Rafael

    2016-01-01

    Differences in prognosis in HPV-positive and HPV-negative oral (oropharyngeal and oral cavity) squamous cell carcinomas (OSCCs) and increasing incidence of HPV-related cancers have spurred interest in demographic and temporal trends in OSCC incidence. We leverage multistage clonal expansion (MSCE) models coupled with age-period-cohort (APC) epidemiological models to analyze OSCC data in the SEER cancer registry (1973-2012). MSCE models are based on the initiation-promotion-malignant conversion paradigm in carcinogenesis and allow for interpretation of trends in terms of biological mechanisms. APC models seek to differentiate between the temporal effects of age, period, and birth cohort on cancer risk. Previous studies have looked at the effect of period and cohort on tumor initiation, and we extend this to compare model fits of period and cohort effects on each of tumor initiation, promotion, and malignant conversion rates. HPV-related, HPV-unrelated except oral tongue, and HPV-unrelated oral tongue sites are best described by placing period and cohort effects on the initiation rate. HPV-related and non-oral-tongue HPV-unrelated cancers have similar promotion rates, suggesting similar tumorigenesis dynamics once initiated. Estimates of promotion rates at oral tongue sites are lower, corresponding to a longer sojourn time; this finding is consistent with the hypothesis of an etiology distinct from HPV or alcohol and tobacco use. Finally, for the three subsite groups, men have higher initiation rates than women of the same race, and black people have higher promotion than white people of the same sex. These differences explain part of the racial and sex differences in OSCC incidence. PMID:26963717

  8. Contraceptive intentions among Christian women in India: a multi-stage Logit model analysis

    Directory of Open Access Journals (Sweden)

    Niyati Joshi

    2014-06-01

    Results: Though spatial factors affect both Christian and non-Christian women, SLI directly affect Christian womens' intention while it operates through education for non-Christian women. The best model for future contraceptive intention among Christian women is affected by unmet need operating through standard of living. Conclusions: The study finds two different paths of causation affecting future contraceptive intentions of Christian and non-Christian women with separate policy concerns and suggests that paths to future contraceptive intentions of Christian women may act as a social learning through diffusion process for non-Christian women. [Int J Reprod Contracept Obstet Gynecol 2014; 3(3.000: 523-532

  9. Formation of porous gas hydrates: Diffraction experiments and multi-stage model

    Science.gov (United States)

    Staykova, D. K.; Genov, G.; Goreshnik, E.; Salamatin, A. N.; Kuhs, W. F.

    2003-04-01

    Laboratory-grown gas hydrates were examined by cryo scanning electron microscopy and found to have a sub-micron porous structure. This microstructure is undistinguishable from the one observed in natural gas hydrates suggesting similar formation processes. In-situ observations of the formation of synthetic porous methane and carbon dioxide hydrates starting from ice Ih powders with known surfaces areas were made using time-resolved neutron diffraction on the high-flux diffractometer D20 (ILL, Grenoble) at different pressures and temperatures. Some runs were also made going through the ice melting point into liquid water. At similar reduced fugacities, the reaction of carbon dioxide was distinctly faster than that of methane. The transient formation of carbon dioxide hydrate crystal structure II was observed in coexistence with the usual type-I hydrate reaching a maximum of 5% after 5 h of the reaction at 272 K. At lower temperatures a temporary inhibition of formation was observed in the case of carbon dioxide. The rate of methane hydrate growth showed little pressure sensitivity in our experiments at low temperatures ~230 K in contrast to the situation at higher temperatures. A phenomenological model for the kinetics of the gas hydrate formation from ice powders is developed with special account of sample consolidation effects. It describes the initial stage (I) of hydrate film spreading over the ice surface and the two subsequent stages which are limited (II) by the clathration reaction at the ice-hydrate interface and (III) by the gas and water transport (diffusion) through the hydrate shells surrounding the shrinking ice cores. Comparable activation energies of the CH4-hydrate formation are found in deuterated and hydrogenated systems for the reaction-limited process (stage II) to be 8.1 and 9.5 kcal/mol, respectively. In the case of a diffusion-limited clathration (stage III) the activation energy can be estimated as 14.3 kcal/mol. The relevance of our

  10. Bioreactors for high cell density and continuous multi-stage cultivations: options for process intensification in cell culture-based viral vaccine production.

    Science.gov (United States)

    Tapia, Felipe; Vázquez-Ramírez, Daniel; Genzel, Yvonne; Reichl, Udo

    2016-03-01

    With an increasing demand for efficacious, safe, and affordable vaccines for human and animal use, process intensification in cell culture-based viral vaccine production demands advanced process strategies to overcome the limitations of conventional batch cultivations. However, the use of fed-batch, perfusion, or continuous modes to drive processes at high cell density (HCD) and overextended operating times has so far been little explored in large-scale viral vaccine manufacturing. Also, possible reductions in cell-specific virus yields for HCD cultivations have been reported frequently. Taking into account that vaccine production is one of the most heavily regulated industries in the pharmaceutical sector with tough margins to meet, it is understandable that process intensification is being considered by both academia and industry as a next step toward more efficient viral vaccine production processes only recently. Compared to conventional batch processes, fed-batch and perfusion strategies could result in ten to a hundred times higher product yields. Both cultivation strategies can be implemented to achieve cell concentrations exceeding 10(7) cells/mL or even 10(8) cells/mL, while keeping low levels of metabolites that potentially inhibit cell growth and virus replication. The trend towards HCD processes is supported by development of GMP-compliant cultivation platforms, i.e., acoustic settlers, hollow fiber bioreactors, and hollow fiber-based perfusion systems including tangential flow filtration (TFF) or alternating tangential flow (ATF) technologies. In this review, these process modes are discussed in detail and compared with conventional batch processes based on productivity indicators such as space-time yield, cell concentration, and product titers. In addition, options for the production of viral vaccines in continuous multi-stage bioreactors such as two- and three-stage systems are addressed. While such systems have shown similar virus titers compared to

  11. A timer inventory based upon manual and automated analysis of ERTS-1 and supporting aircraft data using multistage probability sampling. [Plumas National Forest, California

    Science.gov (United States)

    Nichols, J. D.; Gialdini, M.; Jaakkola, S.

    1974-01-01

    A quasi-operational study demonstrating that a timber inventory based on manual and automated analysis of ERTS-1, supporting aircraft data and ground data was made using multistage sampling techniques. The inventory proved to be a timely, cost effective alternative to conventional timber inventory techniques. The timber volume on the Quincy Ranger District of the Plumas National Forest was estimated to be 2.44 billion board feet with a sampling error of 8.2 percent. Costs per acre for the inventory procedure at 1.1 cent/acre compared favorably with the costs of a conventional inventory at 25 cents/acre. A point-by-point comparison of CALSCAN-classified ERTS data with human-interpreted low altitude photo plots indicated no significant differences in the overall classification accuracies.

  12. Multi-stage complex contagions

    Science.gov (United States)

    Melnik, Sergey; Ward, Jonathan A.; Gleeson, James P.; Porter, Mason A.

    2013-03-01

    The spread of ideas across a social network can be studied using complex contagion models, in which agents are activated by contact with multiple activated neighbors. The investigation of complex contagions can provide crucial insights into social influence and behavior-adoption cascades on networks. In this paper, we introduce a model of a multi-stage complex contagion on networks. Agents at different stages—which could, for example, represent differing levels of support for a social movement or differing levels of commitment to a certain product or idea—exert different amounts of influence on their neighbors. We demonstrate that the presence of even one additional stage introduces novel dynamical behavior, including interplay between multiple cascades, which cannot occur in single-stage contagion models. We find that cascades—and hence collective action—can be driven not only by high-stage influencers but also by low-stage influencers.

  13. Dynamic analysis for solid waste management systems: an inexact multistage integer programming approach.

    Science.gov (United States)

    Li, Yongping; Huang, Guohe

    2009-03-01

    In this study, a dynamic analysis approach based on an inexact multistage integer programming (IMIP) model is developed for supporting municipal solid waste (MSW) management under uncertainty. Techniques of interval-parameter programming and multistage stochastic programming are incorporated within an integer-programming framework. The developed IMIP can deal with uncertainties expressed as probability distributions and interval numbers, and can reflect the dynamics in terms of decisions for waste-flow allocation and facility-capacity expansion over a multistage context. Moreover, the IMIP can be used for analyzing various policy scenarios that are associated with different levels of economic consequences. The developed method is applied to a case study of long-term waste-management planning. The results indicate that reasonable solutions have been generated for binary and continuous variables. They can help generate desired decisions of system-capacity expansion and waste-flow allocation with a minimized system cost and maximized system reliability. PMID:19320267

  14. Coupling methods for multistage sampling

    OpenAIRE

    Chauvet, Guillaume

    2015-01-01

    Multistage sampling is commonly used for household surveys when there exists no sampling frame, or when the population is scattered over a wide area. Multistage sampling usually introduces a complex dependence in the selection of the final units, which makes asymptotic results quite difficult to prove. In this work, we consider multistage sampling with simple random without replacement sampling at the first stage, and with an arbitrary sampling design for further stages. We consider coupling ...

  15. A Multistage Approach for Image Registration.

    Science.gov (United States)

    Bowen, Francis; Hu, Jianghai; Du, Eliza Yingzi

    2016-09-01

    Successful image registration is an important step for object recognition, target detection, remote sensing, multimodal content fusion, scene blending, and disaster assessment and management. The geometric and photometric variations between images adversely affect the ability for an algorithm to estimate the transformation parameters that relate the two images. Local deformations, lighting conditions, object obstructions, and perspective differences all contribute to the challenges faced by traditional registration techniques. In this paper, a novel multistage registration approach is proposed that is resilient to view point differences, image content variations, and lighting conditions. Robust registration is realized through the utilization of a novel region descriptor which couples with the spatial and texture characteristics of invariant feature points. The proposed region descriptor is exploited in a multistage approach. A multistage process allows the utilization of the graph-based descriptor in many scenarios thus allowing the algorithm to be applied to a broader set of images. Each successive stage of the registration technique is evaluated through an effective similarity metric which determines subsequent action. The registration of aerial and street view images from pre- and post-disaster provide strong evidence that the proposed method estimates more accurate global transformation parameters than traditional feature-based methods. Experimental results show the robustness and accuracy of the proposed multistage image registration methodology. PMID:26292357

  16. Multi-stage thermal-economical optimization of compact heat exchangers: A new evolutionary-based design approach for real-world problems

    International Nuclear Information System (INIS)

    The complicated task of design optimization of compact heat exchangers (CHEs) have been effectively performed by using evolutionary algorithms (EAs) in the recent years. However, mainly due to difficulties of handling extra variables, the design approach has been based on constant rates of heat duty in the available literature. In this paper, a new design strategy is presented where variable operating conditions, which better represent real-world problems, are considered. The proposed strategy is illustrated using a case study for design of a plate-fin heat exchanger though it can be employed for all types of heat exchangers without much change. Learning automata based particle swarm optimization (LAPSO), is employed for handling nine design variables while satisfying various equality and inequality constraints. For handling the constraints, a novel feasibility based ranking strategy (FBRS) is introduced. The numerical results indicate that the design based on variable heat duties yields in more cost savings and superior thermodynamics efficiency comparing to a conventional design approach. Furthermore, the proposed algorithm has shown a superior performance in finding the near-optimum solution for this task when it is compared to the most popular evolutionary algorithms in engineering applications, i.e. genetic algorithm (GA) and particle swarm optimization (PSO). - Highlights: • Multi-stage design of heat exchangers is presented. • Feasibility based ranking strategy is employed for constraint handling. • Learning abilities added to particle swarm optimization

  17. Multistage Campaigning in Social Networks

    CERN Document Server

    Farajtabar, Mehrdad; Harati, Sahar; Song, Le; Zha, Hongyuan

    2016-01-01

    We consider the problem of how to optimize multi-stage campaigning over social networks. The dynamic programming framework is employed to balance the high present reward and large penalty on low future outcome in the presence of extensive uncertainties. In particular, we establish theoretical foundations of optimal campaigning over social networks where the user activities are modeled as a multivariate Hawkes process, and we derive a time dependent linear relation between the intensity of exogenous events and several commonly used objective functions of campaigning. We further develop a convex dynamic programming framework for determining the optimal intervention policy that prescribes the required level of external drive at each stage for the desired campaigning result. Experiments on both synthetic data and the real-world MemeTracker dataset show that our algorithm can steer the user activities for optimal campaigning much more accurately than baselines.

  18. Multistage vector (MSV) therapeutics.

    Science.gov (United States)

    Wolfram, Joy; Shen, Haifa; Ferrari, Mauro

    2015-12-10

    One of the greatest challenges in the field of medicine is obtaining controlled distribution of systemically administered therapeutic agents within the body. Indeed, biological barriers such as physical compartmentalization, pressure gradients, and excretion pathways adversely affect localized delivery of drugs to pathological tissue. The diverse nature of these barriers requires the use of multifunctional drug delivery vehicles that can overcome a wide range of sequential obstacles. In this review, we explore the role of multifunctionality in nanomedicine by primarily focusing on multistage vectors (MSVs). The MSV is an example of a promising therapeutic platform that incorporates several components, including a microparticle, nanoparticles, and small molecules. In particular, these components are activated in a sequential manner in order to successively address transport barriers. PMID:26264836

  19. A Multi-stage Carcinogenesis Model to Investigate Caloric Restriction as a Potential Tool for Post-irradiation Mitigation of Cancer Risk

    Science.gov (United States)

    Tani, Shusuke; Blyth, Benjamin John; Shang, Yi; Morioka, Takamitsu; Kakinuma, Shizuko; Shimada, Yoshiya

    2016-01-01

    The risk of radiation-induced cancer adds to anxiety in low-dose exposed populations. Safe and effective lifestyle changes which can help mitigate excess cancer risk might provide exposed individuals the opportunity to pro-actively reduce their cancer risk, and improve mental health and well-being. Here, we applied a mathematical multi-stage carcinogenesis model to the mouse lifespan data using adult-onset caloric restriction following irradiation in early life. We re-evaluated autopsy records with a veterinary pathologist to determine which tumors were the probable causes of death in order to calculate age-specific mortality. The model revealed that in both irradiated and unirradiated mice, caloric restriction reduced the age-specific mortality of all solid tumors and hepatocellular carcinomas across most of the lifespan, with the mortality rate dependent more on age owing to an increase in the number of predicted rate-limiting steps. Conversely, irradiation did not significantly alter the number of steps, but did increase the overall transition rate between the steps. We show that the extent of the protective effect of caloric restriction is independent of the induction of cancer from radiation exposure, and discuss future avenues of research to explore the utility of caloric restriction as an example of a potential post-irradiation mitigation strategy. PMID:27390741

  20. Loss of p19(Arf facilitates the angiogenic switch and tumor initiation in a multi-stage cancer model via p53-dependent and independent mechanisms.

    Directory of Open Access Journals (Sweden)

    Danielle B Ulanet

    Full Text Available The Arf tumor suppressor acts as a sensor of oncogenic signals, countering aberrant proliferation in large part via activation of the p53 transcriptional program, though a number of p53-independent functions have been described. Mounting evidence suggests that, in addition to promoting tumorigenesis via disruptions in the homeostatic balance between cell proliferation and apoptosis of overt cancer cells, genetic alterations leading to tumor suppressor loss of function or oncogene gain of function can also incite tumor development via effects on the tumor microenvironment. In a transgenic mouse model of multi-stage pancreatic neuroendocrine carcinogenesis (PNET driven by inhibition of the canonical p53 and Rb tumor suppressors with SV40 large T-antigen (Tag, stochastic progression to tumors is limited in part by a requirement for initiation of an angiogenic switch. Despite inhibition of p53 by Tag in this mouse PNET model, concomitant disruption of Arf via genetic knockout resulted in a significantly accelerated pathway to tumor formation that was surprisingly not driven by alterations in tumor cell proliferation or apoptosis, but rather via earlier activation of the angiogenic switch. In the setting of a constitutional p53 gene knockout, loss of Arf also accelerated tumor development, albeit to a lesser degree. These findings demonstrate that Arf loss of function can promote tumorigenesis via facilitating angiogenesis, at least in part, through p53-independent mechanisms.

  1. A multi-stage approach to maximizing geocoding success in a large population-based cohort study through automated and interactive processes

    Directory of Open Access Journals (Sweden)

    Jennifer S. Sonderman

    2012-05-01

    Full Text Available To enable spatial analyses within a large, prospective cohort study of nearly 86,000 adults enrolled in a 12-state area in the southeastern United States of America from 2002-2009, a multi-stage geocoding protocol was developed to efficiently maximize the proportion of participants assigned an address level geographic coordinate. Addresses were parsed, cleaned and standardized before applying a combination of automated and interactive geocoding tools. Our full protocol increased the non-Post Office (PO Box match rate from 74.5% to 97.6%. Overall, we geocoded 99.96% of participant addresses, with only 5.2% at the ZIP code centroid level (2.8% PO Box and 2.3% non-PO Box addresses. One key to reducing the need for interactive geocoding was the use of multiple base maps. Still, addresses in areas with population density 920 persons/km2 (odds ratio (OR = 5.24; 95% confidence interval (CI = 4.23, 6.49, as were addresses collected from participants during in-person interviews compared with mailed questionnaires (OR = 1.83; 95% CI = 1.59, 2.11. This study demonstrates that population density and address ascertainment method can influence automated geocoding results and that high success in address level geocoding is achievable for large-scale studies covering wide geographical areas.

  2. Thickness distribution of multi-stage incremental forming with different forming stages and angle intervals

    Institute of Scientific and Technical Information of China (English)

    李军超; 杨芬芬; 周志强

    2015-01-01

    Although multi-stage incremental sheet forming has always been adopted instead of single-stage forming to form parts with a steep wall angle or to achieve a high forming performance, it is largely dependent on empirical designs. In order to research multi-stage forming further, the effect of forming stages (n) and angle interval between the two adjacent stages (Δα) on thickness distribution was investigated. Firstly, a finite element method (FEM) model of multi-stage incremental forming was established and experimentally verified. Then, based on the proposed simulation model, different strategies were adopted to form a frustum of cone with wall angle of 30° to research the thickness distribution of multi-pass forming. It is proved that the minimum thickness increases largely and the variance of sheet thickness decreases significantly as the value of n grows. Further, with the increase of Δα, the minimum thickness increases initially and then decreases, and the optimal thickness distribution is achieved with Δα of 10°. Additionally, a formula is deduced to estimate the sheet thickness after multi-stage forming and proved to be effective. And the simulation results fit well with the experimental results.

  3. Disjoint Paths Multi-stage Interconnection Networks Stability Problem

    CERN Document Server

    Rastogi, Ravi; Chauhan, Durg Singh; Govil, Mahesh Chandra

    2012-01-01

    This research paper emphasizes that the Stable Matching problems are the same as the problems of stable configurations of Multi-stage Interconnection Networks (MIN). The authors have solved the Stability Problem of Existing Regular Gamma Multi-stage Interconnection Network (GMIN), 3-Disjoint Gamma Multi-stage Interconnection Network (3DGMIN) and 3-Disjoint Path Cyclic Gamma Multi-stage Interconnection Network (3DCGMIN) using the approaches and solutions provided by the Stable Matching Problem. Specifically Stable Marriage Problem is used as an example of Stable Matching. For MINs to prove Stable two existing algorithms are used:-the first algorithm generates the MINs Preferences List in time and second algorithm produces a set of most Optimal Pairs of the Switching Elements (SEs) (derived from the MINs Preferences List) in time. Moreover, the paper also solves the problem of Ties that occurs between the Optimal Pairs. The results are promising as the comparison of the MINs based on their stability shows that ...

  4. A Multistage Method for Multiobjective Route Selection

    Science.gov (United States)

    Wen, Feng; Gen, Mitsuo

    The multiobjective route selection problem (m-RSP) is a key research topic in the car navigation system (CNS) for ITS (Intelligent Transportation System). In this paper, we propose an interactive multistage weight-based Dijkstra genetic algorithm (mwD-GA) to solve it. The purpose of the proposed approach is to create enough Pareto-optimal routes with good distribution for the car driver depending on his/her preference. At the same time, the routes can be recalculated according to the driver's preferences by the multistage framework proposed. In the solution approach proposed, the accurate route searching ability of the Dijkstra algorithm and the exploration ability of the Genetic algorithm (GA) are effectively combined together for solving the m-RSP problems. Solutions provided by the proposed approach are compared with the current research to show the effectiveness and practicability of the solution approach proposed.

  5. Transfer Function of Multi-Stage Active Filters: A Solution Based on Pascal's Triangle and a General Expression

    Science.gov (United States)

    Levesque, Luc

    2012-01-01

    A method is proposed to simplify analytical computations of the transfer function for electrical circuit filters, which are made from repetitive identical stages. A method based on the construction of Pascal's triangle is introduced and then a general solution from two initial conditions is provided for the repetitive identical stage. The present…

  6. Experiments for Multi-Stage Processes

    DEFF Research Database (Denmark)

    Tyssedal, John; Kulahci, Murat

    2015-01-01

    Multi-stage processes are very common in both process and manufacturing industries. In this article we present a methodology for designing experiments for multi-stage processes. Typically in these situations the design is expected to involve many factors from different stages. To minimize the req...... number of stages and also show how to identify and estimate the effects. Both regular and non-regular designs are considered as base designs in generating the overall design.......Multi-stage processes are very common in both process and manufacturing industries. In this article we present a methodology for designing experiments for multi-stage processes. Typically in these situations the design is expected to involve many factors from different stages. To minimize the...... required number of experimental runs, we suggest using mirror image pairs of experiments at each stage following the first. As the design criterion, we consider their projectivity and mainly focus on projectivity 3 designs. We provide the methodology for generating these designs for processes with any...

  7. Charcoal Production via Multistage Pyrolysis

    Institute of Scientific and Technical Information of China (English)

    Adetoyese Olajire Oyedun; Ka Leung Lam; Chi Wai Hui

    2012-01-01

    Interests in charcoal usage have recently been re-ignited because it is believed that charcoal is a muchbetter fuel than wood. The conventional charcoal production consumes a large amount of energy due to the prolonged heating time and cooling time which contribute to the process completing in one to several days. Wood py-rolysis consists of both endothermic and exothermic reactions as well as the decomposition of the different components at different temperature range (hemicellulose: 200-260℃; cellulose: 240-350℃ and lignin: 280-500℃). Inthis study we propose a multistagepyrolysis which is an approach to carry out pyrolysis with multiple heating stages so as to gain certain processing benefits. We propose a three-stage approach which includes rapid stepwise heating stage to a variable target temperatures of 250 ℃, 300℃, 350 ℃ and 400 ℃, slow and gradual heatingstage to a tinal temperature of 400℃ and adiabatic with cooling stage. The multi-stage pyrolysis process can save 30% energy and the processing time by using a first temperature target of 300 ℃and heating rate of 5℃.min-1 to produce a fixed-carbon yield of 25.73% as opposed to the base case with a fixed-carbon yield of23.18%.

  8. Multistage growth of Fe-Mg-carpholite and Fe-Mg-chloritoid, from field evidence to thermodynamic modelling

    Science.gov (United States)

    Pourteau, Amaury; Bousquet, Romain; Vidal, Olivier; Plunder, Alexis; Duesterhoeft, Erik; Candan, Osman; Oberhänsli, Roland

    2015-04-01

    We provide new insights into the prograde evolution of HP/LT meta-sedimentary rocks on the basis of detailed petrologic examination, element-partitioning analysis, and thermodynamic modelling of well-preserved Fe-Mg-carpholite- and chloritoid-bearing rocks from the Afyon zone (Anatolia). Study samples, stemming from three different areas of the metamorphic belt, include typical quartz-carpholite veins as well as quartz-free and quartz-bearing phyllites. All samples exhibit multiple stages of carpholite, whereas zoning was until now rarely documented in this type of rocks. We document continuous, and discontinuous compositional (ferro-magnesian substitution) zoning of carpholite (overall XMg = 0.27-0.73) and chloritoid (overall XMg = 0.07-0.30), as well as clear equilibrium, and disequilibrium (i.e. reaction-related) textures involving carpholite and chloritoid, which consistently account for the consistent enrichment in Mg of both minerals through time, and the progressive replacement of carpholite by chloritoid. Mg/Fe distribution coefficients calculated between carpholite and chloritoid vary widely within samples (2.2-20.0). Among this range, only values of 7-11 correlate with equilibrium textures, in agreement with data from the literature. Equilibrium phase diagrams for (NaK)FMASH rock compositions are calculated using a newly modified thermodynamic dataset, including most recent data for carpholite, chloritoid, chlorite, and white mica, as well as further refinements for Fe-carpholite, and both chloritoid end-members, as required to reproduce accurately petrologic observations (phase relations, experimental constraints, Mg/Fe partitioning). Modelling reveals that Mg/Fe partitioning between carpholite and chloritoid is greatly sensitive to temperature, and calls for a future evaluation of possible use as a thermometer, valid for blueschist-facies conditions, which has so far been missing. In addition, calculations show significant effective bulk composition

  9. 大型离心压缩机性能预测的混合建模方法研究%Hybrid modeling method for performance prediction of multi-stage centrifugal compressor

    Institute of Scientific and Technical Information of China (English)

    褚菲; 王福利; 王小刚

    2011-01-01

    提出了一种核函数非线性偏最小二乘(PLS)与机理模型相结合的多级离心压缩机性能预测混合建模方法,用以预测离心压缩机的输出压比.通过分析大型离心压缩机多级压缩过程的机理,利用能最守恒关系,在压缩机各级气流损失计算和等熵效率定义的基础上建立了多级离心压缩机性能预测机理模型;利用核函数非线性PLS对机理模型的误差进行了修正.实验结果验证了该方法相比于机理模型的有效性,将其应用于实际生产过程中,取得了满意的效果.%A hybrid modeling method is proposed to predict the pressure ratio of multi-stage centrifugal compressor, which combines kernel nonlinear partial least squares (PLS) and principle model. Through analyzing the mechanism of multi-stage compression process, calculating airflow loss and defining isentropic efficiency, a principle model for performance prediction of multi-stage centrifugal compressor is established, and kernel nonlinear PLS is also used to correct the error of the principle model. Experiment analysis verifies the validity that the effectiveness of the method is better than that of ordinary principle model. The proposed method was applied to practical industrial process and result demonstrates that the method achieves satisfactory estimation performance.

  10. Neural Network Learning for Principal Component Analysis: A Multistage Decomposition Approach

    Institute of Scientific and Technical Information of China (English)

    FENGDazheng; ZHANGXianda; BAOZheng

    2004-01-01

    This paper presents a novel neural network model for finding the principal components of an Ndimensional data stream. This neural network consists of r (≤N) neurons, where the i-th neuron has only N - i+1 weights and an N- i+1 dimensional input vector, while each neuron in most of the relative classical neural networks includes N weights and an N dimensional input vector. All the neurons are trained by the NIC algorithm under the single component case[7] so as to get a series of dimension-reducing principal components in which the dimension number of the i-th principal component is N- i+1. In multistage dimension-reducing processing, the weight vector of i-th neuron is always orthogonal to the subspace constructed from the weight vectors of the first i-1 neurons. By systematic reconstruction technique, wecan recover all the principal components from a series of dimension-reducing ones. Its remarkable advantage is that its computational efficiency of the neural network learning based on the Novel information criterion (NIC) is improved and the weight storage is reduced, by the multistage dimension-reducing processing (multistage decomposition)for the covariance matrix or the input vector sequence. In addition, we study several important properties of the NIC learning algorithm.

  11. Dynamic-programming approaches to single-and multi-stage stochastic knapsack problems for portfolio optimization

    OpenAIRE

    Khoo, Wai Gea

    1999-01-01

    This thesis proposes new methods, based on dynamic programming, for solving certain single-stage and multi-stage integer stochastic knapsack problems. These problems model stochastic portfolio optimization problems (SPOPs) which assume deterministic unit weight, and normally distributed unit return with known mean and variance for each item type. Given an initial wealth, the objective is to select a portfolio that maximizes the probability of achieving or exceeding a specified final return th...

  12. Interconnected Levels of Multi-Stage Marketing

    DEFF Research Database (Denmark)

    Vedel, Mette; Geersbro, Jens; Ritter, Thomas

    2012-01-01

    different levels of multi-stage marketing and illustrates these stages with a case study. In addition, a triadic perspective is introduced as an analytical tool for multi-stage marketing research. The results from the case study indicate that multi-stage marketing exists on different levels. Thus, managers...... in a multi-stage marketing context. This understanding assists managers in assessing and balancing different aspects of multi- stage marketing. The triadic perspective also offers avenues for further research.......Multi-stage marketing gains increasing attention as knowledge of and influence on the customer's customer become more critical for the firm's success. Despite this increasing managerial relevance, systematic approaches for analyzing multi-stage marketing are still missing. This paper conceptualizes...

  13. Improving the efficiencies of simultaneous organic substance and nitrogen removal in a multi-stage loop membrane bioreactor-based PWWTP using an on-line Knowledge-Based Expert System.

    Science.gov (United States)

    Chen, Zhao-Bo; Nie, Shu-Kai; Ren, Nan-Qi; Chen, Zhi-Qiang; Wang, Hong-Cheng; Cui, Min-Hua

    2011-10-15

    The results of the use of an expert system (ES) to control a novel multi-stage loop membrane bioreactor (MLMBR) for the simultaneous removal of organic substances and nutrients are reported. The study was conducted at a bench-scale plant for the purpose of meeting new discharge standards (GB21904-2008) for the treatment of chemical synthesis-based pharmaceutical wastewater (1200-9600 mg/L COD, 500-2500 mg/L BOD5, 50-200 mg/L NH4+-N and 105-400 mg/L TN in the influent water) by developing a distributed control system. The system allows various expert operational approaches to be deployed with the goal of minimizing organic substances and nitrogen levels in the outlet while using the minimum amount of energy. The proposed distributed control system, which is supervised by a Knowledge-Based Expert System (KBES) constructed with G2 (a tool for expert system development) and a back propagation BP artificial neural network, permits the on-line implementation of every operating strategy of the experimental system. A support vector machine (SVM) is applied to achieve pattern recognition. A set of experiments involving variable sludge retention time (SRT), hydraulic retention time (HRT) and dissolved oxygen (DO) was carried out. Using the proposed system, the amounts of COD, TN and NH4+-N in the effluent decreased by 55%, 62% and 38%, respectively, compared to the usual operating conditions. These improvements were achieved with little energy cost because the performance of the treatment plant was optimized using operating rules implemented in real time. PMID:21862097

  14. Multivalued and Multiple Reflected Raytracing with Extreme Value Based on the Multistage Modified Shortest-path Method%分区多步最短路径极值法多值多次反射波追踪

    Institute of Scientific and Technical Information of China (English)

    唐小平; 白超英; 刘宽厚

    2011-01-01

    The grid-based raytracing algorithms,such as the finite-difference eikonal equation solver and the shortest-path method,are all based on the Fermat (minimum travel time) principle, which is able to track the first reflected arrivals only. In heterogeneous media involving a relatively larger velocity contrast or complex reflected interface. The seismic wavefronts are self-intersected, as a result, the rays are multi-paths. In order to simulate such multivalued and multiple reflected arrivals, we put forward an algorithm to trace the multivalued and multiple reflected arrivals, it referred as the extreme value algorithm based on the multistage modified shortest-path method, which is capable of tracking the multivalued and multiple reflected arrivals in velocity model included complex reflected interfaces. The principles of the extreme value are that;we firstly conduct down-wind raytracing from both sources and receivers to the sampled reflected interfaces and record the traveltimes and raypaths at each sampled reflected point,and sum up traveltime value at each reflected point, and form a stacked' traveltime-distance' curve (or surface for 3D case);secondly we solve extremum values for this stacked'traveltime-distance'curveCor surface).in which the location of the extreme points are the reflected points; finally we link the raypaths and add traveltimes from the source to the reflected point,and then to the receiver. Thus the multivalued and multiple reflected arrivals are successfully traced. This algorithm has a simple principle, high accuracy, fast CPU time and easy adaptation for complex media-Compared with the fast marching method and error analysis.it is evident that the extreme value of the multistage shortest-path method is a feasible and efficient algorithm for tracking the multivalued and multiple reflected arrivals.%基于网格单元扩展的射线追踪算法,如:较为流行的有限差分解程函方程法和最短路径法均是建立在费马(最小

  15. Analysis and Optimization of a Multistage Inventory-Queue System

    OpenAIRE

    Liming Liu; Xiaoming Liu; David D. Yao

    2004-01-01

    An important issue in the management of supply chains and manufacturing systems is to control inventory costs at different locations throughout the system while satisfying an end-customer service-level requirement. The challenge involved is to solve a nonlinear constrained optimization problem that captures the key dynamics of a complex production-inventory system. In this paper, we first develop a multistage inventory-queue model and a job-queue decomposition approach that evaluates the perf...

  16. DeepID-Net: multi-stage and deformable deep convolutional neural networks for object detection

    OpenAIRE

    Ouyang, Wanli; Luo, Ping; Zeng, Xingyu; Qiu, Shi; Tian, Yonglong; Li, Hongsheng; Yang, Shuo; Wang, Zhe; Xiong, Yuanjun; Qian, Chen; Zhu, Zhenyao; Wang, Ruohui; Loy, Chen-Change; Wang, Xiaogang; Tang, Xiaoou

    2014-01-01

    In this paper, we propose multi-stage and deformable deep convolutional neural networks for object detection. This new deep learning object detection diagram has innovations in multiple aspects. In the proposed new deep architecture, a new deformation constrained pooling (def-pooling) layer models the deformation of object parts with geometric constraint and penalty. With the proposed multi-stage training strategy, multiple classifiers are jointly optimized to process samples at different dif...

  17. Return Vane Installed in Multistage Centrifugal Pump

    OpenAIRE

    Miyano, Masafumi; Kanemoto, Toshiaki; Kawashima, Daisuke; Wada, Akihiro; Hara, Takashi; Sakoda, Kazuyuki

    2008-01-01

    To optimize the stationary components in the multistage centrifugal pump, the effects of the return vane profile on the performances of the multistage centrifugal pump were investigated experimentally, taking account of the inlet flow conditions for the next stage impeller. The return vane, whose trailing edge is set at the outer wall position of the annular channel downstream of the vane and which discharges the swirl-less flow, gives better pump performances. By equipping such return vane w...

  18. Multi-stage LTL transport systems in supply chain management

    OpenAIRE

    Gonzalez-Feliu, Jesus

    2013-01-01

    This paper aims to unify concepts and to describe the multi-stage transport systems and their integratyion to supply chain management. Multi-stage distribution systems are common logistics management, and often they are assimilated to multi-stage transport strategies. However, transport is often considered as an external operation or a specific stage, even when it is a multi-stage system. First, the paper presents the main concepts of multi-stage transport systems by defining the concept an m...

  19. Pilot-scale multistage membrane process for the separation of CO2 from LNG-fired flue gas

    KAUST Repository

    Choi, Seung Hak

    2013-06-01

    In this study, a multistage pilot-scale membrane plant was constructed and operated for the separation of CO2 from Liquefied Natural Gas (LNG)-fired boiler flue gas of 1000 Nm3/day. The target purity and recovery of CO2 were 99 vol.% and 90%, respectively. For this purpose, asymmetric polyethersulfone (PES) hollow fibers membranes has been developed in our previous work and has evaluated the effects of operating pressure and feed concentration of CO2 on separation performance. The operating and permeation data obtained were also analyzed in relation with the numerical simulation data using countercurrent flow model. Based on these results, in this study, four-staged membrane process including dehumidification process has been designed, installed, and operated to demonstrate the feasibility of multistage membrane systems for removing CO2 from flue gases. The operation results using this plant were compared to the numerical simulation results on multistage membrane process. The experimental results matched well with the numerical simulation data. The concentration and the recovery of CO2 in the permeate stream of final stage were ranged from 95-99 vol.% and 70-95%, respectively, depending on the operating conditions. This study demonstrated the applicability of the membrane-based pilot plant for CO2 recovery from flue gas. © 2013 Elsevier B.V. All rights reserved.

  20. Fuzzy-like multiple objective multistage decision making

    CERN Document Server

    Xu, Jiuping

    2014-01-01

    Decision has inspired reflection of many thinkers since the ancient times. With the rapid development of science and society, appropriate dynamic decision making has been playing an increasingly important role in many areas of human activity including engineering, management, economy and others. In most real-world problems, decision makers usually have to make decisions sequentially at different points in time and space, at different levels for a component or a system, while facing multiple and conflicting objectives and a hybrid uncertain environment where fuzziness and randomness co-exist in a decision making process. This leads to the development of fuzzy-like multiple objective multistage decision making. This book provides a thorough understanding of the concepts of dynamic optimization from a modern perspective and presents the state-of-the-art methodology for modeling, analyzing and solving the most typical multiple objective multistage decision making practical application problems under fuzzy-like un...

  1. HOMOGENEOUS MULTISTAGE ARCHITECTURE FOR REAL-TIME IMAGE PROCESSING

    Directory of Open Access Journals (Sweden)

    Hanen Chenini

    2012-12-01

    Full Text Available In this article, we present a new multistage architecture oriented to real-time complex processing applications. Given a set of rules, this proposed architecture allows the using of different communication links (point to point link, hardware router… to connect unlimited number of parallel computing elements (software processors to follow the increasing complexity of algorithms. In particular, this work brings out a parallel implementation of multihypothesis approach for road recognition application on the proposed Multiprocessor Systemon-Chip (MP-SoC architecture. This algorithm is usually the main part of the lane keeping applications. Experimental results using images of a real road scene are presented. Using a low cost FPGA-based System-on-Chip, our hardware architecture is able to detect and recognize the roadsides in a time limit of 60 mSec. Moreover, we demonstrate that our multistage architecture may be used to achieve good speed-up in solving automotive applications.

  2. Multi-stage magnetic induction mass accelerator

    International Nuclear Information System (INIS)

    The magnetic induction method of mass acceleration readily lends itself to multi-staging. In the limit of many stages, such an accelerator approaches a distributed energy source system where only closing switches are necessary. We describe the design and performance of a three-stage accelerator, each driven by a separate capacitor bank. This system was modeled using a previously reported computer code. In order to do this the code was modified to calculate projectile acceleration through a succession of driver coils: Thermal conductivity and surface melting models were also added. The former is necessary due to the extended transit time through many stages. The latter is needed in anticipation of the more extreme ohmic heating when the capacitor banks are replaced by explosive-driven, magnetic flux compression generators. The performance goal of this system is to at least double the kinetic energy of a 0.3 kgm copperclad, steel projectile injected at a velocity of 300 m/sec from an explosive-driven gun. We then plan to test the system at the thermal and mechanical limit by using explosive-driven, magnetic flux compression generators as energy sources. We envision a six-stage system driven by three generators

  3. Simulation and analysis of multi-stage centrifugal fractional extraction process of 4-nitrobenzene glycine enantiomers☆

    Institute of Scientific and Technical Information of China (English)

    Ping Wen; Kewen Tang; Jicheng Zhou; Panliang Zhang

    2015-01-01

    Based on the interfacial ligand exchange model and the law of conservation of mass, the multi-stage enantioselective liquid–liquid extraction model has been established to analyze and discuss on multi-stage centrifugal fractional extraction process of 4-nitrobenzene glycine (PGL) enantiomers. The influence of phase ratio, extractant concentra-tion, and PF6−concentration on the concentrations of enantiomers in the extract and raffinate was investigated by experiment and simulation. A good agreement between model and experiment was obtained. On this basis, the influence of many parameters such as location of stage, concentration levels, extractant excess, and number of stages on the symmetric separation performance was simulated. The optimal location of feed stage is the middle of fractional extraction equipment. The feed flow must satisfy a restricted relationship on flow ratios and the liquid throughout of centrifugal device. For desired purity specification, the required flow ratios decrease with extractant concentration and increase with PF6−concentration. When the number of stages is 18 stages at extractant excess of 1.0 or 14 stages at extractant excess of 2.0, the eeeq (equal enantiomeric excess) can reach to 99%.

  4. From the dilute solution to the pure compound:Extraction strategy based on a multi-stage process of phase separation

    Institute of Scientific and Technical Information of China (English)

    GOUTAUDIER; Christelle; TENU; Richard; COUNIOUX; Jean-Jacques

    2010-01-01

    It is very rare that a one-step process of extraction leads to the pure compound with a high degree of purity specified by an industrial application.The various stages of a synthesis process and possible secondary reactions may lead to the synthesis of more or less complex and highly diluted solutions.In this work,the rationale and strategy for extraction and purification of a high added value compound are discussed.All the thinking is based on the knowledge and the exploitation of phase diagrams and then developed for different unit operations of the process.The most significant research tools are the experimental data and the modelling of phase equilibrium to estimate the yield of each step of extraction.The significant example chosen involves all the basic methods of phase separation,starting with liquid-vapour equilibrium:stripping of high volatility components and then more or less complex distillation are classically employed.The theoretical plateau number can be deduced from the equilibrium equation curves.The second step is based on the study of the liquid-liquid equilibrium and is an intermediate step for enrichment of the solution when distillation is not possible.A final step based on solid-liquid equilibrium consists of the selective crystallization of the pure product at low temperature,in order to satisfy the requirements of purity and safety imposed by industrial use.The conclusion includes all isolation operations in the form of a general extraction and purification scheme.

  5. Inspection logistics planning for multi-stage production systems with applications to semiconductor fabrication lines

    Science.gov (United States)

    Chen, Kyle Dakai

    Since the market for semiconductor products has become more lucrative and competitive, research into improving yields for semiconductor fabrication lines has lately received a tremendous amount of attention. One of the most critical tasks in achieving such yield improvements is to plan the in-line inspection sampling efficiently so that any potential yield problems can be detected early and eliminated quickly. We formulate a multi-stage inspection planning model based on configurations in actual semiconductor fabrication lines, specifically taking into account both the capacity constraint and the congestion effects at the inspection station. We propose a new mixed First-Come-First-Serve (FCFS) and Last-Come-First-Serve (LCFS) discipline for serving the inspection samples to expedite the detection of potential yield problems. Employing this mixed FCFS and LCFS discipline, we derive approximate expressions for the queueing delays in yield problem detection time and develop near-optimal algorithms to obtain the inspection logistics planning policies. We also investigate the queueing performance with this mixed type of service discipline under different assumptions and configurations. In addition, we conduct numerical tests and generate managerial insights based on input data from actual semiconductor fabrication lines. To the best of our knowledge, this research is novel in developing, for the first time in the literature, near-optimal results for inspection logistics planning in multi-stage production systems with congestion effects explicitly considered.

  6. Performance and model of a novel multi-sparger multi-stage airlift loop membrane bioreactor to treat high-strength 7-ACA pharmaceutical wastewater: effect of hydraulic retention time, temperature and pH.

    Science.gov (United States)

    Chen, Zhao-bo; He, Zhang-wei; Tang, Cong-cong; Hu, Dong-xue; Cui, Yu-bo; Wang, Ai-jie; Zhang, Ying; Yan, Li-long; Ren, Nan-qi

    2014-09-01

    In this study, three novel multi-sparger multi-stage airlift loop membrane bioreactors (Ms(2)ALMBRs) were set up in parallel for treating synthetic high-strength 7-ACA pharmaceutical wastewater under different HRTs, temperatures and pHs, respectively. During the 200-day operating time, average COD removal efficiencies were 94.96%, 96.05% and 93.9%. While average 7-ACA removal efficiencies were 66.44%, 59.04% and 59.60%, respectively. The optimal conditions were 10h, 15-35°C and 7-9 for HRT, temperature and pH, respectively. Moreover, the sludge characteristics and microorganism drug-resistances were explored. Results showed that different temperatures and pHs influenced contaminant removals by affecting MLSS concentration and β-lactamase activity significantly. In addition, mathematical statistical models, built on the polynomial and linear regression techniques, were developed for exploring the inner relationships between HRT, temperature and pH changes and MLSS concentrations, β-lactamase activities and contaminant removals of the Ms(2)ALMBR system. PMID:24994681

  7. Pressure Transient Analysis and Flux Distribution for Multistage Fractured Horizontal Wells in Triple-Porosity Reservoir Media with Consideration of Stress-Sensitivity Effect

    OpenAIRE

    Jingjing Guo; Haitao Wang; Liehui Zhang; Chengyong Li

    2015-01-01

    Triple-porosity model is usually adopted to describe reservoirs with multiscaled pore spaces, including matrix pores, natural fractures, and vugs. Multiple fractures created by hydraulic fracturing can effectively improve the connectivity between existing natural fractures and thus increase well deliverability. However, little work has been done on pressure transient behavior of multistage fractured horizontal wells in triple-porosity reservoirs. Based on source/sink function method, this pap...

  8. Sensor placement for active control of surge in multi-stage axial compressors

    International Nuclear Information System (INIS)

    In this paper, a methodology is presented to determine the optimal sensor choice for active control of surge in multi-stage axial flow compressors. In this method, the compression system is modeled based on the conservation equations of mass, momentum and energy. The model is then linearized at unstable steady-state points, and the Linear Quadratic Gaussian controllers are designed to stabilize the compression system. The effects of different sensor types and locations on active stabilization process are then investigated for both low and high compressor speeds. Based on this sensor placement methodology, the sensor location and type are selected in order to minimize the estimation error and air bleed mass flow. The results are presented to show the effectiveness of the methodology. These results show that the proper sensor location is dependent on the compressor rotational speed and the instability origination

  9. 财产保险公司投资组合问题的多阶段随机规划模型%Multistage Stochastic Programming Model for the Portfolio Problem of a Property-Liability Insurance Company

    Institute of Scientific and Technical Information of China (English)

    王春峰; 杨建林; 蒋祥林

    2002-01-01

    The current portfolio model for property-liability insurance company is only single period that can not meet the practical demands of portfolio management, and the purpose of this paper is to develop a multiperiod model for its portfolio problem. The model is a multistage stochastic programming which considers transaction costs, cash flow between time periods, and the matching of asset and liability; it does not depend on the assumption for normality of return distribution. Additionally, an investment constraint is added. The numerical example manifests that the multiperiod model can more effectively assist the property-liability insurer to determine the optimal composition of insurance and investment portfolio and outperforms the single period one.%财产保险公司的投资组合模型均是单期的,不能充分满足投资组合管理实践的需要.为提供多期规划工具,建立了一个多阶段的随机规划模型.它考虑了交易成本,分析了不同时期的现金流,讨论了资产负债的匹配问题,去掉了收益分布的正态假定,并增加了一种投资约束.数值实例的计算结果表明,多期模型能更好地帮助财产保险公司选择保险与投资的优化组合,其性能要优于单期模型.

  10. Dynamics of multi-stage infections on networks

    CERN Document Server

    Sherborne, N; Kiss, I Z

    2015-01-01

    This paper investigates the dynamics of infectious diseases with a non-exponentially distributed infectious period. This is achieved by considering a multi-stage infection model on networks. Using pairwise approximation with a standard closure, a number of important characteristics of disease dynamics are derived analytically, including the final size of an epidemic and a threshold for epidemic outbreaks. Stochastic simulations of dynamics on networks are performed and compared to the results of pairwise models for several realistic examples of infectious diseases to illustrate the role played by the number of stages in the disease dynamics. The agreement between the pairwise and simulation methods is excellent in the cases we consider.

  11. Multi-stage shifter for subsecond time resolution of emulsion gamma-ray telescopes

    International Nuclear Information System (INIS)

    To observe gamma-ray sources precisely, a balloon-borne experiment with a new type of detector, the emulsion gamma-ray telescope, is planned. A multi-stage shifter mechanism based on the concept of an analog clock serves as a time stamper with subsecond time resolution and uses multiple moving stages mounted on the emulsion chambers. This new technique was employed in a test experiment using a small-scale model in a short-duration balloon flight. Tracks recorded in nuclear emulsion were read by a fully automated scanning system, were reconstructed, and time information were assigned by analysis of their position displacements in the shifter layers. The estimated time resolution was 0.06–0.15 s. The number of tracks passing through the detector was counted every second, and hadron jets were detected as significant excesses observed in the counting rate. In future, the multi-stage shifter is greatly contributing to ongoing efforts to increase the effective area of emulsion gamma-ray telescopes.

  12. Multi-stage shifter for subsecond time resolution of emulsion gamma-ray telescopes

    Science.gov (United States)

    Rokujo, H.; Aoki, S.; Takahashi, S.; Kamada, K.; Mizutani, S.; Nakagawa, R.; Ozaki, K.

    2013-02-01

    To observe gamma-ray sources precisely, a balloon-borne experiment with a new type of detector, the emulsion gamma-ray telescope, is planned. A multi-stage shifter mechanism based on the concept of an analog clock serves as a time stamper with subsecond time resolution and uses multiple moving stages mounted on the emulsion chambers. This new technique was employed in a test experiment using a small-scale model in a short-duration balloon flight. Tracks recorded in nuclear emulsion were read by a fully automated scanning system, were reconstructed, and time information were assigned by analysis of their position displacements in the shifter layers. The estimated time resolution was 0.06-0.15 s. The number of tracks passing through the detector was counted every second, and hadron jets were detected as significant excesses observed in the counting rate. In future, the multi-stage shifter is greatly contributing to ongoing efforts to increase the effective area of emulsion gamma-ray telescopes.

  13. Interconnected levels of multi-stage marketing: A triadic approach

    OpenAIRE

    Vedel, Mette; Geersbro, Jens; Ritter, Thomas

    2012-01-01

    Multi-stage marketing gains increasing attention as knowledge of and influence on the customer's customer become more critical for the firm's success. Despite this increasing managerial relevance, systematic approaches for analyzing multi-stage marketing are still missing. This paper conceptualizes different levels of multi-stage marketing and illustrates these stages with a case study. In addition, a triadic perspective is introduced as an analytical tool for multi-stage marketing research. ...

  14. Multistage Spectral Relaxation Method for Solving the Hyperchaotic Complex Systems

    Directory of Open Access Journals (Sweden)

    Hassan Saberi Nik

    2014-01-01

    Full Text Available We present a pseudospectral method application for solving the hyperchaotic complex systems. The proposed method, called the multistage spectral relaxation method (MSRM is based on a technique of extending Gauss-Seidel type relaxation ideas to systems of nonlinear differential equations and using the Chebyshev pseudospectral methods to solve the resulting system on a sequence of multiple intervals. In this new application, the MSRM is used to solve famous hyperchaotic complex systems such as hyperchaotic complex Lorenz system and the complex permanent magnet synchronous motor. We compare this approach to the Runge-Kutta based ode45 solver to show that the MSRM gives accurate results.

  15. Experimental studies on the multistage constant modulus array for the estimation of directions-of-arrival

    Institute of Scientific and Technical Information of China (English)

    ZHUO Jie; SUN Chao

    2004-01-01

    The performance of the multistage Constant Modulus (CM) array, one of the most striking blind beamforming algorithms, for the source Directions-of-Arrival (DOA) estimation was analyzed via computer simulations and water tank experiments, and was compared to that of other DOA estimation algorithms including the ‘non-blind' and the ‘blind'. Firstly, a nominal array model and an array model with gain and phase perturbations were established,respectively. Secondly, the multistage CM array algorithm was described and computer simulations were conducted. Simulation results showed that the multistage CM array could correctly estimate the DOA at the same time when the sources were blindly recovered, and the angle separating ability of the algorithm was beyond the Rayleigh resolution limit. By changing the variance of the array model errors, it was also verified that the multistage CM array was more robust to the errors than some other algorithms mentioned in this paper. Finally, water tank experiments and data processing results were provided. Situations with different array sizes and source angular separations were considered. It was shown that the results were in good agreement with computer simulations. Results of computer simulations and water tank experiments verified that the DOAs of the multiple independent sources could be blindly and robustly estimated with the multistage CM array.

  16. Multistage spectral polarimeter based on integrated acousto-optical Ti:LiNbO3 TE-TM converters for WDM system monitoring

    Science.gov (United States)

    Noe, Reinhold; Maucher, A.; Ricken, Raimund

    1999-04-01

    A 4-stage spectral polarimeter based on Ti:LiNbO3 acousto- optical TE-TM converters has been realized. It has about 20 dB stopband suppression and can measure polarimetric spectra as well as the time evolution of the state of polarization. A simple optical spectrum analyzer is also proposed.

  17. Generalisations of the two-mutation and classical multi-stage models of carcinogenesis fitted to the Japanese atomic bomb survivor data

    International Nuclear Information System (INIS)

    Generalisations of the two-mutation carcinogenesis model of Moolgavkar, Venzon and Knudson (to allow for an arbitrary number of mutational stages), and of the model of Armitage and Doll, are fitted to the Japanese atomic bomb survivor mortality data. Models with two or three mutations give adequate descriptions of the excess mortality of solid cancers. For leukaemia the fit of the three-mutation model is preferable to that of the two-mutation model. The optimal three-mutation leukaemia model provides a satisfactory fit only when both first and second mutation rates are radiation-affected. Examination of other epidemiological data leads to the conclusion that without some extra stochastic 'stage' appended (such as might be provided by consideration of the process of development of a malignant clone from a single malignant cell) the two-mutation model is perhaps not well able to describe the pattern of excess risk for solid cancers that is often seen after exposure to radiation. The optimal three-mutation models predict low-dose population risks for a current UK population of 5.5-8.0 x 10-2 excess cancer deaths Sv-1, 6.8-9.8 x 10-2 radiation-induced cancer deaths Sv-1 or 1.0-1.4 years of life lost Sv-1. Risks for a current Japanese population are 6.8 x 10-2 excess cancer deaths Sv-1, 8.0 x 10-2 radiation-induced cancer deaths Sv-1, or 1.2 years of life lost Sv-1. (author)

  18. Multi-stage fuzzy load frequency control using PSO

    International Nuclear Information System (INIS)

    In this paper, a particle swarm optimization (PSO) based multi-stage fuzzy (PSOMSF) controller is proposed for solution of the load frequency control (LFC) problem in a restructured power system that operate under deregulation based on the bilateral policy scheme. In this strategy the control is tuned on line from the knowledge base and fuzzy inference, which request fewer sources and has two rule base sets. In the proposed method, for achieving the desired level of robust performance, exact tuning of membership functions is very important. Thus, to reduce the design effort and find a better fuzzy system control, membership functions are designed automatically by PSO algorithm, that has a strong ability to find the most optimistic results. The motivation for using the PSO technique is to reduce fuzzy system effort and take large parametric uncertainties into account. This newly developed control strategy combines the advantage of PSO and fuzzy system control techniques and leads to a flexible controller with simple stricture that is easy to implement. The proposed PSO based MSF (PSOMSF) controller is tested on a three-area restructured power system under different operating conditions and contract variations. The results of the proposed PSOMSF controller are compared with genetic algorithm based multi-stage fuzzy (GAMSF) control through some performance indices to illustrate its robust performance for a wide range of system parameters and load changes

  19. An integral equation solution for multistage turbomachinery design calculations

    Science.gov (United States)

    Mcfarland, Eric R.

    1993-01-01

    A method was developed to calculate flows in multistage turbomachinery. The method is an extension of quasi-three-dimensional blade-to-blade solution methods. Governing equations for steady compressible inviscid flow are linearized by introducing approximations. The linearized flow equations are solved using integral equation techniques. The flows through both stationary and rotating blade rows are determined in a single calculation. Multiple bodies can be modelled for each blade row, so that arbitrary blade counts can be analyzed. The method's benefits are its speed and versatility.

  20. Model-based geostatistics

    CERN Document Server

    Diggle, Peter J

    2007-01-01

    Model-based geostatistics refers to the application of general statistical principles of modeling and inference to geostatistical problems. This volume provides a treatment of model-based geostatistics and emphasizes on statistical methods and applications. It also features analyses of datasets from a range of scientific contexts.

  1. Health and human rights in eastern Myanmar after the political transition: a population-based assessment using multistaged household cluster sampling.

    Directory of Open Access Journals (Sweden)

    Parveen Kaur Parmar

    Full Text Available Myanmar transitioned to a nominally civilian parliamentary government in March 2011. Qualitative reports suggest that exposure to violence and displacement has declined while international assistance for health services has increased. An assessment of the impact of these changes on the health and human rights situation has not been published.Five community-based organizations conducted household surveys using two-stage cluster sampling in five states in eastern Myanmar from July 2013-September 2013. Data was collected from 6, 178 households on demographics, mortality, health outcomes, water and sanitation, food security and nutrition, malaria, and human rights violations (HRV. Among children aged 6-59 months screened, the prevalence of global acute malnutrition (representing moderate or severe malnutrition was 11.3% (8.0-14.7. A total of 250 deaths occurred during the year prior to the survey. Infant deaths accounted for 64 of these (IMR 94.2; 95% CI 66.5-133.5 and there were 94 child deaths (U5MR 141.9; 95% CI 94.8-189.0. 10.7% of households (95% CI 7.0-14.5 experienced at least one HRV in the past year, while four percent reported 2 or more HRVs. Household exposure to one or more HRVs was associated with moderate-severe malnutrition among children (14.9 vs. 6.8%; prevalence ratio 2.2, 95% CI 1.2-4.2. Household exposure to HRVs was associated with self-reported fair or poor health status among respondents (PR 1.3; 95% CI 1.1-1.5.This large survey of health and human rights demonstrates that two years after political transition, vulnerable populations of eastern Myanmar are less likely to experience human rights violations compared to previous surveys. However, access to health services remains constrained, and risk of disease and death remains higher than the country as a whole. Efforts to address these poor health indicators should prioritize support for populations that remain outside the scope of most formal government and donor programs.

  2. Adaptation of Decoy Fusion Strategy for Existing Multi-Stage Search Workflows

    Science.gov (United States)

    Ivanov, Mark V.; Levitsky, Lev I.; Gorshkov, Mikhail V.

    2016-06-01

    A number of proteomic database search engines implement multi-stage strategies aiming at increasing the sensitivity of proteome analysis. These approaches often employ a subset of the original database for the secondary stage of analysis. However, if target-decoy approach (TDA) is used for false discovery rate (FDR) estimation, the multi-stage strategies may violate the underlying assumption of TDA that false matches are distributed uniformly across the target and decoy databases. This violation occurs if the numbers of target and decoy proteins selected for the second search are not equal. Here, we propose a method of decoy database generation based on the previously reported decoy fusion strategy. This method allows unbiased TDA-based FDR estimation in multi-stage searches and can be easily integrated into existing workflows utilizing popular search engines and post-search algorithms.

  3. Critical assessment of multistage pseudospark switches

    CERN Document Server

    Frank, K; Petzenhauser, I

    2004-01-01

    In repetitive pulsed power there is a strong increasing demand for the development of high voltage pulse forming networks (PFN), which can be operated with high repetition rates and simultaneously with extremely long lifetime. Typical applications for such PFN's are modulators for the next generation of accelerators, pulse generators for flue gas cleaning with electrostatic precipitators, high power gas lasers, accelerators for medical radiography and drivers of high power microwaves. For instance, in the next generation linear collider the traditional thyratron/PFN modulators will no longer meet the new requirements. Multistage thyratrons are available for hold- off voltages up to 240 kV, but their handling is complicated, the reliability poor and the costs are high. To equip the 1600 modulators, which are planned for SLAC's next linear collider, with multistage thyratrons is unaffordable. Solid-state devices in combination with step-up transformers are under discussion, but their performance is not yet sati...

  4. Multi-stage drying of PVA aqueous solution film; PVA suiyoeki no bunri tofu kanso

    Energy Technology Data Exchange (ETDEWEB)

    Kishi, M.; Inoue, S. [Dai Nippon Printing Co. Ltd., Tokyo (Japan); Imakawa, H. [Kobe University, Kobe (Japan), Faculty of Engineering; Okazaki, M. [Kyoto University, Kyoto (Japan). Faculty of Engineering

    1995-07-10

    In a multi-stage coating and drying process, in which PVA (Polyvinyl alcohol) film was formed by repeating twice a set of operations consisting of coating PVA aqueous solution and convective drying of it, the drying process was numerically simulated using a drying model based on mass transfer within a coated film. The possibility of minimizing drying time was also investigated. Total drying time, summed over the first and second stages, required to yield a target mean moisture concentration in the solution film was calculated while changing the final mean moisture concentration of the first stage. It was found that the minimum drying time appeared for each target concentration and the effect of reduction on the total drying time became significant with increasing target concentration. 12 refs., 5 figs., 1 tab.

  5. The optimal multi-stage contest

    OpenAIRE

    Fu, Qiang; Lu, Jingfeng

    2006-01-01

    This paper investigates the optimal (effort-maximizing) structure of multi-stage sequential-elimination contests with pooling competition in each stage. We allow the contest organizer to design the contest structure in two arms: contest sequence (the number of stages, and the number of remaining contestants in each stage), and prize allocation. First, we find that the optimality of "winner-take-all" (single final winner, single final prize, no intermediate prizes) is independent of the contes...

  6. Multi-stage sampling in genetic epidemiology.

    Science.gov (United States)

    Whittemore, A S; Halpern, J

    When data are expensive to collect, it can be cost-efficient to sample in two or more stages. In the first stage a simple random sample is drawn and then stratified according to some easily measured attribute. In each subsequent stage a random subset of previously selected units is sampled for more detailed observation, with a unit's sampling probability determined by its attributes as observed in the previous stages. These designs are useful in many medical studies; here we use them in genetic epidemiology. Two genetic studies illustrate the strengths and limitations of the approach. The first study evaluates nuclear and mitochondrial DNA in U.S. blacks. The goal is to estimate the relative contributions of white male genes and white female genes to the gene pool of African-Americans. This example shows that the Horvitz-Thompson estimators proposed for multi-stage designs can be inefficient, particularly when used with unnecessary stratification. The second example is a multi-stage study of familial prostate cancer. The goal is to gather pedigrees, blood samples and archived tissue for segregation and linkage analysis of familial prostate cancer data by first obtaining crude family data from prostate cancer cases and cancer-free controls. This second example shows the gains in efficiency from multi-stage sampling when the individual likelihood or quasilikelihood scores vary substantially across strata. PMID:9004389

  7. Bayesian synthetic evaluation of multistage reliability growth with instant and delayed fix modes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In the multistage reliability growth tests with instant and delayed fix modes, the failure data can be assumed to follow Weibull processes with different parameters at different stages. For the Weibull process within a stage, by the proper selection of prior distribution form and the parameters, a concise posterior distribution form is obtained, thus simplifying the Bayesian analysis. In the multistage tests, the improvement factor is used to convert the posterior of one stage to the prior of the subsequent stage. The conversion criterion is carefully analyzed to determine the distribution parameters of the subsequent stage's variable reasonably. Based on the mentioned results, a new synthetic Bayesian evaluation program and algorithm framework is put forward to evaluate the multistage reliability growth tests with instant and delayed fix modes. The example shows the effectiveness and flexibility of this method.

  8. Design of intermediate die shape of multistage profile drawing for linear motion guide

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Kon; Lee, Jae Eun; Kim, Sung Min; Kim, Byung Min [Pusan National University, Busan (Korea, Republic of)

    2010-12-15

    The design of an intermediate die shape is very important in multistage profile drawing. In this study, two design methods for the intermediate die shape of a multistage profile drawing for producing a linear motion guide (LM) guide is proposed. One is the electric field analysis method using the equipotential lines generated by electric field analysis, and the other is the virtual die method using a virtual drawing die constructed from the initial material and the final product shape. In order to design the intermediate die shapes of a multistage profile drawing for producing LM guide, the proposed design methods are applied, and then FE analysis and profile drawing experiment are performed. As a result, based on the measurement of dimensional accuracy, it can be known that the intermediate die shape can be designed effectively

  9. Flexible Design and Operation of Multi-Stage Flash (MSF Desalination Process Subject to Variable Fouling and Variable Freshwater Demand

    Directory of Open Access Journals (Sweden)

    Said Alforjani Said

    2013-10-01

    Full Text Available This work describes how the design and operation parameters of the Multi-Stage Flash (MSF desalination process are optimised when the process is subject to variation in seawater temperature, fouling and freshwater demand throughout the day. A simple polynomial based dynamic seawater temperature and variable freshwater demand correlations are developed based on actual data which are incorporated in the MSF mathematical model using gPROMS models builder 3.0.3. In addition, a fouling model based on stage temperature is considered. The fouling and the effect of noncondensable gases are incorporated into the calculation of overall heat transfer co-efficient for condensers. Finally, an optimisation problem is developed where the total daily operating cost of the MSF process is minimised by optimising the design (no of stages and the operating (seawater rejected flowrate and brine recycle flowrate parameters.

  10. Multistage Magnetic Separator of Cells and Proteins

    Science.gov (United States)

    Barton, Ken; Ainsworth, Mark; Daily, Bruce; Dunn, Scott; Metz, Bill; Vellinger, John; Taylor, Brock; Meador, Bruce

    2005-01-01

    The multistage electromagnetic separator for purifying cells and magnetic particles (MAGSEP) is a laboratory apparatus for separating and/or purifying particles (especially biological cells) on the basis of their magnetic susceptibility and magnetophoretic mobility. Whereas a typical prior apparatus based on similar principles offers only a single stage of separation, the MAGSEP, as its full name indicates, offers multiple stages of separation; this makes it possible to refine a sample population of particles to a higher level of purity or to categorize multiple portions of the sample on the basis of magnetic susceptibility and/or magnetophoretic mobility. The MAGSEP includes a processing unit and an electronic unit coupled to a personal computer. The processing unit includes upper and lower plates, a plate-rotation system, an electromagnet, an electromagnet-translation system, and a capture-magnet assembly. The plates are bolted together through a roller bearing that allows the plates to rotate with respect to each other. An interface between the plates acts as a seal for separating fluids. A lower cuvette can be aligned with as many as 15 upper cuvette stations for fraction collection during processing. A two-phase stepping motor drives the rotation system, causing the upper plate to rotate for the collection of each fraction of the sample material. The electromagnet generates a magnetic field across the lower cuvette, while the translation system translates the electromagnet upward along the lower cuvette. The current supplied to the electromagnet, and thus the magnetic flux density at the pole face of the electromagnet, can be set at a programmed value between 0 and 1,400 gauss (0.14 T). The rate of translation can be programmed between 5 and 2,000 m/s so as to align all sample particles in the same position in the cuvette. The capture magnet can be a permanent magnet. It is mounted on an arm connected to a stepping motor. The stepping motor rotates the arm to

  11. Multistage epidermal carcinogenesis in transgenic mice: cooperativity and paradox.

    Science.gov (United States)

    Greenhalgh, D A; Wang, X J; Roop, D R

    1996-04-01

    Skin cancer is one of the most prevalent forms of human neoplasia with a frequency approaching that of all other neoplasms combined. Given this alarming statistic, which may be further exacerbated by increased ultraviolet B irradiation from ozone depletion, it is vital that realistic, relevant model systems are developed to increase our understanding of the underlying molecular mechanisms of carcinogenesis that result in or evaluate new treatment modalities. Toward this goal, the ability to stably introduce genes into the germline of mice has greatly enhanced prospects for generation of transgenic animal models of multistage molecular carcinogenesis. Moreover, when genes are combined with regulatory sequences that target their expression to specific tissues, investigators are able to study neoplasia both in the context of living organisms and in the tissues suspected of being the targets of these genes. The epidermis is an attractive tissue for targeted gene expression; not only is it a model for epithelial diseases in general, but the accessibility of the epidermis allows easy detection of progressive pathological changes that result from transgene expression and facilitates assessment of the potential role played by environmental factors. We have developed a targeting vector based on the human keratin gene (HK1), which is expressed exclusively in the epidermis of transgenic mice, at a late stage in development and in both basal and differentiated cells. Through the use of this targeting ability, rasHa, fos, and TGF alpha transgenic mice have been developed that exhibit preneoplastic epidermal hyperplasia and hyperkeratosis, and later benign, regression prone papillomas. Together, coexpression of two oncogenes cooperated to give autonomous papillomas, which possessed the phenotypic stability to allow assessment of a third genetic event, namely loss of the p53 tumor suppressor gene, via mating with p53 knockout mice. Loss of p53 expression, however, identified a

  12. Sharpening of the multistage modified comb filters

    Directory of Open Access Journals (Sweden)

    Nikolić Marko

    2011-01-01

    Full Text Available This paper describes the application of filter sharpening method to the modified comb filter (MCF in the case of decimation factor, which is product of two or more positive integers. It is shown that in the case of multistage decimation with MCF, filters in each stage are also MCF. Applying the sharpening to the decimation filter in the last stage provides very good results, with savings in the number of operations comparing to the case of sharpening of the complete filter. Direct-form FIR polyphase filter structure is proposed for the filters in each stage.

  13. Multistage Stochastic Programming Problems; Stability and Approximation

    Czech Academy of Sciences Publication Activity Database

    Kaňková, Vlasta

    Berlin: Springer, 2007 - (Waldmann, K.; Stocker, U.), s. 595-600 ISBN 978-3-540-69994-1. [Annual International Conference of the German Operations Research Society (GOR). Karlsruhe (DE), 06.09.2006-08.09.2006] R&D Projects: GA ČR GA402/04/1294; GA ČR GA402/05/0115; GA ČR(CZ) GA402/06/1417 Institutional research plan: CEZ:AV0Z10750506 Keywords : Multistage Sstochastic programming problems * individal probability constraints * autoregressive (generally) nonlinear sequence Subject RIV: BB - Applied Statistics, Operational Research

  14. Unemployment problem via multistage stochastic programming

    Czech Academy of Sciences Publication Activity Database

    Kaňková, Vlasta; Chovanec, Petr

    Bratislava: University of Economics in Bratislava, 2006 - (Pekár, J.; Lukáčik, M.), s. 69-76 ISBN 80-8078-129-X. [Quantitative Methods in Economics. Multiple Criteria Decision Making XIII. Bratislava (SK), 06.12.2006-08.12.2006] R&D Projects: GA ČR GA402/04/1294 Institutional research plan: CEZ:AV0Z10750506 Keywords : Multistage stochastic programming problems * unemployment problem * restructuralization * random element * probability constraints Subject RIV: BB - Applied Statistics, Operational Research

  15. Catalytic multi-stage liquefaction (CMSL)

    Energy Technology Data Exchange (ETDEWEB)

    Comolli, A.G.; Ganguli, P.; Karolkiewicz, W.F.; Lee, T.L.K.; Pradhan, V.R.; Popper, G.A.; Smith, T.; Stalzer, R.

    1996-11-01

    Under contract with the U.S. Department of Energy, Hydrocarbon Technologies, Inc. has conducted a series of eleven catalytic, multi-stage, liquefaction (CMSL) bench scale runs between February, 1991, and September, 1995. The purpose of these runs was to investigate novel approaches to liquefaction relating to feedstocks, hydrogen source, improved catalysts as well as processing variables, all of which are designed to lower the cost of producing coal-derived liquid products. This report summarizes the technical assessment of these runs, and in particular the evaluation of the economic impact of the results.

  16. In situ crosslinked smart polypeptide nanoparticles for multistage responsive tumor-targeted drug delivery

    Science.gov (United States)

    Yi, Huqiang; Liu, Peng; Sheng, Nan; Gong, Ping; Ma, Yifan; Cai, Lintao

    2016-03-01

    Smart tumor-targeted drug delivery is crucial for improving the effect of chemotherapy and reducing the adverse effects. Here, we synthesized a smart polypeptide copolymer based on n-butylamine-poly(l-lysine)-b-poly(l-cysteine) (PLL-PLC) with functionalization of folic acid (FA) and 1,2-dicarboxylic-cyclohexene anhydride (DCA) for multistage responsive tumor-targeted drug delivery. The copolymers (FA-PLL(DCA)-PLC) spontaneously crosslinked in situ to form redox and pH dual responsive FA-PLL(DCA)-PLC nanoparticles (FD-NPs), which had a reversible zeta potential around -30 mV at pH 7.4, but switched to +15 mV at pH 5.0. Moreover, FD-NPs effectively loaded DOX with a loading capacity at 15.7 wt%. At pH 7.4, only 24.5% DOX was released within 60 h. However, at pH 5.0, the presence of 10 mM DTT dramatically accelerated DOX release with over 90% of DOX released within 10 h. Although the FD-NPs only enhanced DOX uptake in FA receptor positive (FR+) cancer cells at pH 7.4, a weak acidic condition promoted FD-NP-facilitated DOX uptake in both FR+ HeLa and FR- A549 cells, as well as significantly improving cellular binding and end/lysosomal escape. In vivo studies in a HeLa cancer model demonstrated that the charge-reversible FD-NPs delivered DOX into tumors more effectively than charge-irreversible nanoparticles. Hence, these multistage responsive FD-NPs would serve as highly efficient drug vectors for targeted cancer chemotherapy.Smart tumor-targeted drug delivery is crucial for improving the effect of chemotherapy and reducing the adverse effects. Here, we synthesized a smart polypeptide copolymer based on n-butylamine-poly(l-lysine)-b-poly(l-cysteine) (PLL-PLC) with functionalization of folic acid (FA) and 1,2-dicarboxylic-cyclohexene anhydride (DCA) for multistage responsive tumor-targeted drug delivery. The copolymers (FA-PLL(DCA)-PLC) spontaneously crosslinked in situ to form redox and pH dual responsive FA-PLL(DCA)-PLC nanoparticles (FD-NPs), which had a reversible

  17. Nonlinear resonances in a multi-stage free-electron laser amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, S. [Graduate Univ. for Advanced Studies, Ibaraki-ken (Japan); Takayama, K. [National Lab. for High Energy Physics, Ibaraki-ken (Japan)

    1995-12-31

    A two-beam accelerator (TBA) is a possible candidate of future linear colliders, in which the demanded rf power is provided by a multi-stage free-electron laser (MFEL). After if amplification in each stage, a driving beam is re-accelerated by an induction unit and propagates into the next stage. Recently it has been recognized that the multi-stage character of the MFEL causes resonances between its periodicity and the synchrotron motion in an rf bucket. Since the synchrotron oscillation is strongly modulated by the resonance and at the worst a large fraction of particles is trapped in the resonance islands, the nonlinear resonances in the FEL longitudinal beam dynamics can lead to notable degradation of the MFEL performance, such as output fluctuation and phase modulation which have been big concerns in the accelerator society. The overall efficiency of the MFEL and the quality of the amplified microwave power are key issues for realizing the TBA/FEL Particularly the rf phase and amplitude errors must be maintained within tolerance. One of significant obstacles is an amplification of undesired modes. If a small-size waveguide is employed, the FEL resonance energies for undesired higher order modes shift very far from that for a fundamental mode; so it is possible to prevent higher order modes from evolving. Such a small-size waveguide, however, gives a high power density in the FEL. Simulation results have demonstrated that the nonlinear resonances occur in die FEL longitudinal motion when the power density exceeds some threshold. An analytical method for studying the nonlinear resonance in the TBA/FEL is developed based on the macroparticle model which can describe analytically the drastic behaviors in the evolutions of the phase and amplitude. In the theory the basic 1D-FEL equations are reduced to a nonlinear pendulum equation with respect to the ponderomotive phase.

  18. Subsychronous vibration of multistage centrifugal compressors forced by rotating stall

    Science.gov (United States)

    Fulton, J. W.

    1987-01-01

    A multistage centrifugal compressor, in natural gas re-injection service on an offshore petroleum production platform, experienced subsynchronous vibrations which caused excessive bearing wear. Field performance testing correlated the subsynchronous amplitude with the discharge flow coefficient, demonstrating the excitation to be aerodynamic. Adding two impellers allowed an increase in the diffuser flow angle (with respect to tangential) to meet the diffuser stability criteria based on factory and field tests correlated using the theory of Senoo (for rotating stall in a vaneless diffuser). This modification eliminated all significant subsynchronous vibrations in field service, thus confirming the correctness of the solution. Other possible sources of aerodynamically induced vibrations were considered, but the judgment that those are unlikely has been confirmed by subsequent experience with other similar compressors.

  19. Silicon nanowire networks for multi-stage thermoelectric modules

    International Nuclear Information System (INIS)

    Highlights: • Fabricated flexible single, double, and quadruple stacked Si thermoelectric modules. • Measured an enhanced power production of 27%, showing vertical stacking is scalable. • Vertically scalable thermoelectric module design of semiconducting nanowires. • Design can utilize either p or n-type semiconductors, both types are not required. • ΔT increases with thickness therefore power/area can increase as modules are stacked. - Abstract: We present the fabrication and characterization of single, double, and quadruple stacked flexible silicon nanowire network based thermoelectric modules. From double to quadruple stacked modules, power production increased 27%, demonstrating that stacking multiple nanowire thermoelectric devices in series is a scalable method to generate power by supplying larger temperature gradient. We present a vertically scalable multi-stage thermoelectric module design using semiconducting nanowires, eliminating the need for both n-type and p-type semiconductors for modules

  20. Análisis de Modelos de Lechos Fuente en Multietapa, utilizando la Distribución del Tiempo de Residencia de los Sólidos Analysis of Models of Spouted Bed Multistage Systems using the Residence Time Distribution of the Solids

    Directory of Open Access Journals (Sweden)

    Enrique Arriola-Guevara

    2007-01-01

    Full Text Available Se presenta un análisis comparativo de modelos de flujo desarrollados para los sólidos de un sistema de lechos fuente en multietapa (multistage spouted bed diseñado por Arriola (1997. Se seleccionaron modelos de distribución del tiempo de residencia de los sólidos adecuados para la aplicación comercial del sistema en el tratamiento de granos y semillas. La determinación experimental de la función de distribución del tiempo de residencia se llevó acabo mediante la técnica estímulo-respuesta utilizando partículas coloreadas. Se compararon cuatro modelos: tres de compartimentos y el de tanques-en-serie. La comparación de esos modelos mostró que los de compartimentos son los más apropiados para aplicaciones comerciales. El análisis estadístico permite afirmar que el modelo más recomendable, debido a su simplicidad, es el modelo de compartimentos propuesto por ArriolaA comparative analysis of flow models developed for the solids in a multistage spouted bed system designed by Arriola (1997, is presented. Models for the residence time distribution, suitable for commercial applications in processing seeds and grains, has been selected in the study. The experimental residence time distribution function was obtained by the stimulus-response technique using colored particles. Four models were compared: three compartment models, and the stirred-tank-in-series model. Evaluation of these models showed that the compartment models are more suitable for commercial applications. The statistical analysis allows to conclude that the best model, due to its simplicity, is the compartment model proposed by Arriola

  1. Paramagnetic defects in multistage ion-implanted polyamide films

    International Nuclear Information System (INIS)

    multistage ion implantation accompanied with the decreasing in the implantation energy thus permits to create the highly conductive channels between the surface and the buried conducting carbonaceous layer appearing in the interior of the implanted region that opens up the fresh opportunities for fabrication the polymer-based planar functional electronic devices

  2. Model-based segmentation

    OpenAIRE

    Heimann, Tobias; Delingette, Hervé

    2011-01-01

    This chapter starts with a brief introduction into model-based segmentation, explaining the basic concepts and different approaches. Subsequently, two segmentation approaches are presented in more detail: First, the method of deformable simplex meshes is described, explaining the special properties of the simplex mesh and the formulation of the internal forces. Common choices for image forces are presented, and how to evolve the mesh to adapt to certain structures. Second, the method of point...

  3. The effectiveness of mother training based on the model of positive parenting on the rate of behavioral disorders symptoms in deaf students

    OpenAIRE

    Mahboobeh Pakzad; Salar Faramarzi; Amir Ghamarani

    2014-01-01

    Background and Aim : Hearing loss affects human adjustment with environment and may be followed by mental complications such as behavioral problems. This study was conducted to investigate the effectiveness of group behavioral management training of mothers based on the model of positive parenting on the rate of behavioral disorders of primary school deaf students in Isfahan.Methods: The research method was semi-experimental with pre and post-test plan and control group. Using multi-stage sam...

  4. Multistage Robust Unit Commitment with Dynamic Uncertainty Sets and Energy Storage

    OpenAIRE

    Lorca, Alvaro; Sun, Xu Andy

    2016-01-01

    The deep penetration of wind and solar power is a critical component of the future power grid. However, the intermittency and stochasticity of these renewable resources bring significant challenges to the reliable and economic operation of power systems. Motivated by these challenges, we present a multistage adaptive robust optimization model for the unit commitment (UC) problem, which models the sequential nature of the dispatch process and utilizes a new type of dynamic uncertainty sets to ...

  5. CFD analysis of unsteady cavitation phenomena in multistage pump with inducer

    International Nuclear Information System (INIS)

    This paper presents the numerical simulation of the cavitating flow phenomena in the suction part of a radial-flow multistage water pump with a high rotational speed. The pump is equipped with an inducer. Besides the usual focus on the cavitation inception or the drop of the pump total head this CFD analysis also studies the possibility of the cavitation surge and attempts to quantify the risk of cavitation erosion for different flow conditions. The ANSYS CFX commercial CFD package was used to solve the URANS equations coupled with the Rayleigh-Plesset Model. The SST-SAS turbulence model was employed to capture unsteady phenomena inside the pump. The model for the prediction of the cavitation erosion risk is based on coupling the CFD analysis of 3D turbulent flow with the analysis of the dynamics of bubbles travelling along selected trajectories using the full Rayleigh-Plesset equation. The model assumes that the water at the pump inlet contains a known number of nuclei with a known size distribution. The erosion potential (or aggressiveness) of the collapse is estimated from the energy dissipated during the collapse. The presented CFD analysis has provided a map of regions endangered by cavitation erosion. The cavitation instability in the backflow vortices has been detected at 60% of the optimal flow coefficient close to the NPSHr value.

  6. Model Based Definition

    Science.gov (United States)

    Rowe, Sidney E.

    2010-01-01

    In September 2007, the Engineering Directorate at the Marshall Space Flight Center (MSFC) created the Design System Focus Team (DSFT). MSFC was responsible for the in-house design and development of the Ares 1 Upper Stage and the Engineering Directorate was preparing to deploy a new electronic Configuration Management and Data Management System with the Design Data Management System (DDMS) based upon a Commercial Off The Shelf (COTS) Product Data Management (PDM) System. The DSFT was to establish standardized CAD practices and a new data life cycle for design data. Of special interest here, the design teams were to implement Model Based Definition (MBD) in support of the Upper Stage manufacturing contract. It is noted that this MBD does use partially dimensioned drawings for auxiliary information to the model. The design data lifecycle implemented several new release states to be used prior to formal release that allowed the models to move through a flow of progressive maturity. The DSFT identified some 17 Lessons Learned as outcomes of the standards development, pathfinder deployments and initial application to the Upper Stage design completion. Some of the high value examples are reviewed.

  7. Synthetic Multiple-Imputation Procedure for Multistage Complex Samples

    Directory of Open Access Journals (Sweden)

    Zhou Hanzhi

    2016-03-01

    Full Text Available Multiple imputation (MI is commonly used when item-level missing data are present. However, MI requires that survey design information be built into the imputation models. For multistage stratified clustered designs, this requires dummy variables to represent strata as well as primary sampling units (PSUs nested within each stratum in the imputation model. Such a modeling strategy is not only operationally burdensome but also inferentially inefficient when there are many strata in the sample design. Complexity only increases when sampling weights need to be modeled. This article develops a generalpurpose analytic strategy for population inference from complex sample designs with item-level missingness. In a simulation study, the proposed procedures demonstrate efficient estimation and good coverage properties. We also consider an application to accommodate missing body mass index (BMI data in the analysis of BMI percentiles using National Health and Nutrition Examination Survey (NHANES III data. We argue that the proposed methods offer an easy-to-implement solution to problems that are not well-handled by current MI techniques. Note that, while the proposed method borrows from the MI framework to develop its inferential methods, it is not designed as an alternative strategy to release multiply imputed datasets for complex sample design data, but rather as an analytic strategy in and of itself.

  8. PARALLEL MULTI-STAGE & MULTI-STEP METHOD IN ODES

    Institute of Scientific and Technical Information of China (English)

    Xiao-qiu Song

    2000-01-01

    In this paper, the theory of parallel multi-stage & multi-step method is dis cussed, which is a form of combining Runge-Kutta method with linear multi-step method that can be used for parallel computation.

  9. A multi-stage heuristic algorithm for matching problem in the modified miniload automated storage and retrieval system of e-commerce

    Science.gov (United States)

    Wang, Wenrui; Wu, Yaohua; Wu, Yingying

    2016-04-01

    E-commerce, as an emerging marketing mode, has attracted more and more attention and gradually changed the way of our life. However, the existing layout of distribution centers can't fulfill the storage and picking demands of e-commerce sufficiently. In this paper, a modified miniload automated storage/retrieval system is designed to fit these new characteristics of e-commerce in logistics. Meanwhile, a matching problem, concerning with the improvement of picking efficiency in new system, is studied in this paper. The problem is how to reduce the travelling distance of totes between aisles and picking stations. A multi-stage heuristic algorithm is proposed based on statement and model of this problem. The main idea of this algorithm is, with some heuristic strategies based on similarity coefficients, minimizing the transportations of items which can not arrive in the destination picking stations just through direct conveyors. The experimental results based on the cases generated by computers show that the average reduced rate of indirect transport times can reach 14.36% with the application of multi-stage heuristic algorithm. For the cases from a real e-commerce distribution center, the order processing time can be reduced from 11.20 h to 10.06 h with the help of the modified system and the proposed algorithm. In summary, this research proposed a modified system and a multi-stage heuristic algorithm that can reduce the travelling distance of totes effectively and improve the whole performance of e-commerce distribution center.

  10. A multi-stage heuristic algorithm for matching problem in the modified miniload automated storage and retrieval system of e-commerce

    Science.gov (United States)

    Wang, Wenrui; Wu, Yaohua; Wu, Yingying

    2016-05-01

    E-commerce, as an emerging marketing mode, has attracted more and more attention and gradually changed the way of our life. However, the existing layout of distribution centers can't fulfill the storage and picking demands of e-commerce sufficiently. In this paper, a modified miniload automated storage/retrieval system is designed to fit these new characteristics of e-commerce in logistics. Meanwhile, a matching problem, concerning with the improvement of picking efficiency in new system, is studied in this paper. The problem is how to reduce the travelling distance of totes between aisles and picking stations. A multi-stage heuristic algorithm is proposed based on statement and model of this problem. The main idea of this algorithm is, with some heuristic strategies based on similarity coefficients, minimizing the transportations of items which can not arrive in the destination picking stations just through direct conveyors. The experimental results based on the cases generated by computers show that the average reduced rate of indirect transport times can reach 14.36% with the application of multi-stage heuristic algorithm. For the cases from a real e-commerce distribution center, the order processing time can be reduced from 11.20 h to 10.06 h with the help of the modified system and the proposed algorithm. In summary, this research proposed a modified system and a multi-stage heuristic algorithm that can reduce the travelling distance of totes effectively and improve the whole performance of e-commerce distribution center.

  11. Multi-stage high order semi-Lagrangian schemes for incompressible flows in Cartesian geometries

    CERN Document Server

    Cameron, Alexandre; Dormy, Emmanuel

    2016-01-01

    Efficient transport algorithms are essential to the numerical resolution of incompressible fluid flow problems. Semi-Lagrangian methods are widely used in grid based methods to achieve this aim. The accuracy of the interpolation strategy then determines the properties of the scheme. We introduce a simple multi-stage procedure which can easily be used to increase the order of accuracy of a code based on multi-linear interpolations. This approach is an extension of a corrective algorithm introduced by Dupont \\& Liu (2003, 2007). This multi-stage procedure can be easily implemented in existing parallel codes using a domain decomposition strategy, as the communications pattern is identical to that of the multi-linear scheme. We show how a combination of a forward and backward error correction can provide a third-order accurate scheme, thus significantly reducing diffusive effects while retaining a non-dispersive leading error term.

  12. Robust Analysis and Parameters Identification of the Nonlinear Multistage Dynamical System in Batch Fermentation of Glycerol

    OpenAIRE

    2014-01-01

    This paper discusses a complex biological problem which is the fermentation of glycerol by Klebsiella pneumoniae in batch culture. We set up an improved multistage model involving the concentration of intracellular substances. Furthermore, the existence, uniqueness, and continuity of solutions with respect to the parameters are discussed. On the condition that glycerol and 1,3-propanediol are assumed to pass the cell membrane by passive diffusion coupled with facilitated transport, we take th...

  13. Three-Dimensional Aerodynamic Instabilities In Multi-Stage Axial Compressors

    Science.gov (United States)

    Tan, Choon S.; Gong, Yifang; Suder, Kenneth L. (Technical Monitor)

    2001-01-01

    This thesis presents the conceptualization and development of a computational model for describing three-dimensional non-linear disturbances associated with instability and inlet distortion in multistage compressors. Specifically, the model is aimed at simulating the non-linear aspects of short wavelength stall inception, part span stall cells, and compressor response to three-dimensional inlet distortions. The computed results demonstrated the first-of-a-kind capability for simulating short wavelength stall inception in multistage compressors. The adequacy of the model is demonstrated by its application to reproduce the following phenomena: (1) response of a compressor to a square-wave total pressure inlet distortion; (2) behavior of long wavelength small amplitude disturbances in compressors; (3) short wavelength stall inception in a multistage compressor and the occurrence of rotating stall inception on the negatively sloped portion of the compressor characteristic; (4) progressive stalling behavior in the first stage in a mismatched multistage compressor; (5) change of stall inception type (from modal to spike and vice versa) due to IGV stagger angle variation, and "unique rotor tip incidence" at these points where the compressor stalls through short wavelength disturbances. The model has been applied to determine the parametric dependence of instability inception behavior in terms of amplitude and spatial distribution of initial disturbance, and intra-blade-row gaps. It is found that reducing the inter-blade row gaps suppresses the growth of short wavelength disturbances. It is also concluded from these parametric investigations that each local component group (rotor and its two adjacent stators) has its own instability point (i.e. conditions at which disturbances are sustained) for short wavelength disturbances, with the instability point for the compressor set by the most unstable component group. For completeness, the methodology has been extended to

  14. A Simulated Annealing Algorithm for the Optimization of Multistage Depressed Collector Efficiency

    Science.gov (United States)

    Vaden, Karl R.; Wilson, Jeffrey D.; Bulson, Brian A.

    2002-01-01

    The microwave traveling wave tube amplifier (TWTA) is widely used as a high-power transmitting source for space and airborne communications. One critical factor in designing a TWTA is the overall efficiency. However, overall efficiency is highly dependent upon collector efficiency; so collector design is critical to the performance of a TWTA. Therefore, NASA Glenn Research Center has developed an optimization algorithm based on Simulated Annealing to quickly design highly efficient multi-stage depressed collectors (MDC).

  15. Solar Multi-stage Refrigeration Systems on the Basis of Absorber with the Internal Evaporative Cooling

    OpenAIRE

    Doroshenko A.V.; Kirillov V.H.; Antonova A.R.; Liudnicky K.V.

    2015-01-01

    In the article, the developed schematics are presented for the alternative refrigeration systems and air-conditioning systems, based on the use of absorbing cycle and solar energy for the regeneration of absorbent solution. Multi-stage principle of construction of drying and cool contours of solar systems is used with growth of concentration of absorbent on the stages of cooler. An absorber with internal evaporative cooling, allowing to remove the separate evaporated cooler, usually included ...

  16. Flash flood detection through a multi-stage probabilistic warning system for heavy precipitation events

    OpenAIRE

    Alfieri, L.; Velasco, D.; Thielen, J.

    2011-01-01

    The deadly combination of short to no warning lead times and the vulnerability of urbanized areas makes flash flood events extremely dangerous for the modern society. This paper contributes to flash flood early warning by proposing a multi-stage warning system for heavy precipitation events based on threshold exceedances within a probabilistic framework. It makes use of meteorological products at different resolutions, namely, numerical weather predictions (NWP), radar-NWP b...

  17. Performance Improvement of a Return Channel in a Multistage Centrifugal Compressor Using Multiobjective Optimization

    OpenAIRE

    Nishida, Yoshifumi; Kobayashi, Hiromi; Nishida, Hideo; Sugimura, Kazuyuki

    2013-01-01

    The effect of the design parameters of a return channel on the performance of a multistage centrifugal compressor was numerically investigated, and the shape of the return channel was optimized using a multiobjective optimization method based on a genetic algorithm to improve the performance of the centrifugal compressor. The results of sensitivity analysis using Latin hypercube sampling suggested that the inlet-to-outlet area ratio of the return vane affected the total pressure loss in the r...

  18. Scalable Layer-2/Layer-3 Multistage Switching Architectures for Software Routers

    OpenAIRE

    Bianco, Andrea; Neri, Fabio; Mellia, Marco

    2006-01-01

    Software routers are becoming an important alternative to proprietary and expensive network devices, because they exploit the economy of scale of the PC market and open-source software. When considering maximum performance in terms of throughput, PC-based routers suffer from limitations stemming from the single PC architecture, e.g., limited bus bandwidth, and high memory access latency. To overcome these limitations, in this paper we present a multistage architecture that combines a layer-2 ...

  19. Some recommendations for multi-arm multi-stage trials.

    Science.gov (United States)

    Wason, James; Magirr, Dominic; Law, Martin; Jaki, Thomas

    2016-04-01

    Multi-arm multi-stage designs can improve the efficiency of the drug-development process by evaluating multiple experimental arms against a common control within one trial. This reduces the number of patients required compared to a series of trials testing each experimental arm separately against control. By allowing for multiple stages experimental treatments can be eliminated early from the study if they are unlikely to be significantly better than control. Using the TAILoR trial as a motivating example, we explore a broad range of statistical issues related to multi-arm multi-stage trials including a comparison of different ways to power a multi-arm multi-stage trial; choosing the allocation ratio to the control group compared to other experimental arms; the consequences of adding additional experimental arms during a multi-arm multi-stage trial, and how one might control the type-I error rate when this is necessary; and modifying the stopping boundaries of a multi-arm multi-stage design to account for unknown variance in the treatment outcome. Multi-arm multi-stage trials represent a large financial investment, and so considering their design carefully is important to ensure efficiency and that they have a good chance of succeeding. PMID:23242385

  20. Pressure Transient Analysis and Flux Distribution for Multistage Fractured Horizontal Wells in Triple-Porosity Reservoir Media with Consideration of Stress-Sensitivity Effect

    Directory of Open Access Journals (Sweden)

    Jingjing Guo

    2015-01-01

    Full Text Available Triple-porosity model is usually adopted to describe reservoirs with multiscaled pore spaces, including matrix pores, natural fractures, and vugs. Multiple fractures created by hydraulic fracturing can effectively improve the connectivity between existing natural fractures and thus increase well deliverability. However, little work has been done on pressure transient behavior of multistage fractured horizontal wells in triple-porosity reservoirs. Based on source/sink function method, this paper presents a triple-porosity model to investigate the transient pressure dynamics and flux distribution for multistage fractured horizontal wells in fractured-vuggy reservoirs with consideration of stress-dependent natural fracture permeability. The model is semianalytically solved by discretizing hydraulic fractures and Pedrosa’s transformation, perturbation theory, and integration transformation method. Type curves of transient pressure dynamics are generated, and flux distribution among hydraulic fractures for a fractured horizontal well with constant production rate is also discussed. Parametric study shows that major influential parameters on transient pressure responses are parameters pertinent to reservoir properties, interporosity mass transfer, and hydraulic fractures. Analysis of flux distribution indicates that flux density gradually increases from the horizontal wellbore to fracture tips, and the flux contribution of outermost fractures is higher than that of inner fractures. The model can also be extended to optimize hydraulic fracture parameters.

  1. ZeroX Algorithms with Free crosstalk in Optical Multistage Interconnection Network

    Directory of Open Access Journals (Sweden)

    M.A.Al- Shabi

    2013-03-01

    Full Text Available Multistage interconnection networks (MINs have been proposed as interconnecting structures in various types of communication applications ranging from parallel systems, switching architectures, to multicore systems and advances. Optical technologies have drawn the interest for optical implementation in MINs to achieve high bandwidth capacity at the rate of terabits per second. Crosstalk is the major problem with optical interconnections; it not only degrades the performance of network but also disturbs the path of communication signals. To avoid crosstalk in Optical MINs many algorithms have been proposed by many researchers and some of the researchers suppose some solution to improve Zero Algorithm. This paper will be illustrated that is no any crosstalk appears in Zero based algorithms (ZeroX, ZeroY and ZeroXY in using refine and unique case functions. Through simulation modeling, the Zero based algorithm approach yields the best performance in terms of minimal routing time in and number of passes comparison to the previous algorithms tested for comparison in this paper.

  2. Scenario trees and policy selection for multistage stochastic programming using machine learning

    CERN Document Server

    Defourny, Boris; Wehenkel, Louis

    2011-01-01

    We propose a hybrid algorithmic strategy for complex stochastic optimization problems, which combines the use of scenario trees from multistage stochastic programming with machine learning techniques for learning a policy in the form of a statistical model, in the context of constrained vector-valued decisions. Such a policy allows one to run out-of-sample simulations over a large number of independent scenarios, and obtain a signal on the quality of the approximation scheme used to solve the multistage stochastic program. We propose to apply this fast simulation technique to choose the best tree from a set of scenario trees. A solution scheme is introduced, where several scenario trees with random branching structure are solved in parallel, and where the tree from which the best policy for the true problem could be learned is ultimately retained. Numerical tests show that excellent trade-offs can be achieved between run times and solution quality.

  3. LSTM based Conversation Models

    OpenAIRE

    Luan, Yi; Ji, Yangfeng; Ostendorf, Mari

    2016-01-01

    In this paper, we present a conversational model that incorporates both context and participant role for two-party conversations. Different architectures are explored for integrating participant role and context information into a Long Short-term Memory (LSTM) language model. The conversational model can function as a language model or a language generation model. Experiments on the Ubuntu Dialog Corpus show that our model can capture multiple turn interaction between participants. The propos...

  4. Minimizing the Switch and Link Conflicts in an Optical Multi-stage Interconnection Network

    CERN Document Server

    Bhardwaj, Ved Prakash; Tyagi, Vipin

    2012-01-01

    Multistage Interconnection Networks (MINs) are very popular in switching and communication applications. A MIN connects N inputs to N outputs and is referred as an N \\times N MIN; having size N. Optical Multistage Interconnection Network (OMIN) represents an important class of Interconnection networks. Crosstalk is the basic problem of OMIN. Switch Conflict and Link Conflict are the two main reason of crosstalk. In this paper, we are considering both problems. A number of techniques like Optical window, Improved Window, Heuristic, Genetic, and Zero have been proposed earlier in this research domain. In this paper, we have proposed two algorithms called Address Selection Algorithm and Route Selection Algorithm (RSA). RSA is based on Improved Window Method. We have applied the proposed algorithms on existing Omega network, having shuffle-exchange connection pattern. The main functionality of ASA and RSA is to minimize the number of switch and link conflicts in the network and to provide conflict free routes.

  5. A multi-stage noise adaptive switching filter for extremely corrupted images

    Science.gov (United States)

    Dinh, Hai; Adhami, Reza; Wang, Yi

    2015-07-01

    A multi-stage noise adaptive switching filter (MSNASF) is proposed for the restoration of images extremely corrupted by impulse and impulse-like noise. The filter consists of two steps: noise detection and noise removal. The proposed extrema-based noise detection scheme utilizes the false contouring effect to get better over detection rate at low noise density. It is adaptive and will detect not only impulse but also impulse-like noise. In the noise removal step, a novel multi-stage filtering scheme is proposed. It replaces corrupted pixel with the nearest uncorrupted median to preserve details. When compared with other methods, MSNASF provides better peak signal to noise ratio (PSNR) and structure similarity index (SSIM). A subjective evaluation carried out online also demonstrates that MSNASF yields higher fidelity.

  6. Particle swarm optimization of ascent trajectories of multistage launch vehicles

    Science.gov (United States)

    Pontani, Mauro

    2014-02-01

    Multistage launch vehicles are commonly employed to place spacecraft and satellites in their operational orbits. If the rocket characteristics are specified, the optimization of its ascending trajectory consists of determining the optimal control law that leads to maximizing the final mass at orbit injection. The numerical solution of a similar problem is not trivial and has been pursued with different methods, for decades. This paper is concerned with an original approach based on the joint use of swarming theory and the necessary conditions for optimality. The particle swarm optimization technique represents a heuristic population-based optimization method inspired by the natural motion of bird flocks. Each individual (or particle) that composes the swarm corresponds to a solution of the problem and is associated with a position and a velocity vector. The formula for velocity updating is the core of the method and is composed of three terms with stochastic weights. As a result, the population migrates toward different regions of the search space taking advantage of the mechanism of information sharing that affects the overall swarm dynamics. At the end of the process the best particle is selected and corresponds to the optimal solution to the problem of interest. In this work the three-dimensional trajectory of the multistage rocket is assumed to be composed of four arcs: (i) first stage propulsion, (ii) second stage propulsion, (iii) coast arc (after release of the second stage), and (iv) third stage propulsion. The Euler-Lagrange equations and the Pontryagin minimum principle, in conjunction with the Weierstrass-Erdmann corner conditions, are employed to express the thrust angles as functions of the adjoint variables conjugate to the dynamics equations. The use of these analytical conditions coming from the calculus of variations leads to obtaining the overall rocket dynamics as a function of seven parameters only, namely the unknown values of the initial state

  7. Dynamic Multi-Stage Placement of Phasor Measurement Units using Bat Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    S. E. Razavi Asfali

    2014-07-01

    Full Text Available In recent years, utilization of phasor measurement units (PMUs has increased in monitoring, control and protection of power systems. In reality, power systems are large scale, accordingly, financial limitations (due to PMU cost and technical problems are avoiding to install all necessary PMUs in one stage. Therefore, the PMUs usually are installed in several stages. This paper proposes a new dynamic multi-stage PMU placement approach by introducing a new index related to network observability in planning stages. Despite of conventional methods, the proposed multi-stage PMU placement is investigated dependently, simultaneously, and dynamically. Moreover, the phasing of PMUs of all stages is achieved in a single optimization process. Furthermore, in order to consider the practical aspect, the channel and communication limitations are covered in this study. According to the complexity of the proposed model, Bat Algorithm is used as an optimization tool to solve the proposed dynamic multi-stage PMU placement model. The proposed approach is applied on standard IEEE 14-, 57- and 118- bus test systems as well as Iranian 230- and 400-kV transmission network. Finally, the obtained results are compared with the results of conventional methods and ability of the proposed approach is investigated.

  8. AERODYNAMIC AND BLADING DESIGN OF MULTISTAGE AXIAL FLOW COMPRESSORS

    Science.gov (United States)

    Crouse, J. E.

    1994-01-01

    The axial-flow compressor is used for aircraft engines because it has distinct configuration and performance advantages over other compressor types. However, good potential performance is not easily obtained. The designer must be able to model the actual flows well enough to adequately predict aerodynamic performance. This computer program has been developed for computing the aerodynamic design of a multistage axial-flow compressor and, if desired, the associated blading geometry input for internal flow analysis. The aerodynamic solution gives velocity diagrams on selected streamlines of revolution at the blade row edges. The program yields aerodynamic and blading design results that can be directly used by flow and mechanical analysis codes. Two such codes are TSONIC, a blade-to-blade channel flow analysis code (COSMIC program LEW-10977), and MERIDL, a more detailed hub-to-shroud flow analysis code (COSMIC program LEW-12966). The aerodynamic and blading design program can reduce the time and effort required to obtain acceptable multistage axial-flow compressor configurations by generating good initial solutions and by being compatible with available analysis codes. The aerodynamic solution assumes steady, axisymmetric flow so that the problem is reduced to solving the two-dimensional flow field in the meridional plane. The streamline curvature method is used for the iterative aerodynamic solution at stations outside of the blade rows. If a blade design is desired, the blade elements are defined and stacked within the aerodynamic solution iteration. The blade element inlet and outlet angles are established by empirical incidence and deviation angles to the relative flow angles of the velocity diagrams. The blade element centerline is composed of two segments tangentially joined at a transition point. The local blade angle variation of each element can be specified as a fourth-degree polynomial function of path distance. Blade element thickness can also be specified

  9. The influence of annular seal clearance to the critical speed of the multistage pump

    International Nuclear Information System (INIS)

    In the multistage pump of high head, pressure difference in two ends of annular seal clearance and rotor eccentric would produce the sealing fluid force, the effect of which can be expressed by a damping and stiffness coefficient. It has a great influence on the critical speed of the rotor system. In order to research the influence of the annular seal to the rotor system, this paper used CFD method to conduct the numerical simulation for the flow field of annular seal clearance. The radial and tangential forces were obtained to calculate the annular dynamic coefficients. Also dynamic coefficient were obtained by Matlab. The rotor system was modeled using ANSYS finite software and the critical speed with and without annular seal clearance were calculated. The result shows: annular seal's fluid field is under the comprehensive effect of pressure difference and rotor entrainment. Due to the huge pressure difference in front annular seal, fluid flows under pressure difference; the low pressure difference results in the more obvious effect on the clearance field in back annular seal. The first order critical speed increases greatly with the annular seal clearance; while the average growth rate of the second order critical speed is only 3.2%; the third and fourth critical speed decreases little. Based on the above result, the annular seal has great influence to the first order speed, while has little influence on the rest

  10. Application of multi-stage Monte Carlo method for solving machining optimization problems

    Directory of Open Access Journals (Sweden)

    Miloš Madić

    2014-08-01

    Full Text Available Enhancing the overall machining performance implies optimization of machining processes, i.e. determination of optimal machining parameters combination. Optimization of machining processes is an active field of research where different optimization methods are being used to determine an optimal combination of different machining parameters. In this paper, multi-stage Monte Carlo (MC method was employed to determine optimal combinations of machining parameters for six machining processes, i.e. drilling, turning, turn-milling, abrasive waterjet machining, electrochemical discharge machining and electrochemical micromachining. Optimization solutions obtained by using multi-stage MC method were compared with the optimization solutions of past researchers obtained by using meta-heuristic optimization methods, e.g. genetic algorithm, simulated annealing algorithm, artificial bee colony algorithm and teaching learning based optimization algorithm. The obtained results prove the applicability and suitability of the multi-stage MC method for solving machining optimization problems with up to four independent variables. Specific features, merits and drawbacks of the MC method were also discussed.

  11. Controllability in Multi-Stage Laser Ion Acceleration

    Science.gov (United States)

    Kawata, S.; Kamiyama, D.; Ohtake, Y.; Barada, D.; Ma, Y. Y.; Kong, Q.; Wang, P. X.; Gu, Y. J.; Li, X. F.; Yu, Q.

    2015-11-01

    The present paper shows a concept for a future laser ion accelerator, which should have an ion source, ion collimators, ion beam bunchers and ion post acceleration devices. Based on the laser ion accelerator components, the ion particle energy and the ion energy spectrum are controlled, and a future compact laser ion accelerator would be designed for ion cancer therapy or for ion material treatment. In this study each component is designed to control the ion beam quality. The energy efficiency from the laser to ions is improved by using a solid target with a fine sub-wavelength structure or a near-critical density gas plasma. The ion beam collimation is performed by holes behind the solid target or a multi-layered solid target. The control of the ion energy spectrum and the ion particle energy, and the ion beam bunching are successfully realized by a multi-stage laser-target interaction. A combination of each component provides a high controllability of the ion beam quality to meet variable requirements in various purposes in the laser ion accelerator. The work was partly supported by MEXT, JSPS, ASHULA project/ ILE, Osaka University, CORE (Center for Optical Research and Education, Utsunomiya University, Japan), Fudan University and CDI (Creative Dept. for Innovation) in CCRD, Utsunomiya University.

  12. Multi-stage methodology to detect health insurance claim fraud.

    Science.gov (United States)

    Johnson, Marina Evrim; Nagarur, Nagen

    2016-09-01

    Healthcare costs in the US, as well as in other countries, increase rapidly due to demographic, economic, social, and legal changes. This increase in healthcare costs impacts both government and private health insurance systems. Fraudulent behaviors of healthcare providers and patients have become a serious burden to insurance systems by bringing unnecessary costs. Insurance companies thus develop methods to identify fraud. This paper proposes a new multistage methodology for insurance companies to detect fraud committed by providers and patients. The first three stages aim at detecting abnormalities among providers, services, and claim amounts. Stage four then integrates the information obtained in the previous three stages into an overall risk measure. Subsequently, a decision tree based method in stage five computes risk threshold values. The final decision stating whether the claim is fraudulent is made by comparing the risk value obtained in stage four with the risk threshold value from stage five. The research methodology performs well on real-world insurance data. PMID:25600704

  13. Water and sodium intake habits and status of ultra-endurance runners during a multi-stage ultra-marathon conducted in a hot ambient environment: an observational field based study

    Directory of Open Access Journals (Sweden)

    Costa Ricardo JS

    2013-01-01

    Full Text Available Abstract Background Anecdotal evidence suggests ultra-runners may not be consuming sufficient water through foods and fluids to maintenance euhydration, and present sub-optimal sodium intakes, throughout multi-stage ultra-marathon (MSUM competitions in the heat. Subsequently, the aims were primarily to assess water and sodium intake habits of recreational ultra-runners during a five stage 225 km semi self-sufficient MSUM conducted in a hot ambient environment (Tmax range: 32°C to 40°C; simultaneously to monitor serum sodium concentration, and hydration status using multiple hydration assessment techniques. Methods Total daily, pre-stage, during running, and post-stage water and sodium ingestion of ultra-endurance runners (UER, n = 74 and control (CON, n = 12 through foods and fluids were recorded on Stages 1 to 4 by trained dietetic researchers using dietary recall interview technique, and analysed through dietary analysis software. Body mass (BM, hydration status, and serum sodium concentration were determined pre- and post-Stages 1 to 5. Results Water (overall mean (SD: total daily 7.7 (1.5 L/day, during running 732 (183 ml/h and sodium (total daily 3.9 (1.3 g/day, during running 270 (151 mg/L ingestion did not differ between stages in UER (p vs. CON. Exercise-induced BM loss was 2.4 (1.2% (p p > 0.05 vs. CON pre-stage. Asymptomatic hyponatraemia (n = 8 UER, corresponding to 42% of sampled participants. Pre- and post-stage urine colour, urine osmolality and urine/plasma osmolality ratio increased (p p  Conclusion Water intake habits of ultra-runners during MSUM conducted in hot ambient conditions appear to be sufficient to maintain baseline euhydration levels. However, fluid over-consumption behaviours were evident along competition, irrespective of running speed and gender. Normonatraemia was observed in the majority of ultra-runners throughout MSUM, despite sodium ingestion under benchmark recommendations.

  14. Model-Based Reasoning

    Science.gov (United States)

    Ifenthaler, Dirk; Seel, Norbert M.

    2013-01-01

    In this paper, there will be a particular focus on mental models and their application to inductive reasoning within the realm of instruction. A basic assumption of this study is the observation that the construction of mental models and related reasoning is a slowly developing capability of cognitive systems that emerges effectively with proper…

  15. Model-based software design

    Science.gov (United States)

    Iscoe, Neil; Liu, Zheng-Yang; Feng, Guohui; Yenne, Britt; Vansickle, Larry; Ballantyne, Michael

    1992-01-01

    Domain-specific knowledge is required to create specifications, generate code, and understand existing systems. Our approach to automating software design is based on instantiating an application domain model with industry-specific knowledge and then using that model to achieve the operational goals of specification elicitation and verification, reverse engineering, and code generation. Although many different specification models can be created from any particular domain model, each specification model is consistent and correct with respect to the domain model.

  16. Development of a model for unsteady deterministic stresses adapted to the multi-stages turbomachines simulation; Developpement d'un modele de tensions deterministes instationnaires adapte a la simulation de turbomachines multi-etagees

    Energy Technology Data Exchange (ETDEWEB)

    Charbonnier, D.

    2004-12-15

    The physical phenomena observed in turbomachines are generally three-dimensional and unsteady. A recent study revealed that a three-dimensional steady simulation can reproduce the time-averaged unsteady phenomena, since the steady flow field equations integrate deterministic stresses. The objective of this work is thus to develop an unsteady deterministic stresses model. The analogy with turbulence makes it possible to write transport equations for these stresses. The equations are implemented in steady flow solver and e model for the energy deterministic fluxes is also developed and implemented. Finally, this work shows that a three-dimensional steady simulation, by taking into account unsteady effects with transport equations of deterministic stresses, increases the computing time by only approximately 30 %, which remains very interesting compared to an unsteady simulation. (author)

  17. Model-based Software Engineering

    DEFF Research Database (Denmark)

    Kindler, Ekkart

    2010-01-01

    The vision of model-based software engineering is to make models the main focus of software development and to automatically generate software from these models. Part of that idea works already today. But, there are still difficulties when it comes to behaviour. Actually, there is no lack in models...

  18. Principles of models based engineering

    Energy Technology Data Exchange (ETDEWEB)

    Dolin, R.M.; Hefele, J.

    1996-11-01

    This report describes a Models Based Engineering (MBE) philosophy and implementation strategy that has been developed at Los Alamos National Laboratory`s Center for Advanced Engineering Technology. A major theme in this discussion is that models based engineering is an information management technology enabling the development of information driven engineering. Unlike other information management technologies, models based engineering encompasses the breadth of engineering information, from design intent through product definition to consumer application.

  19. Model Construct Based Enterprise Model Architecture and Its Modeling Approach

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to support enterprise integration, a kind of model construct based enterprise model architecture and its modeling approach are studied in this paper. First, the structural makeup and internal relationships of enterprise model architecture are discussed. Then, the concept of reusable model construct (MC) which belongs to the control view and can help to derive other views is proposed. The modeling approach based on model construct consists of three steps, reference model architecture synthesis, enterprise model customization, system design and implementation. According to MC based modeling approach a case study with the background of one-kind-product machinery manufacturing enterprises is illustrated. It is shown that proposal model construct based enterprise model architecture and modeling approach are practical and efficient.

  20. Effect of Crosstalk on Permutation in Optical Multistage Interconnection Networks

    CERN Document Server

    Kaur, Er Sandeep; Aggarwal, Er Deepak

    2010-01-01

    Optical MINs hold great promise and have advantages over their electronic networks.they also hold their own challenges. More research has been done on Electronic Multistage Interconnection Networks, (EMINs) but these days optical communication is a good networking choice to meet the increasing demands of high-performance computing communication applications for high bandwidth applications. The electronic Multistage Interconnection Networks (EMINs) and the Optical Multistage Interconnection Networks (OMINs) have many similarities, but there are some fundamental differences between them such as the optical-loss during switching and the crosstalk problem in the optical switches. To reduce the negative effect of crosstalk, various approaches which apply the concept of dilation in either the space or time domain have been proposed. With the space domain approach, extra SEs are used to ensure that at most one input and one output of every SE will be used at any given time. For an Optical network without crosstalk, ...

  1. Multi-Stage Bunch Compressors for the International Linear Collider

    OpenAIRE

    Tenenbaum, Peter G.; Raubenheimer, Tor O.; Wolski, Andrzej

    2005-01-01

    We present bunch compressor designs for the International Linear Collider (ILC) which achieve a reduction in RMS bunch length from 6 mm to 0.3 mm via multiple stages of compression, with stages of acceleration inserted between the stages of compression. The key advantage of multi-stage compression is that the maximum RMS energy spread is reduced to approximately 1 percent, compared to over 3 percent for a single-stage design. Analytic and simulation studies of the multi-stage bunch compr...

  2. Multi-Stage Bunch Compressors for the International Linear Collider

    International Nuclear Information System (INIS)

    We present bunch compressor designs for the International Linear Collider (ILC) which achieve a reduction in RMS bunch length from 6 mm to 0.3 mm via multiple stages of compression, with stages of acceleration inserted between the stages of compression. The key advantage of multi-stage compression is that the maximum RMS energy spread is reduced to approximately 1%, compared to over 3% for a single-stage design. Analytic and simulation studies of the multi-stage bunch compressors are presented, along with performance comparisons to a single-stage system. Parameters for extending the systems to a larger total compression factor are discussed

  3. Multi-Stage Bunch Compressors for the International Linear Collider

    CERN Document Server

    Tenenbaum, P G; Wolski, Andrzej

    2005-01-01

    We present bunch compressor designs for the International Linear Collider (ILC) which achieve a reduction in RMS bunch length from 6 mm to 0.3 mm via multiple stages of compression, with stages of acceleration inserted between the stages of compression. The key advantage of multi-stage compression is that the maximum RMS energy spread is reduced to approximately 1%, compared to over 3% for a single-stage design. Analytic and simulation studies of the multi-stage bunch compressors are presented, along with performance comparisons to a single-stage system. Parameters for extending the systems to a larger total compression factor are discussed.

  4. Bodypart Recognition Using Multi-stage Deep Learning.

    Science.gov (United States)

    Yan, Zhennan; Zhan, Yiqiang; Peng, Zhigang; Liao, Shu; Shinagawa, Yoshihisa; Metaxas, Dimitris N; Zhou, Xiang Sean

    2015-01-01

    Automatic medical image analysis systems often start from identifying the human body part contained in the image; Specifically, given a transversal slice, it is important to know which body part it comes from, namely "slice-based bodypart recognition". This problem has its unique characteristic--the body part of a slice is usually identified by local discriminative regions instead of global image context, e.g., a cardiac slice is differentiated from an aorta arch slice by the mediastinum region. To leverage this characteristic, we design a multi-stage deep learning framework that aims at: (1) discover the local regions that are discriminative to the bodypart recognition, and (2) learn a bodypart identifier based on these local regions. These two tasks are achieved by the two stages of our learning scheme, respectively. In the pre-train stage, a convolutional neural network (CNN) is learned in a multi-instance learning fashion to extract the most discriminative local patches from the training slices. In the boosting stage, the learned CNN is further boosted by these local patches for bodypart recognition. By exploiting the discriminative local appearances, the learned CNN becomes more accurate than global image context-based approaches. As a key hallmark, our method does not require manual annotations of the discriminative local patches. Instead, it automatically discovers them through multi-instance deep learning. We validate our method on a synthetic dataset and a large scale CT dataset (7000+ slices from wholebody CT scans). Our method achieves better performances than state-of-the-art approaches, including the standard CNN. PMID:26221694

  5. A theoretical analysis of price elasticity of energy demand in multistage energy conversion systems

    International Nuclear Information System (INIS)

    The objective of this paper is an analytical exploration of the problem of price elasticity of energy demand in multi-stage energy conversion systems. The paper describes in some detail an analytical model of energy demand in such systems. Under a clearly stated set of assumptions, the model makes it possible to explore both the impacts of the number of sub-systems, and of varying sub-system elasticities on overall system elasticity. The analysis suggests that overall price elasticity of energy demand for such systems will tend asymptotically to unity as the number of sub-systems increases. (author)

  6. A theoretical analysis of price elasticity of energy demand in multi-stage energy conversion systems

    International Nuclear Information System (INIS)

    The objective of this paper is an analytical exploration of the problem of price elasticity of energy demand in multi-stage energy conversion systems. The paper describes in some detail an analytical model of energy demand in such systems. Under a clearly stated set of assumptions, the model makes it possible to explore both the impacts of the number of sub-systems, and of varying sub-system elasticities on overall system elasticity. The analysis suggests that overall price elasticity of energy demand for such systems will tend asymptotically to unity as the number of sub-systems increases

  7. A theoretical analysis of price elasticity of energy demand in multi-stage energy conversion systems

    OpenAIRE

    Lowe, R J

    2003-01-01

    The objective of this paper is an analytical exploration of the problem of price elasticity of energy demand in multi-stage energy conversion systems. The paper describes in some detail an analytical model of energy demand in such systems. Under a clearly stated set of assumptions, the model makes it possible to explore both the impacts of the number of sub-systems, and of varying sub-system elasticities on overall system elasticity. The analysis suggests that overall price elasticity of ener...

  8. Graph Model Based Indoor Tracking

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard; Lu, Hua; Yang, Bin

    2009-01-01

    The tracking of the locations of moving objects in large indoor spaces is important, as it enables a range of applications related to, e.g., security and indoor navigation and guidance. This paper presents a graph model based approach to indoor tracking that offers a uniform data management...... infrastructure for different symbolic positioning technologies, e.g., Bluetooth and RFID. More specifically, the paper proposes a model of indoor space that comprises a base graph and mappings that represent the topology of indoor space at different levels. The resulting model can be used for one or several...... indoor positioning technologies. Focusing on RFID-based positioning, an RFID specific reader deployment graph model is built from the base graph model. This model is then used in several algorithms for constructing and refining trajectories from raw RFID readings. Empirical studies with implementations...

  9. The influence of the "cage" effect on the mechanism of reversible bimolecular multistage chemical reactions proceeding from different sites in solutions.

    Science.gov (United States)

    Doktorov, Alexander B

    2016-08-28

    Manifestations of the "cage" effect at the encounters of reactants have been theoretically treated on the example of multistage reactions (including bimolecular exchange reactions as elementary stages) proceeding from different active sites in liquid solutions. It is shown that for reactions occurring near the contact of reactants, consistent consideration of quasi-stationary kinetics of such multistage reactions (possible in the framework of the encounter theory only) can be made on the basis of chemical concepts of the "cage complex," just as in the case of one-site model described in the literature. Exactly as in the one-site model, the presence of the "cage" effect gives rise to new channels of reactant transformation that cannot result from elementary event of chemical conversion for the given reaction mechanism. Besides, the multisite model demonstrates new (as compared to one-site model) features of multistage reaction course. PMID:27586911

  10. Cluster Based Text Classification Model

    DEFF Research Database (Denmark)

    Nizamani, Sarwat; Memon, Nasrullah; Wiil, Uffe Kock

    2011-01-01

    We propose a cluster based classification model for suspicious email detection and other text classification tasks. The text classification tasks comprise many training examples that require a complex classification model. Using clusters for classification makes the model simpler and increases the...... classifier is trained on each cluster having reduced dimensionality and less number of examples. The experimental results show that the proposed model outperforms the existing classification models for the task of suspicious email detection and topic categorization on the Reuters-21578 and 20 Newsgroups...... datasets. Our model also outperforms A Decision Cluster Classification (ADCC) and the Decision Cluster Forest Classification (DCFC) models on the Reuters-21578 dataset....

  11. Multistage variable probability forest volume inventory. [the Defiance Unit of the Navajo Nation

    Science.gov (United States)

    Anderson, J. E. (Principal Investigator)

    1979-01-01

    An inventory scheme based on the use of computer processed LANDSAT MSS data was developed. Output from the inventory scheme provides an estimate of the standing net saw timber volume of a major timber species on a selected forested area of the Navajo Nation. Such estimates are based on the values of parameters currently used for scaled sawlog conversion to mill output. The multistage variable probability sampling appears capable of producing estimates which compare favorably with those produced using conventional techniques. In addition, the reduction in time, manpower, and overall costs lend it to numerous applications.

  12. MULTISTAGED BURNER DESIGN FOR IN-FURNACE NOX CONTROL

    Science.gov (United States)

    The paper gives results of an evaluation of a multistage combustion modification design, combining two advanced NOx control technologies, on a pilot-scale (0.9 MW) package boiler simulator for in-furnace NOx control of high nitrogen fuel combustion applications. A low NOx precomb...

  13. LOW NOX, HIGH EFFICIENCY MULTISTAGED BURNER: GASEOUS FUEL RESULTS

    Science.gov (United States)

    The paper discusses the evaluation of a multistaged combustion burner design on a 0.6 MW package boiler simulator for in-furnace NOx control and high combustion efficiency. Both deep air staging, resulting in a three-stage configuration, and boiler front wall fuel staging of undo...

  14. Nuclear-Reaction Control by Multistage Mathematical-Programming

    Directory of Open Access Journals (Sweden)

    I. Leikkonen

    1980-04-01

    Full Text Available The method of Multistage Mathematical Programming (MMP has been adapted for optimal control of the spatial power distribution in nuclear reactors. Changes in power distribution arise from variations in the operational conditions of the reactor, and excite oscillations which in large reactors may approach the stability limit.

  15. Defining characteristics of multi-speed multistage hydrocyclone

    Directory of Open Access Journals (Sweden)

    В.О. Михайлюк

    2008-03-01

    Full Text Available  In the given work characteristics of technological petrocontaining water current in multistage hydrocyclones at various speeds containing working chambers with changing cross-section sections are examined. The theoretical substantiation of the conditions promoting their application for division of petrocontaining water in systems of their preparation for reuse or returning in environment is brought.

  16. A multimutation model for cancer based on age-time patterns of radiation effects. 1. Mathematical and epidemiological aspects

    International Nuclear Information System (INIS)

    An idealized mathematical model for carcinogenesis is proposed, based on age-time patterns of excess solid cancer risk seen in the Radiation Effects Research Foundation data on A-bomb survivors. The primary component is similar to the Armitage-Doll multistage model, with the interpretation that the events in that model are somatic mutations. The manner of extending this model to incorporate effects of a specific carcinogen, here an acute irradiation, is novel in the sense that the irradiation can cause any one of the mutations in the multi-event process. The motivation for this formulation is the observation that the excess solid cancer rate associated with radiation exposure appears largely to depend only on attained age, rather than on age at exposure and time since exposure. The model is fitted to the A-bomb survivor data on a class of cancers consisting of the major non-sex-specific types. (author)

  17. Base Flow Model Validation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The program focuses on turbulence modeling enhancements for predicting high-speed rocket base flows. A key component of the effort is the collection of...

  18. Modeling Guru: Knowledge Base for NASA Modelers

    Science.gov (United States)

    Seablom, M. S.; Wojcik, G. S.; van Aartsen, B. H.

    2009-05-01

    Modeling Guru is an on-line knowledge-sharing resource for anyone involved with or interested in NASA's scientific models or High End Computing (HEC) systems. Developed and maintained by the NASA's Software Integration and Visualization Office (SIVO) and the NASA Center for Computational Sciences (NCCS), Modeling Guru's combined forums and knowledge base for research and collaboration is becoming a repository for the accumulated expertise of NASA's scientific modeling and HEC communities. All NASA modelers and associates are encouraged to participate and provide knowledge about the models and systems so that other users may benefit from their experience. Modeling Guru is divided into a hierarchy of communities, each with its own set forums and knowledge base documents. Current modeling communities include those for space science, land and atmospheric dynamics, atmospheric chemistry, and oceanography. In addition, there are communities focused on NCCS systems, HEC tools and libraries, and programming and scripting languages. Anyone may view most of the content on Modeling Guru (available at http://modelingguru.nasa.gov/), but you must log in to post messages and subscribe to community postings. The site offers a full range of "Web 2.0" features, including discussion forums, "wiki" document generation, document uploading, RSS feeds, search tools, blogs, email notification, and "breadcrumb" links. A discussion (a.k.a. forum "thread") is used to post comments, solicit feedback, or ask questions. If marked as a question, SIVO will monitor the thread, and normally respond within a day. Discussions can include embedded images, tables, and formatting through the use of the Rich Text Editor. Also, the user can add "Tags" to their thread to facilitate later searches. The "knowledge base" is comprised of documents that are used to capture and share expertise with others. The default "wiki" document lets users edit within the browser so others can easily collaborate on the

  19. Multistage Off-Line Permutation Packet Routing on a Mesh: An Approach with Elementary Mathematics

    Institute of Scientific and Technical Information of China (English)

    Kevin Chiew; Yingjiu Li

    2009-01-01

    Various methods have been proposed for off-line permutation packet routing on a mesh. One of the methods is known as multistage routing, in which the first stage is crucial. For the first stage of routing, the previous study normally converts it to a problem of graph theory and proves the existence of solutions. However, there is a lack of simple algorithms to the first stage of routing. This article presents an explicit and simple approach for the first stage of routing based on elementary mathematics.

  20. Event-Based Activity Modeling

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    2004-01-01

    We present and discuss a modeling approach that supports event-based modeling of information and activity in information systems. Interacting human actors and IT-actors may carry out such activity. We use events to create meaningful relations between information structures and the related...

  1. Modelling Gesture Based Ubiquitous Applications

    CERN Document Server

    Zacharia, Kurien; Varghese, Surekha Mariam

    2011-01-01

    A cost effective, gesture based modelling technique called Virtual Interactive Prototyping (VIP) is described in this paper. Prototyping is implemented by projecting a virtual model of the equipment to be prototyped. Users can interact with the virtual model like the original working equipment. For capturing and tracking the user interactions with the model image and sound processing techniques are used. VIP is a flexible and interactive prototyping method that has much application in ubiquitous computing environments. Different commercial as well as socio-economic applications and extension to interactive advertising of VIP are also discussed.

  2. Reconstruction of multistage massive rock slope failure: Polymethodical approach in Lake Oeschinen (CH)

    Science.gov (United States)

    Knapp, Sibylle; Gilli, Adrian; Anselmetti, Flavio S.; Hajdas, Irka

    2016-04-01

    Lateglacial and Holocene rock-slope failures occur often as multistage failures where paraglacial adjustment and stress adaptation are hypothesised to control stages of detachment. However, we have only limited datasets to reconstruct detailed stages of large multistage rock-slope failures, and still aim at improving our models in terms of geohazard assessment. Here we use lake sediments, well-established for paleoclimate and paleoseismological reconstruction, with a focus on the reconstruction of rock-slope failures. We present a unique inventory from Lake Oeschinen (Bernese Alps, Switzerland) covering about 2.4 kyrs of rock-slope failure history. The lake sediments have been analysed using sediment-core analysis, radiocarbon dating and seismic-to-core and core-to-core correlations, and these were linked to historical and meteorological records. The results imply that the lake is significantly younger than the ~9 kyrs old Kandersteg rock avalanche (Tinner et al., 2005) and shows multiple rock-slope failures, two of which could be C14-dated. Several events detached from the same area potentially initiated by prehistoric earthquakes (Monecke et al., 2006) and later from stress relaxation processes. The data imply unexpected short recurrence rates that can be related to certain detachment scarps and also help to understand the generation of a historical lake-outburst flood. Here we show how polymethodical analysis of lake sediments can help to decipher massive multistage rock-slope failure. References Monecke, K., Anselmetti, F.S., Becker, A., Schnellmann, M., Sturm, M., Giardini, D., 2006. Earthquake-induced deformation structures in lake deposits: A Late Pleistocene to Holocene paleoseismic record for Central Switzerland. Eclogae Geologicae Helvetiae, 99(3), 343-362. Tinner, W., Kaltenrieder, P., Soom, M., Zwahlen, P., Schmidhalter, M., Boschetti, A., Schlüchter, C., 2005. Der nacheiszeitliche Bergsturz im Kandertal (Schweiz): Alter und Auswirkungen auf die

  3. A multi-stage sampling strategy for the delineation of soil pollution in a contaminated brownfield

    International Nuclear Information System (INIS)

    A multi-stage sampling strategy, based on sequential Gaussian simulation, was presented to optimize the step-wise selection of a small numbers of additional samples to delineate soil pollution. This strategy was applied to a Belgian brownfield of 5.2 ha polluted with lead (Pb). Starting from an initial number of 240 samples in stage 1, additional samples were added, 25 per stage, and the reduction of the uncertainty in the Pb delineation was monitored. Twenty stages were used. Already in stage 6 a local optimum was found based on the median conditional coefficient of variation. An independent validation confirmed that this index was to be preferred over the median conditional variance. So for the brownfield considered our procedure indicated that 365 selected samples would have been sufficient, representing a gain of 70.7% in sampling effort compared to current practice which resulted in a sampling effort of 1245 samples. - A multi-stage sampling strategy based on geostatistics provides an efficient procedure to delineate a pollution in a contaminated brownfield

  4. Realization of Multistage FIR Filters using Pipelining-Interleaving

    Directory of Open Access Journals (Sweden)

    M. Ciric

    2012-11-01

    Full Text Available Multistage digital filters can be one of the solutions for the realization of filters with a narrow transition zone. If requirements for the width of transition zone are too strict, then they are the only alternative, and the decimation/interpolation must be performed in several steps. Combining decimation/interpolation operations related to the implementation of multi-channel filters in the PI (pipelining/interleaving technique can give an efficient structure of multichannel multistage filter. Using the advantages offered by newer generations of FPGA chips in terms of digital design structure, it is possible to realize such filters with considerable savings of hardware resources and reduce the effect of finite length codeword. This paper proposes such an efficient implementation and presents the results of such a realization with FPGA components.

  5. Performance of Multi-Channel Multi-Stage Spectrum Sensing

    CERN Document Server

    Gabran, Wesam; Čabrić, Danijela

    2010-01-01

    We present an analytical framework which enables performance evaluation of different multi-channel multi-stage spectrum sensing protocols for Opportunistic Spectrum Access networks. Analyzed performance metrics include the average secondary user throughput and the average collision probability between the primary and secondary users. The analysis framework takes into account buffering of incoming secondary user traffic, parallel and single channel access, as well as prolonged channel observation periods at the first and last stage of sensing. The main results show that when a constraint is given upon the probability of primary user mis-detection, multi-stage sensing is in most cases superior to the single stage sensing counterpart. Further, prolonged channel observation at the first sensing stage decreases the collision probability considerably while keeping the throughput at an acceptable level. Finally, in most network scenarios considered in this work, two stages of sensing are enough to obtain the maximum...

  6. Numerical Investigation of a First Stage of a Multistage Centrifugal Pump: Impeller, Diffuser with Return Vanes, and Casing

    OpenAIRE

    Nicolas La Roche-Carrier; Guyh Dituba Ngoma; Walid Ghie

    2013-01-01

    This paper deals with the numerical investigation of a liquid flow in a first stage of a multistage centrifugal pump consisting of an impeller, diffuser with return vanes, and casing. The continuity and Navier-Stokes equations with the k-ε turbulence model and standard wall functions were used. To improve the design of the pump's first stage, the impacts of the impeller blade height and diffuser vane height, number of impeller blades, diffuser vanes and diffuser return vanes, and wall roughne...

  7. Sketch-based geologic modeling

    Science.gov (United States)

    Rood, M. P.; Jackson, M.; Hampson, G.; Brazil, E. V.; de Carvalho, F.; Coda, C.; Sousa, M. C.; Zhang, Z.; Geiger, S.

    2015-12-01

    Two-dimensional (2D) maps and cross-sections, and 3D conceptual models, are fundamental tools for understanding, communicating and modeling geology. Yet geologists lack dedicated and intuitive tools that allow rapid creation of such figures and models. Standard drawing packages produce only 2D figures that are not suitable for quantitative analysis. Geologic modeling packages can produce 3D models and are widely used in the groundwater and petroleum communities, but are often slow and non-intuitive to use, requiring the creation of a grid early in the modeling workflow and the use of geostatistical methods to populate the grid blocks with geologic information. We present an alternative approach to rapidly create figures and models using sketch-based interface and modelling (SBIM). We leverage methods widely adopted in other industries to prototype complex geometries and designs. The SBIM tool contains built-in geologic rules that constrain how sketched lines and surfaces interact. These rules are based on the logic of superposition and cross-cutting relationships that follow from rock-forming processes, including deposition, deformation, intrusion and modification by diagenesis or metamorphism. The approach allows rapid creation of multiple, geologically realistic, figures and models in 2D and 3D using a simple, intuitive interface. The user can sketch in plan- or cross-section view. Geologic rules are used to extrapolate sketched lines in real time to create 3D surfaces. Quantitative analysis can be carried our directly on the models. Alternatively, they can be output as simple figures or imported directly into other modeling tools. The software runs on a tablet PC and can be used in a variety of settings including the office, classroom and field. The speed and ease of use of SBIM enables multiple interpretations to be developed from limited data, uncertainty to be readily appraised, and figures and models to be rapidly updated to incorporate new data or concepts.

  8. Process for multi-stage treatment of radioactive waste water

    International Nuclear Information System (INIS)

    For the multi-stage treatment of radioactive waste waters with a decanter the solids contained in the waste waters are dried up to a residual moisture of 10% and are subsequently disposed. Solids remaining in the liquid part are removed with a separator up to the colloidal range, whereas the liquid product of the decanter is filtered up to the molecular range so that it can be used as industrial water. (orig.)

  9. Numerical Study of Multistage Transcritical Organic Rankine Cycle Axial Turbines

    OpenAIRE

    SCIACOVELLI, L.; CINNELLA, Paola

    2014-01-01

    Transonic flows through axial, multi-stage, transcritical ORC turbines, are investigated by using a numerical solver including advanced multiparameter equations of state and a high-order discretization scheme. The working fluids in use are the refrigerants R134a and R245fa, classified as dense gases due to their complex molecules and relatively high molecular weight. Both inviscid and viscous numerical simulations are carried out to quantify the impact of dense gas effects and viscous effe...

  10. Multi-Stage Transportation Problem With Capacity Limit

    OpenAIRE

    I. Brezina; Z. Čičková; J. Pekár; M. Reiff

    2010-01-01

    The classical transportation problem can be applied in a more general way in practice. Related problems as Multi-commodity transportation problem, Transportation problems with different kind of vehicles, Multi-stage transportation problems, Transportation problem with capacity limit is an extension of the classical transportation problem considering the additional special condition. For solving such problems many optimization techniques (dynamic programming, linear programming, special algor...

  11. Use of a continuous multistage bioreactor to mimic winemaking fermentation

    OpenAIRE

    Clement, Tiphaine; Perez, Marc; Mouret, Jean-Roch; Sablayrolles, Jean-Marie; Camarasa, Carole

    2011-01-01

    Continuous fermentation set-ups are of great interest for studying the physiology of microorganisms. In winemaking conditions, yeasts go through a growth phase and a stationary phase during which more than half of the sugar is fermented. A comprehensive study of wine-yeast physiology must therefore include yeasts in a non-growing phase. This condition is impossible to achieve within a chemostat, which led us to design a multi-stage fermentation device. In this study, we evaluated the ability ...

  12. Analysis of multi-stage open shop processing systems

    OpenAIRE

    Eggermont, Christian E.J.; Schrijver, Alexander; Woeginger, Gerhard J.

    2011-01-01

    We study algorithmic problems in multi-stage open shop processing systems that are centered around reachability and deadlock detection questions. We characterize safe and unsafe system states. We show that it is easy to recognize system states that can be reached from the initial state (where the system is empty), but that in general it is hard to decide whether one given system state is reachable from another given system state. We show that the problem of identifying reachable deadlock ...

  13. Numerical simulation and performance prediction in multi-stage submersible centrifugal pump

    International Nuclear Information System (INIS)

    In order to study the inner flow field of multi-stage submersible centrifugal pump, the model named QD3-60/4-1.1 was selected. Steady turbulence characteristics of impellers, diffusers and return channel were calculated by Fluent software, the SIMPLEC algorithm and RNG κ-ε turbulence model with sliding mesh technology. Then, the distributions of pressure, velocity and Turbulence kinetic energy was obtained and the distributions of velocity field of a channel were analysed. The results show that the static pressure in impeller is increasing with the increasing of radius. The circumferential component of relative velocity is in the opposite direction of impeller rotating. At the same radius, the component value of pressure surface is larger than suction surface. With the increasing of flow rate, absolute velocity and relative velocity flow angle are becoming small, in opposite of the relative velocity and absolute velocity flow angle. The high turbulent zone of impeller is located in the gap of impellers and diffusers. Flow similarity and structure similarity of the multi-stage submersible pump are confirmed

  14. Effect Analysis of Geometric Parameters on Stainless Steel Stamping Multistage Pump by Experimental Test and Numerical Calculation

    OpenAIRE

    Chuan Wang; Weidong Shi; Ling Zhou; Weigang Lu

    2013-01-01

    In order to improve the efficiency of stainless steel stamping multistage pump, quadratic regression orthogonal test, hydraulic design, and computational fluid dynamics (CFD) are used to analyze the effect of pump geometric parameters. Sixteen impellers are designed based on the quadratic regression orthogonal test, which have three factors including impeller outlet slope, impeller blade outlet stagger angle, and impeller blade outlet width. Through quadratic regression equation, the function...

  15. HMM-based Trust Model

    DEFF Research Database (Denmark)

    ElSalamouny, Ehab; Nielsen, Mogens; Sassone, Vladimiro

    2010-01-01

    Probabilistic trust has been adopted as an approach to taking security sensitive decisions in modern global computing environments. Existing probabilistic trust frameworks either assume fixed behaviour for the principals or incorporate the notion of ‘decay' as an ad hoc approach to cope with thei...... the major limitation of existing Beta trust model. We show the consistency of the HMM-based trust model and contrast it against the well known Beta trust model with the decay principle in terms of the estimation precision....

  16. 一种对基于耗尽关机多级固体火箭概念设计的改进方法%An Improved Method for Conceptual Design of Multi-stage Solid Rockets Based on Depleted Shutdown

    Institute of Scientific and Technical Information of China (English)

    何麟书; Murad.Y

    2005-01-01

    Solid propellant rocket motors are preferred for most ballistic missiles because they need simple maintenance and can be launched quickly.But the conventional thrust termination devices limit the depletion of every stage's grain and increase some extra-weight.An improved method for designing a multi-stage solid rocket based depleted shutdown was provided.In order to solve the problem of lack of thrust termination devices,a device to adjust the burnout angle will match the final burnout velocity and satisfy the desired range.The method can also limit the detection from anti-ballistic missile system.%由于维护简单和发射快速,弹道导弹多用固体火箭发动机,但繁杂的推力终止装置使各级装药不能耗尽并让结构增重.提出了一种对基于耗尽关机多级固体火箭概念设计的改进方法,此方法满足导弹系统主要的战技要求.为解决无推力终止装置的末速不准问题,可在末级发动机采用姿态调整装置,对射角进行调整,配合末速以满足射程要求.本方法还可抑制敌方反导探测.

  17. A model-based display

    International Nuclear Information System (INIS)

    A model-based display is identified, discussed, and illustrated. The model used in the display is based upon the Rankine Cycle, a heat engine cycle. Plant process data from the loss of main and auxiliary feedwater event at the Davis-Besse Plant on June 9, l985 is used to illustrate the display. The model used in the display fuses individual process variables into process functions. It also serves as a medium to communicate status of the process to human users. The human users may evaluate the goals of operation from the displayed process functions. Because of these display features, the user's cognitive workload is minimized. The opinions expressed herein are the author's personal ones and do not necessarily reflect criteria, requirements, and guidelines of the U.S. Nuclear Regulatory Commission

  18. Multistage heat treatment for super alloys

    International Nuclear Information System (INIS)

    Nickel base alloys of the type γ/γ' are dealt with containing localized regions of low-melting components. The Ni based complex superalloys developed for high demands (temperature, mechanical stressing) are subject to increasing segregation following casting when solidifying. The method compared to previous known processes improves the homogenization of the cast pieces by a special thermal treatment. It is based on diffusion to change the composition of the segregated regions in order to raise their melting point. This can be normally up to 1700C below the melting point of the alloy mixture. Sofar known methods are based on the removal of these segregated regions. The present method does not essentially influence the actual amount (part volume) of these regions, but changes its composition by thermal treatment of 2 to 20 h. in a temperature region of maximum 550C (preferably 300C) below the melting temperature of the entectic. The melting point of the entectic thus rises to a temperature of at least 100C above the γ'solubility curve. A second heat treatment is performed in order to dissolve the γ'-particles occuring in the cast having a particle size of 2-5μm. It takes place at a temperature above that of the γ' solubility curve but below that of the raised temperature of melt start. About 1-10 h are sufficient for practically complete dissolving of the γ'-material. Cooling down to room temperature is carried out at such a rate as to prevent the formation of coarse γ'-particles. Following the invented heat treatment, the particle size of the γ'-phase is of the order of less than 1μm. (IHOE)

  19. Model-based sensor diagnosis

    International Nuclear Information System (INIS)

    Running a nuclear power plant involves monitoring data provided by the installation's sensors. Operators and computerized systems then use these data to establish a diagnostic of the plant. However, the instrumentation system is complex, and is not immune to faults and failures. This paper presents a system for detecting sensor failures using a topological description of the installation and a set of component models. This model of the plant implicitly contains relations between sensor data. These relations must always be checked if all the components are functioning correctly. The failure detection task thus consists of checking these constraints. The constraints are extracted in two stages. Firstly, a qualitative model of their existence is built using structural analysis. Secondly, the models are formally handled according to the results of the structural analysis, in order to establish the constraints on the sensor data. This work constitutes an initial step in extending model-based diagnosis, as the information on which it is based is suspect. This work will be followed by surveillance of the detection system. When the instrumentation is assumed to be sound, the unverified constraints indicate errors on the plant model. (authors). 8 refs., 4 figs

  20. FABRICATION OF MESSAGE DIGEST TO AUTHENTICATE AUDIO SIGNALS WITH ALTERNATION OF COEFFICIENTS OF HARMONICS IN MULTI-STAGES (MDAC

    Directory of Open Access Journals (Sweden)

    Uttam Kr. Mondal

    2011-11-01

    Full Text Available Providing security to audio songs for maintaining its intellectual property right (IPR is one of chanllenging fields in commercial world especially in creative industry. In this paper, an effective approach has been incorporated to fabricate authentication of audio song through application of message digest method with alternation of coefficients of harmonics in multi-stages of higher frequency domain without affecting its audible quality. Decomposing constituent frequency components of song signal using Fourier transform with generating secret code via applying message digest followed by alternating coefficients of specific harmonics in multi-stages generates a secret code and this unique code is utilized to detect the originality of the song. A comparative study has been made with similar existing techniques and experimental results are also supported with mathematical formula based on Microsoft WAVE (".wav" stereo sound file.

  1. Generalized bounds for convex multistage stochastic programs

    CERN Document Server

    Künzi, H; Fandel, G; Trockel, W; Basile, A; Drexl, A; Dawid, H; Inderfurth, K; Kürsten, W; Schittko, U

    2005-01-01

    This work was completed during my tenure as a scientific assistant and d- toral student at the Institute for Operations Research at the University of St. Gallen. During that time, I was involved in several industry projects in the field of power management, on the occasion of which I was repeatedly c- fronted with complex decision problems under uncertainty. Although usually hard to solve, I quickly learned to appreciate the benefit of stochastic progr- ming models and developed a strong interest in their theoretical properties. Motivated both by practical questions and theoretical concerns, I became p- ticularly interested in the art of finding tight bounds on the optimal value of a given model. The present work attempts to make a contribution to this important branch of stochastic optimization theory. In particular, it aims at extending some classical bounding methods to broader problem classes of practical relevance. This book was accepted as a doctoral thesis by the University of St. Gallen in June 2004.1...

  2. A Dynamic Multistage Hybrid Swarm Intelligence Optimization Algorithm for Function Optimization

    Directory of Open Access Journals (Sweden)

    Daqing Wu

    2012-01-01

    Full Text Available A novel dynamic multistage hybrid swarm intelligence optimization algorithm is introduced, which is abbreviated as DM-PSO-ABC. The DM-PSO-ABC combined the exploration capabilities of the dynamic multiswarm particle swarm optimizer (PSO and the stochastic exploitation of the cooperative artificial bee colony algorithm (CABC for solving the function optimization. In the proposed hybrid algorithm, the whole process is divided into three stages. In the first stage, a dynamic multiswarm PSO is constructed to maintain the population diversity. In the second stage, the parallel, positive feedback of CABC was implemented in each small swarm. In the third stage, we make use of the particle swarm optimization global model, which has a faster convergence speed to enhance the global convergence in solving the whole problem. To verify the effectiveness and efficiency of the proposed hybrid algorithm, various scale benchmark problems are tested to demonstrate the potential of the proposed multistage hybrid swarm intelligence optimization algorithm. The results show that DM-PSO-ABC is better in the search precision, and convergence property and has strong ability to escape from the local suboptima when compared with several other peer algorithms.

  3. Hamilton-Jacobi-Bellman framework for optimal control in multistage energy systems

    Science.gov (United States)

    Sieniutycz, Stanislaw

    2000-03-01

    We enunciate parallelism for structures of variational principles in mechanics and thermodynamics in terms of the duality for thermoeconomic problems of maximizing of production profit and net profit which can be transferred to duality for least action and least abbreviated action which appear in mechanics. With the parallelism in mind, we review theory and macroscopic applications of a recently developed discrete formalism of Hamilton-Jacobi type which arises when Bellman's method of dynamic programming is applied to optimize active (work producing) and inactive (entropy generating) multistage energy systems with free intervals of an independent variable. Our original contribution develops a generalized theory for discrete processes in which these intervals can reside in the model inhomogeneously and can be constrained. We consider applications to multistage thermal machines, controlled unit operations, spontaneous relaxations, nonlinear heat conduction, and self-propagating reaction-diffusion fronts. They all satisfy a basic functional equation that leads to the Hamilton-Jacobi-Bellman equation (HJB equation) and a related discrete optimization algorithm with a maximum principle for a Hamiltonian. Correspondence is shown with the well-known HJB theory for continuous processes when the number of stages approaches an infinity. We show that a common unifying criterion, which is the criterion of a minimum generated entropy, can be proven to act locally in the majority of considered cases, although the related global statements can be invalid far from equilibrium. General limits are found which bound the consumption of the classical work potential (exergy) for finite durations.

  4. Interconnected levels of Multi-Stage Marketing – A Triadic approach

    DEFF Research Database (Denmark)

    Vedel, Mette; Geersbro, Jens; Ritter, Thomas

    2012-01-01

    different levels of multi-stage marketing and illustrates these stages with a case study. In addition, a triadic perspective is introduced as an analytical tool for multi-stage marketing research. The results from the case study indicate that multi-stage marketing exists on different levels. Thus, managers......Multi-stage marketing gains increasing attention as knowledge of and influence on the customer's customer become more critical for the firm's success. Despite this increasing managerial relevance, systematic approaches for analyzing multi-stage marketing are still missing. This paper conceptualizes...... must not only decide in general on the merits of multi-stage marketing for their firm, but must also decide on which level they will engage in multi-stage marketing. The triadic perspective enables a rich and multi-dimensional understanding of how different business relationships influence each other...

  5. Purification of High Salinity Brine by Multi-Stage Ion Concentration Polarization Desalination.

    Science.gov (United States)

    Kim, Bumjoo; Kwak, Rhokyun; Kwon, Hyukjin J; Pham, Van Sang; Kim, Minseok; Al-Anzi, Bader; Lim, Geunbae; Han, Jongyoon

    2016-01-01

    There is an increasing need for the desalination of high concentration brine (>TDS 35,000 ppm) efficiently and economically, either for the treatment of produced water from shale gas/oil development, or minimizing the environmental impact of brine from existing desalination plants. Yet, reverse osmosis (RO), which is the most widely used for desalination currently, is not practical for brine desalination. This paper demonstrates technical and economic feasibility of ICP (Ion Concentration Polarization) electrical desalination for the high saline water treatment, by adopting multi-stage operation with better energy efficiency. Optimized multi-staging configurations, dependent on the brine salinity values, can be designed based on experimental and numerical analysis. Such an optimization aims at achieving not just the energy efficiency but also (membrane) area efficiency, lowering the true cost of brine treatment. ICP electrical desalination is shown here to treat brine salinity up to 100,000 ppm of Total Dissolved Solids (TDS) with flexible salt rejection rate up to 70% which is promising in a various application treating brine waste. We also demonstrate that ICP desalination has advantage of removing both salts and diverse suspended solids simultaneously, and less susceptibility to membrane fouling/scaling, which is a significant challenge in the membrane processes. PMID:27545955

  6. Distribution characteristics of holdups in a multi-stage bubble column using electrical resistance tomography

    Institute of Scientific and Technical Information of China (English)

    Haibo Jin; Yicheng Lian; Yujian Qin; Suohe Yang; Guangxiang He

    2013-01-01

    Based on the principle of chemical reaction engineering,the addition of perforated plates can improve the performance of conventional bubble column and decrease the backmixing behaviors.The distribution characteristics of gas holdup in a multi-stage bubble column embedded with five types of sieve plates and three types of tongue plates were studied using electrical resistance tomography (ERT).The effects of superficial gas velocity and the geometric design of perforated plates on the gas holdup and its radial distribution above and below the plates of the bubble column were discussed.Experimental results show ERT is suitable as an online monitoring tool to provide useful information on the hydrodynamic parameters of multi-stage bubble columns.With increasing superficial gas velocity,local gas holdup increases,and gas holdup below the plate increases with decrease of free area (%FA),hole diameters or angle of tongue plates.ERT technique facilitates noninvasive and nonintrusive visualization of cross-sectional distribution of gas holdup in a bubble column.

  7. Multi-Stage, Multi-Resolution Method for Automatic Characterization of Epileptic Spikes in EEG

    Directory of Open Access Journals (Sweden)

    Ganesan.M

    2010-06-01

    Full Text Available In this paper, a technique is proposed for the automatic detection of the spikes in long term 18 channel human electroencephalograms (EEG with less number of data set. The scheme for detecting epileptic and non epileptic spikes in EEG is based on a multi resolution, multi-level analysis and Artificial Neural Network(ANN approach. Wavelet Transform (WT is a powerful tool for signal compression, recognition, restoration and multi-resolutionanalysis of non-stationary signal. The signal on each EEG channel is decomposed into six sub bands using a non-decimated WT. Each sub band is analyzed by using a non-linear energy operator, in order to detect spikes. A parameter extraction stage extracts theparameters of the detected spikes that can be given as the input to ANN classifier. A robust system that combines multiple signal-processing methods in a multistage scheme, integratingwavelet transform and artificial neural network is proposed here. This system is experimented on a simulated EEG pattern waveform as well as with real patient data. The system is evaluated on testing data from 81 patients, totaling more than 800 hours of recordings.90.0% of the epileptic events were correctly detected and the detection rate of non epileptic events was 98.0%. We conclude that the proposed system has good performance in detecting epileptic form activities; further the multistage multiresolution approach is an appropriate way of automatic classification problems in EEG.

  8. Cost effectiveness of a multi-stage return to work program for workers on sick leave due to low back pain, design of a population based controlled trial [ISRCTN60233560

    Directory of Open Access Journals (Sweden)

    Anema Johannes R

    2003-11-01

    Full Text Available Abstract Background To describe the design of a population based randomized controlled trial (RCT, including a cost-effectiveness analysis, comparing participative ergonomics interventions between 2–8 weeks of sick leave and Graded Activity after 8 weeks of sick leave with usual care, in occupational back pain management. Methods Design An RCT and cost-effectiveness evaluation in employees sick-listed for a period of 2 to 6 weeks due to low back pain. Interventions used are 1. Communication between general practitioner and occupational physician plus Participative Ergonomics protocol performed by an ergonomist. 2. Graded Activity based on cognitive behavioural principles by a physiotherapist. 3. Usual care, provided by an occupational physician according to the Dutch guidelines for the occupational health management of workers with low back pain. The primary outcome measure is return to work. Secondary outcome measures are pain intensity, functional status and general improvement. Intermediate variables are kinesiophobia and pain coping. The cost-effectiveness analysis includes the direct and indirect costs due to low back pain. The outcome measures are assessed before randomization (after 2–6 weeks on sick leave and 12 weeks, 26 weeks and 52 weeks after first day of sick leave. Discussion The combination of these interventions has been subject of earlier research in Canada. The results of the current RCT will: 1. crossvalidate the Canadian findings in an different sociocultural environment; 2. add to the cost-effectiveness on treatment options for workers in the sub acute phase of low back pain. Results might lead to alterations of existing (international guidelines.

  9. NEURO FUZZY LINK BASED CLASSIFIER FOR THE ANALYSIS OF BEHAVIOR MODELS IN SOCIAL NETWORKS

    OpenAIRE

    Indira Priya Ponnuvel; Ghosh Dalim Kumar; Kannan Arputharaj; Ganapathy Sannasi

    2014-01-01

    In this study, a new link based classifier using neuro fuzzy logic has been proposed for analyzing the social behavior based on Weblog dataset. In this system, data are processed using a multistage structure. This system provides a diagnosis using a neuro fuzzy link based classifier that analyses the user’s behavior to specific diagnostic categories based on their cluster category in social networks. It uses random walks method to organize the labels. Since the links present in the soci...

  10. ERTS data user investigation to develop a multistage forest sampling inventory system

    Science.gov (United States)

    Langley, P. G.; Vanroessel, J. W. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. A unique digital timber volume estimation system was developed for use with the MSS CCT tapes. The system was tested on a 64-square mile area in Northern California's Trinity Alps. The outcome of a systematic experiment, in which several possible combinations of bands 5 and 7 and a contrast measure were tried, showed that an estimated gain in precision of 50% can be obtained in a multistage sampling design. The difference between bands 5 and 7 proved to be of special importance for the estimation of biomass in the form of timber volume. In addition, an interpretation model for high flight U2 photographs was developed. A maximum multiple correlation coefficient of 0.74 was obtained for the regression model, explaining 55% of the variation in timber volume as estimated from aerial photos and ground measurments. An interpretation model for MSS color composites is in the testing stage.

  11. Model-based requirements engineering

    CERN Document Server

    Holt, Jon

    2012-01-01

    This book provides a hands-on introduction to model-based requirementsengineering and management by describing a set of views that form the basisfor the approach. These views take into account each individual requirement interms of its description, but then also provide each requirement with meaning byputting it into the correct 'context'. A requirement that has been put into a contextis known as a 'use case' and may be based upon either stakeholders or levelsof hierarchy in a system. Each use case must then be analysed and validated bydefining a combination of scenarios and formal mathematica

  12. Multistage chemical carcinogenesis in mouse skin

    Energy Technology Data Exchange (ETDEWEB)

    Slaga, T.J.; Fischer, S.M.; Weeks, C.E.; Klein-Szanto, A.J.P.

    1979-01-01

    Skin tumors in mice can be induced by the sequential application of a subthreshold dose of a carcinogen (initiation phase) followed by repetitive treatment with a noncarcinogenic tumor promoter. The initiation phase requires only a single application of either a direct acting carcinogen or a procarcinogen which has to be metabolized before being active and is essentially an irreversible step which probably involves a somatic cell mutation. There is a good correlation between the skin tumor initiating activites of several polycyclic aromatic hydrocarbons (PAH) and their ability to bind covalently to epidermal DNA. Laboratory results suggest that bay region diol-epoxides are the ultimate carcinogenic form of PAH carcinogens. Potent inhibitors and stimulators of PAH tumor initiation appear to affect the level of the PAH diol-epoxide reacting with specific DNA bases. Reecent data suggests that the tumor promotion stage involves at least three important steps: (1) the induction of embryonic looking cells (dark cells) in adult epidermis; (2) an increased production of epidermal prostaglandins and polyamines; (3) sustained proliferation of dark cells. Retinoic acid specifically inhibits step two whereas the anti-inflammatory steriod fluocinolone acetonide is a potent inhibitor of steps one and three. The mechanism and the importance of a specific sequence for each step in chemical carcinogenesis in mouse skin are detailed.

  13. Model-based tomographic reconstruction

    Science.gov (United States)

    Chambers, David H.; Lehman, Sean K.; Goodman, Dennis M.

    2012-06-26

    A model-based approach to estimating wall positions for a building is developed and tested using simulated data. It borrows two techniques from geophysical inversion problems, layer stripping and stacking, and combines them with a model-based estimation algorithm that minimizes the mean-square error between the predicted signal and the data. The technique is designed to process multiple looks from an ultra wideband radar array. The processed signal is time-gated and each section processed to detect the presence of a wall and estimate its position, thickness, and material parameters. The floor plan of a building is determined by moving the array around the outside of the building. In this paper we describe how the stacking and layer stripping algorithms are combined and show the results from a simple numerical example of three parallel walls.

  14. Differential Geometry Based Multiscale Models

    OpenAIRE

    Wei, Guo-Wei

    2010-01-01

    Large chemical and biological systems such as fuel cells, ion channels, molecular motors, and viruses are of great importance to the scientific community and public health. Typically, these complex systems in conjunction with their aquatic environment pose a fabulous challenge to theoretical description, simulation, and prediction. In this work, we propose a differential geometry based multiscale paradigm to model complex macromolecular systems, and to put macroscopic and microscopic descript...

  15. Optimization of Input Quantities about MTO Multi-stage Production System Based on Qualified Rate%考虑合格率的MTO多阶段生产系统投产量优化

    Institute of Scientific and Technical Information of China (English)

    胡盛强; 张毕西; 张湘伟; 赖玉霞

    2012-01-01

    订单式生产(Make To Order,MTO)人工作业系统(Manual Operation System,MOS)是我国中小制造企业广泛采用的生产系统模式.在MTO/MOS中,产品的质量水平与工人技能水平、工作态度、身心状态及公司激励、惩罚机制等密切相关.实际中,产品的生产需要经过部分人工工序.受人的技能等因素的影响,生产过程可能会产生一定比例的不合格半成品.考虑当各阶段的合格率分别为常数、服从离散随机分布、服从连续随机分布时,对其计划投产量及生产成本进行建模、求解及优化决策.理论及算例分析表明,当不同分布下同阶段合格率均值相等时,各阶段计划投产量及生产成本在连续随机分布下是最大的,而当合格率为常数时是最小的.对于离散随机分布,当其方差越大时,对应的计划投产量及生产成本也越高.%MTO(Make-to-Order) and MOSCManual Operation System) is the general production system mode of the small and medium manufacturing enterprises. About the production system, product quality closely relats to the worker skills, work attitude, work status, incentive and punishment mechanisms etc In practice, several processes are mainly operated by men. Because of the influence of persons' skills and so on, a certain amount of failed semi-finished products are likely to be produced. It considers when the qualified rate of each stage is constant, subjecting to random discrete distribution or continuous distribution, how to solve the problem of planning input quantities and corresponding costs of each stage with modeling and optimization decisions. The theory and numerical analysis shows that,as the qualified rates of the same stage under different distribution are equal, the planning input quantities and corresponding costs are maximum when the distribution is continuous, they are minimum while the qualified rates are constant For the discrete distribution, as the variance is greater, the

  16. Catalytic multi-stage liquefaction of coal at HTI: Bench-scale studies in coal/waste plastics coprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, V.R.; Lee, L.K.; Stalzer, R.H. [Hydrocarbon Technologies, Inc., Lawrenceville, NJ (United States)] [and others

    1995-12-31

    The development of Catalytic Multi-Stage Liquefaction (CMSL) at HTI has focused on both bituminous and sub-bituminous coals using laboratory, bench and PDU scale operations. The crude oil equivalent cost of liquid fuels from coal has been curtailed to about $30 per barrel, thus achieving over 30% reduction in the price that was evaluated for the liquefaction technologies demonstrated in the late seventies and early eighties. Contrary to the common belief, the new generation of catalytic multistage coal liquefaction process is environmentally very benign and can produce clean, premium distillates with a very low (<10ppm) heteroatoms content. The HTI Staff has been involved over the years in process development and has made significant improvements in the CMSL processing of coals. A 24 month program (extended to September 30, 1995) to study novel concepts, using a continuous bench scale Catalytic Multi-Stage unit (30kg coal/day), has been initiated since December, 1992. This program consists of ten bench-scale operations supported by Laboratory Studies, Modelling, Process Simulation and Economic Assessments. The Catalytic Multi-Stage Liquefaction is a continuation of the second generation yields using a low/high temperature approach. This paper covers work performed between October 1994- August 1995, especially results obtained from the microautoclave support activities and the bench-scale operations for runs CMSL-08 and CMSL-09, during which, coal and the plastic components for municipal solid wastes (MSW) such as high density polyethylene (HDPE)m, polypropylene (PP), polystyrene (PS), and polythylene terphthlate (PET) were coprocessed.

  17. Thermochemical production of hydrogen via multistage water splitting processes

    Science.gov (United States)

    Funk, J. E.

    1975-01-01

    This paper presents and reviews the fundamental thermodynamic principles underlying thermochemical water splitting processes. The overall system is considered first and the temperature limitation in process thermal efficiency is developed. The relationship to an ideal water electrolysis cell is described and the nature of efficient multistage reaction processes is discussed. The importance of the reaction entropy change and the relation of the reaction free energy change to the work of separation is described. A procedure for analyzing thermochemical water splitting processes is presented and its use to calculate individual stage efficiency is demonstrated. A number of processes are used to illustrate the concepts and procedures.

  18. Improved Multistage Wiener Filters in Nonhomogeneous Clutter Environments

    Institute of Scientific and Technical Information of China (English)

    Bin Tang; Xue-Gang Wang; Ke-Song Chen

    2008-01-01

    A new method combining space-time preprocessing with multistage Wiener filters (STPMWF) is proposed to improve the performance of space-time adaptive processing (STAP) in nonhomogeneous clutter scenario. The new scheme only requires the data from the primary range bin, thus it can suppress discrete interferers efficiently, without calculating the inverse of covariance matrix. Comparing to the original MWF approach, the proposed scheme can be regarded as practical solutions for robust and effective STAP of nonhomogeneous radar data. The theoretical analysis shows that our STPMWF is simple in implementation and fast in convergence. The numeric results by using simulated data exhibit a good agreement with the proposed theory.

  19. Crowdsourcing Based 3d Modeling

    Science.gov (United States)

    Somogyi, A.; Barsi, A.; Molnar, B.; Lovas, T.

    2016-06-01

    Web-based photo albums that support organizing and viewing the users' images are widely used. These services provide a convenient solution for storing, editing and sharing images. In many cases, the users attach geotags to the images in order to enable using them e.g. in location based applications on social networks. Our paper discusses a procedure that collects open access images from a site frequently visited by tourists. Geotagged pictures showing the image of a sight or tourist attraction are selected and processed in photogrammetric processing software that produces the 3D model of the captured object. For the particular investigation we selected three attractions in Budapest. To assess the geometrical accuracy, we used laser scanner and DSLR as well as smart phone photography to derive reference values to enable verifying the spatial model obtained from the web-album images. The investigation shows how detailed and accurate models could be derived applying photogrammetric processing software, simply by using images of the community, without visiting the site.

  20. An Agent Based Classification Model

    CERN Document Server

    Gu, Feng; Greensmith, Julie

    2009-01-01

    The major function of this model is to access the UCI Wisconsin Breast Can- cer data-set[1] and classify the data items into two categories, which are normal and anomalous. This kind of classifi cation can be referred as anomaly detection, which discriminates anomalous behaviour from normal behaviour in computer systems. One popular solution for anomaly detection is Artifi cial Immune Sys- tems (AIS). AIS are adaptive systems inspired by theoretical immunology and observed immune functions, principles and models which are applied to prob- lem solving. The Dendritic Cell Algorithm (DCA)[2] is an AIS algorithm that is developed specifi cally for anomaly detection. It has been successfully applied to intrusion detection in computer security. It is believed that agent-based mod- elling is an ideal approach for implementing AIS, as intelligent agents could be the perfect representations of immune entities in AIS. This model evaluates the feasibility of re-implementing the DCA in an agent-based simulation environ- ...

  1. A graph based system for multi-stage attacks recognition

    Institute of Scientific and Technical Information of China (English)

    Safaa O. Al-Mamory; Zhai Jianhong; Zhang Hongli

    2008-01-01

    Building attack scenario is one of the most important aspects in network security. This paper proposed a system which collects intrusion alerts, clusters them as sub-attacks using alerts abstraction, aggregates the similar sub-attacks, and then correlates and generates correlation graphs. The scenarios were represented by alert classes instead of alerts themselves so as to reduce the required rules and have the ability of detecting new variations of attacks. The proposed system is capable of passing some of the missed attacks. To evaluate system effectiveness, it was tested with different datasets which contain multi-step attacks. Compressed and easily understandable correlation graphs which reflect attack scenarios were generated. The proposed system can correlate related alerts, uncover the attack strategies, and detect new variations of attacks.

  2. Concept of Powerful Multistage Coaxial Cyclotron for Pulsed and Continuous Beam Production

    CERN Document Server

    Tumanyan, A R; Guiragossian, Z G T; Akopov, N Z

    1999-01-01

    The concept of large-radius multistage coaxial cyclotrons having separated orbits is described, to generate proton beams of 120-2000 MeV energy at tens of GW pulsed and hundreds of MW in continuous beam power operation. Accelerated beam losses must be less than 0.1 W/m for the intercepted average beam power linear density. The concept is inherently configured to actively compensate the longitudinal and transverse space charge expansion in beam bunches. These are based on (1) actively varying the bunch acceleration equilibrium phase while maintaining isochronism, independently for each cyclotron turns; (2) independently changing the acceleration voltage for each turn together with orbit corrections that preserve isochronism; (3) independently changing the transverse betatron oscillation tune shift, to assure non-resonant operation. Also, (4) sextupole lenses are included to compensate for chromaticity effects. Moreover, the concept is based on optimum uses of practical successful results so far achieved in bea...

  3. Model-based Utility Functions

    Science.gov (United States)

    Hibbard, Bill

    2012-05-01

    Orseau and Ring, as well as Dewey, have recently described problems, including self-delusion, with the behavior of agents using various definitions of utility functions. An agent's utility function is defined in terms of the agent's history of interactions with its environment. This paper argues, via two examples, that the behavior problems can be avoided by formulating the utility function in two steps: 1) inferring a model of the environment from interactions, and 2) computing utility as a function of the environment model. Basing a utility function on a model that the agent must learn implies that the utility function must initially be expressed in terms of specifications to be matched to structures in the learned model. These specifications constitute prior assumptions about the environment so this approach will not work with arbitrary environments. But the approach should work for agents designed by humans to act in the physical world. The paper also addresses the issue of self-modifying agents and shows that if provided with the possibility to modify their utility functions agents will not choose to do so, under some usual assumptions.

  4. Reverse engineering a social agent-based hidden markov model--visage.

    Science.gov (United States)

    Chen, Hung-Ching Justin; Goldberg, Mark; Magdon-Ismail, Malik; Wallace, William A

    2008-12-01

    We present a machine learning approach to discover the agent dynamics that drives the evolution of the social groups in a community. We set up the problem by introducing an agent-based hidden Markov model for the agent dynamics: an agent's actions are determined by micro-laws. Nonetheless, We learn the agent dynamics from the observed communications without knowing state transitions. Our approach is to identify the appropriate micro-laws corresponding to an identification of the appropriate parameters in the model. The model identification problem is then formulated as a mixed optimization problem. To solve the problem, we develop a multistage learning process for determining the group structure, the group evolution, and the micro-laws of a community based on the observed set of communications among actors, without knowing the semantic contents. Finally, to test the quality of our approximations and the feasibility of the approach, we present the results of extensive experiments on synthetic data as well as the results on real communities, such as Enron email and Movie newsgroups. Insight into agent dynamics helps us understand the driving forces behind social evolution. PMID:19145665

  5. On modelling planning under uncertainty in manufacturing

    OpenAIRE

    Alonso Ayuso, A.; Escudero, Laureano F.; Ortuño, M. T.

    2007-01-01

    We present a modelling framework for two-stage and multi-stage mixed 0−1 problems under uncertainty for strategic Supply Chain Management, tactical production planning and operations assignment and scheduling. A scenario tree based scheme is used to represent the uncertainty. We present the Deterministic Equivalent Model of the stochastic mixed 0−1 programs with complete recourse that we study. The constraints are modelled by compact and splitting variable representations via scenarios....

  6. Trace-Based Code Generation for Model-Based Testing

    OpenAIRE

    Kanstrén, T.; Piel, E.; Gross, H.-G.

    2009-01-01

    Paper Submitted for review at the Eighth International Conference on Generative Programming and Component Engineering. Model-based testing can be a powerful means to generate test cases for the system under test. However, creating a useful model for model-based testing requires expertise in the (formal) modeling language of the used tool and the general concept of modeling the system under test for effective test generation. A commonly used modeling notation is to describe the model through a...

  7. Simulation of Multi-component Multi-stage Separation Process--An Improved Algorithm and Application

    Institute of Scientific and Technical Information of China (English)

    李春山; 张香平; 张锁江; 谭心舜; 项曙光

    2006-01-01

    This paper presents a flexible model and a robust algorithm for simulation of multi-stage multi-component separation processes in which multiple feeds, side streams, strippers and/or side heat exchangers are involved. The improved algorithm effectively accelerates the speed of convergence and offers better stability by introducing a damping factor for updating the stripping factor, and also reduces the requirement on the initial estimates by updating the Joacobian matrix directly with the stripping factor and enthalpy. On the other hand, an efficient algorithm was proposed to solve the approximate tri-diagonal matrix (containing the off-band elements) derived from the material balance equations (Mequations)and phase equilibrium equations (E equations), the advantages and simplicity of the "inside-out" technique of the Russell are retained. The present algorithm was demonstrated to be effective in simulating complex separation columns with typical case studies.

  8. Numerical investigation of flow through vegetated multi-stage compound cha-nnel

    Institute of Scientific and Technical Information of China (English)

    王雯; 槐文信; 高猛

    2014-01-01

    This paper addresses the problem of the renormalization group k-e turbulence modeling of a vegetated multi-stage compound channel. Results from Micro acoustic Doppler velocimeter (ADV) tests are used with time and spatial averaging (double-averaging method) in the analysis of the flow field and the characterization. Comparisons of the mean velocity, the Reynolds stress, and the turbulent energy distribution show the validity of the computational method. The mean velocity profile sees an obvious de-celeration in the terraces because of vegetation. Secondary flow exists mainly at the junction of the main channel and the vegetation region on the first terrace. The bed shear stress in the main channel is much greater than that in the terraces. The difference of the bed shear stress between two terraces is insignificant, and the presence of vegetation can effectively reduce the bed shear stress.

  9. Solar Multi-stage Refrigeration Systems on the Basis of Absorber with the Internal Evaporative Cooling

    Directory of Open Access Journals (Sweden)

    Doroshenko A.V.

    2015-08-01

    Full Text Available In the article, the developed schematics are presented for the alternative refrigeration systems and air-conditioning systems, based on the use of absorbing cycle and solar energy for the regeneration of absorbent solution. Multi-stage principle of construction of drying and cool contours of solar systems is used with growth of concentration of absorbent on the stages of cooler. An absorber with internal evaporative cooling, allowing to remove the separate evaporated cooler, usually included after the absorber of the proper stage, is developed. Heat-mass-transfer apparatus of film-type, entering in the complement of drying and cool contours compatible and executed on the basis of multichannel compositions from polymeric materials. The preliminary comparative analysis of possibilities of the solar refrigeration systems and air-conditioning systems is executed.

  10. Application of Multistage Homotopy Perturbation Method to the Chaotic Genesio System

    Directory of Open Access Journals (Sweden)

    M. S. H. Chowdhury

    2012-01-01

    Full Text Available Finding accurate solution of chaotic system by using efficient existing numerical methods is very hard for its complex dynamical behaviors. In this paper, the multistage homotopy-perturbation method (MHPM is applied to the Chaotic Genesio system. The MHPM is a simple reliable modification based on an adaptation of the standard homotopy-perturbation method (HPM. The HPM is treated as an algorithm in a sequence of intervals for finding accurate approximate solutions to the Chaotic Genesio system. Numerical comparisons between the MHPM and the classical fourth-order Runge-Kutta (RK4 solutions are made. The results reveal that the new technique is a promising tool for the nonlinear chaotic systems of ordinary differential equations.

  11. A multistage, semi-automated procedure for analyzing the morphology of nanoparticles

    KAUST Repository

    Park, Chiwoo

    2012-07-01

    This article presents a multistage, semi-automated procedure that can expedite the morphology analysis of nanoparticles. Material scientists have long conjectured that the morphology of nanoparticles has a profound impact on the properties of the hosting material, but a bottleneck is the lack of a reliable and automated morphology analysis of the particles based on their image measurements. This article attempts to fill in this critical void. One particular challenge in nanomorphology analysis is how to analyze the overlapped nanoparticles, a problem not well addressed by the existing methods but effectively tackled by the method proposed in this article. This method entails multiple stages of operations, executed sequentially, and is considered semi-automated due to the inclusion of a semi-supervised clustering step. The proposed method is applied to several images of nanoparticles, producing the needed statistical characterization of their morphology. © 2012 "IIE".

  12. Multi-stage full waveform inversion strategy for 2D elastic VTI media

    KAUST Repository

    Oh, Ju-Won

    2015-08-19

    One of the most important issues in the multi-parametric full waveform inversion (FWI) is to find an optimal parameterization, which helps us recover the subsurface anisotropic parameters as well as seismic velocities, with minimal tradeoff. As a result, we analyze three different parameterizations for elastic VTI media in terms of the influence of the S-waves on the gradient direction for c13, the spatial coverage of gradient direction and the degree of trade-offs between the parameters. Based on the dependency results, we design a multi-stage elastic VTI FWI strategy to enhance both the spatial coverage of the FWI and the robustness to the trade-offs among the parameters as well as FWI for the c13 structure.

  13. Optimal design of multistage chemostats in series using different microbial growth kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Qasim, Muhammad [Petroleum Engineering Technology, Abu Dhabi Polytechnic (United Arab Emirates)

    2013-07-01

    In this paper, the optimum design of multistage chemostats (CSTRs) was investigated. The optimal design was based on the minimum overall reactor volume using different volume for each chemostat. The paper investigates three different microbial growth kinetics; Monod kinetics, Contois kinetics and the Logistic equation. The total dimensionless residence time (theta Total) was set as the optimization objective function that was minimized by varying the intermediate dimensionless substrate concentration (alfa i). The effect of inlet substrate concentration (S0) to the first reactor on the optimized total dimensionless residence time was investigated at a constant conversion of 0.90. In addition, the effect of conversion on the optimized total dimensionless residence time was also investigated at constant inlet substrate concentration (S0). For each case, optimization was done using up to five chemostats in series.

  14. Study on hydrodynamics and mass transfer of the critically safe multistage mixer-settler

    International Nuclear Information System (INIS)

    The study on structure of critically safe multistage mixer-settler for the extraction process of high enriched uranium and plutonium has been completed. The mixer-settler has simple structure, good critical safety, flexibility in operation (O/A from 0.5 to 5) and high extraction efficiency (Ex > 90%). These performances have been proved in the hydrodynamics and mass transfer experiments at a three stages cascade mixer-settler. Based on the others experience, a trapezoidal impeller combined with half-open turbine is developed which has stronger pumping and well mixing function at low rotating speed. The optimal rotating speed is 250 to 280 r/min obtained by experiments

  15. Business value modeling based on BPMN models

    OpenAIRE

    Masoumigoudarzi, Farahnaz

    2014-01-01

    In this study we will try to clarify the explanation of modeling and measuring 'Business Values', as it is defined in business context, in the business processes of a company and introduce different methods and select the one which is best for modeling the company's business values. These methods have been used by researchers in business analytics and senior managers of many companies. The focus in this project is business value detection and modeling. The basis of this research is on BPM...

  16. Multistage and multiobjective formulations of globally optimal upgradable expansions for electric power distribution systems

    Science.gov (United States)

    Vaziri Yazdi Pin, Mohammad

    Electric power distribution systems are the last high voltage link in the chain of production, transport, and delivery of the electric energy, the fundamental goals of which are to supply the users' demand safely, reliably, and economically. The number circuit miles traversed by distribution feeders in the form of visible overhead or imbedded underground lines, far exceed those of all other bulk transport circuitry in the transmission system. Development and expansion of the distribution systems, similar to other systems, is directly proportional to the growth in demand and requires careful planning. While growth of electric demand has recently slowed through efforts in the area of energy management, the need for a continued expansion seems inevitable for the near future. Distribution system and expansions are also independent of current issues facing both the suppliers and the consumers of electrical energy. For example, deregulation, as an attempt to promote competition by giving more choices to the consumers, while it will impact the suppliers' planning strategies, it cannot limit the demand growth or the system expansion in the global sense. Curiously, despite presence of technological advancements and a 40-year history of contributions in the area, many of the major utilities still relay on experience and resort to rudimentary techniques when planning expansions. A comprehensive literature review of the contributions and careful analyses of the proposed algorithms for distribution expansion, confirmed that the problem is a complex, multistage and multiobjective problem for which a practical solution remains to be developed. In this research, based on the 15-year experience of a utility engineer, the practical expansion problem has been clearly defined and the existing deficiencies in the previous work identified and analyzed. The expansion problem has been formulated as a multistage planning problem in line with a natural course of development and industry

  17. Optimal pricing decision model based on activity-based costing

    Institute of Scientific and Technical Information of China (English)

    王福胜; 常庆芳

    2003-01-01

    In order to find out the applicability of the optimal pricing decision model based on conventional costbehavior model after activity-based costing has given strong shock to the conventional cost behavior model andits assumptions, detailed analyses have been made using the activity-based cost behavior and cost-volume-profitanalysis model, and it is concluded from these analyses that the theory behind the construction of optimal pri-cing decision model is still tenable under activity-based costing, but the conventional optimal pricing decisionmodel must be modified as appropriate to the activity-based costing based cost behavior model and cost-volume-profit analysis model, and an optimal pricing decision model is really a product pricing decision model construc-ted by following the economic principle of maximizing profit.

  18. Sensor-based interior modeling

    International Nuclear Information System (INIS)

    Robots and remote systems will play crucial roles in future decontamination and decommissioning (D ampersand D) of nuclear facilities. Many of these facilities, such as uranium enrichment plants, weapons assembly plants, research and production reactors, and fuel recycling facilities, are dormant; there is also an increasing number of commercial reactors whose useful lifetime is nearly over. To reduce worker exposure to radiation, occupational and other hazards associated with D ampersand D tasks, robots will execute much of the work agenda. Traditional teleoperated systems rely on human understanding (based on information gathered by remote viewing cameras) of the work environment to safely control the remote equipment. However, removing the operator from the work site substantially reduces his efficiency and effectiveness. To approach the productivity of a human worker, tasks will be performed telerobotically, in which many aspects of task execution are delegated to robot controllers and other software. This paper describes a system that semi-automatically builds a virtual world for remote D ampersand D operations by constructing 3-D models of a robot's work environment. Planar and quadric surface representations of objects typically found in nuclear facilities are generated from laser rangefinder data with a minimum of human interaction. The surface representations are then incorporated into a task space model that can be viewed and analyzed by the operator, accessed by motion planning and robot safeguarding algorithms, and ultimately used by the operator to instruct the robot at a level much higher than teleoperation

  19. Memristor model based on fuzzy window function

    OpenAIRE

    Abdel-Kader, Rabab Farouk; Abuelenin, Sherif M.

    2016-01-01

    Memristor (memory-resistor) is the fourth passive circuit element. We introduce a memristor model based on a fuzzy logic window function. Fuzzy models are flexible, which enables the capture of the pinched hysteresis behavior of the memristor. The introduced fuzzy model avoids common problems associated with window-function based memristor models, such as the terminal state problem, and the symmetry issues. The model captures the memristor behavior with a simple rule-base which gives an insig...

  20. 'Bootstrap' Configuration for Multistage Pulse-Tube Coolers

    Science.gov (United States)

    Nguyen, Bich; Nguyen, Lauren

    2008-01-01

    A bootstrap configuration has been proposed for multistage pulse-tube coolers that, for instance, provide final-stage cooling to temperatures as low as 20 K. The bootstrap configuration supplants the conventional configuration, in which customarily the warm heat exchangers of all stages reject heat at ambient temperature. In the bootstrap configuration, the warm heat exchanger, the inertance tube, and the reservoir of each stage would be thermally anchored to the cold heat exchanger of the next warmer stage. The bootstrapped configuration is superior to the conventional setup, in some cases increasing the 20 K cooler's coefficient of performance two-fold over that of an otherwise equivalent conventional layout. The increased efficiency could translate into less power consumption, less cooler mass, and/or lower cost for a given amount of cooling.

  1. Multistage CSR microbunching gain development in transport or recirculation arcs

    CERN Document Server

    Tsai, Cheng-Ying; Li, Rui; Tennant, Chris

    2015-01-01

    Coherent synchrotron radiation (CSR) induced microbunching instability has been one of the most challenging issues in the design of modern accelerators. A linear Vlasov solver has been developed [1] and applied to investigate the physical processes of microbunching gain amplification for several example lattices [2]. In this paper, by further extending the concept of stage gain as proposed by Huang and Kim [3], we develop a method to characterize the microbunching development in terms of stage orders that allow the quantitative comparison of optics impacts on microbunching gain for different lattices. We find that the microbunching instability in our demonstrated arcs has a distinguishing feature of multistage amplification (e.g, up to 6th stage amplification for our example transport arcs, in contrast to two-stage amplification for a typical 4-dipole bunch compressor chicane). We also try to connect lattice optics pattern with the obtained stage gain functions by a physical interpretation. This Vlasov analys...

  2. A Challenge for Routing Algorithms in Optical Multistage Interconnection Networks

    Directory of Open Access Journals (Sweden)

    Mehrnaz Moudi

    2011-01-01

    Full Text Available Problem statement: A class of dynamic interconnection networks is Multistage Interconnection Networks (MINs that connects input devices to output devices through a number of switch stages. MINs have assumed importance in recent years; because of their cost-effectiveness. Optical MINs are one type of MINs that have large transmission capacity in the communication networks. There is a major problem in Optical MIN that is crosstalk, which is caused by coupling two signals within a switching element. Approach: To avoid crosstalk in Optical MINs many algorithms have been proposed by many researchers that we review applying five routing algorithms and scheduling them in the Optical MINs. Results: The comparative results of routing algorithms show affective of avoiding crosstalk in number of passes and execution time for different algorithm. Conclusion: The challenge between these routing algorithms is thoroughly investigated, by applying them on Optical MIN and showing which algorithm has better performance to avoid crosstalk.

  3. A Hybrid Structured Multistage Wiener Filter for GPS Interference Suppression

    Directory of Open Access Journals (Sweden)

    Qing-Dong Huang

    2013-11-01

    Full Text Available To suppress the influence of impulsive noise spikes (outliers from the direction of arrival of the desired GPS signals, a combination of the Householder multistage Wiener filter (HMSWF and the recently introduced Minimum Module Cascaded Canceller (MMCC is employed to compose a hybrid structured HMSWF (HS-HMSWF method. The enhanced algorithm is employed by space-time anti-jamming processing in GPS receiver, with the ability of natural protection against the impulsive noise spikes influence of weights calculation. In space signal processing, it can avoid the zero pitch formed at the direction of target signal, and prevent the desired signal be diminished. Simulation results demonstrated the favorable anti-jamming performance of the proposed algorithm.  

  4. Multistage Hybrid Arabic/Indian Numeral OCR System

    CERN Document Server

    Alginaih, Yasser M

    2010-01-01

    The use of OCR in postal services is not yet universal and there are still many countries that process mail sorting manually. Automated Arabic/Indian numeral Optical Character Recognition (OCR) systems for Postal services are being used in some countries, but still there are errors during the mail sorting process, thus causing a reduction in efficiency. The need to investigate fast and efficient recognition algorithms/systems is important so as to correctly read the postal codes from mail addresses and to eliminate any errors during the mail sorting stage. The objective of this study is to recognize printed numerical postal codes from mail addresses. The proposed system is a multistage hybrid system which consists of three different feature extraction methods, i.e., binary, zoning, and fuzzy features, and three different classifiers, i.e., Hamming Nets, Euclidean Distance, and Fuzzy Neural Network Classifiers. The proposed system, systematically compares the performance of each of these methods, and ensures t...

  5. Advanced multistage turbine blade aerodynamics, performance, cooling, and heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Fleeter, S.; Lawless, P.B. [Purdue Univ., West Lafayette, IN (United States)

    1995-10-01

    The gas turbine has the potential for power production at the highest possible efficiency. The challenge is to ensure that gas turbines operate at the optimum efficiency so as to use the least fuel and produce minimum emissions. A key component to meeting this challenge is the turbine. Turbine performance, both aerodynamics and heat transfer, is one of the barrier advanced gas turbine development technologies. This is a result of the complex, highly three-dimensional and unsteady flow phenomena in the turbine. Improved turbine aerodynamic performance has been achieved with three-dimensional highly-loaded airfoil designs, accomplished utilizing Euler or Navier-Stokes Computational Fluid Dynamics (CFD) codes. These design codes consider steady flow through isolated blade rows. Thus they do not account for unsteady flow effects. However, unsteady flow effects have a significant impact on performance. Also, CFD codes predict the complete flow field. The experimental verification of these codes has traditionally been accomplished with point data - not corresponding plane field measurements. Thus, although advanced CFD predictions of the highly complex and three-dimensional turbine flow fields are available, corresponding data are not. To improve the design capability for high temperature turbines, a detailed understanding of the highly unsteady and three-dimensional flow through multi-stage turbines is necessary. Thus, unique data are required which quantify the unsteady three-dimensional flow through multi-stage turbine blade rows, including the effect of the film coolant flow. This requires experiments in appropriate research facilities in which complete flow field data, not only point measurements, are obtained and analyzed. Also, as design CFD codes do not account for unsteady flow effects, the next logical challenge and the current thrust in CFD code development is multiple-stage analyses that account for the interactions between neighboring blade rows.

  6. Guide to APA-Based Models

    Science.gov (United States)

    Robins, Robert E.; Delisi, Donald P.

    2008-01-01

    In Robins and Delisi (2008), a linear decay model, a new IGE model by Sarpkaya (2006), and a series of APA-Based models were scored using data from three airports. This report is a guide to the APA-based models.

  7. CEAI: CCM based Email Authorship Identification Model

    DEFF Research Database (Denmark)

    Nizamani, Sarwat; Memon, Nasrullah

    2013-01-01

    reveal that the proposed CCM-based email authorship identification model, along with the proposed feature set, outperforms the state-of-the-art support vector machine (SVM)-based models, as well as the models proposed by Iqbal et al. [1, 2]. The proposed model attains an accuracy rate of 94% for 10...

  8. Multistage evolution of UHT granulites from the southernmost part of the Gföhl Nappe, Bohemian Massif, Lower Austria

    Science.gov (United States)

    Schantl, Philip; Hauzenberger, Christoph; Linner, Manfred

    2016-04-01

    A detailed petrological investigation has been undertaken in leucocratic kyanite-garnet bearing and mesocratic orthopyroxene bearing granulites from the Dunkelsteiner Wald, Pöchlarn-Wieselburg and Zöbing granulite bodies from the Moldanubian Zone in the Bohemian Massif (Austria). A combination of textural observations, conventional geothermobarometry, phase equilibrium modelling as well as major and trace element analyses in garnet enables us to confirm a multistage Variscan metamorphic history. Chemically homogenous garnet cores with near constant grossular-rich plateaus are considered to reflect garnet growth during an early HP/UHP metamorphic evolution. Crystallographically oriented rutile exsolutions restricted to those grossular-rich garnet cores point to a subsequent isothermal decompression of the HP/UHP rocks. Overgrowing garnet rims show a pronounced zonation and are interpreted as the result of dehydration melting reactions during an isobaric heating phase which could have taken place near the base of an overthickened continental crust, where the previously deeply subducted rocks were exhumed to. For this HP granulite facies event maximum PT conditions of ~1050 °C and 1.6 GPa have been estimated from leucocratic granulites comprising the peak mineral assemblage quartz, ternary feldspar, garnet, kyanite and rutile. The pronounced zoning of garnet rims indicates that the HP granulite facies event must have been short lived since diffusion in this temperature region is usually sufficient fast to homogenize a zoning pattern in garnet. A retrogressive metamorphic stage is documented in these rocks by the replacement of kyanite to sillimanite and the growth of biotite. This retrograde event took place within the granulite facies but at significantly lower pressures and temperatures with ~0.8 GPa and ~760 °C. This final stage of re-equilibration is thought to be linked with a second exhumation phase into middle crustal levels accompanied by intensive

  9. Identification and predictive control of a multistage evaporator

    NARCIS (Netherlands)

    Atuonwu, J.C.; Cao, Y.; Rangaiah, G.P.; Tadé, M.O.

    2010-01-01

    A recurrent neural network-based nonlinear model predictive control (NMPC) scheme in parallel with PI control loops is developed for a simulation model of an industrial-scale five-stage evaporator. Input–output data from system identification experiments are used in training the network using the Le

  10. Trace-Based Code Generation for Model-Based Testing

    NARCIS (Netherlands)

    Kanstrén, T.; Piel, E.; Gross, H.-G.

    2009-01-01

    Paper Submitted for review at the Eighth International Conference on Generative Programming and Component Engineering. Model-based testing can be a powerful means to generate test cases for the system under test. However, creating a useful model for model-based testing requires expertise in the (fo

  11. Use of cell proliferation data in modeling urinary bladder carcinogenesis.

    OpenAIRE

    Cohen, S M; Ellwein, L. B.

    1993-01-01

    A multistage, probabilistic, biologically based model of carcinogenesis has been developed involving qualitative and quantitative aspects of the process. A chemical can affect the risk of cancer by directly damaging DNA and/or increasing the number of cell divisions during which errors in DNA replication can occur. Based on this model, carcinogens are classified as genotoxic versus nongenotoxic; nongenotoxic chemicals are further divided on the basis of whether or not they act through a speci...

  12. Rule-based decision making model

    International Nuclear Information System (INIS)

    A rule-based decision making model is designed in G2 environment. A theoretical and methodological frame for the model is composed and motivated. The rule-based decision making model is based on object-oriented modelling, knowledge engineering and decision theory. The idea of safety objective tree is utilized. Advanced rule-based methodologies are applied. A general decision making model 'decision element' is constructed. The strategy planning of the decision element is based on e.g. value theory and utility theory. A hypothetical process model is built to give input data for the decision element. The basic principle of the object model in decision making is division in tasks. Probability models are used in characterizing component availabilities. Bayes' theorem is used to recalculate the probability figures when new information is got. The model includes simple learning features to save the solution path. A decision analytic interpretation is given to the decision making process. (author)

  13. Análisis de Modelos de Lechos Fuente en Multietapa, utilizando la Distribución del Tiempo de Residencia de los Sólidos Analysis of Models of Spouted Bed Multistage Systems using the Residence Time Distribution of the Solids

    OpenAIRE

    Enrique Arriola-Guevara; Guadalupe M Guatemala-Morales; Tania García-Herrera; Jorge A García-Fajardo

    2007-01-01

    Se presenta un análisis comparativo de modelos de flujo desarrollados para los sólidos de un sistema de lechos fuente en multietapa (multistage spouted bed) diseñado por Arriola (1997). Se seleccionaron modelos de distribución del tiempo de residencia de los sólidos adecuados para la aplicación comercial del sistema en el tratamiento de granos y semillas. La determinación experimental de la función de distribución del tiempo de residencia se llevó acabo mediante la técnica estímulo-respuesta ...

  14. Multi-stage and multi-orifice throttling analysis for thermal power generating sets

    Institute of Scientific and Technical Information of China (English)

    郭茂林; 王刚; 张瑞

    2002-01-01

    Multi-stage and multi-orifice throttling analysis for bypass valves in thermal power generating sets is important for normal operation of power generating equipment. It is improper to exclude the factor of flow resistance from the expansion coefficient for the flow formula used for analysing the multi-stage and multi-orifice flow of compressible fluid, which means expansion of gas has nothing to do with resistance. The authors put forward an expanded energy equation and related formula to overcome the drawback, and use them for multi-stage and multi-orifice throttling analysis of compressible fluid for thermal power generating sets.

  15. On Stability Problems of Omega and 3-Disjoint Paths Omega Multi-stage Interconnection Networks

    CERN Document Server

    Rastogi, Ravi; Chauhan, Durg Singh; Govil, Mahesh Chandra

    2012-01-01

    The research paper emphasizes that the Stable Matching problems are the same as the problems of stable configurations of Multi-stage Interconnection Networks (MIN). We have discusses the Stability Problems of Existing Regular Omega Multi-stage Interconnection Network (OMIN) and Proposed 3-Disjoint Paths Omega Multi-stage Interconnection Network (3DON) using the approaches and solutions provided by the Stable Matching Problem. Specifically, Stable Marriage Problem is used as an example of Stable Matching. On application of the concept of the Stable Marriage over the MINs states that OMIN is highly stable in comparison to 3DON.

  16. Electrical Compact Modeling of Graphene Base Transistors

    Directory of Open Access Journals (Sweden)

    Sébastien Frégonèse

    2015-11-01

    Full Text Available Following the recent development of the Graphene Base Transistor (GBT, a new electrical compact model for GBT devices is proposed. The transistor model includes the quantum capacitance model to obtain a self-consistent base potential. It also uses a versatile transfer current equation to be compatible with the different possible GBT configurations and it account for high injection conditions thanks to a transit time based charge model. Finally, the developed large signal model has been implemented in Verilog-A code and can be used for simulation in a standard circuit design environment such as Cadence or ADS. This model has been verified using advanced numerical simulation.

  17. EPR-based material modelling of soils

    Science.gov (United States)

    Faramarzi, Asaad; Alani, Amir M.

    2013-04-01

    In the past few decades, as a result of the rapid developments in computational software and hardware, alternative computer aided pattern recognition approaches have been introduced to modelling many engineering problems, including constitutive modelling of materials. The main idea behind pattern recognition systems is that they learn adaptively from experience and extract various discriminants, each appropriate for its purpose. In this work an approach is presented for developing material models for soils based on evolutionary polynomial regression (EPR). EPR is a recently developed hybrid data mining technique that searches for structured mathematical equations (representing the behaviour of a system) using genetic algorithm and the least squares method. Stress-strain data from triaxial tests are used to train and develop EPR-based material models for soil. The developed models are compared with some of the well-known conventional material models and it is shown that EPR-based models can provide a better prediction for the behaviour of soils. The main benefits of using EPR-based material models are that it provides a unified approach to constitutive modelling of all materials (i.e., all aspects of material behaviour can be implemented within a unified environment of an EPR model); it does not require any arbitrary choice of constitutive (mathematical) models. In EPR-based material models there are no material parameters to be identified. As the model is trained directly from experimental data therefore, EPR-based material models are the shortest route from experimental research (data) to numerical modelling. Another advantage of EPR-based constitutive model is that as more experimental data become available, the quality of the EPR prediction can be improved by learning from the additional data, and therefore, the EPR model can become more effective and robust. The developed EPR-based material models can be incorporated in finite element (FE) analysis.

  18. Model-based DSL frameworks

    NARCIS (Netherlands)

    Kurtev, I.; Bézivin, J.; Jouault, F.; Valduriez, P.

    2006-01-01

    More than five years ago, the OMG proposed the Model Driven Architecture (MDA™) approach to deal with the separation of platform dependent and independent aspects in information systems. Since then, the initial idea of MDA evolved and Model Driven Engineering (MDE) is being increasingly promoted to

  19. Dynamic multi-stage dispatch of isolated wind–diesel power systems

    International Nuclear Information System (INIS)

    Highlights: • Optimal decision-making model for isolated hybrid wind–diesel power system is proposed. • Wind power uncertainty and conditional operating cost are considered. • Battery wear cost of the energy storage system is included in the model. • The results are compared with deterministic dispatch strategies. - Abstract: An optimal dispatch strategy is crucial for an isolated wind–diesel power system to save diesel fuel and maintain the system stability. The uncertainty associated with the stochastic character of the wind is, though, a challenging problem for this optimization. In this paper, a dynamic multi-stage decision-making model is proposed to determine the diesel power output that minimizes the cost of running and maintaining the wind–diesel power system. Optimized operational decisions for each time period are generated dynamically considering the path-dependent nature of the optimal dispatch policy, given the plausible future realizations of the wind power production. A numerical case study is analyzed and it is demonstrated that the proposed stochastic dynamic optimization model significantly outperforms the traditional deterministic dispatch strategies

  20. A multistage mechanism for managing aggressive flows in the next generation internet

    OpenAIRE

    D. Lanzi

    2001-01-01

    In this note, we provide a multistage game form which may be used for managing aggressive flows which may cause network congestion or monopolisation. The mechanism here presented attains economic efficiency, technical efficiency and other desirable properties.

  1. 4 Kelvin Cooling with Innovative Final Stage of Multistage Cryocooler Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Proposed for development is a proof-of-concept prototype for the final stage of a multistage cryocooler. This final stage comprises a high frequency pulse tube cold...

  2. DYNAMIC RESPONSE OF METALS TO SINGLE AND MULTISTAGE, CONSTANT STRAIN RATE COMPRESSION

    OpenAIRE

    Lenard, J

    1985-01-01

    Single and multistage, uniaxial compression tests are conducted on Al-Mg-Si and 0.02% Nb HSLA steel alloys. Rate sensitivity, activation energy and the effect of interruption on the flow strength of the metals are determined.

  3. The Culture Based Model: Constructing a Model of Culture

    Science.gov (United States)

    Young, Patricia A.

    2008-01-01

    Recent trends reveal that models of culture aid in mapping the design and analysis of information and communication technologies. Therefore, models of culture are powerful tools to guide the building of instructional products and services. This research examines the construction of the culture based model (CBM), a model of culture that evolved…

  4. Finite mixture models and model-based clustering

    Directory of Open Access Journals (Sweden)

    Volodymyr Melnykov

    2010-01-01

    Full Text Available Finite mixture models have a long history in statistics, having been used to model population heterogeneity, generalize distributional assumptions, and lately, for providing a convenient yet formal framework for clustering and classification. This paper provides a detailed review into mixture models and model-based clustering. Recent trends as well as open problems in the area are also discussed.

  5. Probabilistic Model-Based Safety Analysis

    CERN Document Server

    Güdemann, Matthias; 10.4204/EPTCS.28.8

    2010-01-01

    Model-based safety analysis approaches aim at finding critical failure combinations by analysis of models of the whole system (i.e. software, hardware, failure modes and environment). The advantage of these methods compared to traditional approaches is that the analysis of the whole system gives more precise results. Only few model-based approaches have been applied to answer quantitative questions in safety analysis, often limited to analysis of specific failure propagation models, limited types of failure modes or without system dynamics and behavior, as direct quantitative analysis is uses large amounts of computing resources. New achievements in the domain of (probabilistic) model-checking now allow for overcoming this problem. This paper shows how functional models based on synchronous parallel semantics, which can be used for system design, implementation and qualitative safety analysis, can be directly re-used for (model-based) quantitative safety analysis. Accurate modeling of different types of proba...

  6. Can multi-stage production explain the home bias in trade?

    OpenAIRE

    Kei-Mu Yi

    2008-01-01

    A large empirical literature finds that there is too little international trade, and too much intra-national trade to be rationalized by observed international trade costs such as tariffs and transport costs. The literature uses frameworks in which goods are assumed to be produced in just one stage. This paper investigates whether the multi-stage nature of production helps explain the home bias in trade. The author shows that multi-stage production magnifies the effects of trade costs. He the...

  7. Throughput and Collision Analysis of Multi-Channel Multi-Stage Spectrum Sensing Algorithms

    OpenAIRE

    Gabran, Wesam; Pawełczak, Przemysław; Čabrić, Danijela

    2010-01-01

    Multi-stage sensing is a novel concept that refers to a general class of spectrum sensing algorithms that divide the sensing process into a number of sequential stages. The number of sensing stages and the sensing technique per stage can be used to optimize performance with respect to secondary user throughput and the collision probability between primary and secondary users. So far, the impact of multi-stage sensing on network throughput and collision probability for a realistic network mode...

  8. P-Graph-based Workflow Modelling

    OpenAIRE

    József Tick

    2007-01-01

    Workflow modelling has been successfully introduced and implemented in severalapplication fields. Therefore, its significance has increased dramatically. Several work flowmodelling techniques have been published so far, out of which quite a number arewidespread applications. For instance the Petri-Net-based modelling has become popularpartly due to its graphical design and partly due to its correct mathematical background.The workflow modelling based on Unified Modelling Language is important...

  9. Stochastic Modelling for Condition Based Maintenance

    OpenAIRE

    Han, Zehan

    2015-01-01

    This Master's thesis covers almost all aspects of Condition Based Maintenance (CBM). All objectives in Chapter 1 are met. The thesis is mainly comprised of three parts. First part introduces the world of CBM to readers. This part presents data acquisition, data processing and databases, which are the foundation to CBM. Then it highlights models which are divided into physics based models, data-driven models and hybrid models, for diagnostic and prognostic use. Three promising diagnostic and p...

  10. Base Flow Model Validation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is the systematic "building-block" validation of CFD/turbulence models employing a GUI driven CFD code (RPFM) and existing as well as new data sets...

  11. Firm Based Trade Models and Turkish Economy

    Directory of Open Access Journals (Sweden)

    Nilüfer ARGIN

    2015-12-01

    Full Text Available Among all international trade models, only The Firm Based Trade Models explains firm’s action and behavior in the world trade. The Firm Based Trade Models focuses on the trade behavior of individual firms that actually make intra industry trade. Firm Based Trade Models can explain globalization process truly. These approaches include multinational cooperation, supply chain and outsourcing also. Our paper aims to explain and analyze Turkish export with Firm Based Trade Models’ context. We use UNCTAD data on exports by SITC Rev 3 categorization to explain total export and 255 products and calculate intensive-extensive margins of Turkish firms.

  12. Distributed Prognostics Based on Structural Model Decomposition

    Data.gov (United States)

    National Aeronautics and Space Administration — Within systems health management, prognostics focuses on predicting the remaining useful life of a system. In the model-based prognostics paradigm, physics-based...

  13. Lévy-based growth models

    DEFF Research Database (Denmark)

    Jónsdóttir, Kristjana Ýr; Schmiegel, Jürgen; Jensen, Eva Bjørn Vedel

    2008-01-01

    In the present paper, we give a condensed review, for the nonspecialist reader, of a new modelling framework for spatio-temporal processes, based on Lévy theory. We show the potential of the approach in stochastic geometry and spatial statistics by studying Lévy-based growth modelling of planar...... objects. The growth models considered are spatio-temporal stochastic processes on the circle. As a by product, flexible new models for space–time covariance functions on the circle are provided. An application of the Lévy-based growth models to tumour growth is discussed....

  14. Traceability in Model-Based Testing

    Directory of Open Access Journals (Sweden)

    Mathew George

    2012-11-01

    Full Text Available The growing complexities of software and the demand for shorter time to market are two important challenges that face today’s IT industry. These challenges demand the increase of both productivity and quality of software. Model-based testing is a promising technique for meeting these challenges. Traceability modeling is a key issue and challenge in model-based testing. Relationships between the different models will help to navigate from one model to another, and trace back to the respective requirements and the design model when the test fails. In this paper, we present an approach for bridging the gaps between the different models in model-based testing. We propose relation definition markup language (RDML for defining the relationships between models.

  15. NDDP multi-stage flash desalination process simulator design

    International Nuclear Information System (INIS)

    A majority of large-scale desalination plants all over the world employ multi-stage flash (MSF) distillation process. Many of these MSF desalination plants have been set up near to nuclear power plants (generally called as nuclear desalination plants) to effectively utilize the low-grade steam from the power plants as the source of energy. A computer program called MSFSIM has been developed to simulate the MSF desalination plant operation both for steady state and various transients including start up. This code predicts the effect of number of stages, flashing temperature, velocity of brine flowing through the tubes of brine heater and evaporators, temperature of the condensing thin film etc. on the plant performance ratio. Such a code can be used for the design of a new plant and to predict its operating and startup characteristics. The code has been extensively validated with available start up data from the pilot MSF desalination plant of 425-m3/day capacity at Trombay, Mumbai. A MSF desalination plant of 4500-m3/day capacity is under construction by BARC at Kalpakkam, which will utilize the steam from Madras Atomic Power Station (MAPS). In this present work extensive parametric study of the 4500-m3/day capacity desalination plant at Kalpakkam has been done using the code MSFSIM for optimizing the operating parameters in order to maximize the performance ratio for stable plant operation. The aim of the work is prediction of plant performance under different operating conditions. (author)

  16. A cascaded three-phase symmetrical multistage voltage multiplier

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Shahid [Faculty of Engineering and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia); Singh, G K [Faculty of Engineering and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia); Besar, R [Faculty of Engineering and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia); Muhammad, G [Faculty of Information Science and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia)

    2006-10-15

    A cascaded three-phase symmetrical multistage Cockcroft-Walton voltage multiplier (CW-VM) is proposed in this report. It consists of three single-phase symmetrical voltage multipliers, which are connected in series at their smoothing columns like string of batteries and are driven by three-phase ac power source. The smoothing column of each voltage multiplier is charged twice every cycle independently by respective oscillating columns and discharged in series through load. The charging discharging process completes six times a cycle and therefore the output voltage ripple's frequency is of sixth order of the drive signal frequency. Thus the proposed approach eliminates the first five harmonic components of load generated voltage ripples and sixth harmonic is the major ripple component. The proposed cascaded three-phase symmetrical voltage multiplier has less than half the voltage ripple, and three times larger output voltage and output power than the conventional single-phase symmetrical CW-VM. Experimental and simulation results of the laboratory prototype are given to show the feasibility of proposed cascaded three-phase symmetrical CW-VM.

  17. Design procedure of capsule with multistage heater control (named MUSTAC)

    International Nuclear Information System (INIS)

    A capsule with electric heaters at multistage (named MUSTAC) is a type of capsule used in JMTR. The heaters are assembled in the capsule. Supply electric current to the heaters can be independently adjusted with a control systems that keeps irradiation specimens to constant temperature. The capsule being used, the irradiation specimen are inserted into specimen holders. Gas-gap size, between outer surface of specimen holders and inner surface of capsule casing, is calculated and determined to be flatten temperature of loaded specimens over the region. The rise or drop of specimen temperature in accordance with reactor power fluctuations is corrected within the target temperature of specimen by using the heaters filled into groove at specimen holder surface. The present report attempts to propose a reasonable design procedure of the capsules by means of compiling experience for designs, works and irradiation data of the capsules and to prepare for useful informations against onward capsule design. The key point of the capsule lies on thermal design. Now design thermal calculations are complicated in case of specimen holder with multihole. Resolving these issues, it is considered from new on that an emphasis have to placed on settling a thermal calculation device, for an example, a computer program on calculation specimen temperature. (author)

  18. A cascaded three-phase symmetrical multistage voltage multiplier

    International Nuclear Information System (INIS)

    A cascaded three-phase symmetrical multistage Cockcroft-Walton voltage multiplier (CW-VM) is proposed in this report. It consists of three single-phase symmetrical voltage multipliers, which are connected in series at their smoothing columns like string of batteries and are driven by three-phase ac power source. The smoothing column of each voltage multiplier is charged twice every cycle independently by respective oscillating columns and discharged in series through load. The charging discharging process completes six times a cycle and therefore the output voltage ripple's frequency is of sixth order of the drive signal frequency. Thus the proposed approach eliminates the first five harmonic components of load generated voltage ripples and sixth harmonic is the major ripple component. The proposed cascaded three-phase symmetrical voltage multiplier has less than half the voltage ripple, and three times larger output voltage and output power than the conventional single-phase symmetrical CW-VM. Experimental and simulation results of the laboratory prototype are given to show the feasibility of proposed cascaded three-phase symmetrical CW-VM

  19. Changes of Hematological Markers during a Multi-stage Ultra-marathon Competition in the Heat.

    Science.gov (United States)

    Rama, L M; Minuzzi, L G; Carvalho, H M; Costa, R J S; Teixeira, A M

    2016-02-01

    This study examined the changes in resting hematological variables in ultra-endurance runners throughout a multi-stage ultra-marathon competition, and compared athletes that completed all stages with those that failed to complete at least one stage within the cut-off time of competition. 19 ultra-endurance runners competing in a 230 km multi-stage ultra-marathon, conducted over 5 consecutive days in hot ambient conditions (32-40°C T(max)), volunteered to participate in the study. Each day, whole blood samples were collected prior to stage commencement and analyzed for full cell counts by Coulter counter. Linear increases were observed for leukocytes, monocytes and lymphocytes; with increases until Stage 3 and a decrease thereafter. Granulocytes showed a cubic growth exponent, indicating decrements to baseline after the significant increments until Stage 3. Hemoglobin and hematocrit showed linear decrements throughout the multi-stage ultra-marathon. No changes in erythrocytes and platelets were observed throughout the multi-stage ultra-marathon. Granulocytes, erythrocytes, hemoglobin and hematocrit changes along the multi-stage ultra-marathon differed in runners that completed all stages compared to those who failed to complete at least one stage within the cut-off time. Multi-stage ultra-marathon in the heat has a large impact on hematological responses of ultra-endurance runners associated with altered performance. PMID:26509375

  20. Model-based Utility Functions

    CERN Document Server

    Hibbard, Bill

    2011-01-01

    At the recent AGI-11 Conference Orseau and Ring, and Dewey, described problems, including self-delusion, with the behavior of AIXI agents using various definitions of utility functions. An agent's utility function is defined in terms of the agent's history of interactions with its environment. This paper argues that the behavior problems can be avoided by formulating the utility function in two steps: 1) inferring a model of the environment from interactions, and 2) computing utility as a function of the environment model. The paper also argues that agents will not choose to modify their utility functions.

  1. PCA-based lung motion model

    CERN Document Server

    Li, Ruijiang; Jia, Xun; Zhao, Tianyu; Lamb, James; Yang, Deshan; Low, Daniel A; Jiang, Steve B

    2010-01-01

    Organ motion induced by respiration may cause clinically significant targeting errors and greatly degrade the effectiveness of conformal radiotherapy. It is therefore crucial to be able to model respiratory motion accurately. A recently proposed lung motion model based on principal component analysis (PCA) has been shown to be promising on a few patients. However, there is still a need to understand the underlying reason why it works. In this paper, we present a much deeper and detailed analysis of the PCA-based lung motion model. We provide the theoretical justification of the effectiveness of PCA in modeling lung motion. We also prove that under certain conditions, the PCA motion model is equivalent to 5D motion model, which is based on physiology and anatomy of the lung. The modeling power of PCA model was tested on clinical data and the average 3D error was found to be below 1 mm.

  2. Power supply to the air-core transformer coils of a large tokamak by a multi-stage inductive energy storage system

    International Nuclear Information System (INIS)

    The multi-stage inductive energy storage circuits have been studied by a simplex method to obtain an optimum design of a power supply system for the air-core transformer coils of a large tokamak. Parameters of the electric circuits subject to various constraints were determined by the method. The multi-stage inductive energy storage system is better than the single-stage system in viewpoint of the energy necessary to build up the plasma current. Circuit analysis including the plasma was made for the two cases: (1) the plasma resistance given as a function of time, and (2) the plasma resistance determined from a zero-dimensional plasma model. The plasma self-inductance and its time variation play an important role during the build up of plasma current, and influence largely on the optimal circuit parameters. (auth.)

  3. An acoustical model based monitoring network

    NARCIS (Netherlands)

    Wessels, P.W.; Basten, T.G.H.; Eerden, F.J.M. van der

    2010-01-01

    In this paper the approach for an acoustical model based monitoring network is demonstrated. This network is capable of reconstructing a noise map, based on the combination of measured sound levels and an acoustic model of the area. By pre-calculating the sound attenuation within the network the noi

  4. Model Validation in Ontology Based Transformations

    Directory of Open Access Journals (Sweden)

    Jesús M. Almendros-Jiménez

    2012-10-01

    Full Text Available Model Driven Engineering (MDE is an emerging approach of software engineering. MDE emphasizes the construction of models from which the implementation should be derived by applying model transformations. The Ontology Definition Meta-model (ODM has been proposed as a profile for UML models of the Web Ontology Language (OWL. In this context, transformations of UML models can be mapped into ODM/OWL transformations. On the other hand, model validation is a crucial task in model transformation. Meta-modeling permits to give a syntactic structure to source and target models. However, semantic requirements have to be imposed on source and target models. A given transformation will be sound when source and target models fulfill the syntactic and semantic requirements. In this paper, we present an approach for model validation in ODM based transformations. Adopting a logic programming based transformational approach we will show how it is possible to transform and validate models. Properties to be validated range from structural and semantic requirements of models (pre and post conditions to properties of the transformation (invariants. The approach has been applied to a well-known example of model transformation: the Entity-Relationship (ER to Relational Model (RM transformation.

  5. Agent-based pedestrian modelling

    OpenAIRE

    Batty, Michael

    2003-01-01

    When the focus of interest in geographical systems is at the very fine scale, at the level of streets and buildings for example, movement becomes central to simulations of how spatial activities are used and develop. Recent advances in computing power and the acquisition of fine scale digital data now mean that we are able to attempt to understand and predict such phenomena with the focus in spatial modelling changing to dynamic simulations of the individual and collective beha...

  6. An Agent Based Classification Model

    OpenAIRE

    Gu, Feng; Aickelin, Uwe; Greensmith, Julie

    2009-01-01

    The major function of this model is to access the UCI Wisconsin Breast Can- cer data-set[1] and classify the data items into two categories, which are normal and anomalous. This kind of classifi cation can be referred as anomaly detection, which discriminates anomalous behaviour from normal behaviour in computer systems. One popular solution for anomaly detection is Artifi cial Immune Sys- tems (AIS). AIS are adaptive systems inspired by theoretical immunology and observed immune functions, p...

  7. Model Based Control of Solidification

    OpenAIRE

    Furenes, Beathe

    2009-01-01

    The objective of this thesis is to develop models for use in the control of a solidification process. Solidification is the phase change from liquid to solid, and takes place in many important processes ranging from production engineering to solid-state physics. Often during solidification, undesired e¤ects like e.g. variation of composition, microstructure, etc. occur. The solidification structure and its associated defects often persist throughout the subsequent operations, and thus good co...

  8. Integration of Simulink Models with Component-based Software Models

    DEFF Research Database (Denmark)

    Marian, Nicolae

    2008-01-01

    constructs and process flow, then software code is generated. A Simulink model is a representation of the design or implementation of a physical system that satisfies a set of requirements. A software component-based system aims to organize system architecture and behaviour as a means of computation...... constraints. COMDES (Component-based Design of Software for Distributed Embedded Systems) is such a component-based system framework developed by the software engineering group of Mads Clausen Institute for Product Innovation (MCI), University of Southern Denmark. Once specified, the software model has to be......Model based development aims to facilitate the development of embedded control systems by emphasizing the separation of the design level from the implementation level. Model based design involves the use of multiple models that represent different views of a system, having different semantics of...

  9. A Multiple Model Approach to Modeling Based on LPF Algorithm

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Input-output data fitting methods are often used for unknown-structure nonlinear system modeling. Based on model-on-demand tactics, a multiple model approach to modeling for nonlinear systems is presented. The basic idea is to find out, from vast historical system input-output data sets, some data sets matching with the current working point, then to develop a local model using Local Polynomial Fitting (LPF) algorithm. With the change of working points, multiple local models are built, which realize the exact modeling for the global system. By comparing to other methods, the simulation results show good performance for its simple, effective and reliable estimation.``

  10. Flat-topped and low loss silicon-nanowire-type optical MUX/DeMUX employing multi-stage microring resonator assisted delayed Mach-Zehnder interferometers.

    Science.gov (United States)

    Jeong, Seok-Hwan; Tanaka, Shinsuke; Akiyama, Tomoyuki; Sekiguchi, Shigeaki; Tanaka, Yu; Morito, Ken

    2012-11-01

    We propose a novel silicon-nanowire-type multiplexer (MUX) / demultiplexer (DeMUX) based on multi-stage microring resonator assisted delayed Mach-Zehnder interferometers. It is theoretically shown that spectral flatness of DeMUX spectra can be accomplished by incorporating nonlinear phase behaviors of microring resonators into the multi-stage delayed Mach-Zehnder interferometers. We experimentally demonstrate flat-topped 400GHz-spacing 1 × 4Ch demultiplexing operation in the fabricated device with silicon-nanowire waveguides. Furthermore, by integrating the micro-heaters on the top cladding layer of the fabricated device, the DeMUX performance is upgraded in terms of excess loss (flatness at each channel grid. PMID:23187415

  11. General theory of the multistage geminate reactions of the isolated pairs of reactants. II. Detailed balance and universal asymptotes of kinetics

    International Nuclear Information System (INIS)

    The analysis of general (matrix) kinetic equations for the mean survival probabilities of any of the species in a sample (or mean concentrations) has been made for a wide class of the multistage geminate reactions of the isolated pairs. These kinetic equations (obtained in the frame of the kinetic approach based on the concept of “effective” particles in Paper I) take into account various possible elementary reactions (stages of a multistage reaction) excluding monomolecular, but including physical and chemical processes of the change in internal quantum states carried out with the isolated pairs of reactants (or isolated reactants). The general basic principles of total and detailed balance have been established. The behavior of the reacting system has been considered on macroscopic time scales, and the universal long-term kinetics has been determined

  12. Model-based internal wave processing

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J.V.; Chambers, D.H.

    1995-06-09

    A model-based approach is proposed to solve the oceanic internal wave signal processing problem that is based on state-space representations of the normal-mode vertical velocity and plane wave horizontal velocity propagation models. It is shown that these representations can be utilized to spatially propagate the modal (dept) vertical velocity functions given the basic parameters (wave numbers, Brunt-Vaisala frequency profile etc.) developed from the solution of the associated boundary value problem as well as the horizontal velocity components. Based on this framework, investigations are made of model-based solutions to the signal enhancement problem for internal waves.

  13. Tools for model-based security engineering: models vs. code

    OpenAIRE

    Jürjens, Jan; Yu, Yijun

    2007-01-01

    We present tools to support model-based security engineering on both the model and the code level. In the approach supported by these tools, one firstly specifies the security-critical part of the system (e.g. a crypto protocol) using the UML security extension UMLsec. The models are automatically verified for security properties using automated theorem provers. These are implemented within a framework that supports implementing verification routines, based on XMI output of the diagrams from ...

  14. Modelling a Peroxidase-based Optical Biosensor

    OpenAIRE

    Juozas Kulys; Evelina Gaidamauskait˙e; Romas Baronas

    2007-01-01

    The response of a peroxidase-based optical biosensor was modelled digitally. A mathematical model of the optical biosensor is based on a system of non-linear reaction-diffusion equations. The modelling biosensor comprises two compartments, an enzyme layer and an outer diffusion layer. The digital simulation was carried out using finite difference technique. The influence of the substrate concentration as well as of the thickness of both the enzyme and diffusion layers on the biosensor respons...

  15. Navigation based on symbolic space models

    OpenAIRE

    Baras, Karolina; Moreira, Adriano; Meneses, Filipe

    2010-01-01

    Existing navigation systems are very appropriate for car navigation, but lack support for convenient pedestrian navigation and cannot be used indoors due to GPS limitations. In addition, the creation and the maintenance of the required models are costly and time consuming, and are usually based on proprietary data structures. In this paper we describe a navigation system based on a human inspired symbolic space model. We argue that symbolic space models are much easier...

  16. P-Graph-based Workflow Modelling

    Directory of Open Access Journals (Sweden)

    József Tick

    2007-03-01

    Full Text Available Workflow modelling has been successfully introduced and implemented in severalapplication fields. Therefore, its significance has increased dramatically. Several work flowmodelling techniques have been published so far, out of which quite a number arewidespread applications. For instance the Petri-Net-based modelling has become popularpartly due to its graphical design and partly due to its correct mathematical background.The workflow modelling based on Unified Modelling Language is important because of itspractical usage. This paper introduces and examines the workflow modelling techniquebased on the Process-graph as a possible new solution next to the already existingmodelling techniques.

  17. Multistage virtual screening and identification of novel HIV-1 protease inhibitors by integrating SVM, shape, pharmacophore and docking methods.

    Science.gov (United States)

    Wei, Yu; Li, Jinlong; Chen, Zeming; Wang, Fengwei; Huang, Weiqiang; Hong, Zhangyong; Lin, Jianping

    2015-08-28

    The HIV-1 protease has proven to be a crucial component of the HIV replication machinery and a reliable target for anti-HIV drug discovery. In this study, we applied an optimized hierarchical multistage virtual screening method targeting HIV-1 protease. The method sequentially applied SVM (Support Vector Machine), shape similarity, pharmacophore modeling and molecular docking. Using a validation set (270 positives, 155,996 negatives), the multistage virtual screening method showed a high hit rate and high enrichment factor of 80.47% and 465.75, respectively. Furthermore, this approach was applied to screen the National Cancer Institute database (NCI), which contains 260,000 molecules. From the final hit list, 6 molecules were selected for further testing in an in vitro HIV-1 protease inhibitory assay, and 2 molecules (NSC111887 and NSC121217) showed inhibitory potency against HIV-1 protease, with IC50 values of 62 μM and 162 μM, respectively. With further chemical development, these 2 molecules could potentially serve as HIV-1 protease inhibitors. PMID:26185005

  18. IP Network Management Model Based on NGOSS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jin-yu; LI Hong-hui; LIU Feng

    2004-01-01

    This paper addresses a management model for IP network based on Next Generation Operation Support System (NGOSS). It makes the network management on the base of all the operation actions of ISP, It provides QoS to user service through the whole path by providing end-to-end Service Level Agreements (SLA) management through whole path. Based on web and coordination technology, this paper gives an implement architecture of this model.

  19. Gradient-based model calibration with proxy-model assistance

    Science.gov (United States)

    Burrows, Wesley; Doherty, John

    2016-02-01

    Use of a proxy model in gradient-based calibration and uncertainty analysis of a complex groundwater model with large run times and problematic numerical behaviour is described. The methodology is general, and can be used with models of all types. The proxy model is based on a series of analytical functions that link all model outputs used in the calibration process to all parameters requiring estimation. In enforcing history-matching constraints during the calibration and post-calibration uncertainty analysis processes, the proxy model is run for the purposes of populating the Jacobian matrix, while the original model is run when testing parameter upgrades; the latter process is readily parallelized. Use of a proxy model in this fashion dramatically reduces the computational burden of complex model calibration and uncertainty analysis. At the same time, the effect of model numerical misbehaviour on calculation of local gradients is mitigated, this allowing access to the benefits of gradient-based analysis where lack of integrity in finite-difference derivatives calculation would otherwise have impeded such access. Construction of a proxy model, and its subsequent use in calibration of a complex model, and in analysing the uncertainties of predictions made by that model, is implemented in the PEST suite.

  20. Performance assessment and microbial diversity of two pilot scale multi-stage sub-surface flow constructed wetland systems.

    Science.gov (United States)

    Babatunde, A O; Miranda-CasoLuengo, Raul; Imtiaz, Mehreen; Zhao, Y Q; Meijer, Wim G

    2016-08-01

    This study assessed the performance and diversity of microbial communities in multi-stage sub-surface flow constructed wetland systems (CWs). Our aim was to assess the impact of configuration on treatment performance and microbial diversity in the systems. Results indicate that at loading rates up to 100gBOD5/(m(2)·day), similar treatment performances can be achieved using either a 3 or 4 stage configuration. In the case of phosphorus (P), the impact of configuration was less obvious and a minimum of 80% P removal can be expected for loadings up to 10gP/(m(2)·day) based on the performance results obtained within the first 16months of operation. Microbial analysis showed an increased bacterial diversity in stage four compared to the first stage. These results indicate that the design and configuration of multi-stage constructed wetland systems may have an impact on the treatment performance and the composition of the microbial community in the systems, and such knowledge can be used to improve their design and performance. PMID:27521934

  1. Multi-stage identification scheme for detecting damage in structures under ambient excitations

    Science.gov (United States)

    Bao, Chunxiao; Hao, Hong; Li, Zhong-Xian

    2013-04-01

    Structural damage identification methods are critical to the successful application of structural health monitoring (SHM) systems to civil engineering structures. The dynamic response of civil engineering structures is usually characterized by high nonlinearity and non-stationarity. Accordingly, an improved Hilbert-Huang transform (HHT) method which is adaptive, output-only and applicable to system identification of in-service structures under ambient excitations is developed in this study. Based on this method, a multi-stage damage detection scheme including the detection of damage occurrence, damage existence, damage location and the estimation of damage severity is developed. In this scheme, the improved HHT method is used to analyse the structural acceleration response, the obtained instantaneous frequency detects the instant of damage occurrence, the instantaneous phase is sensitive to minor damage and provides reliable damage indication, and the damage indicator developed based on statistical analysis of the Hilbert marginal spectrum detects damage locations. Finally, the response sampled at the detected damage location is continuously analysed to estimate the damage severity. Numerical and experimental studies of frame structures under ambient excitations are performed. The results demonstrate that this scheme accomplishes the above damage detection functions within one flow. It is robust, time efficient, simply implemented and applicable to the real-time SHM of in-service structures.

  2. Multi-stage identification scheme for detecting damage in structures under ambient excitations

    International Nuclear Information System (INIS)

    Structural damage identification methods are critical to the successful application of structural health monitoring (SHM) systems to civil engineering structures. The dynamic response of civil engineering structures is usually characterized by high nonlinearity and non-stationarity. Accordingly, an improved Hilbert–Huang transform (HHT) method which is adaptive, output-only and applicable to system identification of in-service structures under ambient excitations is developed in this study. Based on this method, a multi-stage damage detection scheme including the detection of damage occurrence, damage existence, damage location and the estimation of damage severity is developed. In this scheme, the improved HHT method is used to analyse the structural acceleration response, the obtained instantaneous frequency detects the instant of damage occurrence, the instantaneous phase is sensitive to minor damage and provides reliable damage indication, and the damage indicator developed based on statistical analysis of the Hilbert marginal spectrum detects damage locations. Finally, the response sampled at the detected damage location is continuously analysed to estimate the damage severity. Numerical and experimental studies of frame structures under ambient excitations are performed. The results demonstrate that this scheme accomplishes the above damage detection functions within one flow. It is robust, time efficient, simply implemented and applicable to the real-time SHM of in-service structures. (paper)

  3. Multistage Reactive Transmission-Mode Desorption Electrospray Ionization Mass Spectrometry.

    Science.gov (United States)

    Peters, Kevin C; Comi, Troy J; Perry, Richard H

    2015-09-01

    Elucidating reaction mechanisms is important for advancing many areas of science such as catalyst development. It is often difficult to probe fast reactions at ambient conditions with high temporal resolution. In addition, systems involving reagents that cross-react require analytical methods that can minimize interaction time and specify their order of introduction into the reacting system. Here, we explore the utility of transmission mode desorption electrospray ionization (TM-DESI) for reaction monitoring by directing a microdroplet spray towards a series of meshes with micrometer-sized openings coated with reagents, an approach we call multistage reactive TM-DESI (TM (n) -DESI, where n refers to the number of meshes; n = 2 in this report). Various stages of the reaction are initiated at each mesh surface, generating intermediates and products in microdroplet reaction vessels traveling towards the mass spectrometer. Using this method, we investigated the reactivity of iron porphyrin catalytic hydroxylation of propranolol and other substrates. Our experimental results indicate that TM (n) -DESI provides the ability to spatially separate reagents and control their order of introduction into the reacting system, thereby minimizing unwanted reactions that lead to catalyst deactivation and degradation products. In addition, comparison with DESI-MS analyses (the Zare and Latour laboratories published results suggesting accessible reaction times <1 ms) of the reduction of dichlorophenolindophenol by L-ascorbic acid suggest that TM (1) -DESI can access reaction times less than 1 ms. Multiple meshes allow sequential stages of desorption/ionization per MS scan, increasing the number of analytes and reactions that can be characterized in a single experiment. PMID:26091888

  4. Multistage Reactive Transmission-Mode Desorption Electrospray Ionization Mass Spectrometry

    Science.gov (United States)

    Peters, Kevin C.; Comi, Troy J.; Perry, Richard H.

    2015-09-01

    Elucidating reaction mechanisms is important for advancing many areas of science such as catalyst development. It is often difficult to probe fast reactions at ambient conditions with high temporal resolution. In addition, systems involving reagents that cross-react require analytical methods that can minimize interaction time and specify their order of introduction into the reacting system. Here, we explore the utility of transmission mode desorption electrospray ionization (TM-DESI) for reaction monitoring by directing a microdroplet spray towards a series of meshes with micrometer-sized openings coated with reagents, an approach we call multistage reactive TM-DESI (TM n -DESI, where n refers to the number of meshes; n = 2 in this report). Various stages of the reaction are initiated at each mesh surface, generating intermediates and products in microdroplet reaction vessels traveling towards the mass spectrometer. Using this method, we investigated the reactivity of iron porphyrin catalytic hydroxylation of propranolol and other substrates. Our experimental results indicate that TM n -DESI provides the ability to spatially separate reagents and control their order of introduction into the reacting system, thereby minimizing unwanted reactions that lead to catalyst deactivation and degradation products. In addition, comparison with DESI-MS analyses (the Zare and Latour laboratories published results suggesting accessible reaction times <1 ms) of the reduction of dichlorophenolindophenol by L-ascorbic acid suggest that TM 1 -DESI can access reaction times less than 1 ms. Multiple meshes allow sequential stages of desorption/ionization per MS scan, increasing the number of analytes and reactions that can be characterized in a single experiment.

  5. MS3 eliminates ratio distortion in isobaric labeling-based multiplexed quantitative proteomics

    OpenAIRE

    Ting, Lily; Rad, Ramin; Gygi, Steven P.; Haas, Wilhelm

    2011-01-01

    Quantitative mass spectrometry-based proteomics is highly versatile, but not easily multiplexed. Isobaric labeling strategies allow mass spectrometry-based multiplexed proteome quantification; however, ratio distortion due to protein quantification interference is a common effect. We present a multi-proteome model (mixture of human and yeast proteins) in a 6-plex isobaric labeling system to fully document the interference effect, and we report that a multistage MS3-based approach almost compl...

  6. Model-based Abstraction of Data Provenance

    DEFF Research Database (Denmark)

    Probst, Christian W.; Hansen, René Rydhof

    2014-01-01

    to bigger models, and the analyses adapt accordingly. Our approach extends provenance both with the origin of data, the actors and processes involved in the handling of data, and policies applied while doing so. The model and corresponding analyses are based on a formal model of spatial and organisational......Identifying provenance of data provides insights to the origin of data and intermediate results, and has recently gained increased interest due to data-centric applications. In this work we extend a data-centric system view with actors handling the data and policies restricting actions....... This extension is based on provenance analysis performed on system models. System models have been introduced to model and analyse spatial and organisational aspects of organisations, to identify, e.g., potential insider threats. Both the models and analyses are naturally modular; models can be combined...

  7. Agent-based modeling and network dynamics

    CERN Document Server

    Namatame, Akira

    2016-01-01

    The book integrates agent-based modeling and network science. It is divided into three parts, namely, foundations, primary dynamics on and of social networks, and applications. The book begins with the network origin of agent-based models, known as cellular automata, and introduce a number of classic models, such as Schelling’s segregation model and Axelrod’s spatial game. The essence of the foundation part is the network-based agent-based models in which agents follow network-based decision rules. Under the influence of the substantial progress in network science in late 1990s, these models have been extended from using lattices into using small-world networks, scale-free networks, etc. The book also shows that the modern network science mainly driven by game-theorists and sociophysicists has inspired agent-based social scientists to develop alternative formation algorithms, known as agent-based social networks. The book reviews a number of pioneering and representative models in this family. Upon the gi...

  8. Optimal synthesis of liquid-liquid multistage extractors

    OpenAIRE

    Reyes Labarta, Juan Antonio; Grossmann, Ignacio E.

    2001-01-01

    The purpose of this paper is to determine the optimal design of liquid-liquid countercurrent extractor systems. The proposed method calculates the optimum number of equilibrium stages and flowrates to obtain a specified product separation and recovery. Based on a superstructure representation, the problem is formulated as a Generalized Disjunctive Programming (GDP) model to minimize the total cost of the process subject to design specifications. The robustness and computational efficiency of ...

  9. Development of a GHG-mitigation oriented inexact dynamic model for regional energy system management

    International Nuclear Information System (INIS)

    Multiple dynamics and uncertainties are involved in regional energy and greenhouse gas management (REGM) system, confronting decision makers during plan/policy makings. In this study, a greenhouse gas (GHG)-mitigation oriented inexact dynamic energy system management model (IFMP-REGM) is developed for a REGM system. The IFMP-REGM is a hybrid methodology of interval mathematical programming, fuzzy linear programming and multi-stage stochastic programming. It can not only handle uncertainties presented as discrete intervals, fuzzy sets and probability distributions, but also reflect dynamic variations of system conditions, particularly for large-scale multistage problems with sequential structures. The uncertain information can be incorporated within a multi-layer scenario tree; revised decisions are permitted in each time period based on the realized values of the uncertain events. The developed IFMP-REGM model was then applied to a hypothetical regional energy and GHG management system. The results indicate that the IFMP-REGM can effectively address complexities of various system uncertainties as well as dealing with multi-stage stochastic decision problems within energy systems. -- Highlights: → An energy system model is developed for regional energy and GHG-emission management. → Interactions among energy supply, processing, demand, and GHG emission are addressed. → GHG-emission trading is incorporated within the management scheme. → Interval, fuzzy, multi-stage methods are integrated to reflect various uncertainties. → Case study demonstrates its applicability in reflecting system complexities.

  10. Performance Improvement of a Return Channel in a Multistage Centrifugal Compressor Using Multiobjective Optimization.

    Science.gov (United States)

    Nishida, Yoshifumi; Kobayashi, Hiromi; Nishida, Hideo; Sugimura, Kazuyuki

    2013-05-01

    The effect of the design parameters of a return channel on the performance of a multistage centrifugal compressor was numerically investigated, and the shape of the return channel was optimized using a multiobjective optimization method based on a genetic algorithm to improve the performance of the centrifugal compressor. The results of sensitivity analysis using Latin hypercube sampling suggested that the inlet-to-outlet area ratio of the return vane affected the total pressure loss in the return channel, and that the inlet-to-outlet radius ratio of the return vane affected the outlet flow angle from the return vane. Moreover, this analysis suggested that the number of return vanes affected both the loss and the flow angle at the outlet. As a result of optimization, the number of return vane was increased from 14 to 22 and the area ratio was decreased from 0.71 to 0.66. The radius ratio was also decreased from 2.1 to 2.0. Performance tests on a centrifugal compressor with two return channels (the original design and optimized design) were carried out using two-stage test apparatus. The measured flow distribution exhibited a swirl flow in the center region and a reversed swirl flow near the hub and shroud sides. The exit flow of the optimized design was more uniform than that of the original design. For the optimized design, the overall two-stage efficiency and pressure coefficient were increased by 0.7% and 1.5%, respectively. Moreover, the second-stage efficiency and pressure coefficient were respectively increased by 1.0% and 3.2%. It is considered that the increase in the second-stage efficiency was caused by the increased uniformity of the flow, and the rise in the pressure coefficient was caused by a decrease in the residual swirl flow. It was thus concluded from the numerical and experimental results that the optimized return channel improved the performance of the multistage centrifugal compressor. PMID:24891759

  11. Research and Development for Multi-stage and Integrated Approach for Seafloor Massive Sulfides (SMSs) Exploration.

    Science.gov (United States)

    Asakawa, Eiichi; Sumi, Tomonori; Kadoshima, Kazuyuki; Kose, Masami; Lee, Sangkyun; Murakami, Fumitoshi; Tsukahara, Hitoshi; Koizumi, Akira; Koizumi, Yukiko; Ikeda, Makoto; Higashi, Michio

    2016-04-01

    The Cabinet Office, Government Japan started the Cross-ministerial Strategic Innovation Promotion Program (SIP) in 2014. "Next-generation Ocean Resource Exploration Techniques" is scheduled under SIP from 2014 to 2018. J-MARES (Research and Development Partnership for Next Generation Technology of Marine Resources Survey) participates this program and aims "Multi-stage and integrated approach for SMSs exploration" through the development of highly efficient and cost-effective geophysical exploration methods mainly on seismic and electric-magnetic methods, and combination of the known exploration tools and systems. J-MARES proposed Vertical Cable Seismic (VCS) technique as seismic survey. It is one of reflection seismic methods that uses hydrophone arrays vertically moored from the seafloor. It is useful to delineate detailed structures in a spatially-limited area efficiently. JGI, a member of J-MARES, has developed autonomous VCS systems and carried out several VCS surveys in hydrothermal fields in Okinawa Trough. By the VCS survey, the detailed subsurface structure is revealed and velocity is estimated up to 100m. Then we could recognize the buried sulfide deposit beneath the sediments. As for EM survey, the system has been originally developed by Waseda University. The system is towed closely to seafloor using ROV. It is one of Time Domain EM (TDEM) survey systems that consists of a loop coil and a 3 component high-sensitive magnetometer. By analyzing the decay curve of the transient magnetic field induced by the loop coil, the subsurface resistivity structure is estimated. The exploration depth depends on the measurement time and it is designed up to 100m enough for SMS exploration. We carried out the EM surveys around the north mound along VCS survey lines in Izena Hole, Okinawa-trough. The EM survey detects the highly conductive zone around the north mound. The efficiency is 3 times faster than the conventional TDEM measurement on the ocean bottom. Based on

  12. Model-Based Clustering of Large Networks

    CERN Document Server

    Vu, Duy Quang; Schweinberger, Michael

    2012-01-01

    We describe a network clustering framework, based on finite mixture models, that can be applied to discrete-valued networks with hundreds of thousands of nodes and billions of edge variables. Relative to other recent model-based clustering work for networks, we introduce a more flexible modeling framework, improve the variational-approximation estimation algorithm, discuss and implement standard error estimation via a parametric bootstrap approach, and apply these methods to much larger datasets than those seen elsewhere in the literature. The more flexible modeling framework is achieved through introducing novel parameterizations of the model, giving varying degrees of parsimony, using exponential family models whose structure may be exploited in various theoretical and algorithmic ways. The algorithms, which we show how to adapt to the more complicated optimization requirements introduced by the constraints imposed by the novel parameterizations we propose, are based on variational generalized EM algorithms...

  13. Simulation-based Manufacturing System Modeling

    Institute of Scientific and Technical Information of China (English)

    卫东; 金烨; 范秀敏; 严隽琪

    2003-01-01

    In recent years, computer simulation appears to be very advantageous technique for researching the resource-constrained manufacturing system. This paper presents an object-oriented simulation modeling method, which combines the merits of traditional methods such as IDEF0 and Petri Net. In this paper, a four-layer-one-angel hierarchical modeling framework based on OOP is defined. And the modeling description of these layers is expounded, such as: hybrid production control modeling and human resource dispatch modeling. To validate the modeling method, a case study of an auto-product line in a motor manufacturing company has been carried out.

  14. Energy based prediction models for building acoustics

    DEFF Research Database (Denmark)

    Brunskog, Jonas

    2012-01-01

    In order to reach robust and simplified yet accurate prediction models, energy based principle are commonly used in many fields of acoustics, especially in building acoustics. This includes simple energy flow models, the framework of statistical energy analysis (SEA) as well as more elaborated...... principles as, e.g., wave intensity analysis (WIA). The European standards for building acoustic predictions, the EN 12354 series, are based on energy flow and SEA principles. In the present paper, different energy based prediction models are discussed and critically reviewed. Special attention is placed on...

  15. Model-based reasoning and large-knowledge bases

    International Nuclear Information System (INIS)

    In such engineering fields as nuclear power plant engineering, technical information expressed in the form of schematics is frequently used. A new paradigm for model-based reasoning (MBR) and an AI tool called PLEXSYS (plant expert system) using this paradigm has been developed. PLEXSYS and the underlying paradigm are specifically designed to handle schematic drawings, by expressing drawings as models and supporting various sophisticated searches on these models. Two application systems have been constructed with PLEXSYS: one generates PLEXSYS models from existing CAD data files, and the other provides functions for nuclear power plant design support. Since the models can be generated from existing data resources, the design support system automatically has full access to a large-scale model or knowledge base representing actual nuclear power plants. (author)

  16. Cu deficiency in multi-stage co-evaporated Cu(In,Ga)Se2 for solar cells applications: Microstructure and Ga in-depth alloying

    International Nuclear Information System (INIS)

    The objective of this work is to study the influence of the maximum Cu content during the deposition of Cu(In,Ga)Se2 (CIGSe) by multi-stage co-evaporation on the phases present in the final film, the film structure and the electrical properties of resulting solar cell devices. The variation of the composition is controlled by the Cu content in stage 2 of the deposition process. The different phases are identified by Raman spectroscopy. The in-depth Ga gradient distribution is investigated by in-depth resolved Raman scattering and secondary neutral mass spectroscopy. The morphology of the devices is studied by scanning electron microscopy. Efficiencies of 9.2% are obtained for ordered-vacancy-compound-based cells with a Cu/(In + Ga) ratio = 0.35, showing the system's flexibility. This work supports the current growth model: a small amount of Cu excess during the absorber process is required to obtain a quality microstructure and high performance devices.

  17. Ground-Based Telescope Parametric Cost Model

    Science.gov (United States)

    Stahl, H. Philip; Rowell, Ginger Holmes

    2004-01-01

    A parametric cost model for ground-based telescopes is developed using multi-variable statistical analysis, The model includes both engineering and performance parameters. While diameter continues to be the dominant cost driver, other significant factors include primary mirror radius of curvature and diffraction limited wavelength. The model includes an explicit factor for primary mirror segmentation and/or duplication (i.e.. multi-telescope phased-array systems). Additionally, single variable models based on aperture diameter are derived. This analysis indicates that recent mirror technology advances have indeed reduced the historical telescope cost curve.

  18. Comparing a single-stage geocoding method to a multi-stage geocoding method: how much and where do they disagree?

    Directory of Open Access Journals (Sweden)

    Rice Kenneth

    2007-03-01

    Full Text Available Abstract Background Geocoding methods vary among spatial epidemiology studies. Errors in the geocoding process and differential match rates may reduce study validity. We compared two geocoding methods using 8,157 Washington State addresses. The multi-stage geocoding method implemented by the state health department used a sequence of local and national reference files. The single-stage method used a single national reference file. For each address geocoded by both methods, we measured the distance between the locations assigned by each method. Area-level characteristics were collected from census data, and modeled as predictors of the discordance between geocoded address coordinates. Results The multi-stage method had a higher match rate than the single-stage method: 99% versus 95%. Of 7,686 addresses were geocoded by both methods, 96% were geocoded to the same census tract by both methods and 98% were geocoded to locations within 1 km of each other by the two methods. The distance between geocoded coordinates for the same address was higher in sparsely populated and low poverty areas, and counties with local reference files. Conclusion The multi-stage geocoding method had a higher match rate than the single-stage method. An examination of differences in the location assigned to the same address suggested that study results may be most sensitive to the choice of geocoding method in sparsely populated or low-poverty areas.

  19. Software Testing Method Based on Model Comparison

    Institute of Scientific and Technical Information of China (English)

    XIE Xiao-dong; LU Yan-sheng; MAO Cheng-yin

    2008-01-01

    A model comparison based software testing method (MCST) is proposed. In this method, the requirements and programs of software under test are transformed into the ones in the same form, and described by the same model describe language (MDL).Then, the requirements are transformed into a specification model and the programs into an implementation model. Thus, the elements and structures of the two models are compared, and the differences between them are obtained. Based on the diffrences, a test suite is generated. Different MDLs can be chosen for the software under test. The usages of two classical MDLs in MCST, the equivalence classes model and the extended finite state machine (EFSM) model, are described with example applications. The results show that the test suites generated by MCST are more efficient and smaller than some other testing methods, such as the path-coverage testing method, the object state diagram testing method, etc.

  20. Inhibition of VEGF-Dependent Multistage Carcinogenesis by Soluble EphA Receptors

    Directory of Open Access Journals (Sweden)

    Nikki Cheng

    2003-09-01

    Full Text Available Elevated expression of Eph receptors has long been correlated with the growth of solid tumors. However, the functional role of this family of receptor tyrosine kinases in carcinogenesis and tumor angiogenesis has not been well characterized. Here we report that soluble EphA receptors inhibit tumor angiogenesis and tumor progression in vivo in the RIP-Tag transgenic model of vascular endothelial growth factor (VEGF-dependent multistage pancreatic islet cell carcinoma. Soluble EphA receptors delivered either by a transgene or an osmotic minipump inhibited the formation of angiogenic islet, a premalignant lesion, reduced tumor volume of solid islet cell carcinoma. EphA2-Fc or EphA3-Fc treatment resulted in decreased tumor volume but increased tumor and endothelial cell apoptosis in vivo. In addition, soluble EphA receptors inhibited VEGF and βTC tumor cell-conditioned medium-induced endothelial cell migration in vitro and VEGF-induced cornea angiogenesis in vivo. A dominant negative EphA2 mutant inhibited—whereas a gain-of-function EphA2 mutant enhanced—tumor cell-induced endothelial cell migration, suggesting that EphA2 receptor activation is required for tumor cell-endothelial cell interaction. These data provide functional evidence for EphA class receptor regulation of VEGF-dependent tumor angiogenesis, suggesting that the EphA signaling pathway may represent an attractive novel target for antiangiogenic therapy in cancer.

  1. Rigging Test Bed Development for Validation of Multi-Stage Decelerator Extractions

    Science.gov (United States)

    Kenig, Sivan J.; Gallon, John C.; Adams, Douglas S.; Rivellini, Tommaso P.

    2013-01-01

    The Low Density Supersonic Decelerator project is developing new decelerator systems for Mars entry which would include testing with a Supersonic Flight Dynamics Test Vehicle. One of the decelerator systems being developed is a large supersonic ringsail parachute. Due to the configuration of the vehicle it is not possible to deploy the parachute with a mortar which would be the preferred method for a spacecraft in a supersonic flow. Alternatively, a multi-stage extraction process using a ballute as a pilot is being developed for the test vehicle. The Rigging Test Bed is a test venue being constructed to perform verification and validation of this extraction process. The test bed consists of a long pneumatic piston device capable of providing a constant force simulating the ballute drag force during the extraction events. The extraction tests will take place both inside a high-bay for frequent tests of individual extraction stages and outdoors using a mobile hydraulic crane for complete deployment tests from initial pack pull out to canopy extraction. These tests will measure line tensions and use photogrammetry to track motion of the elements involved. The resulting data will be used to verify packing and rigging as well, as validate models and identify potential failure modes in order to finalize the design of the extraction system.

  2. The development of an integrated multistaged fluid bed retorting process. Annual report, October 1991--September 1992

    Energy Technology Data Exchange (ETDEWEB)

    Carter, S.; Vego, A.; Stehn, J.; Taulbee, D.; Robl, T.; Hower, J.; Mahboub, K.; Robertson, R.; Hornsberger, P.; Oduroh, P.; Simpson, A.

    1992-12-01

    This report summarizes the progress made on the development of an integrated multistage fluidized bed retorting process (KENTORT II) during the period of October 1, 1991 through September 30, 1992. The KENTORT II process includes integral fluidized bed zones for pyrolysis (shale oil production), gasification (synthesis gas production), and combustion of the spent oil shale for process heat. The purpose of this program is to design and test the KENTORT II process at the 50-lb/hr scale. The work completed this year involved several different areas. Basic studies of the cracking and coking kinetics of shale oil vapors were carried out in fluidized and fixed bed reactors using both freshly generated shale oil vapors and model compounds. The design and fabrication of the 50-lb/hr KENTORT II reactor was completed and installation of the process components was initiated. The raw oil shale sample (Cleveland Member from Montgomery County, Kentucky) for the program was mined, prepared, characterized and stored. A preliminary study of KENTORT II-derived oil for possible paving applications was completed, and it was concluded that the shale exhibits acceptable properties as an asphalt recycling agent.

  3. INFLUENCE OF NANOFILTRATION PRETREATMENT ON SCALE DEPOSITION IN MULTI-STAGE FLASH THERMAL DESALINATION PLANTS

    Directory of Open Access Journals (Sweden)

    Aiman E Al-Rawajfeh

    2011-01-01

    Full Text Available Scale formation represents a major operational problem encountered in thermal desalination plants. In current installed plants, and to allow for a reasonable safety margin, sulfate scale deposition limits the top brine temperature (TBT in multi-stage flash (MSF distillers up to 110-112oC. This has significant effect on the unit capital, operational and water production cost. In this work, the influence of nanofiltration (NF pretreatment on the scale deposition potential and increasing TBT in MSF thermal desalination plants is modeled on the basis of mass transfer with chemical reaction of solutes in the brine. Full and partial NF-pretreatment of the feed water were investigated. TBT can be increased in MSF by increasing the percentage of NF-treated feed. Full NF pretreatment of the make-up allows TBT in the MSF plant to be raised up to 175oC in the case of di hybrid NF-MSF and up to 165oC in the case of tri hybrid NF-RO-MSF. The significant scale reduction is associated with increasing flashing range, unit recovery, unit performance, and will lead to reduction in heat transfer surface area, pumping power and therefore, water production cost.

  4. Sketch-based Interfaces and Modeling

    CERN Document Server

    Jorge, Joaquim

    2011-01-01

    The field of sketch-based interfaces and modeling (SBIM) is concerned with developing methods and techniques to enable users to interact with a computer through sketching - a simple, yet highly expressive medium. SBIM blends concepts from computer graphics, human-computer interaction, artificial intelligence, and machine learning. Recent improvements in hardware, coupled with new machine learning techniques for more accurate recognition, and more robust depth inferencing techniques for sketch-based modeling, have resulted in an explosion of both sketch-based interfaces and pen-based computing

  5. Location-based Modeling and Analysis: Tropos-based Approach

    OpenAIRE

    Ali, Raian; Dalpiaz, Fabiano; Giorgini, Paolo

    2008-01-01

    The continuous growth of interest in mobile applications makes the concept of location essential to design and develop software systems. Location-based software is supposed to be able to monitor the location and choose accordingly the most appropriate behavior. In this paper, we propose a novel conceptual framework to model and analyze location-based software. We mainly focus on the social facets of locations adopting concepts such as social actor, resource, and location-based behavior. Our a...

  6. Optimal phasing of district heating network investments using multi-stage stochastic programming

    Directory of Open Access Journals (Sweden)

    Romain Stephane Claude Lambert

    2016-06-01

    Full Text Available Most design optimisation studies for district heating systems have focused on the optimal sizing of network assets and on the location of production units. However, the strategic value of the flexibility in phasing of the inherently modular heat networks, which is an important aspect in many feasibility studies for district heating schemes in the UK, is almost always neglected in the scientific literature. This paper considers the sequential problem faced by a decision-maker in the phasing of long-term investments into district heating networks and their expansions. The problem is formulated as a multi-stage stochastic programme to determine the annual capital expenditure that maximises the expected net present value of the project. The optimisation approach is illustrated by applying it to the hypothetical case of the UK’s Marston Vale eco town. It was found that the approach is capable of simulating the optimal growth of a network, from both a single heat source or separate islands of growth, as well as the optimal marginal expansion of an existing district heating network. The proposed approach can be used by decision makers as a framework to determine both the optimal phasing and extension of district heating networks and can be adapted simply to various, more complex real-life situations by introducing additional constraints and parameters. The versatility of the base formulation also makes it a powerful approach regardless of the size of the network and also potentially applicable to cooling networks.

  7. 3D segmentation of medical images using a fast multistage hybrid algorithm

    International Nuclear Information System (INIS)

    In this paper, we propose a fast multistage hybrid algorithm for 3D segmentation of medical images. We first employ a morphological recursive erosion operation to reduce the connectivity between the object to be segmented and its neighborhood; then the fast marching method is used to greatly accelerate the initial propagation of a surface front from the user defined seed structure to a surface close to the desired boundary; a morphological reconstruction method then operates on this surface to achieve an initial segmentation result; and finally morphological recursive dilation is employed to recover any structure lost in the first stage of the algorithm. This approach is tested on 60 CT or MRI images of the brain, heart and urinary system, to demonstrate the robustness of this technique across a variety of imaging modalities and organ systems. The algorithm is also validated against datasets for which ''truth'' is known. These measurements revealed that the algorithm achieved a mean ''similarity index'' of 0.966 across the three organ systems. The execution time for this algorithm, when run on a 550 MHz Dual PIII-based PC runningWindows NT, and extracting the cortex from brain MRIs, the cardiac surface from dynamic CT, and the kidneys from 3D CT, was 38, 46 and 23 s, respectively. (orig.)

  8. Transport line for a multi-staged laser-plasma acceleration: DACTOMUS

    Energy Technology Data Exchange (ETDEWEB)

    Chancé, Antoine, E-mail: antoine.chance@cea.fr [CEA, IRFU, SACM, Centre de Saclay, F-91191 Gif-sur-Yvette (France); Delferrière, Olivier; Schwindling, Jérôme [CEA, IRFU, SACM, Centre de Saclay, F-91191 Gif-sur-Yvette (France); Bruni, Christelle; Delerue, Nicolas [LAL, UMR9607, CNRS and Université Paris Sud, Orsay (France); Specka, Arnd [LLR, UMR7638, CNRS and Ecole Polytechnique, Palaiseau (France); Cros, Brgitte; Maynard, Gillies; Paradkar, Bhooshan S. [LPGP, UMR8578, CNRS and Université Paris Sud, Orsay (France); Mora, Patrick [CPhT, UMR7644, CNRS and Ecole Polytechnique, Palaiseau (France)

    2014-03-11

    Laser-plasma acceleration is one of the most promising techniques to reach very high acceleration gradients up to a few hundreds of GeV/m. In order to push this acceleration scheme in the domain of the very high energies, the CILEX project was launched with the laser APOLLON. One of the main topics of this project is to study multi-staged acceleration. It consists in generating and pre-accelerating electrons in a first laser-plasma stage, to transport them up to a second stage where the electrons are accelerated again thanks to another laser pulse. The DACTOMUS project, based on a collaboration CEA-IRFU, CEA-IRAMIS, LAL, LPGP, LULI and LLR, aims at the study and realization of such a transfer line between these two stages. Firstly, a prototype will be developed and tested by the groups of CEA-IRAMIS-SPAM, LPGP, and LULI on the UHI100 facility (CEA-SPAM). This collaboration must enable to realize the first acceleration stage. For the transport line prototype, the main difficulties are to realize a very compact and energy accepting line with diagnostics to characterize the electron beam. We will present here the optics of this line, its performances and the inserted diagnostics.

  9. Transport line for a multi-staged laser-plasma acceleration: DACTOMUS

    Science.gov (United States)

    Chancé, Antoine; Delferrière, Olivier; Schwindling, Jérôme; Bruni, Christelle; Delerue, Nicolas; Specka, Arnd; Cros, Brgitte; Maynard, Gillies; Paradkar, Bhooshan S.; Mora, Patrick

    2014-03-01

    Laser-plasma acceleration is one of the most promising techniques to reach very high acceleration gradients up to a few hundreds of GeV/m. In order to push this acceleration scheme in the domain of the very high energies, the CILEX project was launched with the laser APOLLON. One of the main topics of this project is to study multi-staged acceleration. It consists in generating and pre-accelerating electrons in a first laser-plasma stage, to transport them up to a second stage where the electrons are accelerated again thanks to another laser pulse. The DACTOMUS project, based on a collaboration CEA-IRFU, CEA-IRAMIS, LAL, LPGP, LULI and LLR, aims at the study and realization of such a transfer line between these two stages. Firstly, a prototype will be developed and tested by the groups of CEA-IRAMIS-SPAM, LPGP, and LULI on the UHI100 facility (CEA-SPAM). This collaboration must enable to realize the first acceleration stage. For the transport line prototype, the main difficulties are to realize a very compact and energy accepting line with diagnostics to characterize the electron beam. We will present here the optics of this line, its performances and the inserted diagnostics.

  10. Short-Term Multi-Stage Stochastic Optimization of Hydropower Reservoirs Under Meteorological Uncertainty

    Science.gov (United States)

    Schwanenberg, D.; Naumann, S.; Allen, C.

    2014-12-01

    Hydroelectric power systems are characterized by variability and uncertainty in yield and water resources obligations. Market volatility and the growing number of operational constraints for flood control, navigation, environmental obligations and ancillary services (including load balancing requirements for renewable resources) further the need to quantify sources of uncertainty. This research presents an integrated framework to handle several sources of uncertainty. Main focus is on the meteorological forecast uncertainty based on deterministic and probabilistic Numerical Weather Predictions (NWP), its consistent propagation through load and streamflow forecasts, and the generation of scenario trees with novel multi-dimensional distance metrics. The scenario trees enable us to extend a deterministic optimization setup to a multi-stage stochastic optimization approach as the mathematical formulation of the short-term system management. The Federal Columbia River Power System (FCRPS), managed by the Bonneville Power Administration, the US Army Corps of Engineers and the Bureau of Reclamation, serves as a large-scale test case for the application of the new framework. We proof the feasibility of the new approach and verify the operational applicability within a real-time environment.

  11. 基于伪动态的混沌人工鱼群算法在多阶段输电网络规划中的应用%Multistage transmission network planning based on pseudo-dynamic chaotic artificial fish school algorithm

    Institute of Scientific and Technical Information of China (English)

    聂宏展; 王毕元

    2011-01-01

    与传统输电网络规划不同,多阶段输电网络规划需要考虑时段因素,在何阶段搭建何种路线使全局规划方案最优.多阶段规划的难点是阶段之间的过渡,后面阶段的决策要根据前面阶段的决策来定,对于大规模输电网规划经典的动态规划方法无法解决.利用伪动态规划的思想处理多阶段问题,这样减少了算法的迭代次数和运算时间.将混沌优化算法和人工鱼群算法相结合,摆脱了混沌搜索的盲目性和人工鱼搜索的局限性,使该混合算法效率高、收敛速度快.对巴西南部46节点系统的计算结果表明,该混合算法具有可行性和高效性.%The traditional transmission network planning is confined to a single-level construction, while the actual transmission network planning needs to take into account the time factor, namely how to build the best route to network planning. The difficulty of the multi-stage planning is the transition between stages, with the later stages of the decision-making depending on earlier stages of decision-making. Classic dynamic programming can not solve largescale transmission network planning program. In this paper, pseudo-dynamic programming deals with the multistage problem, whose objective is to reduce the number of iterations. The combination of Chaotic Optimization Algorithm and Artificial Fish School Algorithm is free from blindness and limitations of the hybrid algorithm search. The hybrid algorithm is efficient and quick in computation. The calculation results of the 46-bus system reveal that applying hybrid algorithm into transmission network planning is not only feasible, but also has a very high computational efficiency.

  12. Model-based clustered-dot screening

    Science.gov (United States)

    Kim, Sang Ho

    2006-01-01

    I propose a halftone screen design method based on a human visual system model and the characteristics of the electro-photographic (EP) printer engine. Generally, screen design methods based on human visual models produce dispersed-dot type screens while design methods considering EP printer characteristics generate clustered-dot type screens. In this paper, I propose a cost function balancing the conflicting characteristics of the human visual system and the printer. By minimizing the obtained cost function, I design a model-based clustered-dot screen using a modified direct binary search algorithm. Experimental results demonstrate the superior quality of the model-based clustered-dot screen compared to a conventional clustered-dot screen.

  13. Multiscale agent-based consumer market modeling.

    Energy Technology Data Exchange (ETDEWEB)

    North, M. J.; Macal, C. M.; St. Aubin, J.; Thimmapuram, P.; Bragen, M.; Hahn, J.; Karr, J.; Brigham, N.; Lacy, M. E.; Hampton, D.; Decision and Information Sciences; Procter & Gamble Co.

    2010-05-01

    Consumer markets have been studied in great depth, and many techniques have been used to represent them. These have included regression-based models, logit models, and theoretical market-level models, such as the NBD-Dirichlet approach. Although many important contributions and insights have resulted from studies that relied on these models, there is still a need for a model that could more holistically represent the interdependencies of the decisions made by consumers, retailers, and manufacturers. When the need is for a model that could be used repeatedly over time to support decisions in an industrial setting, it is particularly critical. Although some existing methods can, in principle, represent such complex interdependencies, their capabilities might be outstripped if they had to be used for industrial applications, because of the details this type of modeling requires. However, a complementary method - agent-based modeling - shows promise for addressing these issues. Agent-based models use business-driven rules for individuals (e.g., individual consumer rules for buying items, individual retailer rules for stocking items, or individual firm rules for advertizing items) to determine holistic, system-level outcomes (e.g., to determine if brand X's market share is increasing). We applied agent-based modeling to develop a multi-scale consumer market model. We then conducted calibration, verification, and validation tests of this model. The model was successfully applied by Procter & Gamble to several challenging business problems. In these situations, it directly influenced managerial decision making and produced substantial cost savings.

  14. Workflow-Based Dynamic Enterprise Modeling

    Institute of Scientific and Technical Information of China (English)

    黄双喜; 范玉顺; 罗海滨; 林慧萍

    2002-01-01

    Traditional systems for enterprise modeling and business process control are often static and cannot adapt to the changing environment. This paper presents a workflow-based method to dynamically execute the enterprise model. This method gives an explicit representation of the business process logic and the relationships between the elements involved in the process. An execution-oriented integrated enterprise modeling system is proposed in combination with other enterprise views. The enterprise model can be established and executed dynamically in the actual environment due to the dynamic properties of the workflow model.

  15. Bayesian Network Based XP Process Modelling

    Directory of Open Access Journals (Sweden)

    Mohamed Abouelela

    2010-07-01

    Full Text Available A Bayesian Network based mathematical model has been used for modelling Extreme Programmingsoftware development process. The model is capable of predicting the expected finish time and theexpected defect rate for each XP release. Therefore, it can be used to determine the success/failure of anyXP Project. The model takes into account the effect of three XP practices, namely: Pair Programming,Test Driven Development and Onsite Customer practices. The model’s predictions were validated againsttwo case studies. Results show the precision of our model especially in predicting the project finish time.

  16. Econophysics of agent-based models

    CERN Document Server

    Aoyama, Hideaki; Chakrabarti, Bikas; Chakraborti, Anirban; Ghosh, Asim

    2014-01-01

    The primary goal of this book is to present the research findings and conclusions of physicists, economists, mathematicians and financial engineers working in the field of "Econophysics" who have undertaken agent-based modelling, comparison with empirical studies and related investigations. Most standard economic models assume the existence of the representative agent, who is “perfectly rational” and applies the utility maximization principle when taking action. One reason for this is the desire to keep models mathematically tractable: no tools are available to economists for solving non-linear models of heterogeneous adaptive agents without explicit optimization. In contrast, multi-agent models, which originated from statistical physics considerations, allow us to go beyond the prototype theories of traditional economics involving the representative agent. This book is based on the Econophys-Kolkata VII Workshop, at which many such modelling efforts were presented. In the book, leading researchers in the...

  17. Evaluating face trustworthiness: a model based approach

    OpenAIRE

    Todorov, Alexander; Baron, Sean G.; Oosterhof, Nikolaas N.

    2008-01-01

    Judgments of trustworthiness from faces determine basic approach/avoidance responses and approximate the valence evaluation of faces that runs across multiple person judgments. Here, based on trustworthiness judgments and using a computer model for face representation, we built a model for representing face trustworthiness (study 1). Using this model, we generated novel faces with an increased range of trustworthiness and used these faces as stimuli in a functional Magnetic Resonance Imaging ...

  18. Agent-Based Modeling in Systems Pharmacology.

    Science.gov (United States)

    Cosgrove, J; Butler, J; Alden, K; Read, M; Kumar, V; Cucurull-Sanchez, L; Timmis, J; Coles, M

    2015-11-01

    Modeling and simulation (M&S) techniques provide a platform for knowledge integration and hypothesis testing to gain insights into biological systems that would not be possible a priori. Agent-based modeling (ABM) is an M&S technique that focuses on describing individual components rather than homogenous populations. This tutorial introduces ABM to systems pharmacologists, using relevant case studies to highlight how ABM-specific strengths have yielded success in the area of preclinical mechanistic modeling. PMID:26783498

  19. Agent-based Models of Financial Markets

    OpenAIRE

    Samanidou, E.; E. Zschischang; Stauffer, D.; Lux, T.

    2007-01-01

    This review deals with several microscopic (``agent-based'') models of financial markets which have been studied by economists and physicists over the last decade: Kim-Markowitz, Levy-Levy-Solomon, Cont-Bouchaud, Solomon-Weisbuch, Lux-Marchesi, Donangelo-Sneppen and Solomon-Levy-Huang. After an overview of simulation approaches in financial economics, we first give a summary of the Donangelo-Sneppen model of monetary exchange and compare it with related models in economics literature. Our sel...

  20. Literature Survey on Model based Slicing

    OpenAIRE

    Sneh Krishna*,; Alekh Dwivedi

    2014-01-01

    Software testing is an activity which aims at evaluating an feature or capability of system and determining that whether it meets required expectations. One way to ease this program slicing technique is to break down the large programs into smaller ones and into other is model based slicing that break down the large software architecture model into smaller models at the early stage of SDLC (Software Development Life Cycle). This is the novel methodology to extract the sub mode...

  1. PARTICIPATION BASED MODEL OF SHIP CREW MANAGEMENT

    OpenAIRE

    Bielić, Toni; Ivanišević, Dalibor; Gundić, Ana

    2014-01-01

    This paper analyse the participation - based model on board the ship as possibly optimal leadership model existing in the shipping industry with accent on decision - making process. In the paper authors have tried to define master’s behaviour model and management style identifying drawbacks and disadvantages of vertical, pyramidal organization with master on the top. Paper describes efficiency of decision making within team organization and optimization of a ship’s organisation by introduci...

  2. Model-based Abstraction of Data Provenance

    OpenAIRE

    Probst, Christian W.; Hansen, René Rydhof

    2014-01-01

    Identifying provenance of data provides insights to the origin of data and intermediate results, and has recently gained increased interest due to data-centric applications. In this work we extend a data-centric system view with actors handling the data and policies restricting actions. This extension is based on provenance analysis performed on system models. System models have been introduced to model and analyse spatial and organisational aspects of organisations, to identify, e.g., potent...

  3. Multi-stage FEL amplifier with diaphragm focusing line as direct energy driver for inertial confinement fusion

    International Nuclear Information System (INIS)

    An FEL based energy driver for Inertial Confinement Fusion (ICF) is proposed. The key element of the scheme is free electron laser system. Novel technical solutions, namely, using of multichannel, multi-stage FEL amplifier with diaphragm focusing line, reveal a possibility to construct the FEL system operating at radiation wavelength λ = 0.5 μm and providing flush energy E = 1 MJ and brightness 4 x 1022 W cm-2 sr-1 within steering pulse duration τ ∼ 0.1-2 ns. Total energy efficiency of the proposed ICF energy driver is about of 11% and repetition rate is 40 Hz. It is shown that the FEL based ICF energy driver may be constructed at the present level of accelerator technique R ampersand D

  4. A probabilistic graphical model based stochastic input model construction

    International Nuclear Information System (INIS)

    Model reduction techniques have been widely used in modeling of high-dimensional stochastic input in uncertainty quantification tasks. However, the probabilistic modeling of random variables projected into reduced-order spaces presents a number of computational challenges. Due to the curse of dimensionality, the underlying dependence relationships between these random variables are difficult to capture. In this work, a probabilistic graphical model based approach is employed to learn the dependence by running a number of conditional independence tests using observation data. Thus a probabilistic model of the joint PDF is obtained and the PDF is factorized into a set of conditional distributions based on the dependence structure of the variables. The estimation of the joint PDF from data is then transformed to estimating conditional distributions under reduced dimensions. To improve the computational efficiency, a polynomial chaos expansion is further applied to represent the random field in terms of a set of standard random variables. This technique is combined with both linear and nonlinear model reduction methods. Numerical examples are presented to demonstrate the accuracy and efficiency of the probabilistic graphical model based stochastic input models. - Highlights: • Data-driven stochastic input models without the assumption of independence of the reduced random variables. • The problem is transformed to a Bayesian network structure learning problem. • Examples are given in flows in random media

  5. Mineral resources estimation based on block modeling

    Science.gov (United States)

    Bargawa, Waterman Sulistyana; Amri, Nur Ali

    2016-02-01

    The estimation in this paper uses three kinds of block models of nearest neighbor polygon, inverse distance squared and ordinary kriging. The techniques are weighting scheme which is based on the principle that block content is a linear combination of the grade data or the sample around the block being estimated. The case study in Pongkor area, here is gold-silver resource modeling that allegedly shaped of quartz vein as a hydrothermal process of epithermal type. Resources modeling includes of data entry, statistical and variography analysis of topography and geological model, the block model construction, estimation parameter, presentation model and tabulation of mineral resources. Skewed distribution, here isolated by robust semivariogram. The mineral resources classification generated in this model based on an analysis of the kriging standard deviation and number of samples which are used in the estimation of each block. Research results are used to evaluate the performance of OK and IDS estimator. Based on the visual and statistical analysis, concluded that the model of OK gives the estimation closer to the data used for modeling.

  6. Modelling a Peroxidase-based Optical Biosensor

    Science.gov (United States)

    Baronas, Romas; Gaidamauskaite, Evelina; Kulys, Juozas

    2007-01-01

    The response of a peroxidase-based optical biosensor was modelled digitally. A mathematical model of the optical biosensor is based on a system of non-linear reaction-diffusion equations. The modelling biosensor comprises two compartments, an enzyme layer and an outer diffusion layer. The digital simulation was carried out using finite difference technique. The influence of the substrate concentration as well as of the thickness of both the enzyme and diffusion layers on the biosensor response was investigated. Calculations showed complex kinetics of the biosensor response, especially at low concentrations of the peroxidase and of the hydrogen peroxide.

  7. Information modelling and knowledge bases XXV

    CERN Document Server

    Tokuda, T; Jaakkola, H

    2014-01-01

    Because of our ever increasing use of and reliance on technology and information systems, information modelling and knowledge bases continue to be important topics in those academic communities concerned with data handling and computer science. As the information itself becomes more complex, so do the levels of abstraction and the databases themselves. This book is part of the series Information Modelling and Knowledge Bases, which concentrates on a variety of themes in the important domains of conceptual modeling, design and specification of information systems, multimedia information modelin

  8. Strategies and limits in multi-stage single-point incremental forming

    DEFF Research Database (Denmark)

    Skjødt, Martin; Silva, M.B.; Martins, P. A. F.;

    2010-01-01

    Multi-stage single-point incremental forming (SPIF) is a state-of-the-art manufacturing process that allows small-quantity production of complex sheet metal parts with vertical walls. This paper is focused on the application of multi-stage SPIF with the objective of producing cylindrical cups with...... vertical walls. The strategy consists of forming a conical cup with a taper angle in the first stage, followed by three subsequent stages that progressively move the conical shape towards the desired cylindrical geometry. The investigation includes material characterization, determination of forming......-limit curves and fracture forming-limit curves (FFLCs), numerical simulation, and experimentation, namely the evaluation of strain paths and fracture strains in actual multi-stage parts. Assessment of numerical simulation with experimentation shows good agreement between computed and measured strain and strain...

  9. Neighborhood Mixture Model for Knowledge Base Completion

    OpenAIRE

    Nguyen, Dat Quoc; Sirts, Kairit; Qu, Lizhen; Johnson, Mark

    2016-01-01

    Knowledge bases are useful resources for many natural language processing tasks, however, they are far from complete. In this paper, we define a novel entity representation as a mixture of its neighborhood in the knowledge base and apply this technique on TransE-a well-known embedding model for knowledge base completion. Experimental results show that the neighborhood information significantly helps to improve the results of the TransE, leading to better performance than obtained by other sta...

  10. Multiagent-Based Model For ESCM

    OpenAIRE

    Delia MARINCAS

    2011-01-01

    Web based applications for Supply Chain Management (SCM) are now a necessity for every company in order to meet the increasing customer demands, to face the global competition and to make profit. Multiagent-based approach is appropriate for eSCM because it shows many of the characteristics a SCM system should have. For this reason, we have proposed a multiagent-based eSCM model which configures a virtual SC, automates the SC activities: selling, purchasing, manufacturing, planning, inventory,...

  11. Modelling carbon nanotubes-based mediatorless biosensor.

    Science.gov (United States)

    Baronas, Romas; Kulys, Juozas; Petrauskas, Karolis; Razumiene, Julija

    2012-01-01

    This paper presents a mathematical model of carbon nanotubes-based mediatorless biosensor. The developed model is based on nonlinear non-stationary reaction-diffusion equations. The model involves four layers (compartments): a layer of enzyme solution entrapped on a terylene membrane, a layer of the single walled carbon nanotubes deposited on a perforated membrane, and an outer diffusion layer. The biosensor response and sensitivity are investigated by changing the model parameters with a special emphasis on the mediatorless transfer of the electrons in the layer of the enzyme-loaded carbon nanotubes. The numerical simulation at transient and steady state conditions was carried out using the finite difference technique. The mathematical model and the numerical solution were validated by experimental data. The obtained agreement between the simulation results and the experimental data was admissible at different concentrations of the substrate. PMID:23012537

  12. Modelling Carbon Nanotubes-Based Mediatorless Biosensor

    Directory of Open Access Journals (Sweden)

    Julija Razumiene

    2012-07-01

    Full Text Available This paper presents a mathematical model of carbon nanotubes-based mediatorless biosensor. The developed model is based on nonlinear non-stationary reaction-diffusion equations. The model involves four layers (compartments: a layer of enzyme solution entrapped on a terylene membrane, a layer of the single walled carbon nanotubes deposited on a perforated membrane, and an outer diffusion layer. The biosensor response and sensitivity are investigated by changing the model parameters with a special emphasis on the mediatorless transfer of the electrons in the layer of the enzyme-loaded carbon nanotubes. The numerical simulation at transient and steady state conditions was carried out using the finite difference technique. The mathematical model and the numerical solution were validated by experimental data. The obtained agreement between the simulation results and the experimental data was admissible at different concentrations of the substrate.

  13. Evaluation of the Stability and Performance of a Multi-Stage Riemann Solver in Relativistic Hydrodynamic Simulations

    CERN Document Server

    Sikorski, J; Kikoła, D; Słodkowski, M; Aszklar, P

    2015-01-01

    The work deals with assessing the quality of a multi-stage Riemann solver for relativistic hydrodynamic simulations of heavy-ion collisions. The physical system is described using hydrodynamic conservation laws and then solved numerically. Because of the nature of such hydrodynamic simulations the numerical method has to cope with problems containing both strong discontinuities and smooth solutions, and reproduce these features with a high precision and stability. Moreover, to verify the correctness of the proposed physical model, a massive number of simulations with a high spatial resolution is needed. Due to the high numerical cost, a highly e?cient implementation for solving such large-scale problems is required. The MUSTA-FORCE algorithm is a universal tool for hydrodynamic simulations. It uses simple central schemes and does not require any knowledge of the physical process's details, thus it can be used for virtually any physical system. We investigate the application of the MUSTA-FORCE scheme for relat...

  14. MEGen: A Physiologically Based Pharmacokinetic Model Generator

    Directory of Open Access Journals (Sweden)

    GeorgeDLoizou

    2011-11-01

    Full Text Available Physiologically based pharmacokinetic models are being used in an increasing number of different areas. These not only include the human safety assessment of pharmaceuticals, pesticides, biocides and environmental chemicals but also for food animal, wild mammal and avian risk assessment. The value of PBPK models is that they are tools for estimating tissue dosimetry by integrating in vitro and in vivo mechanistic, pharmacokinetic and toxicological information through their explicit mathematical description of important anatomical, physiological and biochemical determinants of chemical uptake, disposition and elimination. However, PBPK models are perceived as complex, data hungry, resource intensive and time consuming. In addition, model validation and verification are hindered by the relative complexity of the equations. To begin to address these issues a freely available web application for the rapid construction and documentation of bespoke PBPK models is under development. Here we present an overview of the current capabilities of MEGen, a model equation generator and parameter database and discuss future developments.

  15. A model evaluation checklist for process-based environmental models

    Science.gov (United States)

    Jackson-Blake, Leah

    2015-04-01

    the conceptual model on which it is based. In this study, a number of model structural shortcomings were identified, such as a lack of dissolved phosphorus transport via infiltration excess overland flow, potential discrepancies in the particulate phosphorus simulation and a lack of spatial granularity. (4) Conceptual challenges, as conceptual models on which predictive models are built are often outdated, having not kept up with new insights from monitoring and experiments. For example, soil solution dissolved phosphorus concentration in INCA-P is determined by the Freundlich adsorption isotherm, which could potentially be replaced using more recently-developed adsorption models that take additional soil properties into account. This checklist could be used to assist in identifying why model performance may be poor or unreliable. By providing a model evaluation framework, it could help prioritise which areas should be targeted to improve model performance or model credibility, whether that be through using alternative calibration techniques and statistics, improved data collection, improving or simplifying the model structure or updating the model to better represent current understanding of catchment processes.

  16. PATIENT-CENTRED SCREENING FOR PRIMARY IMMUNODEFICIENCY, A MULTI-STAGE DIAGNOSTIC PROTOCOL DESIGNED FOR NONIMMUNOLOGISTS: 2011 UPDATE

    Directory of Open Access Journals (Sweden)

    E. de Vries

    2013-01-01

    Full Text Available Abstract. Members of the European Society for Immunodeficiencies (ESID and other colleagues have updated themulti-stage expert-opinion-based diagnostic protocol for non-immunologists incorporating newly defined primary immunodeficiency diseases (PIDs. The protocol presented here aims to increase the awareness of PIDs among doctors working in different fields. Prompt identification of PID is important for prognosis, but this may not be an easy task. The protocol therefore starts from the clinical presentation of the patient. Because PIDs may present at all ages, this protocol is aimed at both adult and paediatric physicians. The multi-stage design allows cost-effective screening for PID of the large number of potential cases in the early phases, with more expensive tests reserved for definitive classification in collaboration with a specialist in the field of immunodeficiency at a later stage.

  17. Numerical identification of blade exit angle effect on the performance for a multistage centrifugal pump impeller

    Directory of Open Access Journals (Sweden)

    Babayigit Osman

    2015-01-01

    Full Text Available Nowadays, single and multistage centrifugal pumps are widely used in industrial and mining enterprises. One of the most important components of a centrifugal pump is the impeller. The performance characteristics are related to the pump comprising the head and the overall efficiency rely a great deal on the impeller geometry. In this work, effects of blade exit angle change on hydraulic efficiency of a multi stage pump impeller are investigated via Ansys-Fluent computational fluid dynamics software for constant width impeller entrance and exit gates, blade numbers and blade thickness. Firstly, the flow volume of a centrifugal pump impeller is generated and then mesh structure is formed for the full impeller flow volume. Secondly, rotational periodic flow model are adopted in order to examine the effect of periodic flow assumption on the performance predictions. Corresponding to the available experimental data, inlet mass flow rate, outlet static pressure and rotation of impeller are taken as 0.02m3s-1, 450 kPa and 2950 rpm, respectively for the water fluid. No slip boundary condition is exposed to all solid of surface in the flow volume. The continuity and Navier-Stokes equations with the k-ε turbulence model and the standard wall functions are used. During the study, numerical analyses are conducted for the blade exit angle values of 18°, 20°, 25°, 30° and 35°. In consequence of the performed analyses, it is determined that hydraulic efficiency of the pump impeller value is changed between 81.0-84.6%. The most convenient blade exit angle that yields 84.6% hydraulic efficiency at is 18°. The obtained results show that the blade exit angle range has an impact on the centrifugal pump performance describing the pump head and the hydraulic efficiency.

  18. Numerical identification of blade exit angle effect on the performance for a multistage centrifugal pump impeller

    Science.gov (United States)

    Babayigit, Osman; Kocaaslan, Osman; Hilmi Aksoy, Muharrem; Melih Guleren, Kursad; Ozgoren, Muammer

    2015-05-01

    Nowadays, single and multistage centrifugal pumps are widely used in industrial and mining enterprises. One of the most important components of a centrifugal pump is the impeller. The performance characteristics are related to the pump comprising the head and the overall efficiency rely a great deal on the impeller geometry. In this work, effects of blade exit angle change on hydraulic efficiency of a multi stage pump impeller are investigated via Ansys-Fluent computational fluid dynamics software for constant width impeller entrance and exit gates, blade numbers and blade thickness. Firstly, the flow volume of a centrifugal pump impeller is generated and then mesh structure is formed for the full impeller flow volume. Secondly, rotational periodic flow model are adopted in order to examine the effect of periodic flow assumption on the performance predictions. Corresponding to the available experimental data, inlet mass flow rate, outlet static pressure and rotation of impeller are taken as 0.02m3s-1, 450 kPa and 2950 rpm, respectively for the water fluid. No slip boundary condition is exposed to all solid of surface in the flow volume. The continuity and Navier-Stokes equations with the k-ɛ turbulence model and the standard wall functions are used. During the study, numerical analyses are conducted for the blade exit angle values of 18°, 20°, 25°, 30° and 35°. In consequence of the performed analyses, it is determined that hydraulic efficiency of the pump impeller value is changed between 81.0-84.6%. The most convenient blade exit angle that yields 84.6% hydraulic efficiency at is 18°. The obtained results show that the blade exit angle range has an impact on the centrifugal pump performance describing the pump head and the hydraulic efficiency.

  19. Spatial interactions in agent-based modeling

    CERN Document Server

    Ausloos, Marcel; Merlone, Ugo

    2014-01-01

    Agent Based Modeling (ABM) has become a widespread approach to model complex interactions. In this chapter after briefly summarizing some features of ABM the different approaches in modeling spatial interactions are discussed. It is stressed that agents can interact either indirectly through a shared environment and/or directly with each other. In such an approach, higher-order variables such as commodity prices, population dynamics or even institutions, are not exogenously specified but instead are seen as the results of interactions. It is highlighted in the chapter that the understanding of patterns emerging from such spatial interaction between agents is a key problem as much as their description through analytical or simulation means. The chapter reviews different approaches for modeling agents' behavior, taking into account either explicit spatial (lattice based) structures or networks. Some emphasis is placed on recent ABM as applied to the description of the dynamics of the geographical distribution o...

  20. Model based Software Develeopment: Issues & Challenges

    CERN Document Server

    basha, N Md Jubair; Rizwanullah, Mohammed

    2012-01-01

    One of the goals of software design is to model a system in such a way that it is easily understandable. Nowadays the tendency for software development is changing from manual coding to automatic code generation; it is becoming model-based. This is a response to the software crisis, in which the cost of hardware has decreased and conversely the cost of software development has increased sharply. The methodologies that allowed this change are model-based, thus relieving the human from detailed coding. Still there is a long way to achieve this goal, but work is being done worldwide to achieve this objective. This paper presents the drastic changes related to modeling and important challenging issues and techniques that recur in MBSD.

  1. Graphical model construction based on evolutionary algorithms

    Institute of Scientific and Technical Information of China (English)

    Youlong YANG; Yan WU; Sanyang LIU

    2006-01-01

    Using Bayesian networks to model promising solutions from the current population of the evolutionary algorithms can ensure efficiency and intelligence search for the optimum. However, to construct a Bayesian network that fits a given dataset is a NP-hard problem, and it also needs consuming mass computational resources. This paper develops a methodology for constructing a graphical model based on Bayesian Dirichlet metric. Our approach is derived from a set of propositions and theorems by researching the local metric relationship of networks matching dataset. This paper presents the algorithm to construct a tree model from a set of potential solutions using above approach. This method is important not only for evolutionary algorithms based on graphical models, but also for machine learning and data mining.The experimental results show that the exact theoretical results and the approximations match very well.

  2. PV panel model based on datasheet values

    DEFF Research Database (Denmark)

    Sera, Dezso; Teodorescu, Remus; Rodriguez, Pedro

    This work presents the construction of a model for a PV panel using the single-diode five-parameters model, based exclusively on data-sheet parameters. The model takes into account the series and parallel (shunt) resistance of the panel. The equivalent circuit and the basic equations of the PV cell....../panel in Standard Test Conditions (STC) are shown, as well as the parameters extraction from the data-sheet values. The temperature dependence of the cell dark saturation current is expressed with an alternative formula, which gives better correlation with the datasheet values of the power temperature...... dependence. Based on these equations, a PV panel model, which is able to predict the panel behavior in different temperature and irradiance conditions, is built and tested....

  3. Simulation system of multistage hot rolling process of flat products

    Directory of Open Access Journals (Sweden)

    R. Kawalla

    2010-07-01

    Full Text Available By means of numerical simulation of process it is possible to predict the global and local properties of profiles after each step of deformation. Determination of the influence of each certain stage in experimental way is rather cost-based and therefore resource-demanding. This is the reason why in the past years and decades took place the significant advancement of modeling in connection with the application of the numerical approach. On basis of physical approach it is possible for example to predict the development of material and properties of deformed working piece at every one by one following stage of deformation. The great necessity consists in creating of fast simulation systems, which can rapidly estimate the influence of parameters of deformation process on the properties of product and devices. The significant attention is dedicated to the calculation in real time so that In-Line-Simulation makes it possible to control and to operate the processes and devices.

  4. A contextual modeling approach for model-based recommender systems

    OpenAIRE

    Fernández-Tobías, Ignacio; Campos Soto, Pedro G.; Cantador, Iván; Díez, Fernando

    2013-01-01

    The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-40643-0_5 Proceedings of 15th Conference of the Spanish Association for Artificial Intelligence, CAEPIA 2013, Madrid, Spain, September 17-20, 2013. In this paper we present a contextual modeling approach for model-based recommender systems that integrates and exploits both user preferences and contextual signals in a common vector space. Differently to previous work, we conduct a user study acquiring ...

  5. Efficient Textural Model-Based Mammogram Enhancement

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Remeš, Václav

    Piscataway: IEEE, 2013, s. 522-523. ISBN 978-1-4799-1053-3. [2013 IEEE 26th International Symposium on Computer-Based Medical Systems (CBMS). Porto (PT), 20.06.2013-22.06.2013] Institutional support: RVO:67985556 Keywords : mammogram enhancement * autoregressive texture model * breast tissue modeling Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2013/RO/haindl-0397607.pdf

  6. Application software development via model based design

    OpenAIRE

    Haapala, O. (Olli)

    2015-01-01

    This thesis was set to study the utilization of the MathWorks’ Simulink® program in model based application software development and its compatibility with the Vacon 100 inverter. The target was to identify all the problems related to everyday usage of this method and create a white paper of how to execute a model based design to create a Vacon 100 compatible system software. Before this thesis was started, there was very little knowledge of the compatibility of this method. However durin...

  7. Physically based modeling and animation of tornado

    Institute of Scientific and Technical Information of China (English)

    LIU Shi-guang; WANG Zhang-ye; GONG Zheng; CHEN Fei-fei; PENG Qun-sheng

    2006-01-01

    Realistic modeling and rendering of dynamic tornado scene is recognized as a challenging task for researchers of computer graphics. In this paper a new physically based method for simulating and animating tornado scene is presented. We first propose a Two-Fluid model based on the physical theory of tornado, then we simulate the flow of tornado and its interaction with surrounding objects such as debris, etc. Taking the scattering and absorption of light by the participating media into account, the illumination effects of the tornado scene can be generated realistically. With the support of graphics hardware, various kinds of dynamic tornado scenes can be rendered at interactive rates.

  8. Model-based testing for embedded systems

    CERN Document Server

    Zander, Justyna; Mosterman, Pieter J

    2011-01-01

    What the experts have to say about Model-Based Testing for Embedded Systems: "This book is exactly what is needed at the exact right time in this fast-growing area. From its beginnings over 10 years ago of deriving tests from UML statecharts, model-based testing has matured into a topic with both breadth and depth. Testing embedded systems is a natural application of MBT, and this book hits the nail exactly on the head. Numerous topics are presented clearly, thoroughly, and concisely in this cutting-edge book. The authors are world-class leading experts in this area and teach us well-used

  9. A multivalued knowledge-base model

    CERN Document Server

    Achs, Agnes

    2010-01-01

    The basic aim of our study is to give a possible model for handling uncertain information. This model is worked out in the framework of DATALOG. At first the concept of fuzzy Datalog will be summarized, then its extensions for intuitionistic- and interval-valued fuzzy logic is given and the concept of bipolar fuzzy Datalog is introduced. Based on these ideas the concept of multivalued knowledge-base will be defined as a quadruple of any background knowledge; a deduction mechanism; a connecting algorithm, and a function set of the program, which help us to determine the uncertainty levels of the results. At last a possible evaluation strategy is given.

  10. Energy consumption by multi-stage flash and reverse osmosis desalters

    Energy Technology Data Exchange (ETDEWEB)

    Darwish, M.A.; Al-Najem, N.M. [Kuwait University, Safat (Kuwait). College of Engineering and Petroleum

    2000-04-01

    Kuwait and most of the Gulf countries, depend mainly on desalted water from the sea for satisfying their fresh water needs. These countries are using the multi-stage flash (MSF) desalting system, as the 'work horse' for their water production. This system is less efficient in energy consumption as compared to the reverse osmosis (RO) system. Moreover, large units based on the MSF system have to be combined with steam or gas turbines power plants for better utilization of steam supplied to the MSF units at moderately low temperature and pressure (as compared to steam produced by large steam generators). The value and the cost of the thermal energy supplied to the MSF desalting system depends on the method of supplying this energy. This steam can be supplied directly from a fuel operated boiler or heat recovery steam generator associated with a gas turbine. It can also be supplied from the exhaust of a steam back pressure turbine or bled from condensed extraction steam turbine at a pressure suitable for the desalting process. Any energy comparison should be based on simple criteria, either how much fuel energy is consumed to produce this energy or how much mechanical energy is needed per unit product. The energy consumed in the light of the practice used in most Gulf countries are discussed here. In this study, reference desalting and power plants are used for comparison purposes. This study shows that shifting from MSF desalting System to the RO system can save up to 66% of the fuel energy used to desalt seawater. (author)

  11. Physiologically based synthetic models of hepatic disposition.

    Science.gov (United States)

    Hunt, C Anthony; Ropella, Glen E P; Yan, Li; Hung, Daniel Y; Roberts, Michael S

    2006-12-01

    Current physiologically based pharmacokinetic (PBPK) models are inductive. We present an additional, different approach that is based on the synthetic rather than the inductive approach to modeling and simulation. It relies on object-oriented programming. A model of the referent system in its experimental context is synthesized by assembling objects that represent components such as molecules, cells, aspects of tissue architecture, catheters, etc. The single pass perfused rat liver has been well described in evaluating hepatic drug pharmacokinetics (PK) and is the system on which we focus. In silico experiments begin with administration of objects representing actual compounds. Data are collected in a manner analogous to that in the referent PK experiments. The synthetic modeling method allows for recognition and representation of discrete event and discrete time processes, as well as heterogeneity in organization, function, and spatial effects. An application is developed for sucrose and antipyrine, administered separately and together. PBPK modeling has made extensive progress in characterizing abstracted PK properties but this has also been its limitation. Now, other important questions and possible extensions emerge. How are these PK properties and the observed behaviors generated? The inherent heuristic limitations of traditional models have hindered getting meaningful, detailed answers to such questions. Synthetic models of the type described here are specifically intended to help answer such questions. Analogous to wet-lab experimental models, they retain their applicability even when broken apart into sub-components. Having and applying this new class of models along with traditional PK modeling methods is expected to increase the productivity of pharmaceutical research at all levels that make use of modeling and simulation. PMID:17051440

  12. A subgrid based approach for morphodynamic modelling

    Science.gov (United States)

    Volp, N. D.; van Prooijen, B. C.; Pietrzak, J. D.; Stelling, G. S.

    2016-07-01

    To improve the accuracy and the efficiency of morphodynamic simulations, we present a subgrid based approach for a morphodynamic model. This approach is well suited for areas characterized by sub-critical flow, like in estuaries, coastal areas and in low land rivers. This new method uses a different grid resolution to compute the hydrodynamics and the morphodynamics. The hydrodynamic computations are carried out with a subgrid based, two-dimensional, depth-averaged model. This model uses a coarse computational grid in combination with a subgrid. The subgrid contains high resolution bathymetry and roughness information to compute volumes, friction and advection. The morphodynamic computations are carried out entirely on a high resolution grid, the bed grid. It is key to find a link between the information defined on the different grids in order to guaranty the feedback between the hydrodynamics and the morphodynamics. This link is made by using a new physics-based interpolation method. The method interpolates water levels and velocities from the coarse grid to the high resolution bed grid. The morphodynamic solution improves significantly when using the subgrid based method compared to a full coarse grid approach. The Exner equation is discretised with an upwind method based on the direction of the bed celerity. This ensures a stable solution for the Exner equation. By means of three examples, it is shown that the subgrid based approach offers a significant improvement at a minimal computational cost.

  13. Designing Network-based Business Model Ontology

    DEFF Research Database (Denmark)

    Hashemi Nekoo, Ali Reza; Ashourizadeh, Shayegheh; Zarei, Behrouz

    2015-01-01

    is going to propose e-business model ontology from the network point of view and its application in real world. The suggested ontology for network-based businesses is composed of individuals` characteristics and what kind of resources they own. also, their connections and pre-conceptions of connections...... such as shared-mental model and trust. However, it mostly covers previous business model elements. To confirm the applicability of this ontology, it has been implemented in business angel network and showed how it works....

  14. Physiologically based pharmacokinetic model for acetone.

    OpenAIRE

    Kumagai, S.; Matsunaga, I

    1995-01-01

    OBJECTIVE--This study aimed to develop a physiologically based pharmacokinetic model for acetone and to predict the kinetic behaviour of acetone in the human body with that model. METHODS--The model consists of eight tissue groups in which acetone can be distributed: the mucous layer of the inhaled air tract, the mucous layer of the exhaled air tract, a compartment for gas exchange (alveolus of the lung), a group of blood vessel rich tissues including the brain and heart, a group of tissues i...

  15. Evolutionary modeling-based approach for model errors correction

    Directory of Open Access Journals (Sweden)

    S. Q. Wan

    2012-08-01

    Full Text Available The inverse problem of using the information of historical data to estimate model errors is one of the science frontier research topics. In this study, we investigate such a problem using the classic Lorenz (1963 equation as a prediction model and the Lorenz equation with a periodic evolutionary function as an accurate representation of reality to generate "observational data."

    On the basis of the intelligent features of evolutionary modeling (EM, including self-organization, self-adaptive and self-learning, the dynamic information contained in the historical data can be identified and extracted by computer automatically. Thereby, a new approach is proposed to estimate model errors based on EM in the present paper. Numerical tests demonstrate the ability of the new approach to correct model structural errors. In fact, it can actualize the combination of the statistics and dynamics to certain extent.

  16. Knowledge base system visualization reasoning model based on ICON

    Science.gov (United States)

    Chen, Deyun; Pei, Shujun; Quan, Zhiying

    2005-03-01

    Knowledge base system is one of the most future branches for artificial intelligence facing with practical application. But the reasoning process of system is invisible, not visual and users cannot intervene the reasoning process, therefore for users the system is only a black box. This condition causes many users to take a suspicious attitude to the conclusions analyzing and drawing from the system, that means even though the system has the explanation function, but it is still not far enough. If we adopt graph or image technique to display this reasoning procedure interactively and dynamically which can make this procedure be visual, users can intervene the reasoning procedure which can greatly reduce users" gain giving, and at the same time it can provide a given method for integrity check to knowledge of the knowledge base. Therefore, we can say that reasoning visualization of knowledge base system has a further meaning than general visualization. In this paper the visual problem of reasoning process for knowledge base system on the basis of the formalized analysis for ICON system, Icon operation, syntax and semanteme of the statement is presented, a reasoning model of knowledge base system that has a visual characteristics is established, the model is used to do an integrity check in practical expert system and knowledge base, better effect is got.

  17. Haptics-based dynamic implicit solid modeling.

    Science.gov (United States)

    Hua, Jing; Qin, Hong

    2004-01-01

    This paper systematically presents a novel, interactive solid modeling framework, Haptics-based Dynamic Implicit Solid Modeling, which is founded upon volumetric implicit functions and powerful physics-based modeling. In particular, we augment our modeling framework with a haptic mechanism in order to take advantage of additional realism associated with a 3D haptic interface. Our dynamic implicit solids are semi-algebraic sets of volumetric implicit functions and are governed by the principles of dynamics, hence responding to sculpting forces in a natural and predictable manner. In order to directly manipulate existing volumetric data sets as well as point clouds, we develop a hierarchical fitting algorithm to reconstruct and represent discrete data sets using our continuous implicit functions, which permit users to further design and edit those existing 3D models in real-time using a large variety of haptic and geometric toolkits, and visualize their interactive deformation at arbitrary resolution. The additional geometric and physical constraints afford more sophisticated control of the dynamic implicit solids. The versatility of our dynamic implicit modeling enables the user to easily modify both the geometry and the topology of modeled objects, while the inherent physical properties can offer an intuitive haptic interface for direct manipulation with force feedback. PMID:15794139

  18. Model-Based Power Plant Master Control

    Energy Technology Data Exchange (ETDEWEB)

    Boman, Katarina; Thomas, Jean; Funkquist, Jonas

    2010-08-15

    The main goal of the project has been to evaluate the potential of a coordinated master control for a solid fuel power plant in terms of tracking capability, stability and robustness. The control strategy has been model-based predictive control (MPC) and the plant used in the case study has been the Vattenfall power plant Idbaecken in Nykoeping. A dynamic plant model based on nonlinear physical models was used to imitate the true plant in MATLAB/SIMULINK simulations. The basis for this model was already developed in previous Vattenfall internal projects, along with a simulation model of the existing control implementation with traditional PID controllers. The existing PID control is used as a reference performance, and it has been thoroughly studied and tuned in these previous Vattenfall internal projects. A turbine model was developed with characteristics based on the results of steady-state simulations of the plant using the software EBSILON. Using the derived model as a representative for the actual process, an MPC control strategy was developed using linearization and gain-scheduling. The control signal constraints (rate of change) and constraints on outputs were implemented to comply with plant constraints. After tuning the MPC control parameters, a number of simulation scenarios were performed to compare the MPC strategy with the existing PID control structure. The simulation scenarios also included cases highlighting the robustness properties of the MPC strategy. From the study, the main conclusions are: - The proposed Master MPC controller shows excellent set-point tracking performance even though the plant has strong interactions and non-linearity, and the controls and their rate of change are bounded. - The proposed Master MPC controller is robust, stable in the presence of disturbances and parameter variations. Even though the current study only considered a very small number of the possible disturbances and modelling errors, the considered cases are

  19. UNDERSTANDING, ACCEPTING AND CONTROLLING RISKS - A MULTISTAGE FRAMEWORK FOR RISK COMMUNICATION

    NARCIS (Netherlands)

    VLEK, CAJ

    1995-01-01

    The meanings and functions of cc risk communication a (RC, for shea) are specified on the basis of a multistage framework for handling societal risks. After identifying various reasons for RC, essential components of > are briefly discussed : basic risk communicator positions, different levels of ri

  20. Research on EMI Reduction of Multi-stage Interleaved Bridgeless Power Factor Corrector

    DEFF Research Database (Denmark)

    Li, Qingnan; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2012-01-01

    Working as an electronic pollution eliminator, the Power Factor Corrector's (PFC) own Electromagnetic Interference (EMI) problems have been blocking its performance improvement for long. In this paper, a systematic research on EMI generation of a multi-stage Two-Boost-Circuit Interleaved Bridgeless...

  1. Seven prostate cancer susceptibility loci identified by a multi-stage genome-wide association study

    DEFF Research Database (Denmark)

    Kote-Jarai, Zsofia; Olama, Ali Amin Al; Giles, Graham G;

    2011-01-01

    Prostate cancer (PrCa) is the most frequently diagnosed male cancer in developed countries. We conducted a multi-stage genome-wide association study for PrCa and previously reported the results of the first two stages, which identified 16 PrCa susceptibility loci. We report here the results of st...

  2. Model Predictive Control based on Finite Impulse Response Models

    DEFF Research Database (Denmark)

    Prasath, Guru; Jørgensen, John Bagterp

    2008-01-01

    We develop a regularized l2 finite impulse response (FIR) predictive controller with input and input-rate constraints. Feedback is based on a simple constant output disturbance filter. The performance of the predictive controller in the face of plant-model mismatch is investigated by simulations...

  3. Incident duration modeling using flexible parametric hazard-based models.

    Science.gov (United States)

    Li, Ruimin; Shang, Pan

    2014-01-01

    Assessing and prioritizing the duration time and effects of traffic incidents on major roads present significant challenges for road network managers. This study examines the effect of numerous factors associated with various types of incidents on their duration and proposes an incident duration prediction model. Several parametric accelerated failure time hazard-based models were examined, including Weibull, log-logistic, log-normal, and generalized gamma, as well as all models with gamma heterogeneity and flexible parametric hazard-based models with freedom ranging from one to ten, by analyzing a traffic incident dataset obtained from the Incident Reporting and Dispatching System in Beijing in 2008. Results show that different factors significantly affect different incident time phases, whose best distributions were diverse. Given the best hazard-based models of each incident time phase, the prediction result can be reasonable for most incidents. The results of this study can aid traffic incident management agencies not only in implementing strategies that would reduce incident duration, and thus reduce congestion, secondary incidents, and the associated human and economic losses, but also in effectively predicting incident duration time. PMID:25530753

  4. Incident Duration Modeling Using Flexible Parametric Hazard-Based Models

    Directory of Open Access Journals (Sweden)

    Ruimin Li

    2014-01-01

    Full Text Available Assessing and prioritizing the duration time and effects of traffic incidents on major roads present significant challenges for road network managers. This study examines the effect of numerous factors associated with various types of incidents on their duration and proposes an incident duration prediction model. Several parametric accelerated failure time hazard-based models were examined, including Weibull, log-logistic, log-normal, and generalized gamma, as well as all models with gamma heterogeneity and flexible parametric hazard-based models with freedom ranging from one to ten, by analyzing a traffic incident dataset obtained from the Incident Reporting and Dispatching System in Beijing in 2008. Results show that different factors significantly affect different incident time phases, whose best distributions were diverse. Given the best hazard-based models of each incident time phase, the prediction result can be reasonable for most incidents. The results of this study can aid traffic incident management agencies not only in implementing strategies that would reduce incident duration, and thus reduce congestion, secondary incidents, and the associated human and economic losses, but also in effectively predicting incident duration time.

  5. Model Based Control of Reefer Container Systems

    DEFF Research Database (Denmark)

    Sørensen, Kresten Kjær

    This thesis is concerned with the development of model based control for the Star Cool refrigerated container (reefer) with the objective of reducing energy consumption. This project has been carried out under the Danish Industrial PhD programme and has been financed by Lodam together with the...

  6. Port-based modeling of mechatronic systems

    NARCIS (Netherlands)

    Breedveld, Peter C.

    2004-01-01

    Many engineering activities, including mechatronic design, require that a multidomain or ‘multi-physics’ system and its control system be designed as an integrated system. This contribution discusses the background and tools for a port-based approach to integrated modeling and simulation of physical

  7. Agent Based Modelling for Social Simulation

    NARCIS (Netherlands)

    Smit, S.K.; Ubink, E.M.; Vecht, B. van der; Langley, D.J.

    2013-01-01

    This document is the result of an exploratory project looking into the status of, and opportunities for Agent Based Modelling (ABM) at TNO. The project focussed on ABM applications containing social interactions and human factors, which we termed ABM for social simulation (ABM4SS). During the course

  8. What's Missing in Model-Based Teaching

    Science.gov (United States)

    Khan, Samia

    2011-01-01

    In this study, the author investigated how four science teachers employed model-based teaching (MBT) over a 1-year period. The purpose of the research was to develop a baseline of the fundamental and specific dimensions of MBT that are present and absent in science teaching. Teacher interviews, classroom observations, and pre and post-student…

  9. Introducing Waqf Based Takaful Model in India

    Directory of Open Access Journals (Sweden)

    Syed Ahmed Salman

    2014-03-01

    Full Text Available Objective – Waqf is a unique feature of the socioeconomic system of Islam in a multi- religious and developing country like India. India is a rich country with waqf assets. The history of waqf in India can be traced back to 800 years ago. Most of the researchers, suggest how waqf can be used a tool to mitigate the poverty of Muslims. India has the third highest Muslim population after Indonesia and Pakistan. However, the majority of Muslims belong to the low income group and they are in need of help. It is believed that waqf can be utilized for the betterment of Indian Muslim community. Among the available uses of waqf assets, the main objective of this paper is to introduce waqf based takaful model in India. In addition, how this proposed model can be adopted in India is highlighted.Methods – Library research is applied since this paper relies on secondary data by thoroughlyreviewing the most relevant literature.Result – India as a rich country with waqf assets should fully utilize the resources to help the Muslims through takaful.Conclusion – In this study, we have proposed waqf based takaful model with the combination of the concepts mudarabah and wakalah for India. We recommend this model based on the background of the  country and situations. Since we have not tested the viability of this model in India, future research should be continued on this testing.Keywords : Wakaf, Takaful, Kemiskinan dan India

  10. Unifying Model-Based and Reactive Programming within a Model-Based Executive

    Science.gov (United States)

    Williams, Brian C.; Gupta, Vineet; Norvig, Peter (Technical Monitor)

    1999-01-01

    Real-time, model-based, deduction has recently emerged as a vital component in AI's tool box for developing highly autonomous reactive systems. Yet one of the current hurdles towards developing model-based reactive systems is the number of methods simultaneously employed, and their corresponding melange of programming and modeling languages. This paper offers an important step towards unification. We introduce RMPL, a rich modeling language that combines probabilistic, constraint-based modeling with reactive programming constructs, while offering a simple semantics in terms of hidden state Markov processes. We introduce probabilistic, hierarchical constraint automata (PHCA), which allow Markov processes to be expressed in a compact representation that preserves the modularity of RMPL programs. Finally, a model-based executive, called Reactive Burton is described that exploits this compact encoding to perform efficIent simulation, belief state update and control sequence generation.

  11. A Novel Template-Based Learning Model

    CERN Document Server

    Abolghasemi-Dahaghani, Mohammadreza; Nowroozi, Alireza

    2011-01-01

    This article presents a model which is capable of learning and abstracting new concepts based on comparing observations and finding the resemblance between the observations. In the model, the new observations are compared with the templates which have been derived from the previous experiences. In the first stage, the objects are first represented through a geometric description which is used for finding the object boundaries and a descriptor which is inspired by the human visual system and then they are fed into the model. Next, the new observations are identified through comparing them with the previously-learned templates and are used for producing new templates. The comparisons are made based on measures like Euclidean or correlation distance. The new template is created by applying onion-pealing algorithm. The algorithm consecutively uses convex hulls which are made by the points representing the objects. If the new observation is remarkably similar to one of the observed categories, it is no longer util...

  12. Agent Based Modeling as an Educational Tool

    Science.gov (United States)

    Fuller, J. H.; Johnson, R.; Castillo, V.

    2012-12-01

    Motivation is a key element in high school education. One way to improve motivation and provide content, while helping address critical thinking and problem solving skills, is to have students build and study agent based models in the classroom. This activity visually connects concepts with their applied mathematical representation. "Engaging students in constructing models may provide a bridge between frequently disconnected conceptual and mathematical forms of knowledge." (Levy and Wilensky, 2011) We wanted to discover the feasibility of implementing a model based curriculum in the classroom given current and anticipated core and content standards.; Simulation using California GIS data ; Simulation of high school student lunch popularity using aerial photograph on top of terrain value map.

  13. Multiagent-Based Model For ESCM

    Directory of Open Access Journals (Sweden)

    Delia MARINCAS

    2011-01-01

    Full Text Available Web based applications for Supply Chain Management (SCM are now a necessity for every company in order to meet the increasing customer demands, to face the global competition and to make profit. Multiagent-based approach is appropriate for eSCM because it shows many of the characteristics a SCM system should have. For this reason, we have proposed a multiagent-based eSCM model which configures a virtual SC, automates the SC activities: selling, purchasing, manufacturing, planning, inventory, etc. This model will allow a better coordination of the supply chain network and will increase the effectiveness of Web and intel-ligent technologies employed in eSCM software.

  14. Modeling Leaves Based on Real Image

    Institute of Scientific and Technical Information of China (English)

    CAO Yu-kun; LI Yun-feng; ZHU Qing-sheng; LIU Yin-bin

    2004-01-01

    Plants have complex structures. The shape of a plant component is vital for capturing the characteristics of a species. One of the challenges in computer graphics is to create geometry of objects in an intuitive and direct way while allowing interactive manipulation of the resulting shapes. In this paper,an interactive method for modeling leaves based on real image is proposed using biological data for individual plants. The modeling process begins with a one-dimensional analogue of implicit surfaces,from which a 2D silhouette of a leaf is generated based on image segmentation. The silhouette skeleton is thus obtained. Feature parameters of the leaf are extracted based on biologically experimental data, and the obtained leaf structure is then modified by comparing the synthetic result with the real leaf so as to make the leaf structure more realistic. Finally, the leaf mesh is constructed by sweeps.

  15. [Fast spectral modeling based on Voigt peaks].

    Science.gov (United States)

    Li, Jin-rong; Dai, Lian-kui

    2012-03-01

    Indirect hard modeling (IHM) is a recently introduced method for quantitative spectral analysis, which was applied to the analysis of nonlinear relation between mixture spectrum and component concentration. In addition, IHM is an effectual technology for the analysis of components of mixture with molecular interactions and strongly overlapping bands. Before the establishment of regression model, IHM needs to model the measured spectrum as a sum of Voigt peaks. The precision of the spectral model has immediate impact on the accuracy of the regression model. A spectrum often includes dozens or even hundreds of Voigt peaks, which mean that spectral modeling is a optimization problem with high dimensionality in fact. So, large operation overhead is needed and the solution would not be numerically unique due to the ill-condition of the optimization problem. An improved spectral modeling method is presented in the present paper, which reduces the dimensionality of optimization problem by determining the overlapped peaks in spectrum. Experimental results show that the spectral modeling based on the new method is more accurate and needs much shorter running time than conventional method. PMID:22582612

  16. Mesoscopic model of actin-based propulsion.

    Directory of Open Access Journals (Sweden)

    Jie Zhu

    Full Text Available Two theoretical models dominate current understanding of actin-based propulsion: microscopic polymerization ratchet model predicts that growing and writhing actin filaments generate forces and movements, while macroscopic elastic propulsion model suggests that deformation and stress of growing actin gel are responsible for the propulsion. We examine both experimentally and computationally the 2D movement of ellipsoidal beads propelled by actin tails and show that neither of the two models can explain the observed bistability of the orientation of the beads. To explain the data, we develop a 2D hybrid mesoscopic model by reconciling these two models such that individual actin filaments undergoing nucleation, elongation, attachment, detachment and capping are embedded into the boundary of a node-spring viscoelastic network representing the macroscopic actin gel. Stochastic simulations of this 'in silico' actin network show that the combined effects of the macroscopic elastic deformation and microscopic ratchets can explain the observed bistable orientation of the actin-propelled ellipsoidal beads. To test the theory further, we analyze observed distribution of the curvatures of the trajectories and show that the hybrid model's predictions fit the data. Finally, we demonstrate that the model can explain both concave-up and concave-down force-velocity relations for growing actin networks depending on the characteristic time scale and network recoil. To summarize, we propose that both microscopic polymerization ratchets and macroscopic stresses of the deformable actin network are responsible for the force and movement generation.

  17. Modeling acquaintance networks based on balance theory

    Directory of Open Access Journals (Sweden)

    Vukašinović Vida

    2014-09-01

    Full Text Available An acquaintance network is a social structure made up of a set of actors and the ties between them. These ties change dynamically as a consequence of incessant interactions between the actors. In this paper we introduce a social network model called the Interaction-Based (IB model that involves well-known sociological principles. The connections between the actors and the strength of the connections are influenced by the continuous positive and negative interactions between the actors and, vice versa, the future interactions are more likely to happen between the actors that are connected with stronger ties. The model is also inspired by the social behavior of animal species, particularly that of ants in their colony. A model evaluation showed that the IB model turned out to be sparse. The model has a small diameter and an average path length that grows in proportion to the logarithm of the number of vertices. The clustering coefficient is relatively high, and its value stabilizes in larger networks. The degree distributions are slightly right-skewed. In the mature phase of the IB model, i.e., when the number of edges does not change significantly, most of the network properties do not change significantly either. The IB model was found to be the best of all the compared models in simulating the e-mail URV (University Rovira i Virgili of Tarragona network because the properties of the IB model more closely matched those of the e-mail URV network than the other models

  18. A comprehensive theory-based transport model

    International Nuclear Information System (INIS)

    A new theory based transport model with comprehensive physics (trapping, general toroidal geometry, finite beta, collisions) has been developed. The core of the model is the new trapped-gyro-Landau-fluid (TGLF) equations which provide a fast and accurate approximation to the linear eigenmodes for gyrokinetic drift-wave instabilities (trapped ion and electron modes, ion and electron temperature gradient modes and kinetic ballooning modes). This new TGLF transport model removes the limitation of its predecessor GLF23 and is valid for the same conditions as the gyrokinetic equations. A theory-based philosophy is used in the model construction. The closure coefficients of the TGLF equations are fit to local kinetic theory to give accurate linear eigenmodes. The saturation model is fit to non-linear turbulence simulations. No fitting to experiment is done so applying the model to experiments is a true test of the theory it is approximating. The TGLF model unifies trapped and passing particles in a single set of gyrofluid equations. A model for the averaging of the Landau resonance by the trapped particles makes the equations work seamlessly over the whole drift-wave wavenumber range from trapped ion modes to electron temperature gradient modes. A fast eigenmode solution method enables unrestricted magnetic geometry. Electron-ion collisions and full electromagnetic fluctuations round out the physics. The linear eigenmodes have been benchmarked against comprehensive physics gyrokinetic calculations over a large range of plasma parameters. The deviation between the gyrokinetic and TGLF linear growth rates averages 11.4% in shifted circle geometry. The transport model uses the TGLF eigenmodes to compute quasilinear fluxes of energy and particles. A model for the saturated amplitude of the turbulence completes the calculation. The saturation model is constructed to fit a large set of nonlinear gyrokinetic turbulence simulations. The TGLF model is valid in new physical

  19. A comprehensive theory-based transport model

    International Nuclear Information System (INIS)

    Full text: A new theory based transport model with comprehensive physics (trapping, general toroidal geometry, finite beta, collisions) has been developed. The core of the model is the new trapped-gyro- Landau-fluid (TGLF) equations which provide a fast and accurate approximation to the linear eigenmodes for gyrokinetic drift-wave instabilities (trapped ion and electron modes, ion and electron temperature gradient modes and kinetic ballooning modes). This new TGLF transport model removes the limitation of its predecessor GLF23 and is valid for the same conditions as the gyrokinetic equations. A theory-based philosophy is used in the model construction. The closure coefficients of the TGLF equations are fit to local kinetic theory to give accurate linear eigenmodes. The saturation model is fit to non-linear turbulence simulations. No fitting to experiment is done so applying the model to experiments is a true test of the theory it is approximating. The TGLF model unifies trapped and passing particles in a single set of gyrofluid equations. A model for the averaging of the Landau resonance by the trapped particles makes the equations work seamlessly over the whole drift-wave wavenumber range from trapped ion modes to electron temperature gradient modes. A fast eigenmode solution method enables unrestricted magnetic geometry. Electron-ion collisions and full electromagnetic fluctuations round out the physics. The linear eigenmodes have been benchmarked against comprehensive physics gyrokinetic calculations over a large range of plasma parameters. The deviation between the gyrokinetic and TGLF linear growth rates averages 11.4% in shifted circle geometry. The transport model uses the TGLF eigenmodes to compute quasilinear fluxes of energy and particles. A model for the saturated amplitude of the turbulence completes the calculation. The saturation model is constructed to fit a large set of nonlinear gyrokinetic turbulence simulations. The TGLF model is valid in new

  20. Model design for sequential decisions based upon evaluation of exploration information by capital markets

    International Nuclear Information System (INIS)

    The structure if an exploration model reflects a number of design considerations, one of which is the question or issue to be investigated by the model. Thus, a model designed to evaluate the magnitude of risk and its economic implications to optimal decision making at each decision juncture of a multistage exploration architecture differs considerably from one designed to evaluate, say, the long run average cost of discovery, in which the architecture of exploration is suppressed and risk is simply an element of average cost.The perspective of the model examined in this paper is that exploration is investment in information and that the next stage of an exploration program is undertaken only when the expected value of information to be acquired in that stage exceeds its cost. It is concluded that the degree to which this perspective is honored influences considerably model design

  1. Electrochemistry-based Battery Modeling for Prognostics

    Science.gov (United States)

    Daigle, Matthew J.; Kulkarni, Chetan Shrikant

    2013-01-01

    Batteries are used in a wide variety of applications. In recent years, they have become popular as a source of power for electric vehicles such as cars, unmanned aerial vehicles, and commericial passenger aircraft. In such application domains, it becomes crucial to both monitor battery health and performance and to predict end of discharge (EOD) and end of useful life (EOL) events. To implement such technologies, it is crucial to understand how batteries work and to capture that knowledge in the form of models that can be used by monitoring, diagnosis, and prognosis algorithms. In this work, we develop electrochemistry-based models of lithium-ion batteries that capture the significant electrochemical processes, are computationally efficient, capture the effects of aging, and are of suitable accuracy for reliable EOD prediction in a variety of usage profiles. This paper reports on the progress of such a model, with results demonstrating the model validity and accurate EOD predictions.

  2. An immune based dynamic intrusion detection model

    Institute of Scientific and Technical Information of China (English)

    LI Tao

    2005-01-01

    With the dynamic description method for self and antigen, and the concept of dynamic immune tolerance for lymphocytes in network-security domain presented in this paper, a new immune based dynamic intrusion detection model (Idid) is proposed. In Idid, the dynamic models and the corresponding recursive equations of the lifecycle of mature lymphocytes, and the immune memory are built. Therefore, the problem of the dynamic description of self and nonself in computer immune systems is solved, and the defect of the low efficiency of mature lymphocyte generating in traditional computer immune systems is overcome. Simulations of this model are performed, and the comparison experiment results show that the proposed dynamic intrusion detection model has a better adaptability than the traditional methods.

  3. Internet Supported Model Based Condition Monitoring

    Directory of Open Access Journals (Sweden)

    A Lewlaski,

    2010-04-01

    Full Text Available The importance of condition monitoring for preventive and predictive maintenance has increased through the use of system modelling. This modelling is carried out using manufacturer(s information. Data collection using data acquisition cards provides raw data to support system monitoring, especially when used through internet and network facilities, which make it economically available for larger number of users. A model based condition monitoring system which utilises Internet is presented in this paper. The overall software/hardware for this system will be referred to as MBCM portable unit here. It contains a standalone model of system under consideration. The unit is capable of capturing signals directly from the system, savingthem and producing these data in different formats for further analysis. In order to monitor the performance of the investigated system, the MBCM contains an embedded web-server to enable different signals to be monitored and captured locally, over a network, and via internet connection.

  4. Model-based multiple patterning layout decomposition

    Science.gov (United States)

    Guo, Daifeng; Tian, Haitong; Du, Yuelin; Wong, Martin D. F.

    2015-10-01

    As one of the most promising next generation lithography technologies, multiple patterning lithography (MPL) plays an important role in the attempts to keep in pace with 10 nm technology node and beyond. With feature size keeps shrinking, it has become impossible to print dense layouts within one single exposure. As a result, MPL such as double patterning lithography (DPL) and triple patterning lithography (TPL) has been widely adopted. There is a large volume of literature on DPL/TPL layout decomposition, and the current approach is to formulate the problem as a classical graph-coloring problem: Layout features (polygons) are represented by vertices in a graph G and there is an edge between two vertices if and only if the distance between the two corresponding features are less than a minimum distance threshold value dmin. The problem is to color the vertices of G using k colors (k = 2 for DPL, k = 3 for TPL) such that no two vertices connected by an edge are given the same color. This is a rule-based approach, which impose a geometric distance as a minimum constraint to simply decompose polygons within the distance into different masks. It is not desired in practice because this criteria cannot completely capture the behavior of the optics. For example, it lacks of sufficient information such as the optical source characteristics and the effects between the polygons outside the minimum distance. To remedy the deficiency, a model-based layout decomposition approach to make the decomposition criteria base on simulation results was first introduced at SPIE 2013.1 However, the algorithm1 is based on simplified assumption on the optical simulation model and therefore its usage on real layouts is limited. Recently AMSL2 also proposed a model-based approach to layout decomposition by iteratively simulating the layout, which requires excessive computational resource and may lead to sub-optimal solutions. The approach2 also potentially generates too many stiches. In this

  5. Multivariate statistical modelling based on generalized linear models

    CERN Document Server

    Fahrmeir, Ludwig

    1994-01-01

    This book is concerned with the use of generalized linear models for univariate and multivariate regression analysis. Its emphasis is to provide a detailed introductory survey of the subject based on the analysis of real data drawn from a variety of subjects including the biological sciences, economics, and the social sciences. Where possible, technical details and proofs are deferred to an appendix in order to provide an accessible account for non-experts. Topics covered include: models for multi-categorical responses, model checking, time series and longitudinal data, random effects models, and state-space models. Throughout, the authors have taken great pains to discuss the underlying theoretical ideas in ways that relate well to the data at hand. As a result, numerous researchers whose work relies on the use of these models will find this an invaluable account to have on their desks. "The basic aim of the authors is to bring together and review a large part of recent advances in statistical modelling of m...

  6. Image-based modelling of organogenesis.

    Science.gov (United States)

    Iber, Dagmar; Karimaddini, Zahra; Ünal, Erkan

    2016-07-01

    One of the major challenges in biology concerns the integration of data across length and time scales into a consistent framework: how do macroscopic properties and functionalities arise from the molecular regulatory networks-and how can they change as a result of mutations? Morphogenesis provides an excellent model system to study how simple molecular networks robustly control complex processes on the macroscopic scale despite molecular noise, and how important functional variants can emerge from small genetic changes. Recent advancements in three-dimensional imaging technologies, computer algorithms and computer power now allow us to develop and analyse increasingly realistic models of biological control. Here, we present our pipeline for image-based modelling that includes the segmentation of images, the determination of displacement fields and the solution of systems of partial differential equations on the growing, embryonic domains. The development of suitable mathematical models, the data-based inference of parameter sets and the evaluation of competing models are still challenging, and current approaches are discussed. PMID:26510443

  7. Business Models for NFC Based Mobile Payments

    DEFF Research Database (Denmark)

    Chae, Johannes Sang-Un; Hedman, Jonas

    2015-01-01

    Purpose: The purpose of the paper is to develop a business model framework for NFC based mobile payment solutions consisting of four mutually interdepended components: the value service, value network, value architecture, and value finance. Design: Using a comparative case study method, the paper...... from multiple stakeholders and the creation of an ecosystem. Furthermore, they focus on the scalability of their value propositions. Originality / value: The paper offers an applicable business model framework that allows practitioners and academics to study current and future mobile payment approaches....

  8. Model-based Tomographic Reconstruction Literature Search

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, D H; Lehman, S K

    2005-11-30

    In the process of preparing a proposal for internal research funding, a literature search was conducted on the subject of model-based tomographic reconstruction (MBTR). The purpose of the search was to ensure that the proposed research would not replicate any previous work. We found that the overwhelming majority of work on MBTR which used parameterized models of the object was theoretical in nature. Only three researchers had applied the technique to actual data. In this note, we summarize the findings of the literature search.

  9. History-based trust negotiation model

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yi-zhu; ZHAO Yan-hua; LU Hong-wei

    2009-01-01

    Trust negotiation (TN) is an approach to establish trust between strangers through iterative disclosure of digital credentials. Speeding up subsequent negotiations between the same negotiators is a problem worth of research. This paper introduces the concept of visiting card, and presents a history-based trust negotiation (HBTN) model. HBTN creates an account for a counterpart at the first negotiation and records valid credentials that the counterpart disclosed during each trust negotiation in his historical information base (HIB). For the following negotiation, no more credentials need to be disclosed for both parties. HBTN speeds up subsequent negotiations between the entities that interact with each other frequently without impairing the privacy preservation.

  10. Item Modeling Concept Based on Multimedia Authoring

    Directory of Open Access Journals (Sweden)

    Janez Stergar

    2008-09-01

    Full Text Available In this paper a modern item design framework for computer based assessment based on Flash authoring environment will be introduced. Question design will be discussed as well as the multimedia authoring environment used for item modeling emphasized. Item type templates are a structured means of collecting and storing item information that can be used to improve the efficiency and security of the innovative item design process. Templates can modernize the item design, enhance and speed up the development process. Along with content creation, multimedia has vast potential for use in innovative testing. The introduced item design template is based on taxonomy of innovative items which have great potential for expanding the content areas and construct coverage of an assessment. The presented item design approach is based on GUI's – one for question design based on implemented item design templates and one for user interaction tracking/retrieval. The concept of user interfaces based on Flash technology will be discussed as well as implementation of the innovative approach of the item design forms with multimedia authoring. Also an innovative method for user interaction storage/retrieval based on PHP extending Flash capabilities in the proposed framework will be introduced.

  11. An approach to mechanism-based cancer risk assessment for formaldehyde.

    OpenAIRE

    Conolly, R B; Andersen, M E

    1993-01-01

    The established carcinogenicity of formaldehyde in the rat and suggestive epidemiological evidence that formaldehyde may be a human carcinogen have led to its regulation by U.S. Federal agencies as a probable human carcinogen. These risk assessments have typically been based on tumor data in F344 rats exposed chronically to formaldehyde by inhalation and used the inhaled concentration as a measure of dose and the linearized multistage model (LMS) for dose-response characterization. Low-dose r...

  12. Modelling spatial association in pattern based land use simulation models.

    Science.gov (United States)

    Anputhas, Markandu; Janmaat, Johannus John A; Nichol, Craig F; Wei, Xiaohua Adam

    2016-10-01

    Pattern based land use models are widely used to forecast land use change. These models predict land use change using driving variables observed on the studied landscape. Many of these models have a limited capacity to account for interactions between neighbouring land parcels. Some modellers have used common spatial statistical measures to incorporate neighbour effects. However, these approaches were developed for continuous variables, while land use classifications are categorical. Neighbour interactions are also endogenous, changing as the land use patterns change. In this study we describe a single variable measure that captures aspects of neighbour interactions as reflected in the land use pattern. We use a stepwise updating process to demonstrate how dynamic updating of our measure impacts on model forecasts. We illustrate these results using the CLUE-S (Conversion of Land Use and its Effects at Small regional extent) system to forecast land use change for the Deep Creek watershed in the northern Okanagan Valley of British Columbia, Canada. Results establish that our measure improves model calibration and that ignoring changing spatial influences biases land use change forecasts. PMID:27420169

  13. Graph based model to support nurses' work.

    Science.gov (United States)

    Benedik, Peter; Rajkovič, Uroš; Sušteršič, Olga; Prijatelj, Vesna; Rajkovič, Vladislav

    2014-01-01

    Health care is a knowledge-based community that critically depends on knowledge management activities in order to ensure quality. Nurses are primary stakeholders and need to ensure that their information and knowledge needs are being met in such ways that enable them, to improve the quality and efficiency of health care service delivery for all subjects of health care. This paper describes a system to help nurses to create nursing care plan. It supports focusing nurse's attention on those resources/solutions that are likely to be most relevant to their particular situation/problem in nursing domain. System is based on multi-relational property graph representing a flexible modeling construct. Graph allows modeling a nursing domain (ontology) and the indices that partition domain into an efficient, searchable space where the solution to a problem is seen as abstractly defined traversals through its vertices and edges. PMID:24943559

  14. Requirements Engineering Model: Role Based Goal Oriented Model

    OpenAIRE

    Sandfreni; Surendro Ir. Kridanto

    2016-01-01

    Requirements engineering approach through intentional perspective is one of the arguments that appear in the field of requirement engineering. That approach can explain the characteristics of the behavior of an actor. The usage Goal Based Workflow and KAOS method in iStar modeling might help the system analyst to gain knowledge about the internal process inside each of actor sequentially, such that the whole sequential activity to achieve the goal are exposed clearly in those actor’s internal...

  15. Model-Based Trace-Checking

    CERN Document Server

    Howard, Y; Gravell, A; Ferreira, C; Augusto, J C

    2011-01-01

    Trace analysis can be a useful way to discover problems in a program under test. Rather than writing a special purpose trace analysis tool, this paper proposes that traces can usefully be analysed by checking them against a formal model using a standard model-checker or else an animator for executable specifications. These techniques are illustrated using a Travel Agent case study implemented in J2EE. We added trace beans to this code that write trace information to a database. The traces are then extracted and converted into a form suitable for analysis by Spin, a popular model-checker, and Pro-B, a model-checker and animator for the B notation. This illustrates the technique, and also the fact that such a system can have a variety of models, in different notations, that capture different features. These experiments have demonstrated that model-based trace-checking is feasible. Future work is focussed on scaling up the approach to larger systems by increasing the level of automation.

  16. Agent Based Model of Livestock Movements

    Science.gov (United States)

    Miron, D. J.; Emelyanova, I. V.; Donald, G. E.; Garner, G. M.

    The modelling of livestock movements within Australia is of national importance for the purposes of the management and control of exotic disease spread, infrastructure development and the economic forecasting of livestock markets. In this paper an agent based model for the forecasting of livestock movements is presented. This models livestock movements from farm to farm through a saleyard. The decision of farmers to sell or buy cattle is often complex and involves many factors such as climate forecast, commodity prices, the type of farm enterprise, the number of animals available and associated off-shore effects. In this model the farm agent's intelligence is implemented using a fuzzy decision tree that utilises two of these factors. These two factors are the livestock price fetched at the last sale and the number of stock on the farm. On each iteration of the model farms choose either to buy, sell or abstain from the market thus creating an artificial supply and demand. The buyers and sellers then congregate at the saleyard where livestock are auctioned using a second price sealed bid. The price time series output by the model exhibits properties similar to those found in real livestock markets.

  17. Ecosystem Based Business Model of Smart Grid

    OpenAIRE

    Lundgaard, Morten Raahauge; Ma, Zheng; Jørgensen, Bo Nørregaard

    2015-01-01

    This paper tries to investigate the ecosystem based business model in a smart grid infrastructure and the potential of value capture in the highly complex macro infrastructure such as smart grid. This paper proposes an alternative perspective to study the smart grid business ecosystem to support the infrastructural challenges, such as the interoperability of business components for smart grid. So far little research has explored the business ecosystem in the smart grid concept. The study on t...

  18. Market Segmentation Using Bayesian Model Based Clustering

    OpenAIRE

    Van Hattum, P.

    2009-01-01

    This dissertation deals with two basic problems in marketing, that are market segmentation, which is the grouping of persons who share common aspects, and market targeting, which is focusing your marketing efforts on one or more attractive market segments. For the grouping of persons who share common aspects a Bayesian model based clustering approach is proposed such that it can be applied to data sets that are specifically used for market segmentation. The cluster algorithm can handle very l...

  19. Enhancing the Combat ID Agent Based Model

    OpenAIRE

    Spaans, M.; Petiet, P.J.; Dean, D; Jackson, J.; Bradley, W.; Shan, L. Y.; Ka-Yoon, W.; Yongwei, D.W.; Kai, C.W.

    2007-01-01

    During previous Project Albert and International data Farming Workshops (IDFW) and during discussions between Dstl and TNO, the suitability and feasibility of Agent Based Models (ABMs) to support research on Combat Identification (Combat ID) was examined. The objective of this research is to: Investigate the effect of (a large number of) different variations in Situational Awareness, Situation Awareness (SA), Target Identification (Target ID), Human Factors, and Tactics, Techniques, and Proce...

  20. INVESTOR BASED PSYCHOLOGICAL DECISION MAKING MODEL

    OpenAIRE

    Mohd Alnajjar

    2013-01-01

    Significance of behavioral finance has been realized. Intrinsic value of behavioral finance is to investigate the irrational attitude of investor while making investment decision. This study explores the investor based psychological decision making model for enhancing the understanding about the psychological decision making process of investors in Islamabad Stock Exchange. A self-administered structured questionnaire is used for gathering data from 168 respondents (investors of ISE). Correla...

  1. Building Information Modelling Incorporating Technology Based Assessment

    OpenAIRE

    Murphy, Maurice; Scott, Lloyd

    2011-01-01

    Building Information Modelling (BIM) is currently being developed as a virtual learning tool for construction and surveying students in the Dublin Institute of Technology. This advanced technology is also used to develop a technology based assessment practice for enhancing the learning environment of construction and surveying students. A theoretical design framework is presented in this paper, which combines advanced technology and assessment theory to create a virtual learning environment. ...

  2. CEAI: CCM based Email Authorship Identification Model

    OpenAIRE

    Nizamani, Sarwat; Memon, Nasrullah

    2013-01-01

    In this paper we present a model for email authorship identification (EAI) by employing a Cluster-based Classification (CCM) technique. Traditionally, stylometric features have been successfully employed in various authorship analysis tasks; we extend the traditional feature-set to include some more interesting and effective features for email authorship identification (e.g. the last punctuation mark used in an email, the tendency of an author to use capitalization at the start of an email, o...

  3. Requirements engineering-based conceptual modeling

    OpenAIRE

    Insfrán, E.; O. Pastor; Wieringa, R.J.

    2002-01-01

    The software production process involves a set of phases where a clear relationship and smooth transitions between them should be introduced. In this paper, a requirements engineering-based conceptual modelling approach is introduced as a way to improve the quality of the software production process. The aim of this approach is to provide a set of techniques and methods to capture software requirements and to provide a way to move from requirements to a conceptual schema in a traceable way. T...

  4. Genome Informed Trait-Based Models

    Science.gov (United States)

    Karaoz, U.; Cheng, Y.; Bouskill, N.; Tang, J.; Beller, H. R.; Brodie, E.; Riley, W. J.

    2013-12-01

    Trait-based approaches are powerful tools for representing microbial communities across both spatial and temporal scales within ecosystem models. Trait-based models (TBMs) represent the diversity of microbial taxa as stochastic assemblages with a distribution of traits constrained by trade-offs between these traits. Such representation with its built-in stochasticity allows the elucidation of the interactions between the microbes and their environment by reducing the complexity of microbial community diversity into a limited number of functional ';guilds' and letting them emerge across spatio-temporal scales. From the biogeochemical/ecosystem modeling perspective, the emergent properties of the microbial community could be directly translated into predictions of biogeochemical reaction rates and microbial biomass. The accuracy of TBMs depends on the identification of key traits of the microbial community members and on the parameterization of these traits. Current approaches to inform TBM parameterization are empirical (i.e., based on literature surveys). Advances in omic technologies (such as genomics, metagenomics, metatranscriptomics, and metaproteomics) pave the way to better-initialize models that can be constrained in a generic or site-specific fashion. Here we describe the coupling of metagenomic data to the development of a TBM representing the dynamics of metabolic guilds from an organic carbon stimulated groundwater microbial community. Illumina paired-end metagenomic data were collected from the community as it transitioned successively through electron-accepting conditions (nitrate-, sulfate-, and Fe(III)-reducing), and used to inform estimates of growth rates and the distribution of metabolic pathways (i.e., aerobic and anaerobic oxidation, fermentation) across a spatially resolved TBM. We use this model to evaluate the emergence of different metabolisms and predict rates of biogeochemical processes over time. We compare our results to observational

  5. Model based risk assessment - the CORAS framework

    Energy Technology Data Exchange (ETDEWEB)

    Gran, Bjoern Axel; Fredriksen, Rune; Thunem, Atoosa P-J.

    2004-04-15

    Traditional risk analysis and assessment is based on failure-oriented models of the system. In contrast to this, model-based risk assessment (MBRA) utilizes success-oriented models describing all intended system aspects, including functional, operational and organizational aspects of the target. The target models are then used as input sources for complementary risk analysis and assessment techniques, as well as a basis for the documentation of the assessment results. The EU-funded CORAS project developed a tool-supported methodology for the application of MBRA in security-critical systems. The methodology has been tested with successful outcome through a series of seven trial within the telemedicine and ecommerce areas. The CORAS project in general and the CORAS application of MBRA in particular have contributed positively to the visibility of model-based risk assessment and thus to the disclosure of several potentials for further exploitation of various aspects within this important research field. In that connection, the CORAS methodology's possibilities for further improvement towards utilization in more complex architectures and also in other application domains such as the nuclear field can be addressed. The latter calls for adapting the framework to address nuclear standards such as IEC 60880 and IEC 61513. For this development we recommend applying a trial driven approach within the nuclear field. The tool supported approach for combining risk analysis and system development also fits well with the HRP proposal for developing an Integrated Design Environment (IDE) providing efficient methods and tools to support control room systems design. (Author)

  6. Realistic face modeling based on multiple deformations

    Institute of Scientific and Technical Information of China (English)

    GONG Xun; WANG Guo-yin

    2007-01-01

    On the basis of the assumption that the human face belongs to a linear class, a multiple-deformation model is proposed to recover face shape from a few points on a single 2D image. Compared to the conventional methods, this study has the following advantages. First, the proposed modified 3D sparse deforming model is a noniterative approach that can compute global translation efficiently and accurately. Subsequently, the overfitting problem can be alleviated based on the proposed multiple deformation model. Finally, by keeping the main features, the texture generated is realistic. The comparison results show that this novel method outperforms the existing methods by using ground truth data and that realistic 3D faces can be recovered efficiently from a single photograph.

  7. Model based monitoring of stormwater runoff quality

    DEFF Research Database (Denmark)

    Birch, Heidi; Vezzaro, Luca; Mikkelsen, Peter Steen

    2012-01-01

    average and maximum event mean concentrations. Use of this model reduced the uncertainty of predicted annual average concentrations compared to a simple stochastic method based solely on data. The predicted annual average obtained by using passive sampler measurements (one month installation) for......Monitoring of micropollutants (MP) in stormwater is essential to evaluate the impacts of stormwater on the receiving aquatic environment. The aim of this study was to investigate how different strategies for monitoring of stormwater quality (combination of model with field sampling) affect the...... information obtained about MPs discharged from the monitored system. A dynamic stormwater quality model was calibrated using MP data collected by volume-proportional and passive sampling in a storm drainage system in the outskirts of Copenhagen (Denmark) and a 10-year rain series was used to find annual...

  8. On Reading-Based Writing Instruction Model

    Institute of Scientific and Technical Information of China (English)

    李大艳; 王建安

    2012-01-01

    English writing is a complex integrative process of comprehensive skills. A host of students are still unable to write a coherent English paragraph after having learned English for many years at school. To help college students improve their writing competence is a great challenge facing the English teaching in China. Researches on writing teaching method abroad have experienced prosperity. In China, however, researches in this field are far behind. There is great need to search for more efficient writing instruction model so that it can serve well in Chinese context. Enlightened by Krashen's input hypothesis and Swain's output hypothesis, the writer put forward Reading-Based Writing Instruction Model. This paper aims to discuss the effectiveness of this model from the different perspectives.

  9. Business Models for NFC based mobile payments

    Directory of Open Access Journals (Sweden)

    Johannes Sang Un Chae

    2015-01-01

    Full Text Available Purpose: The purpose of the paper is to develop a business model framework for NFC based mobile payment solutions consisting of four mutually interdepended components: the value service, value network, value architecture, and value finance. Design: Using a comparative case study method, the paper investigates Google Wallet and ISIS Mobile Wallet and their underlying business models. Findings: Google Wallet and ISIS Mobile Wallet are focusing on providing an enhanced customer experience with their mobile wallet through a multifaceted value proposition. The delivery of its offering requires cooperation from multiple stakeholders and the creation of an ecosystem. Furthermore, they focus on the scalability of their value propositions. Originality / value: The paper offers an applicable business model framework that allows practitioners and academics to study current and future mobile payment approaches.

  10. Model-based vision for space applications

    Science.gov (United States)

    Chaconas, Karen; Nashman, Marilyn; Lumia, Ronald

    1992-01-01

    This paper describes a method for tracking moving image features by combining spatial and temporal edge information with model based feature information. The algorithm updates the two-dimensional position of object features by correlating predicted model features with current image data. The results of the correlation process are used to compute an updated model. The algorithm makes use of a high temporal sampling rate with respect to spatial changes of the image features and operates in a real-time multiprocessing environment. Preliminary results demonstrate successful tracking for image feature velocities between 1.1 and 4.5 pixels every image frame. This work has applications for docking, assembly, retrieval of floating objects and a host of other space-related tasks.

  11. Model-based target and background characterization

    Science.gov (United States)

    Mueller, Markus; Krueger, Wolfgang; Heinze, Norbert

    2000-07-01

    Up to now most approaches of target and background characterization (and exploitation) concentrate solely on the information given by pixels. In many cases this is a complex and unprofitable task. During the development of automatic exploitation algorithms the main goal is the optimization of certain performance parameters. These parameters are measured during test runs while applying one algorithm with one parameter set to images that constitute of image domains with very different domain characteristics (targets and various types of background clutter). Model based geocoding and registration approaches provide means for utilizing the information stored in GIS (Geographical Information Systems). The geographical information stored in the various GIS layers can define ROE (Regions of Expectations) and may allow for dedicated algorithm parametrization and development. ROI (Region of Interest) detection algorithms (in most cases MMO (Man- Made Object) detection) use implicit target and/or background models. The detection algorithms of ROIs utilize gradient direction models that have to be matched with transformed image domain data. In most cases simple threshold calculations on the match results discriminate target object signatures from the background. The geocoding approaches extract line-like structures (street signatures) from the image domain and match the graph constellation against a vector model extracted from a GIS (Geographical Information System) data base. Apart from geo-coding the algorithms can be also used for image-to-image registration (multi sensor and data fusion) and may be used for creation and validation of geographical maps.

  12. Inference-based procedural modeling of solids

    KAUST Repository

    Biggers, Keith

    2011-11-01

    As virtual environments become larger and more complex, there is an increasing need for more automated construction algorithms to support the development process. We present an approach for modeling solids by combining prior examples with a simple sketch. Our algorithm uses an inference-based approach to incrementally fit patches together in a consistent fashion to define the boundary of an object. This algorithm samples and extracts surface patches from input models, and develops a Petri net structure that describes the relationship between patches along an imposed parameterization. Then, given a new parameterized line or curve, we use the Petri net to logically fit patches together in a manner consistent with the input model. This allows us to easily construct objects of varying sizes and configurations using arbitrary articulation, repetition, and interchanging of parts. The result of our process is a solid model representation of the constructed object that can be integrated into a simulation-based environment. © 2011 Elsevier Ltd. All rights reserved.

  13. Néron models and base change

    CERN Document Server

    Halle, Lars Halvard

    2016-01-01

    Presenting the first systematic treatment of the behavior of Néron models under ramified base change, this book can be read as an introduction to various subtle invariants and constructions related to Néron models of semi-abelian varieties, motivated by concrete research problems and complemented with explicit examples. Néron models of abelian and semi-abelian varieties have become an indispensable tool in algebraic and arithmetic geometry since Néron introduced them in his seminal 1964 paper. Applications range from the theory of heights in Diophantine geometry to Hodge theory. We focus specifically on Néron component groups, Edixhoven’s filtration and the base change conductor of Chai and Yu, and we study these invariants using various techniques such as models of curves, sheaves on Grothendieck sites and non-archimedean uniformization. We then apply our results to the study of motivic zeta functions of abelian varieties. The final chapter contains a list of challenging open questions. This book is a...

  14. Concept Tree Based Information Retrieval Model

    Directory of Open Access Journals (Sweden)

    Chunyan Yuan

    2014-05-01

    Full Text Available This paper proposes a novel concept-based query expansion technique named Markov concept tree model (MCTM, discovering term relationship through the concept tree deduced by term markov network. We address two important issues for query expansion: the selection and the weighting of expansion search terms. In contrast to earlier methods, queries are expanded by adding those terms that are most similar to the concept of the query, rather than selecting terms that are similar to a signal query terms. Utilizing Markov network which is constructed according to the co-occurrence information of the terms in collection, it generate concept tree for each original query term, remove the redundant and irrelevant nodes in concept tree, then adjust the weight of original query and the weight of expansion term based on a pruning algorithm. We use this model for query expansion and evaluate the effectiveness of the model by examining the accuracy and robustness of the expansion methods, Compared with the baseline model, the experiments on standard dataset reveal that this method can achieve a better query quality

  15. Model-based explanation of plant knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Huuskonen, P.J. [VTT Electronics, Oulu (Finland). Embedded Software

    1997-12-31

    This thesis deals with computer explanation of knowledge related to design and operation of industrial plants. The needs for explanation are motivated through case studies and literature reviews. A general framework for analysing plant explanations is presented. Prototypes demonstrate key mechanisms for implementing parts of the framework. Power plants, steel mills, paper factories, and high energy physics control systems are studied to set requirements for explanation. The main problems are seen to be either lack or abundance of information. Design knowledge in particular is found missing at plants. Support systems and automation should be enhanced with ways to explain plant knowledge to the plant staff. A framework is formulated for analysing explanations of plant knowledge. It consists of three parts: 1. a typology of explanation, organised by the class of knowledge (factual, functional, or strategic) and by the target of explanation (processes, automation, or support systems), 2. an identification of explanation tasks generic for the plant domain, and 3. an identification of essential model types for explanation (structural, behavioural, functional, and teleological). The tasks use the models to create the explanations of the given classes. Key mechanisms are discussed to implement the generic explanation tasks. Knowledge representations based on objects and their relations form a vocabulary to model and present plant knowledge. A particular class of models, means-end models, are used to explain plant knowledge. Explanations are generated through searches in the models. Hypertext is adopted to communicate explanations over dialogue based on context. The results are demonstrated in prototypes. The VICE prototype explains the reasoning of an expert system for diagnosis of rotating machines at power plants. The Justifier prototype explains design knowledge obtained from an object-oriented plant design tool. Enhanced access mechanisms into on-line documentation are

  16. Model-based vision for car following

    Science.gov (United States)

    Schneiderman, Henry; Nashman, Marilyn; Lumia, Ronald

    1993-08-01

    This paper describes a vision processing algorithm that supports autonomous car following. The algorithm visually tracks the position of a `lead vehicle' from the vantage of a pursuing `chase vehicle.' The algorithm requires a 2-D model of the back of the lead vehicle. This model is composed of line segments corresponding to features that give rise to strong edges. There are seven sequential stages of computation: (1) Extracting edge points; (2) Associating extracted edge points with the model features; (3) Determining the position of each model feature; (4) Determining the model position; (5) Updating the motion model of the object; (6) Predicting the position of the object in next image; (7) Predicting the location of all object features from prediction of object position. All processing is confined to the 2-D image plane. The 2-D model location computed in this processing is used to determine the position of the lead vehicle with respect to a 3-D coordinate frame affixed to the chase vehicle. This algorithm has been used as part of a complete system to drive an autonomous vehicle, a High Mobility Multipurpose Wheeled Vehicle (HMMWV) such that it follows a lead vehicle at speeds up to 35 km/hr. The algorithm runs at an update rate of 15 Hertz and has a worst case computational delay of 128 ms. The algorithm is implemented under the NASA/NBS Standard Reference Model for Telerobotic Control System Architecture (NASREM) and runs on a dedicated vision processing engine and a VME-based multiprocessor system.

  17. A Visual Attention Model Based Image Fusion

    Directory of Open Access Journals (Sweden)

    Rishabh Gupta

    2013-12-01

    Full Text Available To develop an efficient image fusion algorithm based on visual attention model for images with distinct objects. Image fusion is a process of combining complementary information from multiple images of the same scene into an image, so that the resultant image contains a more accurate description of the scene than any of the individual source images. The two basic fusion techniques are pixel level and region level fusion. Pixel level fusion deals with the operations on each and every pixel separately. The various pixel level techniques are averaging, stationary wavelet transforms, discrete wavelet transforms, Principal Component Analysis (PCA. But because of less sensitivity to noise and mis-registration, the region level image fusion is an emerging approach in the field of multifocus image fusion. The most appreciated approaches in region-based methods are multifocus image fusion using the concept of focal connectivity and spatial frequency. These two methods works well on still images as well as on video frames as inputs. A new region based technique is been proposed for the multifocus images having distinct objects. The method is based on the visual attention models and results obtained are appreciating for the distinct objects input images. The Proposed method results are highlighted using tenengrade and extended spatial frequency as performance parameters by taking several pairs of multi-focus input images like microscopic images, forensic images and video frames.

  18. Model-Based Method for Sensor Validation

    Science.gov (United States)

    Vatan, Farrokh

    2012-01-01

    Fault detection, diagnosis, and prognosis are essential tasks in the operation of autonomous spacecraft, instruments, and in situ platforms. One of NASA s key mission requirements is robust state estimation. Sensing, using a wide range of sensors and sensor fusion approaches, plays a central role in robust state estimation, and there is a need to diagnose sensor failure as well as component failure. Sensor validation can be considered to be part of the larger effort of improving reliability and safety. The standard methods for solving the sensor validation problem are based on probabilistic analysis of the system, from which the method based on Bayesian networks is most popular. Therefore, these methods can only predict the most probable faulty sensors, which are subject to the initial probabilities defined for the failures. The method developed in this work is based on a model-based approach and provides the faulty sensors (if any), which can be logically inferred from the model of the system and the sensor readings (observations). The method is also more suitable for the systems when it is hard, or even impossible, to find the probability functions of the system. The method starts by a new mathematical description of the problem and develops a very efficient and systematic algorithm for its solution. The method builds on the concepts of analytical redundant relations (ARRs).

  19. Flow based vs. demand based energy-water modelling

    Science.gov (United States)

    Rozos, Evangelos; Nikolopoulos, Dionysis; Efstratiadis, Andreas; Koukouvinos, Antonios; Makropoulos, Christos

    2015-04-01

    The water flow in hydro-power generation systems is often used downstream to cover other type of demands like irrigation and water supply. However, the typical case is that the energy demand (operation of hydro-power plant) and the water demand do not coincide. Furthermore, the water inflow into a reservoir is a stochastic process. Things become more complicated if renewable resources (wind-turbines or photovoltaic panels) are included into the system. For this reason, the assessment and optimization of the operation of hydro-power systems are challenging tasks that require computer modelling. This modelling should not only simulate the water budget of the reservoirs and the energy production/consumption (pumped-storage), but should also take into account the constraints imposed by the natural or artificial water network using a flow routing algorithm. HYDRONOMEAS, for example, uses an elegant mathematical approach (digraph) to calculate the flow in a water network based on: the demands (input timeseries), the water availability (simulated) and the capacity of the transmission components (properties of channels, rivers, pipes, etc.). The input timeseries of demand should be estimated by another model and linked to the corresponding network nodes. A model that could be used to estimate these timeseries is UWOT. UWOT is a bottom up urban water cycle model that simulates the generation, aggregation and routing of water demand signals. In this study, we explore the potentials of UWOT in simulating the operation of complex hydrosystems that include energy generation. The evident advantage of this approach is the use of a single model instead of one for estimation of demands and another for the system simulation. An application of UWOT in a large scale system is attempted in mainland Greece in an area extending over 130×170 km². The challenges, the peculiarities and the advantages of this approach are examined and critically discussed.

  20. Grid based calibration of SWAT hydrological models

    Directory of Open Access Journals (Sweden)

    D. Gorgan

    2012-07-01

    Full Text Available The calibration and execution of large hydrological models, such as SWAT (soil and water assessment tool, developed for large areas, high resolution, and huge input data, need not only quite a long execution time but also high computation resources. SWAT hydrological model supports studies and predictions of the impact of land management practices on water, sediment, and agricultural chemical yields in complex watersheds. The paper presents the gSWAT application as a web practical solution for environmental specialists to calibrate extensive hydrological models and to run scenarios, by hiding the complex control of processes and heterogeneous resources across the grid based high computation infrastructure. The paper highlights the basic functionalities of the gSWAT platform, and the features of the graphical user interface. The presentation is concerned with the development of working sessions, interactive control of calibration, direct and basic editing of parameters, process monitoring, and graphical and interactive visualization of the results. The experiments performed on different SWAT models and the obtained results argue the benefits brought by the grid parallel and distributed environment as a solution for the processing platform. All the instances of SWAT models used in the reported experiments have been developed through the enviroGRIDS project, targeting the Black Sea catchment area.