Operational derivation of Boltzmann distribution with Maxwell's demon model.
Hosoya, Akio; Maruyama, Koji; Shikano, Yutaka
2015-11-24
The resolution of the Maxwell's demon paradox linked thermodynamics with information theory through information erasure principle. By considering a demon endowed with a Turing-machine consisting of a memory tape and a processor, we attempt to explore the link towards the foundations of statistical mechanics and to derive results therein in an operational manner. Here, we present a derivation of the Boltzmann distribution in equilibrium as an example, without hypothesizing the principle of maximum entropy. Further, since the model can be applied to non-equilibrium processes, in principle, we demonstrate the dissipation-fluctuation relation to show the possibility in this direction.
Validation of mixing heights derived from the operational NWP models at the German weather service
Energy Technology Data Exchange (ETDEWEB)
Fay, B.; Schrodin, R.; Jacobsen, I. [Deutscher Wetterdienst, Offenbach (Germany); Engelbart, D. [Deutscher Wetterdienst, Meteorol. Observ. Lindenberg (Germany)
1997-10-01
NWP models incorporate an ever-increasing number of observations via four-dimensional data assimilation and are capable of providing comprehensive information about the atmosphere both in space and time. They describe not only near surface parameters but also the vertical structure of the atmosphere. They operate daily, are well verified and successfully used as meteorological pre-processors in large-scale dispersion modelling. Applications like ozone forecasts, emission or power plant control calculations require highly resolved, reliable, and routine values of the temporal evolution of the mixing height (MH) which is a critical parameter in determining the mixing and transformation of substances and the resulting pollution levels near the ground. The purpose of development at the German Weather Service is a straightforward mixing height scheme that uses only parameters derived from NWP model variables and thus automatically provides spatial and temporal fields of mixing heights on an operational basis. An universal parameter to describe stability is the Richardson number Ri. Compared to the usual diagnostic or rate equations, the Ri number concept of determining mixing heights has the advantage of using not only surface layer parameters but also regarding the vertical structure of the boundary layer resolved in the NWP models. (au)
Deriving belief operators from preferences
Asheim, Geir B.
2000-01-01
A belief operator derived from preferences is presented. It generalizes ‘belief with probability1’ to incomplete preferences and satisﬁes minimal requirements for belief operators under weak conditions.
Energy Technology Data Exchange (ETDEWEB)
Krishnaswami, Govind S [Institute for Theoretical Physics and Spinoza Institute, Utrecht University, Postbus 80.195, 3508 TD, Utrecht (Netherlands)], E-mail: govind.krishnaswami@durham.ac.uk
2008-04-11
We consider large-N multi-matrix models whose action closely mimics that of Yang-Mills theory, including gauge-fixing and ghost terms. We show that the factorized Schwinger-Dyson loop equations, expressed in terms of the generating series of gluon and ghost correlations G({xi}), are quadratic equations S{sup i}G=G{xi}{sup i}G in concatenation of correlations. The Schwinger-Dyson operator S{sup i} is built from the left annihilation operator, which does not satisfy the Leibnitz rule with respect to concatenation. So the loop equations are not differential equations. We show that left annihilation is a derivation of the graded shuffle product of gluon and ghost correlations. The shuffle product is the point-wise product of Wilson loops, expressed in terms of correlations. So in the limit where concatenation is approximated by shuffle products, the loop equations become differential equations. Remarkably, the Schwinger-Dyson operator as a whole is also a derivation of the graded shuffle product. This allows us to turn the loop equations into linear equations for the shuffle reciprocal, which might serve as a starting point for an approximation scheme.
Pseudo-invariant Eigen-operator for Deriving Energy-Level Gap for Jaynes-Cummings Model
International Nuclear Information System (INIS)
Fan Hongyi; Da Cheng
2006-01-01
We extend the concept of invariant eigen-operator to pseudo-invariant eigen-operator case through analyzing the standard Jaynes-Cummings model. We find the pseudo-invariant eigen-operator in terms of supersymmetric generators of this model, which diretly leads to the energy-level gap for Jaynes-Cummings Hamiltonian.
Itkin, Andrey
2017-01-01
This monograph presents a novel numerical approach to solving partial integro-differential equations arising in asset pricing models with jumps, which greatly exceeds the efficiency of existing approaches. The method, based on pseudo-differential operators and several original contributions to the theory of finite-difference schemes, is new as applied to the Lévy processes in finance, and is herein presented for the first time in a single volume. The results within, developed in a series of research papers, are collected and arranged together with the necessary background material from Lévy processes, the modern theory of finite-difference schemes, the theory of M-matrices and EM-matrices, etc., thus forming a self-contained work that gives the reader a smooth introduction to the subject. For readers with no knowledge of finance, a short explanation of the main financial terms and notions used in the book is given in the glossary. The latter part of the book demonstrates the efficacy of the method by solvin...
Operations and Modeling Analysis
Ebeling, Charles
2005-01-01
The Reliability and Maintainability Analysis Tool (RMAT) provides NASA the capability to estimate reliability and maintainability (R&M) parameters and operational support requirements for proposed space vehicles based upon relationships established from both aircraft and Shuttle R&M data. RMAT has matured both in its underlying database and in its level of sophistication in extrapolating this historical data to satisfy proposed mission requirements, maintenance concepts and policies, and type of vehicle (i.e. ranging from aircraft like to shuttle like). However, a companion analyses tool, the Logistics Cost Model (LCM) has not reached the same level of maturity as RMAT due, in large part, to nonexistent or outdated cost estimating relationships and underlying cost databases, and it's almost exclusive dependence on Shuttle operations and logistics cost input parameters. As a result, the full capability of the RMAT/LCM suite of analysis tools to take a conceptual vehicle and derive its operations and support requirements along with the resulting operating and support costs has not been realized.
AbdelRahman, Samir E; Zhang, Mingyuan; Bray, Bruce E; Kawamoto, Kensaku
2014-05-27
The aim of this study was to propose an analytical approach to develop high-performing predictive models for congestive heart failure (CHF) readmission using an operational dataset with incomplete records and changing data over time. Our analytical approach involves three steps: pre-processing, systematic model development, and risk factor analysis. For pre-processing, variables that were absent in >50% of records were removed. Moreover, the dataset was divided into a validation dataset and derivation datasets which were separated into three temporal subsets based on changes to the data over time. For systematic model development, using the different temporal datasets and the remaining explanatory variables, the models were developed by combining the use of various (i) statistical analyses to explore the relationships between the validation and the derivation datasets; (ii) adjustment methods for handling missing values; (iii) classifiers; (iv) feature selection methods; and (iv) discretization methods. We then selected the best derivation dataset and the models with the highest predictive performance. For risk factor analysis, factors in the highest-performing predictive models were analyzed and ranked using (i) statistical analyses of the best derivation dataset, (ii) feature rankers, and (iii) a newly developed algorithm to categorize risk factors as being strong, regular, or weak. The analysis dataset consisted of 2,787 CHF hospitalizations at University of Utah Health Care from January 2003 to June 2013. In this study, we used the complete-case analysis and mean-based imputation adjustment methods; the wrapper subset feature selection method; and four ranking strategies based on information gain, gain ratio, symmetrical uncertainty, and wrapper subset feature evaluators. The best-performing models resulted from the use of a complete-case analysis derivation dataset combined with the Class-Attribute Contingency Coefficient discretization method and a voting
Wallis, Stuart A; Georgeson, Mark A
2012-12-21
Ernst Mach observed that light or dark bands could be seen at abrupt changes of luminance gradient in the absence of peaks or troughs in luminance. Many models of feature detection share the idea that bars, lines, and Mach bands are found at peaks and troughs in the output of even-symmetric spatial filters. Our experiments assessed the appearance of Mach bands (position and width) and the probability of seeing them on a novel set of generalized Gaussian edges. Mach band probability was mainly determined by the shape of the luminance profile and increased with the sharpness of its corners, controlled by a single parameter (n). Doubling or halving the size of the images had no significant effect. Variations in contrast (20%-80%) and duration (50-300 ms) had relatively minor effects. These results rule out the idea that Mach bands depend simply on the amplitude of the second derivative, but a multiscale model, based on Gaussian-smoothed first- and second-derivative filtering, can account accurately for the probability and perceived spatial layout of the bands. A key idea is that Mach band visibility depends on the ratio of second- to first-derivative responses at peaks in the second-derivative scale-space map. This ratio is approximately scale-invariant and increases with the sharpness of the corners of the luminance ramp, as observed. The edges of Mach bands pose a surprisingly difficult challenge for models of edge detection, but a nonlinear third-derivative operation is shown to predict the locations of Mach band edges strikingly well. Mach bands thus shed new light on the role of multiscale filtering systems in feature coding.
Additive derivations on algebras of measurable operators
International Nuclear Information System (INIS)
Ayupov, Sh.A.; Kudaybergenov, K.K.
2009-08-01
Given a von Neumann algebra M we introduce the so-called central extension mix(M) of M. We show that mix(M) is a *-subalgebra in the algebra LS(M) of all locally measurable operators with respect to M, and this algebra coincides with LS(M) if and only if M does not admit type II direct summands. We prove that if M is a properly infinite von Neumann algebra then every additive derivation on the algebra mix(M) is inner. This implies that on the algebra LS(M), where M is a type I ∞ or a type III von Neumann algebra, all additive derivations are inner derivations. (author)
On Derivations of Operator Algebras with Involution
Directory of Open Access Journals (Sweden)
Širovnik Nejc
2014-12-01
Full Text Available The purpose of this paper is to prove the following result. Let X be a complex Hilbert space, let L(X be an algebra of all bounded linear operators on X and let A(X ⊂ L(X be a standard operator algebra, which is closed under the adjoint operation. Suppose there exists a linear mapping D : A(X → L(X satisfying the relation 2D(AA*A = D(AA*A + AA*D(A + D(AA*A + AD(A*A for all A ∈ A(X. In this case, D is of the form D(A = [A,B] for all A ∈ A(X and some fixed B ∈ L(X, which means that D is a derivation.
Radon-Nikodym derivatives of quantum operations
International Nuclear Information System (INIS)
Raginsky, Maxim
2003-01-01
Given a completely positive (CP) map T, there is a theorem of the Radon-Nikodym type [W. B. Arveson, Acta Math. 123, 141 (1969); V. P. Belavkin and P. Staszewski, Rep. Math. Phys. 24, 49 (1986)] that completely characterizes all CP maps S such that T-S is also a CP map. This theorem is reviewed, and several alternative formulations are given along the way. We then use the Radon-Nikodym formalism to study the structure of order intervals of quantum operations, as well as a certain one-to-one correspondence between CP maps and positive operators, already fruitfully exploited in many quantum information-theoretic treatments. We also comment on how the Radon-Nikodym theorem can be used to derive norm estimates for differences of CP maps in general, and of quantum operations in particular
Krishnaswami, G.S.
2008-01-01
We consider large-N multi-matrix models whose action closely mimics that of Yang-Mills theory, including gauge-fixing and ghost terms. We show that the factorized Schwinger-Dyson loop equations, expressed in terms of the generating series of gluon and ghost correlations G( ), are quadratic equations
Invariant 'eigen-operator' of the square of Schroedinger operator for deriving energy-level gap
International Nuclear Information System (INIS)
Fan Hongyi; Li Chao
2004-01-01
We propose the conception of invariant 'eigen-operator' of the square of the Schroedinger operator, which can be used to derive energy-level gap formulas for some dynamic Hamiltonians. We list some examples, coupled oscillators models and the degenerate amplifier, etc., to demonstrate the feasibility of this approach
Bayesian operational risk models
Silvia Figini; Lijun Gao; Paolo Giudici
2013-01-01
Operational risk is hard to quantify, for the presence of heavy tailed loss distributions. Extreme value distributions, used in this context, are very sensitive to the data, and this is a problem in the presence of rare loss data. Self risk assessment questionnaires, if properly modelled, may provide the missing piece of information that is necessary to adequately estimate op- erational risks. In this paper we propose to embody self risk assessment data into suitable prior distributions, and ...
Financial derivative pricing under probability operator via Esscher transfomation
Achi, Godswill U.
2014-10-01
The problem of pricing contingent claims has been extensively studied for non-Gaussian models, and in particular, Black- Scholes formula has been derived for the NIG asset pricing model. This approach was first developed in insurance pricing9 where the original distortion function was defined in terms of the normal distribution. This approach was later studied6 where they compared the standard Black-Scholes contingent pricing and distortion based contingent pricing. So, in this paper, we aim at using distortion operators by Cauchy distribution under a simple transformation to price contingent claim. We also show that we can recuperate the Black-Sholes formula using the distribution. Similarly, in a financial market in which the asset price represented by a stochastic differential equation with respect to Brownian Motion, the price mechanism based on characteristic Esscher measure can generate approximate arbitrage free financial derivative prices. The price representation derived involves probability Esscher measure and Esscher Martingale measure and under a new complex valued measure φ (u) evaluated at the characteristic exponents φx(u) of Xt we recuperate the Black-Scholes formula for financial derivative prices.
Financial derivative pricing under probability operator via Esscher transfomation
Energy Technology Data Exchange (ETDEWEB)
Achi, Godswill U., E-mail: achigods@yahoo.com [Department of Mathematics, Abia State Polytechnic Aba, P.M.B. 7166, Aba, Abia State (Nigeria)
2014-10-24
The problem of pricing contingent claims has been extensively studied for non-Gaussian models, and in particular, Black- Scholes formula has been derived for the NIG asset pricing model. This approach was first developed in insurance pricing{sup 9} where the original distortion function was defined in terms of the normal distribution. This approach was later studied6 where they compared the standard Black-Scholes contingent pricing and distortion based contingent pricing. So, in this paper, we aim at using distortion operators by Cauchy distribution under a simple transformation to price contingent claim. We also show that we can recuperate the Black-Sholes formula using the distribution. Similarly, in a financial market in which the asset price represented by a stochastic differential equation with respect to Brownian Motion, the price mechanism based on characteristic Esscher measure can generate approximate arbitrage free financial derivative prices. The price representation derived involves probability Esscher measure and Esscher Martingale measure and under a new complex valued measure φ (u) evaluated at the characteristic exponents φ{sub x}(u) of X{sub t} we recuperate the Black-Scholes formula for financial derivative prices.
Academic Education Chain Operation Model
Ruskov, Petko; Ruskov, Andrey
2007-01-01
This paper presents an approach for modelling the educational processes as a value added chain. It is an attempt to use a business approach to interpret and compile existing business and educational processes towards reference models and suggest an Academic Education Chain Operation Model. The model can be used to develop an Academic Chain Operation Reference Model.
Gabriela ANGHELACHE; Ana Cornelia OLTEANU
2011-01-01
Losses resulting from operational risk events from a complex interaction between organizational factors, personal and market participants that do not fit a simple classification scheme. Taking into account past losses (ex. Barings, Daiwa, etc.) we can say that operational risk is a major financial losses in the banking sector, although until recently have been underestimated, considering that they are generally minor, note setting survival of a bank.
Directory of Open Access Journals (Sweden)
Gabriela ANGHELACHE
2011-06-01
Full Text Available Losses resulting from operational risk events from a complex interaction between organizational factors, personal and market participants that do not fit a simple classification scheme. Taking into account past losses (ex. Barings, Daiwa, etc. we can say that operational risk is a major financial losses in the banking sector, although until recently have been underestimated, considering that they are generally minor, note setting survival of a bank.
International Nuclear Information System (INIS)
Knee, H.E.; Schryver, J.C.
1991-01-01
Models of human behavior and cognition (HB and C) are necessary for understanding the total response of complex systems. Many such models have come available over the past thirty years for various applications. Unfortunately, many potential model users remain skeptical about their practicality, acceptability, and usefulness. Such hesitancy stems in part to disbelief in the ability to model complex cognitive processes, and a belief that relevant human behavior can be adequately accounted for through the use of commonsense heuristics. This paper will highlight several models of HB and C and identify existing and potential applications in attempt to dispel such notions. (author)
International Nuclear Information System (INIS)
Stary, I.
2004-01-01
A brief explanation is presented of the mental model concept, properties of mental models and fundamentals of mental models theory. Possible applications of such models in nuclear power plants are described in more detail. They include training of power plant operators, research into their behaviour and design of the operator-control process interface. The design of a mental model of an operator working in abnormal conditions due to power plant malfunction is outlined as an example taken from the literature. The model has been created based on analysis of experiments performed on a nuclear power plant simulator, run by a training center. (author)
Academic Education Chain Operation Model
Ruskov, Petko; Ruskov, Andrey
2007-01-01
This paper presents an approach for modelling the educational processes as a value added chain. It is an attempt to use a business approach to interpret and compile existing business and educational processes towards reference models and suggest an Academic Education Chain Operation Model. The model
Reliability analysis and operator modelling
International Nuclear Information System (INIS)
Hollnagel, Erik
1996-01-01
The paper considers the state of operator modelling in reliability analysis. Operator models are needed in reliability analysis because operators are needed in process control systems. HRA methods must therefore be able to account both for human performance variability and for the dynamics of the interaction. A selected set of first generation HRA approaches is briefly described in terms of the operator model they use, their classification principle, and the actual method they propose. In addition, two examples of second generation methods are also considered. It is concluded that first generation HRA methods generally have very simplistic operator models, either referring to the time-reliability relationship or to elementary information processing concepts. It is argued that second generation HRA methods must recognise that cognition is embedded in a context, and be able to account for that in the way human reliability is analysed and assessed
Modelling of Batch Process Operations
DEFF Research Database (Denmark)
Abdul Samad, Noor Asma Fazli; Cameron, Ian; Gani, Rafiqul
2011-01-01
Here a batch cooling crystalliser is modelled and simulated as is a batch distillation system. In the batch crystalliser four operational modes of the crystalliser are considered, namely: initial cooling, nucleation, crystal growth and product removal. A model generation procedure is shown that s...
Operators Control of Railway Model
Directory of Open Access Journals (Sweden)
Roman PAVLAS
2009-06-01
Full Text Available This article describes digital control of trains on a railway model and it implements option of monitoring and controlling of model from graphical interface by operator. Constituent components and their function, control system and its possibilities, a software applications needed for practical realization of assignment are described. On the base of knowledge of safe railway traffic [5] is created program which controls movement of trains, setting of train ways and signal-safe components on the model [7]. Next is described graphical interface which shows situation on railway and which allows to operator to set train ways and control movement of train. A new way of trains movement was created.
Extended Riemann-Liouville type fractional derivative operator with applications
Directory of Open Access Journals (Sweden)
Agarwal P.
2017-12-01
Full Text Available The main purpose of this paper is to introduce a class of new extended forms of the beta function, Gauss hypergeometric function and Appell-Lauricella hypergeometric functions by means of the modified Bessel function of the third kind. Some typical generating relations for these extended hypergeometric functions are obtained by defining the extension of the Riemann-Liouville fractional derivative operator. Their connections with elementary functions and Fox’s H-function are also presented.
Battery failure model derived from flaw theory
Schulman, I.
1981-01-01
A previously derived failure model for battery lifetime is discussed in terms of growth rate of the flaw, distribution of flaw sizes, and number of flaws. Equations are presented for determining the failure model for a nickel cadmium battery.
Making Deformable Template Models Operational
DEFF Research Database (Denmark)
Fisker, Rune
2000-01-01
for estimation of the model parameters, which applies a combination of a maximum likelihood and minimum distance criterion. Another contribution is a very fast search based initialization algorithm using a filter interpretation of the likelihood model. These two methods can be applied to most deformable template......Deformable template models are a very popular and powerful tool within the field of image processing and computer vision. This thesis treats this type of models extensively with special focus on handling their common difficulties, i.e. model parameter selection, initialization and optimization....... A proper handling of the common difficulties is essential for making the models operational by a non-expert user, which is a requirement for intensifying and commercializing the use of deformable template models. The thesis is organized as a collection of the most important articles, which has been...
Spatiality of Derivations of Operator Algebras in Banach Spaces
Directory of Open Access Journals (Sweden)
Quanyuan Chen
2011-01-01
Full Text Available Suppose that A is a transitive subalgebra of B(X and its norm closure A¯ contains a nonzero minimal left ideal I. It is shown that if δ is a bounded reflexive transitive derivation from A into B(X, then δ is spatial and implemented uniquely; that is, there exists T∈B(X such that δ(A=TA−AT for each A∈A, and the implementation T of δ is unique only up to an additive constant. This extends a result of E. Kissin that “if A¯ contains the ideal C(H of all compact operators in B(H, then a bounded reflexive transitive derivation from A into B(H is spatial and implemented uniquely.” in an algebraic direction and provides an alternative proof of it. It is also shown that a bounded reflexive transitive derivation from A into B(X is spatial and implemented uniquely, if X is a reflexive Banach space and A¯ contains a nonzero minimal right ideal I.
Performing derivative and integral operations for optical waves with optical metamaterials
Energy Technology Data Exchange (ETDEWEB)
Dai, Cun-Li [College of Engineering, Nanjing Agriculture University, Nanjing Jiangsu, 210031 (China); College of Science, Nanjing Agriculture University, Nanjing Jiangsu, 210095 (China); Zhao, Zhi-Gang; Li, Xiao-Lin [College of Engineering, Nanjing Agriculture University, Nanjing Jiangsu, 210031 (China); Yang, Hong-Wei, E-mail: phd_hwyang@njau.edu.cn [College of Science, Nanjing Agriculture University, Nanjing Jiangsu, 210095 (China)
2016-12-01
The graded refractive index waveguides can perform Fourier transform for an optical wave. According to this characteristic, simpler optical metamaterials with three waveguides are theoretically proposed, in which all of the waveguides are materials with a positive refractive index. By selecting the appropriate refractive index and structure size, the theory and simulations demonstrated that these metamaterials can perform mathematical operations for the outline of incident optical waves, including the first-order derivative, second-order derivative and the integral. - Highlights: • The derivative and integral operations of optical waves are achieved with a simpler model. • Both negative and positive refractive index boast the same functions. • The mathematical operations can be implemented only by changing the refractive index of the intermediate material. • The results will greatly expand the possible applications, including photon computers, picture processing, video displays and data storage.
Topological Structures of Derivative Weighted Composition Operators on the Bergman Space
Directory of Open Access Journals (Sweden)
Ce-Zhong Tong
2015-01-01
Full Text Available We characterize the difference of derivative weighted composition operators on the Bergman space in the unit disk and determine when linear-fractional derivative weighted composition operators belong to the same component of the space of derivative weighted composition operators on the Bergman space under the operator norm topology.
Operational Street Pollution Model (OSPM)
DEFF Research Database (Denmark)
Kakosimos, k.E.; Hertel, Ole; Ketzel, Matthias
2010-01-01
Environmental context Trafficked streets are air pollution hot spots where people experience high exposure to hazardous pollutants. Although monitoring networks provide crucial information about measured pollutant levels, the measurements are resource demanding and thus can be performed at only few...... selected sites. Fast and easily applied street pollution models are therefore necessary tools to provide information about the loadings in streets without measurement activities. We evaluate the Operational Street Pollution Model, one of the most commonly applied models in air pollution management...... and research worldwide. Abstract Traffic emissions constitute a major source of health hazardous air pollution in urban areas. Models describing pollutant levels in urban streets are thus important tools in air pollution management as a supplement to measurements in routine monitoring programmes. A widely used...
NERVA-Derived Nuclear Thermal Propulsion Dual Mode Operation
Zweig, Herbert R.; Hundal, Rolv
1994-07-01
Generation of electrical power using the nuclear heat source of a NERVA-derived nuclear thermal rocket engine is presented. A 111,200 N thrust engine defined in a study for NASA-LeRC in FY92 is the reference engine for a three-engine vehicle for which a 50 kWe capacity is required. Processes are described for energy extraction from the reactor and for converting the energy to electricity. The tie tubes which support the reactor fuel elements are the source of thermal energy. The study focuses on process systems using Stirling cycle energy conversion operating at 980 K and an alternate potassium-Rankine system operating at 1,140 K. Considerations are given of the effect of the power production on turbopump operation, ZrH moderator dissociation, creep strain in the tie tubes, hydrogen permeation through the containment materials, requirements for a backup battery system, and the effects of potential design changes on reactor size and criticality. Nuclear considerations include changing tie tube materials to TZM, changing the moderator to low vapor-pressure yttrium hydride, and changing the fuel form from graphite matrix to a carbon-carbide composite.
Lunar Landing Operational Risk Model
Mattenberger, Chris; Putney, Blake; Rust, Randy; Derkowski, Brian
2010-01-01
Characterizing the risk of spacecraft goes beyond simply modeling equipment reliability. Some portions of the mission require complex interactions between system elements that can lead to failure without an actual hardware fault. Landing risk is currently the least characterized aspect of the Altair lunar lander and appears to result from complex temporal interactions between pilot, sensors, surface characteristics and vehicle capabilities rather than hardware failures. The Lunar Landing Operational Risk Model (LLORM) seeks to provide rapid and flexible quantitative insight into the risks driving the landing event and to gauge sensitivities of the vehicle to changes in system configuration and mission operations. The LLORM takes a Monte Carlo based approach to estimate the operational risk of the Lunar Landing Event and calculates estimates of the risk of Loss of Mission (LOM) - Abort Required and is Successful, Loss of Crew (LOC) - Vehicle Crashes or Cannot Reach Orbit, and Success. The LLORM is meant to be used during the conceptual design phase to inform decision makers transparently of the reliability impacts of design decisions, to identify areas of the design which may require additional robustness, and to aid in the development and flow-down of requirements.
Rational Models for Inflation-Linked Derivatives
DEFF Research Database (Denmark)
Dam, Henrik; Macrina, Andrea; Skovmand, David
2018-01-01
We construct models for the pricing and risk management of inflation-linked derivatives. The model is rational in the sense that affine payoffs written on the consumer price index have prices that are rational functions of the state variables. The nominal pricing kernel is constructed in a multip......We construct models for the pricing and risk management of inflation-linked derivatives. The model is rational in the sense that affine payoffs written on the consumer price index have prices that are rational functions of the state variables. The nominal pricing kernel is constructed...... in a multiplicative manner that allows for closed-form pricing of vanilla inflation products suchlike zero-coupon swaps, caps and floors, year-on-year swaps, caps and floors, and the exotic limited price index swap. The model retains the attractive features of a nominal multi-curve interest rate model such as closed...
Schwinger model with higher derivative couplings
Energy Technology Data Exchange (ETDEWEB)
Barcelos-Neto, J.; Natividade, C.P. (Universidade Federal do Rio de Janeiro, RJ (Brazil). Inst. de Fisica)
1991-02-01
We study a version of the Schwinger model where fermion and gauge fields are coupled by means of higher derivatives. We show that, regardless of possible existence of ghosts and non-unitarity, the model is completely soluble and the anomalous axial divergence and the mass generated for the photon field are the same as in the usual model. The confinement of the electric charge is also discussed. (orig.).
Modelling Environment Changes for Pricing Weather Derivatives
Directory of Open Access Journals (Sweden)
Kabaivanov Stanimir
2017-12-01
Full Text Available This paper focuses on modelling environment changes in a way that allows to price weather derivatives in a flexible and efficient way. Applications and importance of climate and weather contracts extends beyond financial markets and hedging as they can be used as complementary tools for risk assessment. In addition, option-based approach toward resource management can offer very special insights on rare-events and allow to reuse derivative pricing methods to improve natural resources management. To demonstrate this general concept, we use Monte Carlo and stochastic modelling of temperatures to evaluate weather options. Research results are accompanied by R and Python code.
Operational models for forecasting Dst
Watanabe, S.; Sagawa, E.; Ohtaka, K.; Shimazu, H.
We have constructed operational models for forecasting the geomagnetic storm index (Dst) two hours in advance from six parameters: the velocity and density of the solar wind, the magnitude of the interplanetary magnetic field (IMF), and the x, y, and z components of the IMF. Our models use an Elman-type neural network, and we forecast space weather by using real-time solar-wind data from the Advanced Composition Explorer spacecraft.The models have worked well since April of 1998 and the Dst values forecast using them have been made available to the public at http://www.crl.go.jp/uk/uk223/service/nnw/index.html. From February to October 1998 there were 11 storms with minimum Dst values below -80 nT, and for ten the difference between the forecast minimum Dst and the Dst calculated from data measured by ground stations was less than 23%.For the storm starting on 19 October, however, the difference was 40% because of the weak correlation between the ACE environment and the earth's environment during this event.The Dst depends on the orientation of the IMF relative to the solar magnetospheric x-y plane and seems to be relatively large when the y component of the IMF is positive and perhaps also when the x component is positive.
Temperature stochastic modeling and weather derivatives pricing ...
African Journals Online (AJOL)
... over a sufficient period to apply a stochastic process that describes the evolution of the temperature. A numerical example of a swap contract pricing is presented, using an approximation formula as well as Monte Carlo simulations. Keywords: Weather derivatives, temperature stochastic model, Monte Carlo simulation.
Testing Expected Shortfall Models for Derivative Positions
Kerkhof, F.L.J.; Melenberg, B.; Schumacher, J.M.
2003-01-01
In this paper we test several risk management models for computing expected shortfall for one-period hedge errors of hedged derivatives positions.Contrary to value-at-risk, expected shortfall cannot be tested using the standard binomial test, since we need information of the distribution in the
Modelling ocean-colour-derived chlorophyll a
Dutkiewicz, Stephanie; Hickman, Anna E.; Jahn, Oliver
2018-01-01
This article provides a proof of concept for using a biogeochemical/ecosystem/optical model with a radiative transfer component as a laboratory to explore aspects of ocean colour. We focus here on the satellite ocean colour chlorophyll a (Chl a) product provided by the often-used blue/green reflectance ratio algorithm. The model produces output that can be compared directly to the real-world ocean colour remotely sensed reflectance. This model output can then be used to produce an ocean colour satellite-like Chl a product using an algorithm linking the blue versus green reflectance similar to that used for the real world. Given that the model includes complete knowledge of the (model) water constituents, optics and reflectance, we can explore uncertainties and their causes in this proxy for Chl a (called derived Chl a in this paper). We compare the derived Chl a to the actual model Chl a field. In the model we find that the mean absolute bias due to the algorithm is 22 % between derived and actual Chl a. The real-world algorithm is found using concurrent in situ measurement of Chl a and radiometry. We ask whether increased in situ measurements to train the algorithm would improve the algorithm, and find a mixed result. There is a global overall improvement, but at the expense of some regions, especially in lower latitudes where the biases increase. Not surprisingly, we find that region-specific algorithms provide a significant improvement, at least in the annual mean. However, in the model, we find that no matter how the algorithm coefficients are found there can be a temporal mismatch between the derived Chl a and the actual Chl a. These mismatches stem from temporal decoupling between Chl a and other optically important water constituents (such as coloured dissolved organic matter and detrital matter). The degree of decoupling differs regionally and over time. For example, in many highly seasonal regions, the timing of initiation and peak of the spring bloom in
Price models for oil derivates in Slovenia
International Nuclear Information System (INIS)
Nemac, F.; Saver, A.
1995-01-01
In Slovenia, a law is currently applied according to which any change in the price of oil derivatives is subject to the Governmental approval. Following the target of getting closer to the European Union, the necessity has arisen of finding ways for the introduction of liberalization or automated approach to price modifications depending on oscillations of oil derivative prices on the world market and the rate of exchange of the American dollar. It is for this reason that at the Agency for Energy Restructuring we made a study for the Ministry of Economic Affairs and Development regarding this issue. We analysed the possible models for the formation of oil derivative prices for Slovenia. Based on the assessment of experiences of primarily the west European countries, we proposed three models for the price formation for Slovenia. In future, it is expected that the Government of the Republic of Slovenia will make a selection of one of the proposed models to be followed by enforcement of price liberalization. The paper presents two representative models for price formation as used in Austria and Portugal. In the continuation the authors analyse the application of three models that they find suitable for the use in Slovenia. (author)
Derivative processes for modelling metabolic fluxes
Žurauskienė, Justina; Kirk, Paul; Thorne, Thomas; Pinney, John; Stumpf, Michael
2014-01-01
Motivation: One of the challenging questions in modelling biological systems is to characterize the functional forms of the processes that control and orchestrate molecular and cellular phenotypes. Recently proposed methods for the analysis of metabolic pathways, for example, dynamic flux estimation, can only provide estimates of the underlying fluxes at discrete time points but fail to capture the complete temporal behaviour. To describe the dynamic variation of the fluxes, we additionally require the assumption of specific functional forms that can capture the temporal behaviour. However, it also remains unclear how to address the noise which might be present in experimentally measured metabolite concentrations. Results: Here we propose a novel approach to modelling metabolic fluxes: derivative processes that are based on multiple-output Gaussian processes (MGPs), which are a flexible non-parametric Bayesian modelling technique. The main advantages that follow from MGPs approach include the natural non-parametric representation of the fluxes and ability to impute the missing data in between the measurements. Our derivative process approach allows us to model changes in metabolite derivative concentrations and to characterize the temporal behaviour of metabolic fluxes from time course data. Because the derivative of a Gaussian process is itself a Gaussian process, we can readily link metabolite concentrations to metabolic fluxes and vice versa. Here we discuss how this can be implemented in an MGP framework and illustrate its application to simple models, including nitrogen metabolism in Escherichia coli. Availability and implementation: R code is available from the authors upon request. Contact: j.norkunaite@imperial.ac.uk; m.stumpf@imperial.ac.uk Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24578401
Jordan (α,β-Derivations on Operator Algebras
Directory of Open Access Journals (Sweden)
Quanyuan Chen
2017-01-01
Full Text Available Let A be a CSL subalgebra of a von Neumann algebra acting on a Hilbert space H. It is shown that any Jordan (α,β-derivation on A is an (α,β-derivation, where α,β are any automorphisms on A. Moreover, the nth power (α,β-maps on A are investigated.
The DIAMOND Model of Peace Support Operations
National Research Council Canada - National Science Library
Bailey, Peter
2005-01-01
DIAMOND (Diplomatic And Military Operations in a Non-warfighting Domain) is a high-level stochastic simulation developed at Dstl as a key centerpiece within the Peace Support Operations (PSO) 'modelling jigsaw...
Initialization of a mesoscale model with satellite derived temperature profiles
Kalb, Michael W.
1986-01-01
The abilities of rawinsonde data and Tiros-N satellite derived temperature profile data to depict mesoscale precipitation accumulation are evaluated. Four mesoscale simulations using combinations of temperature, low-level wind, and low-level wind initialization were performed with the limited area mesoscale prediction system (LAMPS) model. Comparisons of the simulations with operational LFM forecast accumulations reveal that the LAMPS model simulations provide a better depiction of the observed precipitation accumulation than the LFM forecasts, and the satellite temperature profiles produce better mesoscale precipitation accumulation forecasts than the rawinsonde temperature data.
Petosić, Antonio; Ivancević, Bojan; Svilar, Dragoljub
2009-06-01
The method for measuring derived acoustic power of an ultrasound point source in the form of a sonotrode tip has been considered in the free acoustic field, according to the IEC 61847 standard. The main objective of this work is measuring averaged pressure magnitude spatial distribution of an sonotrode tip in the free acoustic field conditions at different electrical excitation levels and calculation of the derived acoustic power at excitation frequency (f0 approximately 25 kHz). Finding the derived acoustic power of an ultrasonic surgical device in the strong cavitation regime of working, even in the considered laboratory conditions (anechoic pool), will enable better understanding of the biological effects on the tissue produced during operation with the considered device. The pressure magnitude spatial distribution is measured using B&K 8103 hydrophone connected with a B&K 2626 conditioning amplifier, digital storage oscilloscope LeCroy Waverunner 474, where pressure waveforms in the field points are recorded. Using MATLAB with DSP processing toolbox, averaged power spectrum density of recorded pressure signals in different field positions is calculated. The measured pressure magnitude spatial distributions are fitted with the appropriate theoretical models. In the linear operating mode, using the acoustic reciprocity principle, the sonotrode tip is theoretically described as radially oscillating sphere (ROS) and transversely oscillating sphere (TOS) in the vicinity of pressure release boundary. The measured pressure magnitude spatial distribution is fitted with theoretical curves, describing the pressure field of the considered theoretical models. The velocity and displacement magnitudes with derived acoustic power of equivalent theoretical sources are found, and the electroacoustic efficiency factor is calculated. When the transmitter is excited at higher electrical power levels, the displacement magnitude of sonotrode tip is increased, and nonlinear behaviour
On a certain class of operator algebras and their derivations
International Nuclear Information System (INIS)
Ayupov, S. A.; Abdullaev, R.Z.; Kudaybergenov, K.K.
2009-08-01
Given a von Neumann algebra M with a faithful normal finite trace, we introduce the so-called finite tracial algebra M f as the intersection of L p -spaces L p (M, μ) over all p ≥ and over all faithful normal finite traces μ on M. Basic algebraic and topological properties of finite tracial algebras are studied. We prove that all derivations on these algebras are inner. (author)
A Derivational Approach to the Operational Semantics of Functional Languages
DEFF Research Database (Denmark)
Biernacka, Malgorzata
We study the connections between different forms of operational semantics for functional programming languages and we present systematic methods of interderiving reduction semantics, abstract machines and higher-order evaluators. We first consider two methods based on program transformations: a s...
Why operational risk modelling creates inverse incentives
Doff, R.
2015-01-01
Operational risk modelling has become commonplace in large international banks and is gaining popularity in the insurance industry as well. This is partly due to financial regulation (Basel II, Solvency II). This article argues that operational risk modelling is fundamentally flawed, despite efforts
Operational Models of Infrastructure Resilience
2015-01-01
Wiemer S. A stochastic forecast of California earth - quakes based on fault slip and smoothed seismicity. Bulletin of the Seismological Society of America...mean time between failures). For so- called rare events there is ongoing debate about how to model the frequencies with which disruptions oc- cur (e.g...in a simple priority list of importance; however, the frequency with which a link appears in attack or defense solutions provides an indication of
Modeling Operating Modes during Plant Life Cycle
DEFF Research Database (Denmark)
Jørgensen, Sten Bay; Lind, Morten
2012-01-01
of candidate control structures. The present contribution focuses on development of a model ensemble for a plant with an illustartive example for a bioreactor. Starting from a functional model a process plant may be conceptually designed and qualitative operating models may be developed to cover the different...... regions within the plant operating window, including transitions between operating regions. Subsequently qualitative functional models may be developed when the means for achieving the desired functionality are sufficiently specified during the design process. Quantitative mathematical models of plant...... physics can be used for detailed design and optimization. However the qualitative functional models already provide a systematic framework based on the notion of means-end abstraction hierarchies. Thereby functional modeling provides a scientific basis for managing complexity. A functional modelling...
A tracer diffusion model derived from microstructure
International Nuclear Information System (INIS)
Lehikoinen, Jarmo; Muurinen, Arto; Olin, Markus
2012-01-01
of reference, is shown to be given by the ratio of the effective diffusivity to the apparent diffusivity for an assumed non-interacting solute, such as tritiated water. Finally, the utility of the model and derivation of the model parameters are demonstrated with tracer diffusion data from the open literature for compacted bentonite. (authors)
MODEL OF PRIORITY SERVICE FOR AIRDROME'S OPERATIONS
Directory of Open Access Journals (Sweden)
A. K. Mitrofanov
2015-01-01
Full Text Available The model of process of priority service of departure and arrival operations is discussed. Priorities are operatively appointed by the controllers personnel according to requirements of documents of the civil aviation authorities and a situation developing on the earth and in air around airfield. Expressions for an assessment of properties of service of flights are received.
Comparing models of offensive cyber operations
CSIR Research Space (South Africa)
Grant, T
2015-10-01
Full Text Available would be needed by a Cyber Security Operations Centre in order to perform offensive cyber operations?". The analysis was performed, using as a springboard seven models of cyber-attack, and resulted in the development of what is described as a canonical...
Stochastic Modelling and Analysis of Warehouse Operations
Y. Gong (Yeming)
2009-01-01
textabstractThis thesis has studied stochastic models and analysis of warehouse operations. After an overview of stochastic research in warehouse operations, we explore the following topics. Firstly, we search optimal batch sizes in a parallel-aisle warehouse with online order arrivals. We employ a
Modeling Control Situations in Power System Operations
DEFF Research Database (Denmark)
Saleem, Arshad; Lind, Morten; Singh, Sri Niwas
2010-01-01
Increased interconnection and loading of the power system along with deregulation has brought new challenges for electric power system operation, control and automation. Traditional power system models used in intelligent operation and control are highly dependent on the task purpose. Thus, a model...... of explicit principles for model construction. This paper presents a work on using explicit means-ends model based reasoning about complex control situations which results in maintaining consistent perspectives and selecting appropriate control action for goal driven agents. An example of power system...... for intelligent operation and control must represent system features, so that information from measurements can be related to possible system states and to control actions. These general modeling requirements are well understood, but it is, in general, difficult to translate them into a model because of the lack...
Visualization study of operators' plant knowledge model
International Nuclear Information System (INIS)
Kanno, Tarou; Furuta, Kazuo; Yoshikawa, Shinji
1999-03-01
Nuclear plants are typically very complicated systems and are required extremely high level safety on the operations. Since it is never possible to include all the possible anomaly scenarios in education/training curriculum, plant knowledge formation is desired for operators to enable thein to act against unexpected anomalies based on knowledge base decision making. The authors have been conducted a study on operators' plant knowledge model for the purpose of supporting operators' effort in forming this kind of plant knowledge. In this report, an integrated plant knowledge model consisting of configuration space, causality space, goal space and status space is proposed. The authors examined appropriateness of this model and developed a prototype system to support knowledge formation by visualizing the operators' knowledge model and decision making process in knowledge-based actions with this model on a software system. Finally the feasibility of this prototype as a supportive method in operator education/training to enhance operators' ability in knowledge-based performance has been evaluated. (author)
Study on modeling of operator's learning mechanism
International Nuclear Information System (INIS)
Yoshimura, Seichi; Hasegawa, Naoko
1998-01-01
One effective method to analyze the causes of human errors is to model the behavior of human and to simulate it. The Central Research Institute of Electric Power Industry (CRIEPI) has developed an operator team behavior simulation system called SYBORG (Simulation System for the Behavior of an Operating Group) to analyze the human errors and to establish the countermeasures for them. As an operator behavior model which composes SYBORG has no learning mechanism and the knowledge of a plant is fixed, it cannot take suitable actions when unknown situations occur nor learn anything from the experience. However, considering actual operators, learning is an essential human factor to enhance their abilities to diagnose plant anomalies. In this paper, Q learning with 1/f fluctuation was proposed as a learning mechanism of an operator and simulation using the mechanism was conducted. The results showed the effectiveness of the learning mechanism. (author)
Relaxed memory models: an operational approach
Boudol , Gérard; Petri , Gustavo
2009-01-01
International audience; Memory models define an interface between programs written in some language and their implementation, determining which behaviour the memory (and thus a program) is allowed to have in a given model. A minimal guarantee memory models should provide to the programmer is that well-synchronized, that is, data-race free code has a standard semantics. Traditionally, memory models are defined axiomatically, setting constraints on the order in which memory operations are allow...
Operational policy for disposal of land-derived wastewater to the marine environment of South Africa
CSIR Research Space (South Africa)
Taljaard, Susan
2006-10-01
Full Text Available , amongst others. To fulfil its legal obligation in terms of the management and control of land-derived wastewater discharges (classified as a water use under the National Water Act), DWAF adopted the operational policy for disposal of land-derived water...
The Launch Systems Operations Cost Model
Prince, Frank A.; Hamaker, Joseph W. (Technical Monitor)
2001-01-01
One of NASA's primary missions is to reduce the cost of access to space while simultaneously increasing safety. A key component, and one of the least understood, is the recurring operations and support cost for reusable launch systems. In order to predict these costs, NASA, under the leadership of the Independent Program Assessment Office (IPAO), has commissioned the development of a Launch Systems Operations Cost Model (LSOCM). LSOCM is a tool to predict the operations & support (O&S) cost of new and modified reusable (and partially reusable) launch systems. The requirements are to predict the non-recurring cost for the ground infrastructure and the recurring cost of maintaining that infrastructure, performing vehicle logistics, and performing the O&S actions to return the vehicle to flight. In addition, the model must estimate the time required to cycle the vehicle through all of the ground processing activities. The current version of LSOCM is an amalgamation of existing tools, leveraging our understanding of shuttle operations cost with a means of predicting how the maintenance burden will change as the vehicle becomes more aircraft like. The use of the Conceptual Operations Manpower Estimating Tool/Operations Cost Model (COMET/OCM) provides a solid point of departure based on shuttle and expendable launch vehicle (ELV) experience. The incorporation of the Reliability and Maintainability Analysis Tool (RMAT) as expressed by a set of response surface model equations gives a method for estimating how changing launch system characteristics affects cost and cycle time as compared to today's shuttle system. Plans are being made to improve the model. The development team will be spending the next few months devising a structured methodology that will enable verified and validated algorithms to give accurate cost estimates. To assist in this endeavor the LSOCM team is part of an Agency wide effort to combine resources with other cost and operations professionals to
An Ionospheric Metric Study Using Operational Models
Sojka, J. J.; Schunk, R. W.; Thompson, D. C.; Scherliess, L.; Harris, T. J.
2006-12-01
One of the outstanding challenges in upgrading ionospheric operational models is quantifying their improvement. This challenge is not necessarily an absolute accuracy one, but rather answering the question, "Is the newest operational model an improvement over its predecessor under operational scenarios?" There are few documented cases where ionospheric models are compared either with each other or against "ground truth". For example a CEDAR workshop team, PRIMO, spent almost a decade carrying out a models comparison with ionosonde and incoherent scatter radar measurements from the Millstone Hill, Massachusetts location [Anderson et al.,1998]. The result of this study was that all models were different and specific conditions could be found when each was the "best" model. Similarly, a National Space Weather Metrics ionospheric challenge was held and results were presented at a National Space Weather meeting. The results were again found to be open to interpretation, and issues with the value of the specific metrics were raised (Fuller-Rowell, private communication, 2003). Hence, unlike the tropospheric weather community, who have established metrics and exercised them on new models over many decades to quantify improvement, the ionospheric community has not yet settled on a metric of both scientific and operational value. We report on a study in which metrics were used to compare various forms of the International Reference Ionosphere (IRI), the Ionospheric Forecast Model (IFM), and the Utah State University Global Assimilation of Ionospheric Measurements Model (USU-GAIM) models. The ground truth for this study was a group of 11 ionosonde data sets taken between 20 March and 19 April 2004. The metric parameter was the ionosphere's critical frequency. The metric was referenced to the IRI. Hence, the study addressed the specific question what improvement does IFM and USU-GAIM have over IRI. Both strengths (improvements) and weaknesses of these models are discussed
Bender, S.; Burgess, A.; Goodale, C. E.; Mattmann, C. A.; Miller, W. P.; Painter, T. H.; Rittger, K. E.; Stokes, M.; Werner, K.
2013-12-01
Water managers in the western United States depend heavily on the timing and magnitude of snowmelt-driven runoff for municipal supply, irrigation, maintenance of environmental flows, and power generation. The Colorado Basin River Forecast Center (CBRFC) of the National Weather Service issues operational forecasts of snowmelt-driven streamflow for watersheds within the Colorado River Basin (CRB) and eastern Great Basin (EGB), across a wide variety of scales. Therefore, the CBRFC and its stakeholders consider snowpack observations to be highly valuable. Observations of fractional snow covered area (fSCA) from satellite-borne instrumentation can better inform both forecasters and water users with respect to subsequent snowmelt runoff, particularly when combined with observations from ground-based station networks and/or airborne platforms. As part of a multi-year collaborative effort, CBRFC has partnered with the Jet Propulsion Laboratory (JPL) under funding from NASA to incorporate observations of fSCA from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) into the operational CBRFC hydrologic forecasting and modeling process. In the first year of the collaboration, CBRFC and NASA/JPL integrated snow products into the forecasting and decision making processes of the CBRFC and showed preliminary improvement in operational streamflow forecasts. In late 2012, CBRFC and NASA/JPL began retrospective analysis of relationships between the MODIS Snow Covered Area and Grain size (MODSCAG) fSCA and streamflow patterns for several watersheds within the CRB and the EGB. During the 2013 snowmelt runoff season, CBRFC forecasters used MODIS-derived fSCA semi-quantitatively as a binary indicator of the presence or lack of snow. Indication of the presence or lack of snow by MODIS assisted CBRFC forecasters in determining the cause of divergence between modeled and recently observed streamflow. Several examples of improved forecasts from across the CRB and EGB, informed by
Modeling for operational event risk assessment
International Nuclear Information System (INIS)
Sattison, M.B.
1997-01-01
The U.S. Nuclear Regulatory Commission has been using risk models to evaluate the risk significance of operational events in U.S. commercial nuclear power plants for more seventeen years. During that time, the models have evolved in response to the advances in risk assessment technology and insights gained with experience. Evaluation techniques fall into two categories, initiating event assessments and condition assessments. The models used for these analyses have become uniquely specialized for just this purpose
Renormalizations and operator expansion in sigma model
International Nuclear Information System (INIS)
Terentyev, M.V.
1988-01-01
The operator expansion (OPE) is studied for the Green function at x 2 → 0 (n(x) is the dynamical field ofσ-model) in the framework of the two-dimensional σ-model with the O(N) symmetry group at large N. As a preliminary step we formulate the renormalization scheme which permits introduction of an arbitrary intermediate scale μ 2 in the framework of 1/N expansion and discuss factorization (separation) of small (p μ) momentum region. It is shown that definition of composite local operators and coefficient functions figuring in OPE is unambiguous only in the leading order in 1/N expansion when dominant are the solutions with extremum of action. Corrections of order f(μ 2 )/N (here f(μ 2 ) is the effective interaction constant at the point μ 2 ) in composite operators and coefficient functions essentially depend on factorization method of high and low momentum regions. It is shown also that contributions to the power corrections of order m 2 x 2 f(μ 2 )/N in the Green function (here m is the dynamical mass-scale factor in σ-model) arise simultaneously from two sources: from the mean vacuum value of the composite operator n ∂ 2 n and from the hard particle contributions in the coefficient function of unite operator. Due to the analogy between σ-model and QCD the obtained result indicates theoretical limitations to the sum rule method in QCD. (author)
Modeling Operations Costs for Human Exploration Architectures
Shishko, Robert
2013-01-01
Operations and support (O&S) costs for human spaceflight have not received the same attention in the cost estimating community as have development costs. This is unfortunate as O&S costs typically comprise a majority of life-cycle costs (LCC) in such programs as the International Space Station (ISS) and the now-cancelled Constellation Program. Recognizing this, the Constellation Program and NASA HQs supported the development of an O&S cost model specifically for human spaceflight. This model, known as the Exploration Architectures Operations Cost Model (ExAOCM), provided the operations cost estimates for a variety of alternative human missions to the moon, Mars, and Near-Earth Objects (NEOs) in architectural studies. ExAOCM is philosophically based on the DoD Architecture Framework (DoDAF) concepts of operational nodes, systems, operational functions, and milestones. This paper presents some of the historical background surrounding the development of the model, and discusses the underlying structure, its unusual user interface, and lastly, previous examples of its use in the aforementioned architectural studies.
Deriving minimal models for resource utilization
te Brinke, Steven; Bockisch, Christoph; Bergmans, Lodewijk; Malakuti Khah Olun Abadi, Somayeh; Aksit, Mehmet; Katz, Shmuel
2013-01-01
We show how compact Resource Utilization Models (RUMs) can be extracted from concrete overly-detailed models of systems or sub-systems in order to model energy-aware software. Using the Counterexample-Guided Abstraction Refinement (CEGAR) approach, along with model-checking tools, abstract models
An operator model-based filtering scheme
International Nuclear Information System (INIS)
Sawhney, R.S.; Dodds, H.L.; Schryer, J.C.
1990-01-01
This paper presents a diagnostic model developed at Oak Ridge National Laboratory (ORNL) for off-normal nuclear power plant events. The diagnostic model is intended to serve as an embedded module of a cognitive model of the human operator, one application of which could be to assist control room operators in correctly responding to off-normal events by providing a rapid and accurate assessment of alarm patterns and parameter trends. The sequential filter model is comprised of two distinct subsystems --- an alarm analysis followed by an analysis of interpreted plant signals. During the alarm analysis phase, the alarm pattern is evaluated to generate hypotheses of possible initiating events in order of likelihood of occurrence. Each hypothesis is further evaluated through analysis of the current trends of state variables in order to validate/reject (in the form of increased/decreased certainty factor) the given hypothesis. 7 refs., 4 figs
Model Based Autonomy for Robust Mars Operations
Kurien, James A.; Nayak, P. Pandurang; Williams, Brian C.; Lau, Sonie (Technical Monitor)
1998-01-01
Space missions have historically relied upon a large ground staff, numbering in the hundreds for complex missions, to maintain routine operations. When an anomaly occurs, this small army of engineers attempts to identify and work around the problem. A piloted Mars mission, with its multiyear duration, cost pressures, half-hour communication delays and two-week blackouts cannot be closely controlled by a battalion of engineers on Earth. Flight crew involvement in routine system operations must also be minimized to maximize science return. It also may be unrealistic to require the crew have the expertise in each mission subsystem needed to diagnose a system failure and effect a timely repair, as engineers did for Apollo 13. Enter model-based autonomy, which allows complex systems to autonomously maintain operation despite failures or anomalous conditions, contributing to safe, robust, and minimally supervised operation of spacecraft, life support, In Situ Resource Utilization (ISRU) and power systems. Autonomous reasoning is central to the approach. A reasoning algorithm uses a logical or mathematical model of a system to infer how to operate the system, diagnose failures and generate appropriate behavior to repair or reconfigure the system in response. The 'plug and play' nature of the models enables low cost development of autonomy for multiple platforms. Declarative, reusable models capture relevant aspects of the behavior of simple devices (e.g. valves or thrusters). Reasoning algorithms combine device models to create a model of the system-wide interactions and behavior of a complex, unique artifact such as a spacecraft. Rather than requiring engineers to all possible interactions and failures at design time or perform analysis during the mission, the reasoning engine generates the appropriate response to the current situation, taking into account its system-wide knowledge, the current state, and even sensor failures or unexpected behavior.
Effective operator treatment of the Lipkin model
International Nuclear Information System (INIS)
Abraham, K.J.; Vary, J.P.
2004-01-01
We analyze the Lipkin model in the strong coupling limit using effective operator techniques. We present both analytical and numerical results for low energy effective Hamiltonians. We investigate the reliability of various approximations used to simplify the nuclear many body problem, such as the cluster approximation. We demonstrate, in explicit examples, certain limits to the validity of the cluster approximation but caution that these limits may be particular to this model where the interactions are of unlimited range
Operation and modeling of the MOS transistor
Tsividis, Yannis
2011-01-01
Operation and Modeling of the MOS Transistor has become a standard in academia and industry. Extensively revised and updated, the third edition of this highly acclaimed text provides a thorough treatment of the MOS transistor - the key element of modern microelectronic chips.
A practical model for sustainable operational performance
International Nuclear Information System (INIS)
Vlek, C.A.J.; Steg, E.M.; Feenstra, D.; Gerbens-Leenis, W.; Lindenberg, S.; Moll, H.; Schoot Uiterkamp, A.; Sijtsma, F.; Van Witteloostuijn, A.
2002-01-01
By means of a concrete model for sustainable operational performance enterprises can report uniformly on the sustainability of their contributions to the economy, welfare and the environment. The development and design of a three-dimensional monitoring system is presented and discussed [nl
Modeling Casualty Sustainment During Peacekeeping Operations
2003-10-09
Medicine, 1999, 164(8), Supplement. 23. Blood CG, Anderson ME. The Battle for Hue: Casualty and Disease Rates during Urban Warfare, Military Medicine...NAVAL HEALTH RESEARCH CENTER MODELING CASUALTY SUSTAINMENT DURING PEACEKEEPING OPERATIONS G. J. Walker C. G. Bloodl...Report No. 03-21 Approved for public release; distribution unlimited. NAVAL HEALTH RESEARCH
Business intelligence modeling in launch operations
Bardina, Jorge E.; Thirumalainambi, Rajkumar; Davis, Rodney D.
2005-05-01
The future of business intelligence in space exploration will focus on the intelligent system-of-systems real-time enterprise. In present business intelligence, a number of technologies that are most relevant to space exploration are experiencing the greatest change. Emerging patterns of set of processes rather than organizational units leading to end-to-end automation is becoming a major objective of enterprise information technology. The cost element is a leading factor of future exploration systems. This technology project is to advance an integrated Planning and Management Simulation Model for evaluation of risks, costs, and reliability of launch systems from Earth to Orbit for Space Exploration. The approach builds on research done in the NASA ARC/KSC developed Virtual Test Bed (VTB) to integrate architectural, operations process, and mission simulations for the purpose of evaluating enterprise level strategies to reduce cost, improve systems operability, and reduce mission risks. The objectives are to understand the interdependency of architecture and process on recurring launch cost of operations, provide management a tool for assessing systems safety and dependability versus cost, and leverage lessons learned and empirical models from Shuttle and International Space Station to validate models applied to Exploration. The systems-of-systems concept is built to balance the conflicting objectives of safety, reliability, and process strategy in order to achieve long term sustainability. A planning and analysis test bed is needed for evaluation of enterprise level options and strategies for transit and launch systems as well as surface and orbital systems. This environment can also support agency simulation based acquisition process objectives. The technology development approach is based on the collaborative effort set forth in the VTB's integrating operations, process models, systems and environment models, and cost models as a comprehensive disciplined
Business Intelligence Modeling in Launch Operations
Bardina, Jorge E.; Thirumalainambi, Rajkumar; Davis, Rodney D.
2005-01-01
This technology project is to advance an integrated Planning and Management Simulation Model for evaluation of risks, costs, and reliability of launch systems from Earth to Orbit for Space Exploration. The approach builds on research done in the NASA ARC/KSC developed Virtual Test Bed (VTB) to integrate architectural, operations process, and mission simulations for the purpose of evaluating enterprise level strategies to reduce cost, improve systems operability, and reduce mission risks. The objectives are to understand the interdependency of architecture and process on recurring launch cost of operations, provide management a tool for assessing systems safety and dependability versus cost, and leverage lessons learned and empirical models from Shuttle and International Space Station to validate models applied to Exploration. The systems-of-systems concept is built to balance the conflicting objectives of safety, reliability, and process strategy in order to achieve long term sustainability. A planning and analysis test bed is needed for evaluation of enterprise level options and strategies for transit and launch systems as well as surface and orbital systems. This environment can also support agency simulation .based acquisition process objectives. The technology development approach is based on the collaborative effort set forth in the VTB's integrating operations. process models, systems and environment models, and cost models as a comprehensive disciplined enterprise analysis environment. Significant emphasis is being placed on adapting root cause from existing Shuttle operations to exploration. Technical challenges include cost model validation, integration of parametric models with discrete event process and systems simulations. and large-scale simulation integration. The enterprise architecture is required for coherent integration of systems models. It will also require a plan for evolution over the life of the program. The proposed technology will produce
A Derivative Based Estimator for Semiparametric Index Models
Donkers, A.C.D.; Schafgans, M.
2003-01-01
This paper proposes a semiparametric estimator for single- and multiple index models.It provides an extension of the average derivative estimator to the multiple index model setting.The estimator uses the average of the outer product of derivatives and is shown to be root-N consistent and
Remarks on the microscopic derivation of the collective model
International Nuclear Information System (INIS)
Toyoda, T.; Wildermuth, K.
1984-01-01
The rotational part of the phenomenological collective model of Bohr and Mottelson and others is derived microscopically, starting with the Schrodinger equation written in projection form and introducing a new set of 'relative Euler angles'. In order to derive the local Schrodinger equation of the collective model, it is assumed that the intrinsic wave functions give strong peaking properties to the overlapping kernels
The national operational environment model (NOEM)
Salerno, John J.; Romano, Brian; Geiler, Warren
2011-06-01
The National Operational Environment Model (NOEM) is a strategic analysis/assessment tool that provides insight into the complex state space (as a system) that is today's modern operational environment. The NOEM supports baseline forecasts by generating plausible futures based on the current state. It supports what-if analysis by forecasting ramifications of potential "Blue" actions on the environment. The NOEM also supports sensitivity analysis by identifying possible pressure (leverage) points in support of the Commander that resolves forecasted instabilities, and by ranking sensitivities in a list for each leverage point and response. The NOEM can be used to assist Decision Makers, Analysts and Researchers with understanding the inter-workings of a region or nation state, the consequences of implementing specific policies, and the ability to plug in new operational environment theories/models as they mature. The NOEM is built upon an open-source, license-free set of capabilities, and aims to provide support for pluggable modules that make up a given model. The NOEM currently has an extensive number of modules (e.g. economic, security & social well-being pieces such as critical infrastructure) completed along with a number of tools to exercise them. The focus this year is on modeling the social and behavioral aspects of a populace within their environment, primarily the formation of various interest groups, their beliefs, their requirements, their grievances, their affinities, and the likelihood of a wide range of their actions, depending on their perceived level of security and happiness. As such, several research efforts are currently underway to model human behavior from a group perspective, in the pursuit of eventual integration and balance of populace needs/demands within their respective operational environment and the capacity to meet those demands. In this paper we will provide an overview of the NOEM, the need for and a description of its main components
Operator formulation of the droplet model
International Nuclear Information System (INIS)
Lee, B.W.
1987-01-01
We study in detail the implications of the operator formulation of the droplet model. The picture of high-energy scattering that emerges from this model attributed the interaction between two colliding particles at high energies to an instantaneous, multiple exchange between two extended charge distributions. Thus the study of charge correlation functions becomes the most important problem in the droplet model. We find that in order for the elastic cross section to have a finite limit at infinite energy, the charge must be a conserved one. In quantum electrodynamics the charge in question is the electric charge. In hadronic physics, we conjecture, it is the baryonic charge. Various arguments for and implications of this hypothesis are presented. We study formal properties of the charge correlation functions that follow from microcausality, T, C, P invariances, and charge conservation. Perturbation expansion of the correlation functions is studied, and their cluster properties are deduced. A cluster expansion of the high-energy T matrix is developed, and the exponentiation of the interaction potential in this scheme is noted. The operator droplet model is put to the test of reproducing the high-energy limit of elastic scattering quantum electrodynamics found by Cheng and Wu in perturbation theory. We find that the droplet model reproduces exactly the results of Cheng and Wu as to the impact factor. In fact, the ''impact picture'' of Cheng and Wu is completely equivalent to the droplet model in the operator version. An appraisal is made of the possible limitation of the model. (author). 13 refs
Disease prediction models and operational readiness.
Directory of Open Access Journals (Sweden)
Courtney D Corley
Full Text Available The objective of this manuscript is to present a systematic review of biosurveillance models that operate on select agents and can forecast the occurrence of a disease event. We define a disease event to be a biological event with focus on the One Health paradigm. These events are characterized by evidence of infection and or disease condition. We reviewed models that attempted to predict a disease event, not merely its transmission dynamics and we considered models involving pathogens of concern as determined by the US National Select Agent Registry (as of June 2011. We searched commercial and government databases and harvested Google search results for eligible models, using terms and phrases provided by public health analysts relating to biosurveillance, remote sensing, risk assessments, spatial epidemiology, and ecological niche modeling. After removal of duplications and extraneous material, a core collection of 6,524 items was established, and these publications along with their abstracts are presented in a semantic wiki at http://BioCat.pnnl.gov. As a result, we systematically reviewed 44 papers, and the results are presented in this analysis. We identified 44 models, classified as one or more of the following: event prediction (4, spatial (26, ecological niche (28, diagnostic or clinical (6, spread or response (9, and reviews (3. The model parameters (e.g., etiology, climatic, spatial, cultural and data sources (e.g., remote sensing, non-governmental organizations, expert opinion, epidemiological were recorded and reviewed. A component of this review is the identification of verification and validation (V&V methods applied to each model, if any V&V method was reported. All models were classified as either having undergone Some Verification or Validation method, or No Verification or Validation. We close by outlining an initial set of operational readiness level guidelines for disease prediction models based upon established Technology
Disease Prediction Models and Operational Readiness
Energy Technology Data Exchange (ETDEWEB)
Corley, Courtney D.; Pullum, Laura L.; Hartley, David M.; Benedum, Corey M.; Noonan, Christine F.; Rabinowitz, Peter M.; Lancaster, Mary J.
2014-03-19
INTRODUCTION: The objective of this manuscript is to present a systematic review of biosurveillance models that operate on select agents and can forecast the occurrence of a disease event. One of the primary goals of this research was to characterize the viability of biosurveillance models to provide operationally relevant information for decision makers to identify areas for future research. Two critical characteristics differentiate this work from other infectious disease modeling reviews. First, we reviewed models that attempted to predict the disease event, not merely its transmission dynamics. Second, we considered models involving pathogens of concern as determined by the US National Select Agent Registry (as of June 2011). Methods: We searched dozens of commercial and government databases and harvested Google search results for eligible models utilizing terms and phrases provided by public health analysts relating to biosurveillance, remote sensing, risk assessments, spatial epidemiology, and ecological niche-modeling, The publication date of search results returned are bound by the dates of coverage of each database and the date in which the search was performed, however all searching was completed by December 31, 2010. This returned 13,767 webpages and 12,152 citations. After de-duplication and removal of extraneous material, a core collection of 6,503 items was established and these publications along with their abstracts are presented in a semantic wiki at http://BioCat.pnnl.gov. Next, PNNL’s IN-SPIRE visual analytics software was used to cross-correlate these publications with the definition for a biosurveillance model resulting in the selection of 54 documents that matched the criteria resulting Ten of these documents, However, dealt purely with disease spread models, inactivation of bacteria, or the modeling of human immune system responses to pathogens rather than predicting disease events. As a result, we systematically reviewed 44 papers and the
Game Theory for Speculative Derivatives: A Possible Stabilizing Regulatory Model
Directory of Open Access Journals (Sweden)
Francesco Musolino
2012-10-01
Full Text Available The aim of this paper is to propose a methodology to stabilize the financial markets using Game Theory, specifically the Complete Study of a Differentiable Game. Initially, we intend to make a quick discussion of peculiarities and recent development of derivatives, and then we move on to the main topic of the paper: forwards and futures. We illustrate their pricing and the functioning of markets for this particular derivatives type. We also will examine the short or long hedging strategies, used by companies to try to cancel the risk associated with market variables. At this purpose, we present a game theory model. Specifically, we focus on two economic operators: a real economic subject and a financial institute (a bank, for example with a big economic availability. For this purpose, we discuss about an interaction between the two above economic subjects: the Enterprise, our first player, and the Financial Institute, our second player. We propose a tax on financial transactions with speculative purposes in order to stabilize the financial market, protecting it from speculations. This tax hits only the speculative profits and we find a cooperative solution that allows, however, both players to obtain a gain.
Policy advice derived from simulation models
Brenner, T.; Werker, C.
2009-01-01
When advising policy we face the fundamental problem that economic processes are connected with uncertainty and thus policy can err. In this paper we show how the use of simulation models can reduce policy errors. We suggest that policy is best based on socalled abductive simulation models, which
Modelling Team Adversarial Actions in UAV Operations
2007-11-01
organization and behaviour of a (possible large and heterogeneous) network of assets, and its ability to perform tasks over a region and time of interest...the number of requests fulfilled, and the time taken to satisfy requests [13]. Here “theatre” is used to denote a specific geographic region within... Desenvolvimento . REFERENCES [1] Cruz, J.B., Simaan, M.A., Gacic, A. Jiang, H., Letellier, B. and Li, M. “Modelling and Control of Military Operations
A variable-order fractal derivative model for anomalous diffusion
Directory of Open Access Journals (Sweden)
Liu Xiaoting
2017-01-01
Full Text Available This paper pays attention to develop a variable-order fractal derivative model for anomalous diffusion. Previous investigations have indicated that the medium structure, fractal dimension or porosity may change with time or space during solute transport processes, results in time or spatial dependent anomalous diffusion phenomena. Hereby, this study makes an attempt to introduce a variable-order fractal derivative diffusion model, in which the index of fractal derivative depends on temporal moment or spatial position, to characterize the above mentioned anomalous diffusion (or transport processes. Compared with other models, the main advantages in description and the physical explanation of new model are explored by numerical simulation. Further discussions on the dissimilitude such as computational efficiency, diffusion behavior and heavy tail phenomena of the new model and variable-order fractional derivative model are also offered.
Weather Derivatives and Stochastic Modelling of Temperature
Directory of Open Access Journals (Sweden)
Fred Espen Benth
2011-01-01
Full Text Available We propose a continuous-time autoregressive model for the temperature dynamics with volatility being the product of a seasonal function and a stochastic process. We use the Barndorff-Nielsen and Shephard model for the stochastic volatility. The proposed temperature dynamics is flexible enough to model temperature data accurately, and at the same time being analytically tractable. Futures prices for commonly traded contracts at the Chicago Mercantile Exchange on indices like cooling- and heating-degree days and cumulative average temperatures are computed, as well as option prices on them.
ODEs with Preisach operator under the derivative and with discontinuous in time right-hand side
International Nuclear Information System (INIS)
Zhezherun, A; Flynn, D
2006-01-01
We consider ordinary Differential equations with a Preisach operator under the derivative. A special case when the right-hand side has discontinuities in time is studied. We present theorems about the existence and uniqueness of solutions. We also prove a theorem which describes the behavior of a solution at the points of discontinuity of the right-hand side
Khoma, Mykhaylo; Jaquet, Ralph
2017-09-01
The kinetic energy operator for triatomic molecules with coordinate or distance-dependent nuclear masses has been derived. By combination of the chain rule method and the analysis of infinitesimal variations of molecular coordinates, a simple and general technique for the construction of the kinetic energy operator has been proposed. The asymptotic properties of the Hamiltonian have been investigated with respect to the ratio of the electron and proton mass. We have demonstrated that an ad hoc introduction of distance (and direction) dependent nuclear masses in Cartesian coordinates preserves the total rotational invariance of the problem. With the help of Wigner rotation functions, an effective Hamiltonian for nuclear motion can be derived. In the derivation, we have focused on the effective trinuclear Hamiltonian. All necessary matrix elements are given in closed analytical form. Preliminary results for the influence of non-adiabaticity on vibrational band origins are presented for H3+.
Khoma, Mykhaylo; Jaquet, Ralph
2017-09-21
The kinetic energy operator for triatomic molecules with coordinate or distance-dependent nuclear masses has been derived. By combination of the chain rule method and the analysis of infinitesimal variations of molecular coordinates, a simple and general technique for the construction of the kinetic energy operator has been proposed. The asymptotic properties of the Hamiltonian have been investigated with respect to the ratio of the electron and proton mass. We have demonstrated that an ad hoc introduction of distance (and direction) dependent nuclear masses in Cartesian coordinates preserves the total rotational invariance of the problem. With the help of Wigner rotation functions, an effective Hamiltonian for nuclear motion can be derived. In the derivation, we have focused on the effective trinuclear Hamiltonian. All necessary matrix elements are given in closed analytical form. Preliminary results for the influence of non-adiabaticity on vibrational band origins are presented for H 3 + .
Snow model design for operational purposes
Kolberg, Sjur
2017-04-01
A parsimonious distributed energy balance snow model intended for operational use is evaluated using discharge, snow covered area and grain size; the latter two as observed from the MODIS sensor. The snow model is an improvement of the existing GamSnow model, which is a part of the Enki modelling framework. Core requirements for the new version have been: 1. Reduction of calibration freedom, motivated by previous experience of non-identifiable parameters in the existing version 2. Improvement of process representation based on recent advances in physically based snow modelling 3. Limiting the sensitivity to forcing data which are poorly known over the spatial domain of interest (often in mountainous areas) 4. Preference for observable states, and the ability to improve from updates. The albedo calculation is completely revised, now based on grain size through an emulation of the SNICAR model (Flanner and Zender, 2006; Gardener and Sharp, 2010). The number of calibration parameters in the albedo model is reduced from 6 to 2. The wind function governing turbulent energy fluxes has been reduced from 2 to 1 parameter. Following Raleigh et al (2011), snow surface radiant temperature is split from the top layer thermodynamic temperature, using bias-corrected wet-bulb temperature to model the former. Analyses are ongoing, and the poster will bring evaluation results from 16 years of MODIS observations and more than 25 catchments in southern Norway.
Fang, Li
The Geostationary Operational Environmental Satellites (GOES) have been continuously monitoring the earth surface since 1970, providing valuable and intensive data from a very broad range of wavelengths, day and night. The National Oceanic and Atmospheric Administration's (NOAA's) National Environmental Satellite, Data, and Information Service (NESDIS) is currently operating GOES-15 and GOES-13. The design of the GOES series is now heading to the 4 th generation. GOES-R, as a representative of the new generation of the GOES series, is scheduled to be launched in 2015 with higher spatial and temporal resolution images and full-time soundings. These frequent observations provided by GOES Image make them attractive for deriving information on the diurnal land surface temperature (LST) cycle and diurnal temperature range (DTR). These parameters are of great value for research on the Earth's diurnal variability and climate change. Accurate derivation of satellite-based LSTs from thermal infrared data has long been an interesting and challenging research area. To better support the research on climate change, the generation of consistent GOES LST products for both GOES-East and GOES-West from operational dataset as well as historical archive is in great demand. The derivation of GOES LST products and the evaluation of proposed retrieval methods are two major objectives of this study. Literature relevant to satellite-based LST retrieval techniques was reviewed. Specifically, the evolution of two LST algorithm families and LST retrieval methods for geostationary satellites were summarized in this dissertation. Literature relevant to the evaluation of satellite-based LSTs was also reviewed. All the existing methods are a valuable reference to develop the GOES LST product. The primary objective of this dissertation is the development of models for deriving consistent GOES LSTs with high spatial and high temporal coverage. Proper LST retrieval algorithms were studied
Silicon Carbide Derived Carbons: Experiments and Modeling
Energy Technology Data Exchange (ETDEWEB)
Kertesz, Miklos [Georgetown University, Washington DC 20057
2011-02-28
The main results of the computational modeling was: 1. Development of a new genealogical algorithm to generate vacancy clusters in diamond starting from monovacancies combined with energy criteria based on TBDFT energetics. The method revealed that for smaller vacancy clusters the energetically optimal shapes are compact but for larger sizes they tend to show graphitized regions. In fact smaller clusters of the size as small as 12 already show signatures of this graphitization. The modeling gives firm basis for the slit-pore modeling of porous carbon materials and explains some of their properties. 2. We discovered small vacancy clusters and their physical characteristics that can be used to spectroscopically identify them. 3. We found low barrier pathways for vacancy migration in diamond-like materials by obtaining for the first time optimized reaction pathways.
Neural Networks for Hydrological Modeling Tool for Operational Purposes
Bhatt, Divya; Jain, Ashu
2010-05-01
Hydrological models are useful in many water resources applications such as flood control, irrigation and drainage, hydro power generation, water supply, erosion and sediment control, etc. Estimates of runoff are needed in many water resources planning, design development, operation and maintenance activities. Runoff is generally computed using rainfall-runoff models. Computer based hydrologic models have become popular for obtaining hydrological forecasts and for managing water systems. Rainfall-runoff library (RRL) is computer software developed by Cooperative Research Centre for Catchment Hydrology (CRCCH), Australia consisting of five different conceptual rainfall-runoff models, and has been in operation in many water resources applications in Australia. Recently, soft artificial intelligence tools such as Artificial Neural Networks (ANNs) have become popular for research purposes but have not been adopted in operational hydrological forecasts. There is a strong need to develop ANN models based on real catchment data and compare them with the conceptual models actually in use in real catchments. In this paper, the results from an investigation on the use of RRL and ANNs are presented. Out of the five conceptual models in the RRL toolkit, SimHyd model has been used. Genetic Algorithm has been used as an optimizer in the RRL to calibrate the SimHyd model. Trial and error procedures were employed to arrive at the best values of various parameters involved in the GA optimizer to develop the SimHyd model. The results obtained from the best configuration of the SimHyd model are presented here. Feed-forward neural network model structure trained by back-propagation training algorithm has been adopted here to develop the ANN models. The daily rainfall and runoff data derived from Bird Creek Basin, Oklahoma, USA have been employed to develop all the models included here. A wide range of error statistics have been used to evaluate the performance of all the models
Wind gust models derived from field data
Gawronski, W.
1995-01-01
Wind data measured during a field experiment were used to verify the analytical model of wind gusts. Good coincidence was observed; the only discrepancy occurred for the azimuth error in the front and back winds, where the simulated errors were smaller than the measured ones. This happened because of the assumption of the spatial coherence of the wind gust model, which generated a symmetric antenna load and, in consequence, a low azimuth servo error. This result indicates a need for upgrading the wind gust model to a spatially incoherent one that will reflect the real gusts in a more accurate manner. In order to design a controller with wind disturbance rejection properties, the wind disturbance should be known at the input to the antenna rate loop model. The second task, therefore, consists of developing a digital filter that simulates the wind gusts at the antenna rate input. This filter matches the spectrum of the measured servo errors. In this scenario, the wind gusts are generated by introducing white noise to the filter input.
Impacts of supersymmetric higher derivative terms on inflation models in supergravity
International Nuclear Information System (INIS)
Aoki, Shuntaro; Yamada, Yusuke
2015-01-01
We show the effects of supersymmetric higher derivative terms on inflation models in supergravity. The results show that such terms generically modify the effective kinetic coefficient of the inflaton during inflation if the cut off scale of the higher derivative operators is sufficiently small. In such a case, the η-problem in supergravity does not occur, and we find that the effective potential of the inflaton generically becomes a power type potential with a power smaller than two
Nordic Model of Subregional Co-Operation
Directory of Open Access Journals (Sweden)
Grzela Joanna
2017-12-01
Full Text Available Nordic co-operation is renowned throughout the world and perceived as the collaboration of a group of countries which are similar in their views and activities. The main pillars of the Nordic model of co-operation are the tradition of constitutional principles, activity of public movements and organisations, freedom of speech, equality, solidarity, and respect for the natural environment. In connection with labour and entrepreneurship, these elements are the features of a society which favours efficiency, a sense of security and balance between an individual and a group. Currently, the collaboration is a complex process, including many national, governmental and institutional connections which form the “Nordic family”.
Modeling decisions information fusion and aggregation operators
Torra, Vicenc
2007-01-01
Information fusion techniques and aggregation operators produce the most comprehensive, specific datum about an entity using data supplied from different sources, thus enabling us to reduce noise, increase accuracy, summarize and extract information, and make decisions. These techniques are applied in fields such as economics, biology and education, while in computer science they are particularly used in fields such as knowledge-based systems, robotics, and data mining. This book covers the underlying science and application issues related to aggregation operators, focusing on tools used in practical applications that involve numerical information. Starting with detailed introductions to information fusion and integration, measurement and probability theory, fuzzy sets, and functional equations, the authors then cover the following topics in detail: synthesis of judgements, fuzzy measures, weighted means and fuzzy integrals, indices and evaluation methods, model selection, and parameter extraction. The method...
International Nuclear Information System (INIS)
Raoelina Andriambololona; Ranaivoson, R.T.R; Hanitriarivo, R.; Harison, V.
2014-01-01
We establish equations for scalar and fermion fields using results obtained from a study on a phase space representation of quantum theory that we have performed in a previous work. Our approaches are similar to the historical ones to obtain Klein-Gordon and Dirac equations but the main difference is that ours are based on the use of properties of operators called dispersion-codispersion operators. We begin with a brief recall about the dispersion-codispersion operators. Then, introducing a mass operator with its canonical conjugate coordinate and applying rules of quantization, based on the use of dispersion - codispersion operators , we deduce a second order differential operator relation from the relativistic expression relying energy, momentum and mass. Using Dirac matrices, we derive from this second order differential operator relation a first order one. The application of the second order differential operator relation on a scalar function gives the equation for the scalar field and the use of the first order differential operator relation leads to the equation for fermion field.
Dipole operator constraints on composite Higgs models.
König, Matthias; Neubert, Matthias; Straub, David M
Flavour- and CP-violating electromagnetic or chromomagnetic dipole operators in the quark sector are generated in a large class of new physics models and are strongly constrained by measurements of the neutron electric dipole moment and observables sensitive to flavour-changing neutral currents, such as the [Formula: see text] branching ratio and [Formula: see text]. After a model-independent discussion of the relevant constraints, we analyze these effects in models with partial compositeness, where the quarks get their masses by mixing with vector-like composite fermions. These scenarios can be seen as the low-energy limit of composite Higgs or warped extra dimensional models. We study different choices for the electroweak representations of the composite fermions motivated by electroweak precision tests as well as different flavour structures, including flavour anarchy and [Formula: see text] or [Formula: see text] flavour symmetries in the strong sector. In models with "wrong-chirality" Yukawa couplings, we find a strong bound from the neutron electric dipole moment, irrespective of the flavour structure. In the case of flavour anarchy, we also find strong bounds from flavour-violating dipoles, while these constraints are mild in the flavour-symmetric models.
Dipole operator constraints on composite Higgs models
Energy Technology Data Exchange (ETDEWEB)
Koenig, Matthias [Johannes Gutenberg University, PRISMA Cluster of Excellence and Mainz Institute for Theoretical Physics, Mainz (Germany); Neubert, Matthias [Johannes Gutenberg University, PRISMA Cluster of Excellence and Mainz Institute for Theoretical Physics, Mainz (Germany); Cornell University, Department of Physics, LEPP, Ithaca, NY (United States); Straub, David M. [Excellence Cluster Universe, Technische Universitaet Muenchen, Garching (Germany)
2014-07-15
Flavour- and CP-violating electromagnetic or chromomagnetic dipole operators in the quark sector are generated in a large class of new physics models and are strongly constrained by measurements of the neutron electric dipolemoment and observables sensitive to flavour-changing neutral currents, such as the B→ X{sub s}γ branching ratio and ε'/ε. After a model-independent discussion of the relevant constraints, we analyze these effects in models with partial compositeness, where the quarks get their masses by mixing with vector-like composite fermions. These scenarios can be seen as the low-energy limit of composite Higgs or warped extra dimensional models. We study different choices for the electroweak representations of the composite fermions motivated by electroweak precision tests as well as different flavour structures, including flavour anarchy and U(3){sup 3} or U(2){sup 3} flavour symmetries in the strong sector. In models with ''wrong-chirality'' Yukawa couplings, we find a strong bound from the neutron electric dipole moment, irrespective of the flavour structure. In the case of flavour anarchy, we also find strong bounds from flavour-violating dipoles, while these constraints are mild in the flavour-symmetric models. (orig.)
Operational ocean models in the Adriatic Sea: a skill assessment
Directory of Open Access Journals (Sweden)
J. Chiggiato
2008-02-01
Full Text Available In the framework of the Mediterranean Forecasting System (MFS project, the performance of regional numerical ocean forecasting systems is assessed by means of model-model and model-data comparison. Three different operational systems considered in this study are: the Adriatic REGional Model (AREG; the Adriatic Regional Ocean Modelling System (AdriaROMS and the Mediterranean Forecasting System General Circulation Model (MFS-GCM. AREG and AdriaROMS are regional implementations (with some dedicated variations of POM and ROMS, respectively, while MFS-GCM is an OPA based system. The assessment is done through standard scores. In situ and remote sensing data are used to evaluate the system performance. In particular, a set of CTD measurements collected in the whole western Adriatic during January 2006 and one year of satellite derived sea surface temperature measurements (SST allow to asses a full three-dimensional picture of the operational forecasting systems quality during January 2006 and to draw some preliminary considerations on the temporal fluctuation of scores estimated on surface quantities between summer 2005 and summer 2006.
The regional systems share a negative bias in simulated temperature and salinity. Nonetheless, they outperform the MFS-GCM in the shallowest locations. Results on amplitude and phase errors are improved in areas shallower than 50 m, while degraded in deeper locations, where major models deficiencies are related to vertical mixing overestimation. In a basin-wide overview, the two regional models show differences in the local displacement of errors. In addition, in locations where the regional models are mutually correlated, the aggregated mean squared error was found to be smaller, that is a useful outcome of having several operational systems in the same region.
Cancer treatment model with the Caputo-Fabrizio fractional derivative
Ali Dokuyucu, Mustafa; Celik, Ercan; Bulut, Hasan; Mehmet Baskonus, Haci
2018-03-01
In this article, a model for cancer treatment is examined. The model is integrated into the Caputo-Fabrizio fractional derivative first, to examine the existence of the solution. Then, the uniqueness of the solution is investigated and we identified under which conditions the model provides a unique solution.
Simultaneous inference for model averaging of derived parameters
DEFF Research Database (Denmark)
Jensen, Signe Marie; Ritz, Christian
2015-01-01
Model averaging is a useful approach for capturing uncertainty due to model selection. Currently, this uncertainty is often quantified by means of approximations that do not easily extend to simultaneous inference. Moreover, in practice there is a need for both model averaging and simultaneous...... inference for derived parameters calculated in an after-fitting step. We propose a method for obtaining asymptotically correct standard errors for one or several model-averaged estimates of derived parameters and for obtaining simultaneous confidence intervals that asymptotically control the family...
Modeling lift operations with SASmacr Simulation Studio
Kar, Leow Soo
2016-10-01
Lifts or elevators are an essential part of multistorey buildings which provide vertical transportation for its occupants. In large and high-rise apartment buildings, its occupants are permanent, while in buildings, like hospitals or office blocks, the occupants are temporary or users of the buildings. They come in to work or to visit, and thus, the population of such buildings are much higher than those in residential apartments. It is common these days that large office blocks or hospitals have at least 8 to 10 lifts serving its population. In order to optimize the level of service performance, different transportation schemes are devised to control the lift operations. For example, one lift may be assigned to solely service the even floors and another solely for the odd floors, etc. In this paper, a basic lift system is modelled using SAS Simulation Studio to study the effect of factors such as the number of floors, capacity of the lift car, arrival rate and exit rate of passengers at each floor, peak and off peak periods on the system performance. The simulation is applied to a real lift operation in Sunway College's North Building to validate the model.
Zhang, J.; Lei, X.; Liu, P.; Wang, H.; Li, Z.
2017-12-01
Flood control operation of multi-reservoir systems such as parallel reservoirs and hybrid reservoirs often suffer from complex interactions and trade-off among tributaries and the mainstream. The optimization of such systems is computationally intensive due to nonlinear storage curves, numerous constraints and complex hydraulic connections. This paper aims to derive the optimal flood control operating rules based on the trade-off among tributaries and the mainstream using a new algorithm known as weighted non-dominated sorting genetic algorithm II (WNSGA II). WNSGA II could locate the Pareto frontier in non-dominated region efficiently due to the directed searching by weighted crowding distance, and the results are compared with those of conventional operating rules (COR) and single objective genetic algorithm (GA). Xijiang river basin in China is selected as a case study, with eight reservoirs and five flood control sections within four tributaries and the mainstream. Furthermore, the effects of inflow uncertainty have been assessed. Results indicate that: (1) WNSGA II could locate the non-dominated solutions faster and provide better Pareto frontier than the traditional non-dominated sorting genetic algorithm II (NSGA II) due to the weighted crowding distance; (2) WNSGA II outperforms COR and GA on flood control in the whole basin; (3) The multi-objective operating rules from WNSGA II deal with the inflow uncertainties better than COR. Therefore, the WNSGA II can be used to derive stable operating rules for large-scale reservoir systems effectively and efficiently.
Large deflection of viscoelastic beams using fractional derivative model
International Nuclear Information System (INIS)
Bahranini, Seyed Masoud Sotoodeh; Eghtesad, Mohammad; Ghavanloo, Esmaeal; Farid, Mehrdad
2013-01-01
This paper deals with large deflection of viscoelastic beams using a fractional derivative model. For this purpose, a nonlinear finite element formulation of viscoelastic beams in conjunction with the fractional derivative constitutive equations has been developed. The four-parameter fractional derivative model has been used to describe the constitutive equations. The deflected configuration for a uniform beam with different boundary conditions and loads is presented. The effect of the order of fractional derivative on the large deflection of the cantilever viscoelastic beam, is investigated after 10, 100, and 1000 hours. The main contribution of this paper is finite element implementation for nonlinear analysis of viscoelastic fractional model using the storage of both strain and stress histories. The validity of the present analysis is confirmed by comparing the results with those found in the literature.
Crop growth modelling and crop yield forecasting using satellite derived meteorological inputs
Wit, de A.J.W.; Diepen, van K.
2006-01-01
One of the key challenges for operational crop monitoring and yield forecasting using crop models is to find spatially representative meteorological input data. Currently, weather inputs are often interpolated from low density networks of weather stations or derived from output from coarse (0.5
Operational model updating of spinning finite element models for HAWT blades
Velazquez, Antonio; Swartz, R. Andrew; Loh, Kenneth J.; Zhao, Yingjun; La Saponara, Valeria; Kamisky, Robert J.; van Dam, Cornelis P.
2014-04-01
Structural health monitoring (SHM) relies on collection and interrogation of operational data from the monitored structure. To make this data meaningful, a means of understanding how damage sensitive data features relate to the physical condition of the structure is required. Model-driven SHM applications achieve this goal through model updating. This study proposed a novel approach for updating of aero-elastic turbine blade vibrational models for operational horizontal-axis wind turbines (HAWTs). The proposed approach updates estimates of modal properties for spinning HAWT blades intended for use in SHM and load estimation of these structures. Spinning structures present additional challenges for model updating due to spinning effects, dependence of modal properties on rotational velocity, and gyroscopic effects that lead to complex mode shapes. A cyclo-stationary stochastic-based eigensystem realization algorithm (ERA) is applied to operational turbine data to identify data-driven modal properties including frequencies and mode shapes. Model-driven modal properties are derived through modal condensation of spinning finite element models with variable physical parameters. Complex modes are converted into equivalent real modes through reduction transformation. Model updating is achieved through use of an adaptive simulated annealing search process, via Modal Assurance Criterion (MAC) with complex-conjugate modes, to find the physical parameters that best match the experimentally derived data.
International Nuclear Information System (INIS)
Cheon, Se Woo; Sur, Sang Moon; Lee, Yong Hee; Park, Young Taeck; Moon, Sang Joon
1994-01-01
Computer modeling of an operator's cognitive behavior is a promising approach for the purpose of human factors study and man-machine systems assessment. In this paper, the states of the art in modeling operator behavior and the current status in developing an operator's model (MINERVA - NPP) are presented. The model is constructed as a knowledge-based system of a blackboard framework and is simulated based on emergency operating procedures
An Operational Model for the Prediction of Jet Blast
2012-01-09
This paper presents an operational model for the prediction of jet blast. The model was : developed based upon three modules including a jet exhaust model, jet centerline decay : model and aircraft motion model. The final analysis was compared with d...
Modelling of Reservoir Operations using Fuzzy Logic and ANNs
Van De Giesen, N.; Coerver, B.; Rutten, M.
2015-12-01
Today, almost 40.000 large reservoirs, containing approximately 6.000 km3 of water and inundating an area of almost 400.000 km2, can be found on earth. Since these reservoirs have a storage capacity of almost one-sixth of the global annual river discharge they have a large impact on the timing, volume and peaks of river discharges. Global Hydrological Models (GHM) are thus significantly influenced by these anthropogenic changes in river flows. We developed a parametrically parsimonious method to extract operational rules based on historical reservoir storage and inflow time-series. Managing a reservoir is an imprecise and vague undertaking. Operators always face uncertainties about inflows, evaporation, seepage losses and various water demands to be met. They often base their decisions on experience and on available information, like reservoir storage and the previous periods inflow. We modeled this decision-making process through a combination of fuzzy logic and artificial neural networks in an Adaptive-Network-based Fuzzy Inference System (ANFIS). In a sensitivity analysis, we compared results for reservoirs in Vietnam, Central Asia and the USA. ANFIS can indeed capture reservoirs operations adequately when fed with a historical monthly time-series of inflows and storage. It was shown that using ANFIS, operational rules of existing reservoirs can be derived without much prior knowledge about the reservoirs. Their validity was tested by comparing actual and simulated releases with each other. For the eleven reservoirs modelled, the normalised outflow, , was predicted with a MSE of 0.002 to 0.044. The rules can be incorporated into GHMs. After a network for a specific reservoir has been trained, the inflow calculated by the hydrological model can be combined with the release and initial storage to calculate the storage for the next time-step using a mass balance. Subsequently, the release can be predicted one time-step ahead using the inflow and storage.
Deriving the Dividend Discount Model in the Intermediate Microeconomics Class
Norman, Stephen; Schlaudraff, Jonathan; White, Karianne; Wills, Douglas
2013-01-01
In this article, the authors show that the dividend discount model can be derived using the basic intertemporal consumption model that is introduced in a typical intermediate microeconomics course. This result will be of use to instructors who teach microeconomics to finance students in that it demonstrates the value of utility maximization in…
Higher derivative operators from Scherk-Schwarz supersymmetry breaking on T2/Z2
International Nuclear Information System (INIS)
Ghilencea, Dumitru M.; Lee, Hyun Min
2005-01-01
In orbifold compactifications on T 2 /Z 2 with Scherk-Schwarz supersymmetry breaking, it is shown that (brane-localised) superpotential interactions and (bulk) gauge interactions generate at one-loop higher derivative counterterms to the mass of the brane (or zero-mode of the bulk) scalar field. These brane-localised operators are generated by integrating out the bulk modes of the initial theory which, although supersymmetric, is nevertheless non-renormalisable. It is argued that such operators, of non-perturbative origin and not protected by non-renormalisation theorems, are generic in orbifold compactifications and play a crucial role in the UV behaviour of the two-point Green function of the scalar field self-energy. Their presence in the action with unknown coefficients prevents one from making predictions about physics at (momentum) scales close to/above the compactification scale(s). Our results extend to the case of two dimensional orbifolds, previous findings for S 1 /Z 2 and S 1 /(Z 2 x Z 2 ') compactifications where brane-localised higher derivative operators are also dynamically generated at loop level, regardless of the details of the supersymmetry breaking mechanism. We stress the importance of these operators for the hierarchy and the cosmological constant problems in compactified theories
A Secure Operational Model for Mobile Payments
Directory of Open Access Journals (Sweden)
Tao-Ku Chang
2014-01-01
Full Text Available Instead of paying by cash, check, or credit cards, customers can now also use their mobile devices to pay for a wide range of services and both digital and physical goods. However, customers’ security concerns are a major barrier to the broad adoption and use of mobile payments. In this paper we present the design of a secure operational model for mobile payments in which access control is based on a service-oriented architecture. A customer uses his/her mobile device to get authorization from a remote server and generate a two-dimensional barcode as the payment certificate. This payment certificate has a time limit and can be used once only. The system also provides the ability to remotely lock and disable the mobile payment service.
A secure operational model for mobile payments.
Chang, Tao-Ku
2014-01-01
Instead of paying by cash, check, or credit cards, customers can now also use their mobile devices to pay for a wide range of services and both digital and physical goods. However, customers' security concerns are a major barrier to the broad adoption and use of mobile payments. In this paper we present the design of a secure operational model for mobile payments in which access control is based on a service-oriented architecture. A customer uses his/her mobile device to get authorization from a remote server and generate a two-dimensional barcode as the payment certificate. This payment certificate has a time limit and can be used once only. The system also provides the ability to remotely lock and disable the mobile payment service.
A Secure Operational Model for Mobile Payments
2014-01-01
Instead of paying by cash, check, or credit cards, customers can now also use their mobile devices to pay for a wide range of services and both digital and physical goods. However, customers' security concerns are a major barrier to the broad adoption and use of mobile payments. In this paper we present the design of a secure operational model for mobile payments in which access control is based on a service-oriented architecture. A customer uses his/her mobile device to get authorization from a remote server and generate a two-dimensional barcode as the payment certificate. This payment certificate has a time limit and can be used once only. The system also provides the ability to remotely lock and disable the mobile payment service. PMID:25386607
Vulnerable Derivatives and Good Deal Bounds: A Structural Model
DEFF Research Database (Denmark)
Murgoci, Agatha
2013-01-01
We price vulnerable derivatives -- i.e. derivatives where the counterparty may default. These are basically the derivatives traded on the over-the-counter (OTC) markets. Default is modeled in a structural framework. The technique employed for pricing is good deal bounds (GDBs). The method imposes...... can be obtained. We provide a link between the objective probability measure and the range of potential risk-neutral measures, which has an intuitive economic meaning. We also provide tight pricing bounds for European calls and show how to extend the call formula to pricing other financial products...
Chen, Fengzhi; Zhang, Haibo; Wang, Zhiqiang; Ding, Wei; Zeng, Qinyu; Liu, Wenbing; Huang, Can; He, Shuhua; Wei, Anyang
2017-09-01
The efficacy of adipose-derived stem cells (ADSCs) in alleviating erectile dysfunction (ED) of diabetic rats has been demonstrated mainly through a paracrine effect. However, exosomes (EXOs), which are important bioactive substance vectors secreted by ADSCs, have never been associated with ED. To investigate the effect of ADSC-derived EXOs on erectile function in a type 2 diabetic ED rat model. EXOs were isolated from the supernatants of cultured ADSCs by ultracentrifugation. We constructed a type 2 diabetic rat model using a high-fat diet and low-dose streptozotocin administered by intraperitoneal injection. In total, 24 diabetic rats were randomly assigned to three groups and were treated with an intracavernous injection of ADSC-derived EXOs, ADSCs, or phosphate buffered saline. Another eight age-matched rats underwent sham operation and composed the normal control group. Intracavernous pressure and mean arterial pressure testing and histologic and western blot analyses were performed 4 weeks after the intracavernous injection. ADSC-derived EXOs and ADSCs administered by intracavernous injection led to an increase in the ratio of intracavernous pressure to mean arterial pressure compared with that for phosphate buffered saline treatment. Histologic and western blot analyses demonstrated an increased ratio of smooth muscle to collagen, increased expression of an endothelial marker (CD31), a smooth muscle marker (α-smooth muscle actin), and antiapoptotic protein Bcl-2 and decreased the expression of the apoptotic protein cleaved caspase-3 and apoptosis of endothelial and smooth muscle cells in the corpus cavernosum tissue after EXO or ADSC injection compared with values for the phosphate buffered saline treatment. The present results are expected to provide a scientific foundation for clinical application in the near future. Although the results demonstrated that intracavernous injection of ADSC-derived EXOs could ameliorate ED of diabetic rats, the optimum dose
International Nuclear Information System (INIS)
Suh, Sang Moon; Cheon, Se Woo; Lee, Yong Hee; Lee, Jung Woon; Park, Young Taek
1996-01-01
SACOM(Simulation Analyser with Cognitive Operator Model) is being developed at Korea Atomic Energy Research Institute to simulate human operator's cognitive characteristics during the emergency situations of nuclear power plans. An operator model with error mechanisms has been developed and combined into SACOM to simulate human operator's cognitive information process based on the Rasmussen's decision ladder model. The operational logic for five different cognitive activities (Agents), operator's attentional control (Controller), short-term memory (Blackboard), and long-term memory (Knowledge Base) have been developed and implemented on blackboard architecture. A trial simulation with a scenario for emergency operation has been performed to verify the operational logic. It was found that the operator model with error mechanisms is suitable for the simulation of operator's cognitive behavior in emergency situation
Modeling of a three-phase reactor for bitumen-derived gas oil hydrotreating
Directory of Open Access Journals (Sweden)
R. Chacón
2012-03-01
Full Text Available A three-phase reactor model for describing the hydrotreating reactions of bitumen-derived gas oil was developed. The model incorporates the mass-transfer resistance at the gas-liquid and liquid-solid interfaces and a kinetic rate expression based on a Langmuir-Hinshelwood-type model. We derived three correlations for determining the solubility of hydrogen (H2, hydrogen sulfide (H2S and ammonia (NH3 in hydrocarbon mixtures and the calculation of the catalyst effectiveness factor was included. Experimental data taken from the literature were used to determine the kinetic parameters (stoichiometric coefficients, reaction orders, reaction rate and adsorption constants for hydrodesulfuration (HDS and hydrodenitrogenation (HDN and to validate the model under various operating conditions. Finally, we studied the effect of operating conditions such as pressure, temperature, LHSV, H2/feed ratio and the inhibiting effect of H2S on HDS and NH3 on HDN.
Dynamic Modeling for the Design and Cyclic Operation of an Atomic Layer Deposition (ALD) Reactor
Travis, Curtisha; Adomaitis, Raymond
2013-01-01
A laboratory-scale atomic layer deposition (ALD) reactor system model is derived for alumina deposition using trimethylaluminum and water as precursors. Model components describing the precursor thermophysical properties, reactor-scale gas-phase dynamics and surface reaction kinetics derived from absolute reaction rate theory are integrated to simulate the complete reactor system. Limit-cycle solutions defining continuous cyclic ALD reactor operation are computed with a fixed point algorithm ...
Improving traffic signal management and operations : a basic service model.
2009-12-01
This report provides a guide for achieving a basic service model for traffic signal management and : operations. The basic service model is based on simply stated and defensible operational objectives : that consider the staffing level, expertise and...
State-Space Modelling of Loudspeakers using Fractional Derivatives
DEFF Research Database (Denmark)
King, Alexander Weider; Agerkvist, Finn T.
2015-01-01
This work investigates the use of fractional order derivatives in modeling moving-coil loudspeakers. A fractional order state-space solution is developed, leading the way towards incorporating nonlinearities into a fractional order system. The method is used to calculate the response of a fractio......This work investigates the use of fractional order derivatives in modeling moving-coil loudspeakers. A fractional order state-space solution is developed, leading the way towards incorporating nonlinearities into a fractional order system. The method is used to calculate the response...... of a fractional harmonic oscillator, representing the mechanical part of a loudspeaker, showing the effect of the fractional derivative and its relationship to viscoelasticity. Finally, a loudspeaker model with a fractional order viscoelastic suspension and fractional order voice coil is fit to measurement data...
International Nuclear Information System (INIS)
Pan, Yi; Shi, Yupeng; Chen, Junying; Wong, Chap-Mo; Zhang, Heng; Li, Mei-Jin; Li, Cheuk-Wing; Yi, Changqing
2016-01-01
In this study, a highly sensitive and selective fluorescent Zn 2+ probe which exhibited excellent biocompatibility, water solubility, and cell-membrane permeability, was facilely synthesized in a single step by grafting polyethyleneimine (PEI) with quinoline derivatives. The primary amino groups in the branched PEI can increase water solubility and cell permeability of the probe PEIQ, while quinoline derivatives can specifically recognize Zn 2+ and reduce the potential cytotoxicity of PEI. Basing on fluorescence off-on mechanism, PEIQ demonstrated excellent sensing capability towards Zn 2+ in absolute aqueous solution, where a high sensitivity with a detection limit as low as 38.1 nM, and a high selectivity over competing metal ions and potential interfering amino acids, were achieved. Inspired by these results, elementary logic operations (YES, NOT and INHIBIT) have been constructed by employing PEIQ as the gate while Zn 2+ and EDTA as chemical inputs. Together with the low cytotoxicity and good cell-permeability, the practical application of PEIQ in living cell imaging was satisfactorily demonstrated, emphasizing its wide application in fundamental biology research. - Graphical abstract: The fluorescent Zn 2+ probe, PEIQ, is facilely synthesized by grafting PEI with 8-CAAQ, and demonstrated for the pratical applications in Zn 2+ imaging and implementation of molecular logic operations within biological cells. - Highlights: • PEIQ, fluorescent Zn 2+ probe, is synthesized by grafting PEI with quinoline derivatives. • PEIQ exhibits high sensitivity and selectivity in absolute aqueous solution. • PEIQ is biocompatible, water soluble, and cell-membrane permeable. • Elementary logic operations have been demonstrated for PEIQ/Zn 2+ /EDTA system. • The practical application of PEIQ in living cell imaging is demonstrated.
Directory of Open Access Journals (Sweden)
Fatima G. Khushtova
2016-03-01
Full Text Available In this paper Cauchy problem for a parabolic equation with Bessel operator and with Riemann–Liouville partial derivative is considered. The representation of the solution is obtained in terms of integral transform with Wright function in the kernel. It is shown that when this equation becomes the fractional diffusion equation, obtained solution becomes the solution of Cauchy problem for the corresponding equation. The uniqueness of the solution in the class of functions that satisfy the analogue of Tikhonov condition is proved.
Modeling the Interest Rate Term Structure: Derivatives Contracts Dynamics and Evaluation
Directory of Open Access Journals (Sweden)
Pedro L. Valls Pereira
2005-06-01
Full Text Available This article deals with a model for the term structure of interest rates and the valuation of derivative contracts directly dependent on it. The work is of a theoretical nature and deals, exclusively, with continuous time models, making ample use of stochastic calculus results and presents original contributions that we consider relevant to the development of the fixed income market modeling. We develop a new multifactorial model of the term structure of interest rates. The model is based on the decomposition of the yield curve into the factors level, slope, curvature, and the treatment of their collective dynamics. We show that this model may be applied to serve various objectives: analysis of bond price dynamics, valuation of derivative contracts and also market risk management and formulation of operational strategies which is presented in another article.
Epps, Brenden; Cushman-Roisin, Benoit
2017-11-01
Fluid turbulence is an outstanding unsolved problem in classical physics, despite 120+ years of sustained effort. Given this history, we assert that a new mathematical framework is needed to make a transformative breakthrough. This talk offers one such framework, based upon kinetic theory tied to the statistics of turbulent transport. Starting from the Boltzmann equation and ``Lévy α-stable distributions'', we derive a turbulence model that expresses the turbulent stresses in the form of a fractional derivative, where the fractional order is tied to the transport behavior of the flow. Initial results are presented herein, for the cases of Couette-Poiseuille flow and 2D boundary layers. Among other results, our model is able to reproduce the logarithmic Law of the Wall in shear turbulence.
Modeling and Forecasting Average Temperature for Weather Derivative Pricing
Directory of Open Access Journals (Sweden)
Zhiliang Wang
2015-01-01
Full Text Available The main purpose of this paper is to present a feasible model for the daily average temperature on the area of Zhengzhou and apply it to weather derivatives pricing. We start by exploring the background of weather derivatives market and then use the 62 years of daily historical data to apply the mean-reverting Ornstein-Uhlenbeck process to describe the evolution of the temperature. Finally, Monte Carlo simulations are used to price heating degree day (HDD call option for this city, and the slow convergence of the price of the HDD call can be found through taking 100,000 simulations. The methods of the research will provide a frame work for modeling temperature and pricing weather derivatives in other similar places in China.
QSAR models for antioxidant activity of new coumarin derivatives.
Erzincan, P; Saçan, M T; Yüce-Dursun, B; Danış, Ö; Demir, S; Erdem, S S; Ogan, A
2015-01-01
This study presents 37 new antioxidant coumarin derivatives and strategies for structural modification to improve their antioxidant activities, the main ferric-reducing antioxidant power (FRAP) assay used to evaluate their antioxidant properties and the generation of validated quantitative structure-activity (antioxidant activity) relationship (QSAR) models. In an attempt to generate QSAR models, structures of all coumarin derivatives in the data set were fully optimized by semi-empirical PM6 method using SPARTAN 10 software. Descriptors were calculated by DRAGON 6.0 software. Multiple linear regression (MLR) models were developed with different training/test set combinations using QSARINS 2.2.1 software. Robustness, reliability and predictive power of the models were tested by internal and external validations. Applicability domain of the best two-descriptor model (nTR = 30; r(2) = 0.924; RMSETR = 0.213; nTEST = 7; r(2)ext = 0.887; RMSEext = 0.255; CCCext = 0.939) was determined. Descriptors appeared in the model revealed that complexity, H-bond donor and lipophilic character are important parameters in describing the antioxidant activity. Apart from the compounds in the data set, we also designed 31 new antioxidant coumarin derivatives and predicted their antioxidant activity using the best two-descriptor model. Most of these compounds are promising antioxidants.
A direct carbon solid oxide fuel cell operated on a plant derived biofuel with natural catalyst
International Nuclear Information System (INIS)
Cai, Weizi; Zhou, Qian; Xie, Yongmin; Liu, Jiang; Long, Guohui; Cheng, Shuang; Liu, Meilin
2016-01-01
Graphical abstract: A plant-derived biochar, with biologically accumulated chemical elements as catalyst for the Boudouard reaction, is a superior fuel to the all-solid-state direct carbon solid oxide fuel cells (DC-SOFCs), and, it enables DC-SOFCs to be a novel technology, of high efficient, low cost and environmental friendliness, for distributed power generation. - Highlights: • Orchid leaf char is a good fuel of all-solid-state DC-SOFCs. • Performance of DC-SOFC with leaf char is better than that with Fe-loaded carbon. • Biologically accumulated Ca in leaf char acts as catalyst for Boudouard reaction. • Leaf char with natural Ca performs better than C with Ca added by mechanical mixing. • Biochar with natural catalyst provides low cost and low pollutant fuel to DC-SOFCs. - Abstract: Biochar derived from orchid tree leaves is utilised as the fuel of a direct carbon solid oxide fuel cell (DC-SOFC), with yttrium stabilized zirconia (YSZ) as electrolyte and cermet of silver and gadolinium doped ceria (Ag-GDC) as the material of both cathode and anode, operating without any liquid medium or feeding gas. The performance of the DC-SOFC operated on the leaf char is higher than that operated on the best reported carbon fuel for DC-SOFCs, Fe-loaded activated carbon. XRD, Raman spectroscopy, SEM and EDX are applied to characterize the leaf char. It turns out that the leaf char is with porous structure and there is much Ca along with some K and Mg uniformly distributing in the leaf char. The effects of the naturally existing alkaline earth metal and alkaline metal and their distribution on the performance of the DC-SOFCs operated on the leaf char are analyzed in detail.
A Consistent Pricing Model for Index Options and Volatility Derivatives
DEFF Research Database (Denmark)
Kokholm, Thomas
We propose a flexible modeling framework for the joint dynamics of an index and a set of forward variance swap rates written on this index. Our model reproduces various empirically observed properties of variance swap dynamics and enables volatility derivatives and options on the underlying index...... to be priced consistently, while allowing for jumps in volatility and returns. An affine specification using Lévy processes as building blocks leads to analytically tractable pricing formulas for volatility derivatives, such as VIX options, as well as efficient numerical methods for pricing of European options...... on the underlying asset. The model has the convenient feature of decoupling the vanilla skews from spot/volatility correlations and allowing for different conditional correlations in large and small spot/volatility moves. We show that our model can simultaneously fit prices of European options on S&P 500 across...
A Consistent Pricing Model for Index Options and Volatility Derivatives
DEFF Research Database (Denmark)
Cont, Rama; Kokholm, Thomas
2013-01-01
We propose a flexible modeling framework for the joint dynamics of an index and a set of forward variance swap rates written on this index. Our model reproduces various empirically observed properties of variance swap dynamics and enables volatility derivatives and options on the underlying index...... to be priced consistently, while allowing for jumps in volatility and returns. An affine specification using Lévy processes as building blocks leads to analytically tractable pricing formulas for volatility derivatives, such as VIX options, as well as efficient numerical methods for pricing of European options...... on the underlying asset. The model has the convenient feature of decoupling the vanilla skews from spot/volatility correlations and allowing for different conditional correlations in large and small spot/volatility moves. We show that our model can simultaneously fit prices of European options on S&P 500 across...
Modelling of the Blood Plasma Species of Biguanide Derivatives ...
African Journals Online (AJOL)
NJD
Modelling of the Blood Plasma Species of. Biguanide Derivatives Exhibiting Potential as. Diagnostic Radiopharmaceuticals. Judith M. Wagenera*, Midred K. Dithebea, Daniel Moganob, Ignacy Cukrowskib and Jan Rijn Zeevaartc. aRadiochemistry, NECSA, P.O. Box 582, Pretoria 0001, South Africa. bDepartment of ...
Microscopic Derivation of the Ginzburg-Landau Model
DEFF Research Database (Denmark)
Frank, Rupert; Hainzl, Christian; Seiringer, Robert
2014-01-01
We present a summary of our recent rigorous derivation of the celebrated Ginzburg-Landau (GL) theory, starting from the microscopic Bardeen-Cooper-Schrieffer (BCS) model. Close to the critical temperature, GL arises as an effective theory on the macroscopic scale. The relevant scaling limit...
Modelling ocean-colour-derived chlorophyll a
Directory of Open Access Journals (Sweden)
S. Dutkiewicz
2018-01-01
Full Text Available This article provides a proof of concept for using a biogeochemical/ecosystem/optical model with a radiative transfer component as a laboratory to explore aspects of ocean colour. We focus here on the satellite ocean colour chlorophyll a (Chl a product provided by the often-used blue/green reflectance ratio algorithm. The model produces output that can be compared directly to the real-world ocean colour remotely sensed reflectance. This model output can then be used to produce an ocean colour satellite-like Chl a product using an algorithm linking the blue versus green reflectance similar to that used for the real world. Given that the model includes complete knowledge of the (model water constituents, optics and reflectance, we can explore uncertainties and their causes in this proxy for Chl a (called derived Chl a in this paper. We compare the derived Chl a to the actual model Chl a field. In the model we find that the mean absolute bias due to the algorithm is 22 % between derived and actual Chl a. The real-world algorithm is found using concurrent in situ measurement of Chl a and radiometry. We ask whether increased in situ measurements to train the algorithm would improve the algorithm, and find a mixed result. There is a global overall improvement, but at the expense of some regions, especially in lower latitudes where the biases increase. Not surprisingly, we find that region-specific algorithms provide a significant improvement, at least in the annual mean. However, in the model, we find that no matter how the algorithm coefficients are found there can be a temporal mismatch between the derived Chl a and the actual Chl a. These mismatches stem from temporal decoupling between Chl a and other optically important water constituents (such as coloured dissolved organic matter and detrital matter. The degree of decoupling differs regionally and over time. For example, in many highly seasonal regions, the timing of initiation
A Consistent Pricing Model for Index Options and Volatility Derivatives
DEFF Research Database (Denmark)
Kokholm, Thomas
We propose a flexible modeling framework for the joint dynamics of an index and a set of forward variance swap rates written on this index. Our model reproduces various empirically observed properties of variance swap dynamics and enables volatility derivatives and options on the underlying index...... on the underlying asset. The model has the convenient feature of decoupling the vanilla skews from spot/volatility correlations and allowing for different conditional correlations in large and small spot/volatility moves. We show that our model can simultaneously fit prices of European options on S&P 500 across...
Derivation of Output Power of Induction Heater Model
Directory of Open Access Journals (Sweden)
Riyadh K. Chillab
2016-12-01
Full Text Available The work is concerned with the study of the single phase cylindrical induction heating systems and derive equation power. The presented analysis is analytical and a multi-layer model using cylindrical geometry which is used to obtain the theoretical results. To validate the theoretical results, a practical model is constructed, tested and the results are compared with the theoretical ones. Comparison showed that the adopted analytical method is efficient in describing the performance of such induction heater systems
Numerical Model Metrics Tools in Support of Navy Operations
Dykes, J. D.; Fanguy, P.
2017-12-01
Increasing demands of accurate ocean forecasts that are relevant to the Navy mission decision makers demand tools that quickly provide relevant numerical model metrics to the forecasters. Increasing modelling capabilities with ever-higher resolution domains including coupled and ensemble systems as well as the increasing volume of observations and other data sources to which to compare the model output requires more tools for the forecaster to enable doing more with less. These data can be appropriately handled in a geographic information system (GIS) fused together to provide useful information and analyses, and ultimately a better understanding how the pertinent model performs based on ground truth.. Oceanographic measurements like surface elevation, profiles of temperature and salinity, and wave height can all be incorporated into a set of layers correlated to geographic information such as bathymetry and topography. In addition, an automated system that runs concurrently with the models on high performance machines matches routinely available observations to modelled values to form a database of matchups with which statistics can be calculated and displayed, to facilitate validation of forecast state and derived variables. ArcMAP, developed by Environmental Systems Research Institute, is a GIS application used by the Naval Research Laboratory (NRL) and naval operational meteorological and oceanographic centers to analyse the environment in support of a range of Navy missions. For example, acoustic propagation in the ocean is described with a three-dimensional analysis of sound speed that depends on profiles of temperature, pressure and salinity predicted by the Navy Coastal Ocean Model. The data and model output must include geo-referencing information suitable for accurately placing the data within the ArcMAP framework. NRL has developed tools that facilitate merging these geophysical data and their analyses, including intercomparisons between model
Developing Operator Models for UAV Search Scheduling
Bertuccelli, L.F.; Beckers, N.W.M.; Cummings, M.L.
2010-01-01
With the increased use of Unmanned Aerial Vehicles (UAVs), it is envisioned that UAV operators will become high level mission supervisors, responsible for information management and task planning. In the context of search missions, operators supervising a large number of UAVs can become overwhelmed
Empirically derived neighbourhood rules for urban land-use modelling
DEFF Research Database (Denmark)
Hansen, Henning Sten
2012-01-01
interaction between neighbouring land uses is an important component in urban cellular automata. Nevertheless, this component is often calibrated through trial-and-error estimation. The aim of this project has been to develop an empirically derived landscape metric supporting cellular-automata-based land......-use modelling. Through access to very detailed urban land-use data it has been possible to derive neighbourhood rules empirically, and test their sensitivity to the land-use classification applied, the regional variability of the rules, and their time variance. The developed methodology can be implemented...
Evolution of Geometric Sensitivity Derivatives from Computer Aided Design Models
Jones, William T.; Lazzara, David; Haimes, Robert
2010-01-01
The generation of design parameter sensitivity derivatives is required for gradient-based optimization. Such sensitivity derivatives are elusive at best when working with geometry defined within the solid modeling context of Computer-Aided Design (CAD) systems. Solid modeling CAD systems are often proprietary and always complex, thereby necessitating ad hoc procedures to infer parameter sensitivity. A new perspective is presented that makes direct use of the hierarchical associativity of CAD features to trace their evolution and thereby track design parameter sensitivity. In contrast to ad hoc methods, this method provides a more concise procedure following the model design intent and determining the sensitivity of CAD geometry directly to its respective defining parameters.
Modeling Temperature and Pricing Weather Derivatives Based on Temperature
Directory of Open Access Journals (Sweden)
Birhan Taştan
2017-01-01
Full Text Available This study first proposes a temperature model to calculate the temperature indices upon which temperature-based derivatives are written. The model is designed as a mean-reverting process driven by a Levy process to represent jumps and other features of temperature. Temperature indices are mainly measured as deviations from a base temperature, and, hence, the proposed model includes jumps because they may constitute an important part of this deviation for some locations. The estimated value of a temperature index and its distribution in this model apply an inversion formula to the temperature model. Second, this study develops a pricing process over calculated index values, which returns a customized price for temperature-based derivatives considering that temperature has unique effects on every economic entity. This personalized price is also used to reveal the trading behavior of a hypothesized entity in a temperature-based derivative trade with profit maximization as the objective. Thus, this study presents a new method that does not need to evaluate the risk-aversion behavior of any economic entity.
Development of operator thinking model and its application to nuclear reactor plant operation system
International Nuclear Information System (INIS)
Miki, Tetsushi; Endou, Akira; Himeno, Yoshiaki
1992-01-01
At first, this paper presents the developing method of an operator thinking model and the outline of the developed model. In next, it describes the nuclear reactor plant operation system which has been developed based on this model. Finally, it has been confirmed that the method described in this paper is very effective in order to construct expert systems which replace the reactor operator's role with AI (artificial intelligence) systems. (author)
International Nuclear Information System (INIS)
Xu Xue-Xiang; Hu Li-Yun; Guo Qin; Fan Hong-Yi
2013-01-01
Following the spirit of thermo field dynamics initiated by Takahashi and Umezawa, we employ the technique of integration within an ordered product of operators to derive the thermal vacuum state (TVS) for the Hamiltonian H of the two-coupled-oscillator model. The ensemble averages of the system are derived conveniently by using the TVS. In addition, the entropy for this system is discussed based on the relation between the generalized Hellmann—Feynman theorem and the entroy variation in the context of the TVS. (general)
Differential geometry of viscoelastic models with fractional-order derivatives
International Nuclear Information System (INIS)
Yajima, Takahiro; Nagahama, Hiroyuki
2010-01-01
Viscoelastic materials with memory effect are studied based on the fractional rheonomic geometry. The geometric objects are regarded as basic quantities of fractional viscoelastic models, i.e. the metric tensor and torsion tensor are interpreted as the strain and the fractional strain rate, respectively. The generalized viscoelastic equations are expressed by the geometric objects. Especially, the basic constitutive equations such as Voigt and Maxwell models can be derived geometrically from the generalized equation. This leads to the fact that various viscoelastic models can be unified into one geometric expression.
Tactical Medical Logistics Planning Tool: Modeling Operational Risk Assessment
National Research Council Canada - National Science Library
Konoske, Paula
2004-01-01
...) models the patient flow from the point of injury through more definitive care, and (2) supports operations research and systems analysis studies, operational risk assessment, and field medical services planning. TML+...
Relativistic nuclear matter with alternative derivative coupling models
International Nuclear Information System (INIS)
Delfino, A.; Coelho, C.T.; Malheiro, M.
1994-01-01
Effective Lagrangians involving nucleons coupled to scalar and vector fields are investigated within the framework of relativistic mean-field theory. The study presents the traditional Walecka model and different kinds of scalar derivative coupling suggested by Zimanyi and Moszkowski. The incompressibility (presented in an analytical form), scalar potential, and vector potential at the saturation point of nuclear matter are compared for these models. The real optical potential for the models are calculated and one of the models fits well the experimental curve from-50 to 400 MeV while also gives a soft equation of state. By varying the coupling constants and keeping the saturation point of nuclear matter approximately fixed, only the Walecka model presents a first order phase transition of finite temperature at zero density. (author)
Novel Thiazole Derivatives of Medicinal Potential: Synthesis and Modeling
Directory of Open Access Journals (Sweden)
Nour E. A. Abdel-Sattar
2017-01-01
Full Text Available This paper reports on the synthesis of new thiazole derivatives that could be profitably exploited in medical treatment of tumors. Molecular electronic structures have been modeled within density function theory (DFT framework. Reactivity indices obtained from the frontier orbital energies as well as electrostatic potential energy maps are discussed and correlated with the molecular structure. X-ray crystallographic data of one of the new compounds is measured and used to support and verify the theoretical results.
Energy Technology Data Exchange (ETDEWEB)
Borges, L.H.C., E-mail: luizhenriqueunifei@yahoo.com.br [Universidade Federal do ABC, Centro de Ciências Naturais e Humanas, Av. dos Estados, 5001, Santo André, SP, 09210-580 (Brazil); Dias, A.G., E-mail: alex.dias@ufabc.edu.br [Universidade Federal do ABC, Centro de Ciências Naturais e Humanas, Av. dos Estados, 5001, Santo André, SP, 09210-580 (Brazil); Ferrari, A.F., E-mail: alysson.ferrari@ufabc.edu.br [Universidade Federal do ABC, Centro de Ciências Naturais e Humanas, Av. dos Estados, 5001, Santo André, SP, 09210-580 (Brazil); Nascimento, J.R., E-mail: jroberto@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, João Pessoa, Paraíba, 58051-970 (Brazil); Petrov, A.Yu., E-mail: petrov@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, João Pessoa, Paraíba, 58051-970 (Brazil)
2016-05-10
We study the perturbative generation of higher-derivative Lorentz violating operators as quantum corrections to the photon effective action, originated from a specific Lorentz violation background, which has already been studied in connection with the physics of light pseudoscalars. We calculate the complete one loop effective action of the photon field through the proper-time method, using the zeta function regularization. This result can be used as a starting point to study possible effects of the Lorentz violating background we are considering in photon physics. As an example, we focus on the lowest order corrections and investigate whether they could influence the propagation of electromagnetic waves through the vacuum. We show, however, that no effects of the kind of Lorentz violation we consider can be detected in such a context, so that other aspects of photon physics have to be studied.
Directory of Open Access Journals (Sweden)
L.H.C. Borges
2016-05-01
Full Text Available We study the perturbative generation of higher-derivative Lorentz violating operators as quantum corrections to the photon effective action, originated from a specific Lorentz violation background, which has already been studied in connection with the physics of light pseudoscalars. We calculate the complete one loop effective action of the photon field through the proper-time method, using the zeta function regularization. This result can be used as a starting point to study possible effects of the Lorentz violating background we are considering in photon physics. As an example, we focus on the lowest order corrections and investigate whether they could influence the propagation of electromagnetic waves through the vacuum. We show, however, that no effects of the kind of Lorentz violation we consider can be detected in such a context, so that other aspects of photon physics have to be studied.
Hasse-Schmidt derivations on Grassmann algebras with applications to vertex operators
Gatto, Letterio
2016-01-01
This book provides a comprehensive advanced multi-linear algebra course based on the concept of Hasse-Schmidt derivations on a Grassmann algebra (an analogue of the Taylor expansion for real-valued functions), and shows how this notion provides a natural framework for many ostensibly unrelated subjects: traces of an endomorphism and the Cayley-Hamilton theorem, generic linear ODEs and their Wronskians, the exponential of a matrix with indeterminate entries (Putzer's method revisited), universal decomposition of a polynomial in the product of two monic polynomials of fixed smaller degree, Schubert calculus for Grassmannian varieties, and vertex operators obtained with the help of Schubert calculus tools (Giambelli's formula). Significant emphasis is placed on the characterization of decomposable tensors of an exterior power of a free abelian group of possibly infinite rank, which then leads to the celebrated Hirota bilinear form of the Kadomtsev-Petviashvili (KP) hierarchy describing the Plücker embedding of ...
Higher derivative extensions of 3d Chern-Simons models: conservation laws and stability
Energy Technology Data Exchange (ETDEWEB)
Kaparulin, D.S.; Karataeva, I.Yu.; Lyakhovich, S.L. [Tomsk State University, Physics Faculty, Tomsk (Russian Federation)
2015-11-15
We consider the class of higher derivative 3d vector field models with the field equation operator being a polynomial of the Chern-Simons operator. For the nth-order theory of this type, we provide a general recipe for constructing n-parameter family of conserved second rank tensors. The family includes the canonical energy-momentum tensor, which is unbounded, while there are bounded conserved tensors that provide classical stability of the system for certain combinations of the parameters in the Lagrangian. We also demonstrate the examples of consistent interactions which are compatible with the requirement of stability. (orig.)
Data Scaling for Operational Risk Modelling
H.S. Na; L. Couto Miranda; J.H. van den Berg (Jan); M. Leipoldt
2006-01-01
textabstractIn 2004, the Basel Committee on Banking Supervision defined Operational Risk (OR) as the risk of loss resulting from inadequate or failed internal processes, people and systems or from external events. After publication of the new capital accord containing this dfinition, statistical
Modeling the Coordinated Operation between Bus Rapid Transit and Bus
Directory of Open Access Journals (Sweden)
Jiaqing Wu
2015-01-01
Full Text Available The coordination between bus rapid transit (BRT and feeder bus service is helpful in improving the operational efficiency and service level of urban public transport system. Therefore, a coordinated operation model of BRT and bus is intended to develop in this paper. The total costs are formulated and optimized by genetic algorithm. Moreover, the skip-stop BRT operation is considered when building the coordinated operation model. A case of the existing bus network in Beijing is studied, the proposed coordinated operation model of BRT and bus is applied, and the optimized headway and costs are obtained. The results show that the coordinated operation model could effectively decrease the total costs of the transit system and the transfer time of passengers. The results also suggest that the coordination between the skip-stop BRT and bus during peak hour is more effective than non-coordination operation.
Schönberger, Jörn
2005-01-01
The modern freight carrier business requires a sophisticated automatic decision support in order to ensure the efficiency and reliability and therefore the survival of transport service providers. This book addresses these challenges and provides generic decision models for the short-term operations planning as well as advanced metaheuristics to obtain efficient operation plans. After a thorough analysis of the operations planning in the freight carrier business, decision models are derived. Their suitability is proven within a large number of numerical experiments, in which a new class of hybrid genetic search approaches demonstrate their appropriateness.
Tominaga, Makoto; Nishioka, Yukihiro; Tani, Seiji; Suzuki, Yasutaka; Kawamata, Jun
2017-08-09
We propose a methodology for applying a pseudo uniaxial pressure to an organic molecule under ordinary temperature and pressure, namely by intercalation into smectites. The pseudo pressure on a biphenyl derivative (BP) was estimated from the averaged dihedral angle around the central bond of BP. In a high hydrostatic pressure field, biphenyl takes a planar conformation. In the interlayer space of synthetic saponite (SSA), the averaged dihedral angle of BP at a loading level of 27% versus the cation exchange capacity was ~26.3°, which indicates that the pseudo pressure applied to BP in the SSA interlayer space corresponds to 0.99 GPa. The high pseudo-pressure field in the interlayer space of SSA was also confirmed by absorption measurements. The dihedral angle around the central bond of the biphenyl moiety decreased to enhance the planarity of the molecule, mainly in response to the electrostatic force that operates between the negatively charged SSA layer and the interlayer cation. The pseudo pressure operating on BP in the smectite interlayer space could be controlled by varying the smectite layer charge density and/or the BP loading level. By using this methodology, controllable pseudo high-pressure properties of organic molecules can be obtained at ordinary temperatures and pressures.
QSAR MODELING OF ANTIBACTERIAL ACTIVITY OF SOME BENZIMIDAZOLE DERIVATIVES
Directory of Open Access Journals (Sweden)
SANJA O. PODUNAVAC-KUZMANOVIĆ
2011-03-01
Full Text Available A quantitative structure-activity relationship (QSAR study has been carried out for a training set of 12 benzimidazole derivatives to correlate and predict the antibacterial activity of studied compounds against Gram-negative bacteria Pseudomonas aeruginosa. Multiple linear regression was used to select the descriptors and to generate the best prediction model that relates the structural features to inhibitory activity. The predictivity of the model was estimated by cross-validation with the leave-one-out method. Our results suggest a QSAR model based on the following descriptors: parameter of lipophilicity (logP and hydration energy (HE. Good agreement between experimental and predicted inhibitory values, obtained in the validation procedure, indicated the good quality of the generated QSAR model.
Dilger, Mathias Georg; Jovanović, Tanja; Voigt, Kai-Ingo
2017-08-01
Practice and theory have proven the relevance of energy co-operatives for civic participation in the energy turnaround. However, due to a still low awareness and changing regulation, there seems an unexploited potential of utilizing the legal form 'co-operative' in this context. The aim of this study is therefore to investigate the crowdfunding implementation in the business model of energy co-operatives in order to cope with the mentioned challenges. Based on a theoretical framework, we derive a Business Model Innovation (BMI) through crowdfunding including synergies and differences. A qualitative study design, particularly a multiple-case study of energy co-operatives, was chosen to prove the BMI and to reveal barriers. The results show that although most co-operatives are not familiar with crowdfunding, there is strong potential in opening up predominantly local structures to a broader group of members. Building on this, equity-based crowdfunding is revealed to be suitable for energy co-operatives as BMI and to accompany other challenges in the same way. Copyright © 2017 Elsevier Ltd. All rights reserved.
Mapping Relational Operations onto Hypergraph Model
Directory of Open Access Journals (Sweden)
2010-10-01
. However, the hypergraph model is non-tabular; thus, loses the simplicity of the relational model. In this study, we consider the means to convert a relational model into a hypergraph model in two layers. At the bottom layer, each relational tuple can be considered as a star graph centered where the primary key node is surrounded by non-primary key attributes. At the top layer, each tuple is a hypernode, and a relation is a set of hypernodes. We presented a reference implementation of relational operators (project, rename, select, inner join, natural join, left join, right join, outer join and Cartesian join on a hypergraph model. Using a simple example, we demonstrate that a relation and relational operators can be implemented on this hypergraph model.
A knowledge-Induced Operator Model
Directory of Open Access Journals (Sweden)
M.A. Choudhury
2007-06-01
Full Text Available Learning systems are in the forefront of analytical investigation in the sciences. In the social sciences they occupy the study of complexity and strongly interactive world-systems. Sometimes they are diversely referred to as symbiotics and semiotics when studied in conjunction with logical expressions. In the mathematical sciences the methodology underlying learning systems with complex behavior is based on formal logic or systems analysis. In this paper relationally learning systems are shown to transcend the space-time domain of scientific investigation into the knowledge dimension. Such a knowledge domain is explained by pervasive interaction leading to integration and followed by continuous evolution as complementary processes existing between entities and systemic domains in world-systems, thus the abbreviation IIE-processes. This paper establishes a mathematical characterization of the properties of knowledge-induced process-based world-systems in the light of the epistemology of unity of knowledge signified in this paper by extensive complementarities caused by the epistemic and ontological foundation of the text of unity of knowledge, the prime example of which is the realm of the divine laws. The result is formalism in mathematical generalization of the learning phenomenon by means of an operator. This operator summarizes the properties of interaction, integration and evolution (IIE in the continuum domain of knowledge formation signified by universal complementarities across entities, systems and sub-systems in unifying world-systems. The opposite case of ‘de-knowledge’ and its operator is also briefly formalized.
DEFF Research Database (Denmark)
Rasmussen, Jeppe Grøndahl; Frøbert, Ole; Holst-Hansen, Claus
2012-01-01
Background: Treatment of myocardial infarction with bone marrow-derived mesenchymal stem cells and recently also adipose-derived stem cells has shown promising results. In contrast to clinical trials and their use of autologous bone marrow-derived cells from the ischemic patient, the animal...... myocardial infarction models are often using young donors and young, often immune-compromised, recipient animals. Our objective was to compare bone marrow-derived mesenchymal stem cells with adipose-derived stem cells from an elderly ischemic patient in the treatment of myocardial infarction, using a fully...... randomised to receive intramyocardial injections of adipose-derived stem cells, bone marrow derived mesenchymal stem cells or phosphate-buffered saline one week following induction of myocardial infarction. Results: After four weeks, left ventricular ejection fraction was improved in the adipose-derived stem...
Spectral decomposition of model operators in de Branges spaces
International Nuclear Information System (INIS)
Gubreev, Gennady M; Tarasenko, Anna A
2011-01-01
The paper is devoted to studying a class of completely continuous nonselfadjoint operators in de Branges spaces of entire functions. Among other results, a class of unconditional bases of de Branges spaces consisting of values of their reproducing kernels is constructed. The operators that are studied are model operators in the class of completely continuous non-dissipative operators with two-dimensional imaginary parts. Bibliography: 22 titles.
A model of the gas analysis system operation process
Yakimenko, I. V.; Kanishchev, O. A.; Lyamets, L. L.; Volkova, I. V.
2017-12-01
The characteristic features of modeling the gas-analysis measurement system operation process on the basis of the semi-Markov process theory are discussed. The model of the measuring gas analysis system operation process is proposed, which makes it possible to take into account the influence of the replacement interval, the level of reliability and maintainability and to evaluate the product reliability.
Deterministic operations research models and methods in linear optimization
Rader, David J
2013-01-01
Uniquely blends mathematical theory and algorithm design for understanding and modeling real-world problems Optimization modeling and algorithms are key components to problem-solving across various fields of research, from operations research and mathematics to computer science and engineering. Addressing the importance of the algorithm design process. Deterministic Operations Research focuses on the design of solution methods for both continuous and discrete linear optimization problems. The result is a clear-cut resource for understanding three cornerstones of deterministic operations resear
Models for filtration during drilling, completion and stimulation operations
Xie, Jing
Filtration of solid suspensions is encountered in many operations during drilling, completing and stimulating oil and gas wells. Filtration of drilling muds, completion and fracturing fluids, gravel packing slurries are a few examples. Most of these applications involve the filtration of non-Newtonian fluids into a porous medium containing compressible fluids. Internal and external compressible filter cakes can form under static or dynamic filtration conditions. Models for static filtration of solid-laden polymer fluids have been developed. These models solve the basic filtration equations to obtain the depth of invasion of solids and polymer into the formation. The buildup of an external filter cake is modeled after a transition time is reached when no more additional particles invade the formation. It is shown that a square root of time dependence is obtained during external filtration of polymer fluids. During the spurt loss period (internal filtration) the model allows us to calculate the extent of solids and filtrate invasion and the duration of spurt loss. The model for the first time presents a formulation where the spurt loss can be obtained from the model directly. Fluid compressibility effects as well as cake compressibility can be accounted for in the model. The results of the model allow us to better interpret leak-off data during the period in which the polymer is being squeezed into the formation. Comparisons with experiments show that fluid leak-off during the spurt loss period can be accurately estimated with the equations presented. During drilling or when a fracture is created in a frac-and-pack operation, fluid leak-off occurs by a dynamic filtration process. In this process, particles are constantly sheared away by the flow of the polymer slurry parallel to the face of the fracture with fluid leak-off occurring into the rock. A new model for dynamic filtration has been developed which takes into account the particle size distribution of the wall
Modeling Human Cardiac Hypertrophy in Stem Cell-Derived Cardiomyocytes
Directory of Open Access Journals (Sweden)
Ekaterina Ovchinnikova
2018-03-01
Full Text Available Summary: Cardiac hypertrophy accompanies many forms of cardiovascular diseases. The mechanisms behind the development and regulation of cardiac hypertrophy in the human setting are poorly understood, which can be partially attributed to the lack of a human cardiomyocyte-based preclinical test system recapitulating features of diseased myocardium. The objective of our study is to determine whether human embryonic stem cell-derived cardiomyocytes (hESC-CMs subjected to mechanical stretch can be used as an adequate in vitro model for studying molecular mechanisms of cardiac hypertrophy. We show that hESC-CMs subjected to cyclic stretch, which mimics mechanical overload, exhibit essential features of a hypertrophic state on structural, functional, and gene expression levels. The presented hESC-CM stretch approach provides insight into molecular mechanisms behind mechanotransduction and cardiac hypertrophy and lays groundwork for the development of pharmacological approaches as well as for discovering potential circulating biomarkers of cardiac dysfunction. : In this article, Berezikov, van der Meer, and colleagues used stem cell-derived cardiomyocytes to model human cardiac hypertrophy. Their approach provides novel insights into molecular mechanisms behind mechanotransduction and cardiac hypertrophy and lays groundwork for the development of new pharmacological approaches as well as for discovering new potential circulating biomarkers of cardiac dysfunction. Keywords: stem cells, human cardiomyocytes, hypertrophy, in vitro disease modeling, cardiomyocytes stretch response, mechanotransduction
Impact of Scattering Model on Disdrometer Derived Attenuation Scaling
Zemba, Michael; Luini, Lorenzo; Nessel, James; Riva, Carlo (Compiler)
2016-01-01
NASA Glenn Research Center (GRC), the Air Force Research Laboratory (AFRL), and the Politecnico di Milano (POLIMI) are currently entering the third year of a joint propagation study in Milan, Italy utilizing the 20 and 40 GHz beacons of the Alphasat TDP5 Aldo Paraboni scientific payload. The Ka- and Q-band beacon receivers were installed at the POLIMI campus in June of 2014 and provide direct measurements of signal attenuation at each frequency. Collocated weather instrumentation provides concurrent measurement of atmospheric conditions at the receiver; included among these weather instruments is a Thies Clima Laser Precipitation Monitor (optical disdrometer) which records droplet size distributions (DSD) and droplet velocity distributions (DVD) during precipitation events. This information can be used to derive the specific attenuation at frequencies of interest and thereby scale measured attenuation data from one frequency to another. Given the ability to both predict the 40 GHz attenuation from the disdrometer and the 20 GHz timeseries as well as to directly measure the 40 GHz attenuation with the beacon receiver, the Milan terminal is uniquely able to assess these scaling techniques and refine the methods used to infer attenuation from disdrometer data.In order to derive specific attenuation from the DSD, the forward scattering coefficient must be computed. In previous work, this has been done using the Mie scattering model, however, this assumes a spherical droplet shape. The primary goal of this analysis is to assess the impact of the scattering model and droplet shape on disdrometer derived attenuation predictions by comparing the use of the Mie scattering model to the use of the T-matrix method, which does not assume a spherical droplet. In particular, this paper will investigate the impact of these two scattering approaches on the error of the resulting predictions as well as on the relationship between prediction error and rain rate.
Modeling Grinding Processes as Micro-Machining Operation ...
African Journals Online (AJOL)
A computational based model for surface grinding process as a micro-machined operation has been developed. In this model, grinding forces are made up of chip formation force and sliding force. Mathematical expressions for Modeling tangential grinding force and normal grinding force were obtained. The model was ...
Computer-aided operations engineering with integrated models of systems and operations
Malin, Jane T.; Ryan, Dan; Fleming, Land
1994-01-01
CONFIG 3 is a prototype software tool that supports integrated conceptual design evaluation from early in the product life cycle, by supporting isolated or integrated modeling, simulation, and analysis of the function, structure, behavior, failures and operation of system designs. Integration and reuse of models is supported in an object-oriented environment providing capabilities for graph analysis and discrete event simulation. Integration is supported among diverse modeling approaches (component view, configuration or flow path view, and procedure view) and diverse simulation and analysis approaches. Support is provided for integrated engineering in diverse design domains, including mechanical and electro-mechanical systems, distributed computer systems, and chemical processing and transport systems. CONFIG supports abstracted qualitative and symbolic modeling, for early conceptual design. System models are component structure models with operating modes, with embedded time-related behavior models. CONFIG supports failure modeling and modeling of state or configuration changes that result in dynamic changes in dependencies among components. Operations and procedure models are activity structure models that interact with system models. CONFIG is designed to support evaluation of system operability, diagnosability and fault tolerance, and analysis of the development of system effects of problems over time, including faults, failures, and procedural or environmental difficulties.
Lange, Martin; Paul, Gerhard; Potthast, Roland
2014-05-01
Sea ice cover is a crucial parameter for surface fluxes of heat and moisture over water areas. The isolating effect and the much higher albedo strongly reduces the turbulent exchange of heat and moisture from the surface to the atmosphere and allows for cold and dry air mass flow with strong impact on the stability of the whole boundary layer and consequently cloud formation as well as precipitation in the downstream regions. Numerical weather centers as, ECMWF, MetoFrance or DWD use external products to initialize SST and sea ice cover in their NWP models. To the knowledge of the author there are mainly two global sea ice products well established with operational availability, one from NOAA NCEP that combines measurements with satellite data, and the other from OSI-SAF derived from SSMI/S sensors. The latter one is used in the Ostia product. DWD additionally uses a regional product for the Baltic Sea provided by the national center for shipping and hydrografie which combines observations from ships (and icebreakers) for the German part of the Baltic Sea and model analysis from the hydrodynamic HIROMB model of the Swedish meteorological service for the rest of the domain. The temporal evolution of the three different products are compared for a cold period in Februar 2012. Goods and bads will be presented and suggestions for a harmonization of strong day to day jumps over large areas are suggested.
Comparing models of offensive cyber operations
CSIR Research Space (South Africa)
Grant, T
2012-03-01
Full Text Available system, few represent target selection, attack planning, and Denial of Service attacks, and none specifically represent attack coordination within distributed groups. Finally, a canonical model has been constructed by rational reconstruction (Habermas... logical form? (Habermas, 1976). RR has been applied in computing research to redesign a seminal expert system (Cendrowski & Bramer, 1984) and to formalise Boyd?s (1996) Observe-Orient-Decide-Act (OODA) loop (Grant & Kooter, 2005). In the research...
Directory of Open Access Journals (Sweden)
Yin Luo
2012-01-01
Full Text Available Traditional pump scheduling models neglect the operation reliability which directly relates with the unscheduled maintenance cost and the wear cost during the operation. Just for this, based on the assumption that the vibration directly relates with the operation reliability and the degree of wear, it could express the operation reliability as the normalization of the vibration level. The characteristic of the vibration with the operation point was studied, it could be concluded that idealized flow versus vibration plot should be a distinct bathtub shape. There is a narrow sweet spot (80 to 100 percent BEP to obtain low vibration levels in this shape, and the vibration also follows similar law with the square of the rotation speed without resonance phenomena. Then, the operation reliability could be modeled as the function of the capacity and rotation speed of the pump and add this function to the traditional model to form the new. And contrast with the tradition method, the result shown that the new model could fix the result produced by the traditional, make the pump operate in low vibration, then the operation reliability could increase and the maintenance cost could decrease.
A proposal for operator team behavior model and operator's thinking mechanism
International Nuclear Information System (INIS)
Yoshimura, Seiichi; Takano, Kenichi; Sasou, Kunihide
1995-01-01
Operating environment in huge systems like nuclear power plants or airplanes is changing rapidly with the advance of computer technology. It is necessary to elucidate thinking process of operators and decision-making process of an operator team in abnormal situations, in order to prevent human errors under such environment. The Central Research Institute of Electric Power Industry is promoting a research project to establish human error prevention countermeasures by modeling and simulating the thinking process of operators and decision-making process of an operator team. In the previous paper, application of multilevel flow modeling was proposed to a mental model which conducts future prediction and cause identification, and the characteristics were verified by experienced plant operators. In this paper, an operator team behavior model and a fundamental operator's thinking mechanism especially 'situation understanding' are proposed, and the proposals are evaluated by experiments using a full-scale simulator. The results reveal that some assumptions such as 'communication is done between a leader and a follower' are almost appropriate and that the situation understanding can be represented by 'probable candidates for cause, determination of a parameter which changes when an event occurs, determination of parameters which are influenced by the change of the previous parameter, determination of a principal parameter and future prediction of the principal parameter'. (author)
Operational risk quantification and modelling within Romanian insurance industry
Directory of Open Access Journals (Sweden)
Tudor Răzvan
2017-07-01
Full Text Available This paper aims at covering and describing the shortcomings of various models used to quantify and model the operational risk within insurance industry with a particular focus on Romanian specific regulation: Norm 6/2015 concerning the operational risk issued by IT systems. While most of the local insurers are focusing on implementing the standard model to compute the Operational Risk solvency capital required, the local regulator has issued a local norm that requires to identify and assess the IT based operational risks from an ISO 27001 perspective. The challenges raised by the correlations assumed in the Standard model are substantially increased by this new regulation that requires only the identification and quantification of the IT operational risks. The solvency capital requirement stipulated by the implementation of Solvency II doesn’t recommend a model or formula on how to integrate the newly identified risks in the Operational Risk capital requirements. In this context we are going to assess the academic and practitioner’s understanding in what concerns: The Frequency-Severity approach, Bayesian estimation techniques, Scenario Analysis and Risk Accounting based on risk units, and how they could support the modelling of operational risk that are IT based. Developing an internal model only for the operational risk capital requirement proved to be, so far, costly and not necessarily beneficial for the local insurers. As the IT component will play a key role in the future of the insurance industry, the result of this analysis will provide a specific approach in operational risk modelling that can be implemented in the context of Solvency II, in a particular situation when (internal or external operational risk databases are scarce or not available.
Implications for modeling casualty sustainment during peacekeeping operations.
Blood, Christopher G; Zhang, Jinjin; Walker, G Jay
2002-10-01
Projections of the casualties expected during peacekeeping operations allow medical planners to assess in advance the medical resources needed to support such operations. Data detailing fatalities incurred in previous peacekeeping operations were extracted from several U.N. sources. From these data, rates of killed-in-action were computed for the deployed forces. One hundred eighty-eight peacekeeping incidents in which casualties were sustained were also examined to derive wounded-in-action rates. The estimated mean wounded-in-action rate for these operations was 3.16 per 1,000 strength per year; the estimated wounded-in-action rate for individual operations ranged from 0.49 to 12.50. There were an average of 3.8 wounded and 0.86 killed in the 188 casualty incidents examined. Thirty-eight percent of the wounds were described as serious. The casualty incidence derived in this study can provide a basis for estimating the casualties likely in future peacekeeping operations.
International Nuclear Information System (INIS)
Parisot, M.
2011-01-01
This work is dedicated study of a problem resulting from plasma physics: the thermal transfer of electrons in a plasma close to equilibrium Maxwellian. Firstly, a dimensional study of the Vlasov-Fokker-Planck-Maxwell system is performed, allowing one hand to identify a physically relevant parameter of scale and also to define mathematically the contours of validity domain. The asymptotic regime called Spitzer-Harm is studied for a relatively general class of collision operator. The following part of this work is devoted to the derivation and study of the hydrodynamic limit of the system of Vlasov-Maxwell-Landau outside the strictly asymptotic. A model proposed by Schurtz and Nicolais located in this context and analyzed. The particularity of this model lies in the application of a delocalization operation in the heat flux. The link with non-local models of Luciani and Mora is established as well as mathematics properties as the principle of maximum and entropy dissipation. Then a formal derivation from the Vlasov equations with a simplified collision operator, is proposed. The derivation, inspired by the recent work of D. Levermore, involves decomposition methods according to the spherical harmonics and methods of closing called diffusion methods. A hierarchy of intermediate models between the kinetic equations and the hydrodynamic limit is described. In particular a new hydrodynamic system integro-differential by nature, is proposed. The Schurtz and Nicolai model appears as a simplification of the system resulting from the derivation, assuming a steady flow of heat. The above results are then generalized to account for the internal energy dependence which appears naturally in the equation establishment. The existence and uniqueness of the solution of the nonstationary system are established in a simplified framework. The last part is devoted was the implementation of a specific numerical scheme to solve these models. We propose a finite volume approach can be
Mori, Yoshikazu; Hirokawa, Takatsugu; Aoki, Katsuyuki; Satomi, Hisanori; Takeda, Shuichi; Aburada, Masaki; Miyamoto, Ken-ichi
2008-05-01
We previously reported a quinoxalin-2-one compound (Compound 1) that had inhibitory activity equivalent to existing platelet-derived growth factor-beta receptor (PDGFbeta R) inhibitors. Lead optimization of Compound 1 to increase its activity and selectivity, using structural information regarding PDGFbeta R-ligand interactions, is urgently needed. Here we present models of the PDGFbeta R kinase domain complexed with quinoxalin-2-one derivatives. The models were constructed using comparative modeling, molecular dynamics (MD) and ligand docking. In particular, conformations derived from MD, and ligand binding site information presented by alpha-spheres in the pre-docking processing, allowed us to identify optimal protein structures for docking of target ligands. By carrying out molecular modeling and MD of PDGFbeta R in its inactive state, we obtained two structural models having good Compound 1 binding potentials. In order to distinguish the optimal candidate, we evaluated the structural activity relationships (SAR) between the ligand-binding free energies and inhibitory activity values (IC50 values) for available quinoxalin-2-one derivatives. Consequently, a final model with a high SAR was identified. This model included a molecular interaction between the hydrophobic pocket behind the ATP binding site and the substitution region of the quinoxalin-2-one derivatives. These findings should prove useful in lead optimization of quinoxalin-2-one derivatives as PDGFb R inhibitors.
Modelling of material handling operations using controlled traffic
DEFF Research Database (Denmark)
Bochtis, Dionysis; Sørensen, Claus Aage Grøn; Jørgensen, Rasmus Nyholm
2009-01-01
and maintaining permanent traffic lanes within the fields. Furthermore, field efficiency is affected by CTF due to significant increases in idle time of in-field transport and the way the fields are traversed in material handling operations. During fertilisation, when tramline length and the driving distance......, makes existing models inadequate for evaluating field efficiency. In this paper, the development of a discrete-event model for the prediction of travelled distances of a machine operating in material handling operations using the concept of CTF is presented. The model is based on the mathematical...
Deriving a model for influenza epidemics from historical data.
Energy Technology Data Exchange (ETDEWEB)
Ray, Jaideep; Lefantzi, Sophia
2011-09-01
In this report we describe how we create a model for influenza epidemics from historical data collected from both civilian and military societies. We derive the model when the population of the society is unknown but the size of the epidemic is known. Our interest lies in estimating a time-dependent infection rate to within a multiplicative constant. The model form fitted is chosen for its similarity to published models for HIV and plague, enabling application of Bayesian techniques to discriminate among infectious agents during an emerging epidemic. We have developed models for the progression of influenza in human populations. The model is framed as a integral, and predicts the number of people who exhibit symptoms and seek care over a given time-period. The start and end of the time period form the limits of integration. The disease progression model, in turn, contains parameterized models for the incubation period and a time-dependent infection rate. The incubation period model is obtained from literature, and the parameters of the infection rate are fitted from historical data including both military and civilian populations. The calibrated infection rate models display a marked difference in which the 1918 Spanish Influenza pandemic differed from the influenza seasons in the US between 2001-2008 and the progression of H1N1 in Catalunya, Spain. The data for the 1918 pandemic was obtained from military populations, while the rest are country-wide or province-wide data from the twenty-first century. We see that the initial growth of infection in all cases were about the same; however, military populations were able to control the epidemic much faster i.e., the decay of the infection-rate curve is much higher. It is not clear whether this was because of the much higher level of organization present in a military society or the seriousness with which the 1918 pandemic was addressed. Each outbreak to which the influenza model was fitted yields a separate set of
Operation quality assessment model for video conference system
Du, Bangshi; Qi, Feng; Shao, Sujie; Wang, Ying; Li, Weijian
2018-01-01
Video conference system has become an important support platform for smart grid operation and management, its operation quality is gradually concerning grid enterprise. First, the evaluation indicator system covering network, business and operation maintenance aspects was established on basis of video conference system's operation statistics. Then, the operation quality assessment model combining genetic algorithm with regularized BP neural network was proposed, which outputs operation quality level of the system within a time period and provides company manager with some optimization advice. The simulation results show that the proposed evaluation model offers the advantages of fast convergence and high prediction accuracy in contrast with regularized BP neural network, and its generalization ability is superior to LM-BP neural network and Bayesian BP neural network.
Spectra of operators in large N tensor models
Bulycheva, Ksenia; Klebanov, Igor R.; Milekhin, Alexey; Tarnopolsky, Grigory
2018-01-01
We study the operators in the large N tensor models, focusing mostly on the fermionic quantum mechanics with O (N )3 symmetry which may be either global or gauged. In the model with global symmetry, we study the spectra of bilinear operators, which are in either the symmetric traceless or the antisymmetric representation of one of the O (N ) groups. In the symmetric traceless case, the spectrum of scaling dimensions is the same as in the Sachdev-Ye-Kitaev (SYK) model with real fermions; it includes the h =2 zero mode. For the operators antisymmetric in the two indices, the scaling dimensions are the same as in the additional sector found in the complex tensor and SYK models; the lowest h =0 eigenvalue corresponds to the conserved O (N ) charges. A class of singlet operators may be constructed from contracted combinations of m symmetric traceless or antisymmetric two-particle operators. Their two-point functions receive contributions from m melonic ladders. Such multiple ladders are a new phenomenon in the tensor model, which does not seem to be present in the SYK model. The more typical 2 k -particle operators do not receive any ladder corrections and have quantized large N scaling dimensions k /2 . We construct pictorial representations of various singlet operators with low k . For larger k , we use available techniques to count the operators and show that their number grows as 2kk !. As a consequence, the theory has a Hagedorn phase transition at the temperature which approaches zero in the large N limit. We also study the large N spectrum of low-lying operators in the Gurau-Witten model, which has O (N )6 symmetry. We argue that it corresponds to one of the generalized SYK models constructed by Gross and Rosenhaus. Our paper also includes studies of the invariants in large N tensor integrals with various symmetries.
Mathematical modeling of wastewater-derived biodegradable dissolved organic nitrogen.
Simsek, Halis
2016-11-01
Wastewater-derived dissolved organic nitrogen (DON) typically constitutes the majority of total dissolved nitrogen (TDN) discharged to surface waters from advanced wastewater treatment plants (WWTPs). When considering the stringent regulations on nitrogen discharge limits in sensitive receiving waters, DON becomes problematic and needs to be reduced. Biodegradable DON (BDON) is a portion of DON that is biologically degradable by bacteria when the optimum environmental conditions are met. BDON in a two-stage trickling filter WWTP was estimated using artificial intelligence techniques, such as adaptive neuro-fuzzy inference systems, multilayer perceptron, radial basis neural networks (RBNN), and generalized regression neural networks. Nitrite, nitrate, ammonium, TDN, and DON data were used as input neurons. Wastewater samples were collected from four different locations in the plant. Model performances were evaluated using root mean square error, mean absolute error, mean bias error, and coefficient of determination statistics. Modeling results showed that the R(2) values were higher than 0.85 in all four models for all wastewater samples, except only R(2) in the final effluent sample for RBNN modeling was low (0.52). Overall, it was found that all four computing techniques could be employed successfully to predict BDON.
Derivation of Event-B Models from OWL Ontologies
Directory of Open Access Journals (Sweden)
Alkhammash Eman H.
2016-01-01
Full Text Available The derivation of formal specifications from large and complex requirements is a key challenge in systems engineering. In this paper we present an approach that aims to address this challenge by building formal models from OWL ontologies. An ontology is used in the field of knowledge representation to capture a clear view of the domain and to produce a concise and unambiguous set of domain requirements. We harness the power of ontologies to handle inconsistency of domain requirements and produce clear, concise and unambiguous set of domain requirements for Event-B modelling. The proposed approach works by generating Attempto Controlled English (ACE from the OWL ontology and then maps the ACE requirements to develop Event-B models. ACE is a subset of English that can be unambiguously translated into first-order logic. There is an injective mapping between OWL ontology and a subset of ACE. ACE is a suitable interlingua for producing the mapping between OWL and Event-B models for many reasons. Firstly, ACE is easy to learn and understand, it hides the math of OWL and would be natural to use by everybody. Secondly ACE has a parser that converts ACE texts into Discourse Representation Structures (DRS. Finally, ACE can be extended to target a richer syntactic subset of Event-B which ultimately would facilitate the translation of ACE requirements to Event-B.
Designing visual displays and system models for safe reactor operations
Energy Technology Data Exchange (ETDEWEB)
Brown-VanHoozer, S.A.
1995-12-31
The material presented in this paper is based on two studies involving the design of visual displays and the user`s prospective model of a system. The studies involve a methodology known as Neuro-Linguistic Programming and its use in expanding design choices from the operator`s perspective image. The contents of this paper focuses on the studies and how they are applicable to the safety of operating reactors.
Simulation Modeling of a Facility Layout in Operations Management Classes
Yazici, Hulya Julie
2006-01-01
Teaching quantitative courses can be challenging. Similarly, layout modeling and lean production concepts can be difficult to grasp in an introductory OM (operations management) class. This article describes a simulation model developed in PROMODEL to facilitate the learning of layout modeling and lean manufacturing. Simulation allows for the…
Cognitive-Operative Model of Intelligent Learning Systems Behavior
Laureano-Cruces, Ana Lilia; Ramirez-Rodriguez, Javier; Mora-Torres, Martha; de Arriaga, Fernando; Escarela-Perez, Rafael
2010-01-01
In this paper behavior during the teaching-learning process is modeled by means of a fuzzy cognitive map. The elements used to model such behavior are part of a generic didactic model, which emphasizes the use of cognitive and operative strategies as part of the student-tutor interaction. Examples of possible initial scenarios for the…
Modeling of a three-phase reactor for bitumen-derived gas oil hydrotreating
Energy Technology Data Exchange (ETDEWEB)
Chacon, R.; Canale, A.; Bouza, A. [Departamento de Termodinamica y Fenomenos de Transporte. Universidad Simon Bolivar, Caracas (Venezuela, Bolivarian Republic of); Sanchez, Y. [Departamento de Procesos y Sistemas. Universidad Simon Bolivar (Venezuela, Bolivarian Republic of)
2012-01-15
A three-phase reactor model for describing the hydrotreating reactions of bitumen-derived gas oil was developed. The model incorporates the mass-transfer resistance at the gas-liquid and liquid-solid interfaces and a kinetic rate expression based on a Langmuir-Hinshelwood-type model. We derived three correlations for determining the solubility of hydrogen (H{sub 2}), hydrogen sulfide (H{sub 2}S) and ammonia (NH{sub 3}) in hydrocarbon mixtures and the calculation of the catalyst effectiveness factor was included. Experimental data taken from the literature were used to determine the kinetic parameters (stoichiometric coefficients, reaction orders, reaction rate and adsorption constants for hydrodesulfuration (HDS) and hydrodenitrogenation (HDN)) and to validate the model under various operating conditions. Finally, we studied the effect of operating conditions such as pressure, temperature, LHSV, H{sub 2}/feed ratio and the inhibiting effect of H{sub 2}S on HDS and NH{sub 3} on HDN. (author)
A model of CCTV surveillance operator performance | Donald ...
African Journals Online (AJOL)
cognitive processes involved in visual search and monitoring – key activities of operators. The aim of this paper was to integrate the factors into a holistic theoretical model of performance for CCTV operators, drawing on areas such as vigilance, ...
Quantitative modelling in design and operation of food supply systems
Beek, van P.
2004-01-01
During the last two decades food supply systems not only got interest of food technologists but also from the field of Operations Research and Management Science. Operations Research (OR) is concerned with quantitative modelling and can be used to get insight into the optimal configuration and
Design and modeling of reservoir operation strategies for sediment management
Sloff, C.J.; Omer, A.Y.A.; Heynert, K.V.; Mohamed, Y.A.
2015-01-01
Appropriate operation strategies that allow for sediment flushing and sluicing (sediment routing) can reduce rapid storage losses of (hydropower and water-supply) reservoirs. In this study we have shown, using field observations and computational models, that the efficiency of these operations
Modeling Methodologies for Representing Urban Cultural Geographies in Stability Operations
National Research Council Canada - National Science Library
Ferris, Todd P
2008-01-01
... 2.0.0, in an effort to provide modeling methodologies for a single simulation tool capable of exploring the complex world of urban cultural geographies undergoing Stability Operations in an irregular warfare (IW) environment...
JELO: A Model of Joint Expeditionary Logistics Operations
National Research Council Canada - National Science Library
Boensel, Matthew
2004-01-01
JELO is an Excel spreadsheet model of joint expeditionary logistics operations and allows end-to-end analysis of the options for closing forces from CONUS, through the sea base, to objectives ashore...
Aviation Shipboard Operations Modeling and Simulation (ASOMS) Laboratory
Federal Laboratory Consortium — Purpose:It is the mission of the Aviation Shipboard Operations Modeling and Simulation (ASOMS) Laboratory to provide a means by which to virtually duplicate products...
Aerial Search Optimization Model (ASOM) for UAVs in Special Operations
National Research Council Canada - National Science Library
Kress, Moshe; Royset, Johannes O
2007-01-01
.... The special operations team is equipped with short-range surveillance UAVs. We combine intelligence regarding the targets with availability and capability of UAVs in an integer linear programming model...
Deriving the operational procedure for the Universal Thermal Climate Index (UTCI).
Bröde, Peter; Fiala, Dusan; Błażejczyk, Krzysztof; Holmér, Ingvar; Jendritzky, Gerd; Kampmann, Bernhard; Tinz, Birger; Havenith, George
2012-05-01
The Universal Thermal Climate Index (UTCI) aimed for a one-dimensional quantity adequately reflecting the human physiological reaction to the multi-dimensionally defined actual outdoor thermal environment. The human reaction was simulated by the UTCI-Fiala multi-node model of human thermoregulation, which was integrated with an adaptive clothing model. Following the concept of an equivalent temperature, UTCI for a given combination of wind speed, radiation, humidity and air temperature was defined as the air temperature of the reference environment, which according to the model produces an equivalent dynamic physiological response. Operationalising this concept involved (1) the definition of a reference environment with 50% relative humidity (but vapour pressure capped at 20 hPa), with calm air and radiant temperature equalling air temperature and (2) the development of a one-dimensional representation of the multivariate model output at different exposure times. The latter was achieved by principal component analyses showing that the linear combination of 7 parameters of thermophysiological strain (core, mean and facial skin temperatures, sweat production, skin wettedness, skin blood flow, shivering) after 30 and 120 min exposure time accounted for two-thirds of the total variation in the multi-dimensional dynamic physiological response. The operational procedure was completed by a scale categorising UTCI equivalent temperature values in terms of thermal stress, and by providing simplified routines for fast but sufficiently accurate calculation, which included look-up tables of pre-calculated UTCI values for a grid of all relevant combinations of climate parameters and polynomial regression equations predicting UTCI over the same grid. The analyses of the sensitivity of UTCI to humidity, radiation and wind speed showed plausible reactions in the heat as well as in the cold, and indicate that UTCI may in this regard be universally useable in the major areas of
Deriving the operational procedure for the Universal Thermal Climate Index (UTCI)
Bröde, Peter; Fiala, Dusan; Błażejczyk, Krzysztof; Holmér, Ingvar; Jendritzky, Gerd; Kampmann, Bernhard; Tinz, Birger; Havenith, George
2012-05-01
The Universal Thermal Climate Index (UTCI) aimed for a one-dimensional quantity adequately reflecting the human physiological reaction to the multi-dimensionally defined actual outdoor thermal environment. The human reaction was simulated by the UTCI-Fiala multi-node model of human thermoregulation, which was integrated with an adaptive clothing model. Following the concept of an equivalent temperature, UTCI for a given combination of wind speed, radiation, humidity and air temperature was defined as the air temperature of the reference environment, which according to the model produces an equivalent dynamic physiological response. Operationalising this concept involved (1) the definition of a reference environment with 50% relative humidity (but vapour pressure capped at 20 hPa), with calm air and radiant temperature equalling air temperature and (2) the development of a one-dimensional representation of the multivariate model output at different exposure times. The latter was achieved by principal component analyses showing that the linear combination of 7 parameters of thermophysiological strain (core, mean and facial skin temperatures, sweat production, skin wettedness, skin blood flow, shivering) after 30 and 120 min exposure time accounted for two-thirds of the total variation in the multi-dimensional dynamic physiological response. The operational procedure was completed by a scale categorising UTCI equivalent temperature values in terms of thermal stress, and by providing simplified routines for fast but sufficiently accurate calculation, which included look-up tables of pre-calculated UTCI values for a grid of all relevant combinations of climate parameters and polynomial regression equations predicting UTCI over the same grid. The analyses of the sensitivity of UTCI to humidity, radiation and wind speed showed plausible reactions in the heat as well as in the cold, and indicate that UTCI may in this regard be universally useable in the major areas of
Advancing reservoir operation description in physically based hydrological models
Anghileri, Daniela; Giudici, Federico; Castelletti, Andrea; Burlando, Paolo
2016-04-01
Last decades have seen significant advances in our capacity of characterizing and reproducing hydrological processes within physically based models. Yet, when the human component is considered (e.g. reservoirs, water distribution systems), the associated decisions are generally modeled with very simplistic rules, which might underperform in reproducing the actual operators' behaviour on a daily or sub-daily basis. For example, reservoir operations are usually described by a target-level rule curve, which represents the level that the reservoir should track during normal operating conditions. The associated release decision is determined by the current state of the reservoir relative to the rule curve. This modeling approach can reasonably reproduce the seasonal water volume shift due to reservoir operation. Still, it cannot capture more complex decision making processes in response, e.g., to the fluctuations of energy prices and demands, the temporal unavailability of power plants or varying amount of snow accumulated in the basin. In this work, we link a physically explicit hydrological model with detailed hydropower behavioural models describing the decision making process by the dam operator. In particular, we consider two categories of behavioural models: explicit or rule-based behavioural models, where reservoir operating rules are empirically inferred from observational data, and implicit or optimization based behavioural models, where, following a normative economic approach, the decision maker is represented as a rational agent maximising a utility function. We compare these two alternate modelling approaches on the real-world water system of Lake Como catchment in the Italian Alps. The water system is characterized by the presence of 18 artificial hydropower reservoirs generating almost 13% of the Italian hydropower production. Results show to which extent the hydrological regime in the catchment is affected by different behavioural models and reservoir
Bayesian network modeling of operator's state recognition process
International Nuclear Information System (INIS)
Hatakeyama, Naoki; Furuta, Kazuo
2000-01-01
Nowadays we are facing a difficult problem of establishing a good relation between humans and machines. To solve this problem, we suppose that machine system need to have a model of human behavior. In this study we model the state cognition process of a PWR plant operator as an example. We use a Bayesian network as an inference engine. We incorporate the knowledge hierarchy in the Bayesian network and confirm its validity using the example of PWR plant operator. (author)
An Expansion Formula with Higher-Order Derivatives for Fractional Operators of Variable Order
Directory of Open Access Journals (Sweden)
Ricardo Almeida
2013-01-01
Full Text Available We obtain approximation formulas for fractional integrals and derivatives of Riemann-Liouville and Marchaud types with a variable fractional order. The approximations involve integer-order derivatives only. An estimation for the error is given. The efficiency of the approximation method is illustrated with examples. As applications, we show how the obtained results are useful to solve differential equations, and problems of the calculus of variations that depend on fractional derivatives of Marchaud type.
An Expansion Formula with Higher-Order Derivatives for Fractional Operators of Variable Order
Almeida, Ricardo
2013-01-01
We obtain approximation formulas for fractional integrals and derivatives of Riemann-Liouville and Marchaud types with a variable fractional order. The approximations involve integer-order derivatives only. An estimation for the error is given. The efficiency of the approximation method is illustrated with examples. As applications, we show how the obtained results are useful to solve differential equations, and problems of the calculus of variations that depend on fractional derivatives of Marchaud type. PMID:24319382
Comparison of digital elevation models and relevant derived attributes
Li, Xinchuan; Zhang, Youjing; Jin, Xiuliang; He, Qiaoning; Zhang, Xiuping
2017-10-01
The digital elevation model (DEM) and its derivative attributes are important parameters for evaluating any process using digital terrain analysis. Five freely available global DEM products including Advanced Spaceborne Thermal Emission and Reflection Radiometer-Global Digital Elevation Model version 2 (ASTER GDEM2), Shuttle Radar Topographic Mission version 4.1 (SRTM V4.1), Global Multiresolution Terrain Elevation Data 2010 (GMTED2010), EarthEnv-DEM90, and Global 30 Arc-Second Elevation (GTOPO30) were assessed in this study. The objective of this study was to compare the differences of elevations, slopes, and topographic wetness indices (TWIs) derived from these five DEM products. SRTM V4.1 showed a better accuracy [root mean square error (RMSE)=4.87 m] than ASTER GDEM2 (RMSE=7.08 m) based on ICESat/GLAS (the Ice, Cloud, and land Elevation Satellite/Geoscience Laser Altimeter System) laser altimetry points. ICESat/GLAS data were then selected as the benchmark to rectify the SRTM V4.1 data using the simple kriging (SK) interpolation method. The corrected high-accuracy SRTM V4.1 data (RMSE=1.14 m) were then regarded as the reference data. EarthEnv-DEM90 displayed the best accuracy in the DEM and slope, whereas the TWI accuracy of GMTED2010 was best. The accuracy of topographic attributes was sensitive to the roughness of the terrain. DEM and slope displayed a larger error variance as the elevation increased. DEM was sensitive to the data source and slope was sensitive to the data source and spatial resolution. TWI was influenced by data source and spatial resolution. As the spatial resolution decreased, the differences of topographic attributes tended to decrease.
Protein model discrimination using mutational sensitivity derived from deep sequencing.
Adkar, Bharat V; Tripathi, Arti; Sahoo, Anusmita; Bajaj, Kanika; Goswami, Devrishi; Chakrabarti, Purbani; Swarnkar, Mohit K; Gokhale, Rajesh S; Varadarajan, Raghavan
2012-02-08
A major bottleneck in protein structure prediction is the selection of correct models from a pool of decoys. Relative activities of ∼1,200 individual single-site mutants in a saturation library of the bacterial toxin CcdB were estimated by determining their relative populations using deep sequencing. This phenotypic information was used to define an empirical score for each residue (RankScore), which correlated with the residue depth, and identify active-site residues. Using these correlations, ∼98% of correct models of CcdB (RMSD ≤ 4Å) were identified from a large set of decoys. The model-discrimination methodology was further validated on eleven different monomeric proteins using simulated RankScore values. The methodology is also a rapid, accurate way to obtain relative activities of each mutant in a large pool and derive sequence-structure-function relationships without protein isolation or characterization. It can be applied to any system in which mutational effects can be monitored by a phenotypic readout. Copyright © 2012 Elsevier Ltd. All rights reserved.
Directory of Open Access Journals (Sweden)
Dumitru Baleanu
2013-01-01
Full Text Available We obtain the approximate analytical solution for the fractional quadratic Riccati differential equation with the Riemann-Liouville derivative by using the Bernstein polynomials (BPs operational matrices. In this method, we use the operational matrix for fractional integration in the Riemann-Liouville sense. Then by using this matrix and operational matrix of product, we reduce the problem to a system of algebraic equations that can be solved easily. The efficiency and accuracy of the proposed method are illustrated by several examples.
van der Ent, R.; Van Beek, R.; Sutanudjaja, E.; Wang-Erlandsson, L.; Hessels, T.; Bastiaanssen, W.; Bierkens, M. F.
2017-12-01
The storage and dynamics of water in the root zone control many important hydrological processes such as saturation excess overland flow, interflow, recharge, capillary rise, soil evaporation and transpiration. These processes are parameterized in hydrological models or land-surface schemes and the effect on runoff prediction can be large. Root zone parameters in global hydrological models are very uncertain as they cannot be measured directly at the scale on which these models operate. In this paper we calibrate the global hydrological model PCR-GLOBWB using a state-of-the-art ensemble of evaporation fields derived by solving the energy balance for satellite observations. We focus our calibration on the root zone parameters of PCR-GLOBWB and derive spatial patterns of maximum root zone storage. We find these patterns to correspond well with previous research. The parameterization of our model allows for the conversion of maximum root zone storage to root zone depth and we find that these correspond quite well to the point observations where available. We conclude that climate and soil type should be taken into account when regionalizing measured root depth for a certain vegetation type. We equally find that using evaporation rather than discharge better allows for local adjustment of root zone parameters within a basin and thus provides orthogonal data to diagnose and optimize hydrological models and land surface schemes.
Clinical CVVH model removes endothelium-derived microparticles from circulation
Directory of Open Access Journals (Sweden)
Abdelhafeez H. Abdelhafeez
2014-02-01
Full Text Available Background: Endothelium-derived microparticles (EMPs are submicron vesicles released from the plasma membrane of endothelial cells in response to injury, apoptosis or activation. We have previously demonstrated EMP-induced acute lung injury (ALI in animal models and endothelial barrier dysfunction in vitro. Current treatment options for ALI are limited and consist of supportive therapies. We hypothesize that standard clinical continuous venovenous hemofiltration (CVVH reduces serum EMP levels and may be adapted as a potential therapeutic intervention. Materials and methods: EMPs were generated from plasminogen activation inhibitor-1 (PAI-1-stimulated human umbilical vein endothelial cells (HUVECs. Flow cytometric analysis was used to characterize EMPs as CD31- and annexin V-positive events in a submicron size gate. Enumeration was completed against a known concentration of latex beads. Ultimately, a concentration of ~650,000 EMP/mL perfusate fluid (total 470 mL was circulated through a standard CVVH filter (pore size 200 μm, flow rate 250 mL/hr for a period of 70 minutes. 0.5 mL aliquots were removed at 5- to 10-minute intervals for flow cytometric analysis. EMP concentration in the dialysate was measured at the end of 4 hours to better understand the fate of EMPs. Results: A progressive decrease in circulating EMP concentration was noted using standard CVVH at 250 mL/hr (a clinical standard rate from a 470 mL volume modelling a patient's circulation. A 50% reduction was noted within the first 30 minutes. EMPs entering the dialysate after 4 hours were 5.7% of the EMP original concentration. Conclusion: These data demonstrate that standard CVVH can remove EMPs from circulation in a circuit modelling a patient. An animal model of hemofiltration with induction of EMP release is required to test the therapeutic potential of this finding and potential of application in early treatment of ALI.
Operational semi-physical spectral-spatial wheat yield model development
Tripathy, R.; Chaudhary, K. N.; Nigam, R.; Manjunath, K. R.; Chauhan, P.; Ray, S. S.; Parihar, J. S.
2014-11-01
Spectral yield models based on Vegetation Index (VI) and the mechanistic crop simulation models are being widely used for crop yield prediction. However, past experience has shown that the empirical nature of the VI based models and the intensive data requirement of the complex mechanistic models has limited their use for regional and spatial crop yield prediction especially for operational use. The present study was aimed at development of an intermediate method based on the use of remote sensing and the physiological concepts such as the photo-synthetically active solar radiation (PAR) and the fraction of PAR absorbed by the crop (fAPAR) in Monteith's radiation use efficiency based equation (Monteith, 1977) for operational wheat yield forecasting by the Department of Agriculture (DoA). Net Primary Product (NPP) has been computed using the Monteith model and stress has been applied to convert the potential NPP to actual NPP. Wheat grain yield has been computed using the actual NPP and Harvest index. Kalpana-VHRR insolation has been used for deriving the PAR. Maximum radiation use efficiency has been collected from literature and wheat crop mask was derived at MNCFC, New Delhi using RS2-AWiFS data. Water stress has been derived from the Land Surface Water Index (LSWI) which has been derived periodically from the MODIS surface reflectance data (NIR and SWIR1). Temperature stress has been derived from the interpolated daily mean temperature. Results indicated that this model underestimated the yield by 3.45 % as compared to the reported yield at state level and hence can be used to predict wheat yield at state level. This study will be able to provide the spatial wheat yield map, as well as the district-wise and state level aggregated wheat yield forecast. It is possible to operationalize this remote sensing based modified Monteith's efficiency model for future yield forecasting with around 0.15 t ha-1 RMSE at state level.
International Nuclear Information System (INIS)
Han, In-Su; Park, Sang-Kyun; Chung, Chang-Bock
2016-01-01
Highlights: • A proton exchange membrane fuel cell system is operationally optimized. • A constrained optimization problem is formulated to maximize fuel cell efficiency. • Empirical and semi-empirical models for most system components are developed. • Sensitivity analysis is performed to elucidate the effects of major operating variables. • The optimization results are verified by comparison with actual operation data. - Abstract: This paper presents an operation optimization method and demonstrates its application to a proton exchange membrane fuel cell system. A constrained optimization problem was formulated to maximize the efficiency of a fuel cell system by incorporating practical models derived from actual operations of the system. Empirical and semi-empirical models for most of the system components were developed based on artificial neural networks and semi-empirical equations. Prior to system optimizations, the developed models were validated by comparing simulation results with the measured ones. Moreover, sensitivity analyses were performed to elucidate the effects of major operating variables on the system efficiency under practical operating constraints. Then, the optimal operating conditions were sought at various system power loads. The optimization results revealed that the efficiency gaps between the worst and best operation conditions of the system could reach 1.2–5.5% depending on the power output range. To verify the optimization results, the optimal operating conditions were applied to the fuel cell system, and the measured results were compared with the expected optimal values. The discrepancies between the measured and expected values were found to be trivial, indicating that the proposed operation optimization method was quite successful for a substantial increase in the efficiency of the fuel cell system.
DFT application for chlorin derivatives photosensitizer drugs modeling
Machado, Neila; Carvalho, B. G.; Téllez Soto, C. A.; Martin, A. A.; Favero, P. P.
2018-04-01
Photodynamic therapy is an alternative form of cancer treatment that meets the desire for a less aggressive approach to the body. It is based on the interaction between a photosensitizer, activating light, and molecular oxygen. This interaction results in a cascade of reactions that leads to localized cell death. Many studies have been conducted to discover an ideal photosensitizer, which aggregates all the desirable characteristics of a potent cell killer and generates minimal side effects. Using Density Functional Theory (DFT) implemented in the program Vienna Ab-initio Simulation Package, new chlorin derivatives with different functional groups were simulated to evaluate the different absorption wavelengths to permit resonant absorption with the incident laser. Gaussian 09 program was used to determine vibrational wave numbers and Natural Bond Orbitals. The chosen drug with the best characteristics for the photosensitizer was a modified model of the original chlorin, which was called as Thiol chlorin. According to our calculations it is stable and is 19.6% more efficient at optical absorption in 708 nm in comparison to the conventional chlorin e6. Vibrational modes, optical and electronic properties were predicted. In conclusion, this study is an attempt to improve the development of new photosensitizer drugs through computational methods that save time and contribute to decrease the numbers of animals for model application.
Modeling bleaching of tomato derivatives at subzero temperatures.
Manzocco, Lara; Calligaris, Sonia; Nicoli, Maria Cristina
2006-02-22
This work was addressed to obtain a predictive model of the rate of bleaching in tomato derivatives at subzero temperatures. To this aim, a tomato puree was freeze-dried and equilibrated at increasing solid fractions. The bleaching rate was assessed by measuring tomato color during storage for up to 18 months at temperatures from -30 to 0 degrees C. The temperature dependence of the tomato-bleaching rate was neither predictable using the Arrhenius equation nor simply related to tomato physical state. The lack of a clear Arrhenius relation was attributed to the occurrence of temperature-dependent phenomena, such as ice crystallization and oxygen solubility modifications, which strongly changed the local concentration of reactants. A modified Arrhenius equation predicting the tomato-bleaching rate in the entire temperature range was proposed. Tomato concentration, and hence its physical state, affected the temperature dependence of bleaching, modifying apparent activation energy and frequency factor of the modified Arrhenius equation. In light of these considerations, a mathematical model was set up and validated to accurately predict the tomato-bleaching rate on the basis of only its concentration and storage temperature.
A model to predict productivity of different chipping operations ...
African Journals Online (AJOL)
Additional international case studies from North America, South America, and central and northern Europe were used to test the accuracy of the model, in which 15 studies confirmed the model's validity and two failed to pass the test. Keywords: average piece size, chipper, power, sensitivity analysis, type of operation, unit ...
A Model for Resource Allocation Using Operational Knowledge Assets
Andreou, Andreas N.; Bontis, Nick
2007-01-01
Purpose: The paper seeks to develop a business model that shows the impact of operational knowledge assets on intellectual capital (IC) components and business performance and use the model to show how knowledge assets can be prioritized in driving resource allocation decisions. Design/methodology/approach: Quantitative data were collected from 84…
The development of a model of control room operator cognition
International Nuclear Information System (INIS)
Harrison, C. Felicity
1998-01-01
The nuclear generation station CRO is one of the main contributors to plant performance and safety. In the past, studies of operator behaviour have been made under emergency or abnormal situations, with little consideration being given to the more routine aspects of plant operation. One of the tasks of the operator is to detect the early signs of a problem, and to take steps to prevent a transition to an abnormal plant state. In order to do this CRO must determine that plant indications are no longer in the normal range, and take action to prevent a further move away from normal. This task is made more difficult by the extreme complexity of the control room, and by the may hindrances that the operator must face. It would therefore be of great benefit to understand CRO cognitive performance, especially under normal operating conditions. Through research carried out at several Canadian nuclear facilities we were able to develop a deeper understanding of CRO monitoring of highly automated systems during normal operations, and specifically to investigate the contributions of cognitive skills to monitoring performance. The consultants were asked to develop a deeper understanding of CRO monitoring during normal operations, and specifically to investigate the contributions of cognitive skills to monitoring performance. The overall objective of this research was to develop and validate a model of CRO monitoring. The findings of this research have practical implications for systems integration, training, and interface design. The result of this work was a model of operator monitoring activities. (author)
Estimation of pump operational state with model-based methods
International Nuclear Information System (INIS)
Ahonen, Tero; Tamminen, Jussi; Ahola, Jero; Viholainen, Juha; Aranto, Niina; Kestilae, Juha
2010-01-01
Pumps are widely used in industry, and they account for 20% of the industrial electricity consumption. Since the speed variation is often the most energy-efficient method to control the head and flow rate of a centrifugal pump, frequency converters are used with induction motor-driven pumps. Although a frequency converter can estimate the operational state of an induction motor without external measurements, the state of a centrifugal pump or other load machine is not typically considered. The pump is, however, usually controlled on the basis of the required flow rate or output pressure. As the pump operational state can be estimated with a general model having adjustable parameters, external flow rate or pressure measurements are not necessary to determine the pump flow rate or output pressure. Hence, external measurements could be replaced with an adjustable model for the pump that uses estimates of the motor operational state. Besides control purposes, modelling the pump operation can provide useful information for energy auditing and optimization purposes. In this paper, two model-based methods for pump operation estimation are presented. Factors affecting the accuracy of the estimation methods are analyzed. The applicability of the methods is verified by laboratory measurements and tests in two pilot installations. Test results indicate that the estimation methods can be applied to the analysis and control of pump operation. The accuracy of the methods is sufficient for auditing purposes, and the methods can inform the user if the pump is driven inefficiently.
Derivation of a Clinical Model to Predict Unchanged Inpatient Echocardiograms.
Gunderson, Craig G; Gromisch, Elizabeth S; Chang, John J; Malm, Brian J
2018-03-01
Transthoracic echocardiography (TTE) is one of the most commonly ordered tests in healthcare. Repeat TTE, defined as a TTE done within 1 year of a prior TTE, represents 24% to 42% of all studies. The purpose of this study was to derive a clinical prediction model to predict unchanged repeat TTE, with the goal of defining a subset of studies that are unnecessary. Single-center retrospective cohort study of all hospitalized patients who had a repeat TTE between October 1, 2013, and September 30, 2014. Two hundred eleven of 601 TTEs were repeat studies, of which 78 (37%) had major changes. Five variables were independent predictors of major new TTE changes, including history of intervening acute myocardial infarction, cardiothoracic surgery, major new electrocardiogram (ECG) changes, prior valve disease, and chronic kidney disease. Using the β-coefficient for each of these variables, we defined a clinical prediction model that we named the CAVES score. The acronym CAVES stands for chronic kidney disease, acute myocardial infarction, valvular disease, ECG changes, and surgery (cardiac). The prevalence of major TTE change for the full cohort was 35%. For the group with a CAVES score of -1, that probability was only 5.6%; for the group with a score of 0, the probability was 17.7%; and for the group with a score ≥1, the probability was 55.3%. The bootstrap corrected C statistic for the model was 0.78 (95% confidence interval, 0.72-0.85), indicating good discrimination. Overall, the CAVES score had good discrimination and calibration. If further validated, it may be useful to predict repeat TTEs that are unlikely to have major changes.
Koopman Operator Framework for Time Series Modeling and Analysis
Surana, Amit
2018-01-01
We propose an interdisciplinary framework for time series classification, forecasting, and anomaly detection by combining concepts from Koopman operator theory, machine learning, and linear systems and control theory. At the core of this framework is nonlinear dynamic generative modeling of time series using the Koopman operator which is an infinite-dimensional but linear operator. Rather than working with the underlying nonlinear model, we propose two simpler linear representations or model forms based on Koopman spectral properties. We show that these model forms are invariants of the generative model and can be readily identified directly from data using techniques for computing Koopman spectral properties without requiring the explicit knowledge of the generative model. We also introduce different notions of distances on the space of such model forms which is essential for model comparison/clustering. We employ the space of Koopman model forms equipped with distance in conjunction with classical machine learning techniques to develop a framework for automatic feature generation for time series classification. The forecasting/anomaly detection framework is based on using Koopman model forms along with classical linear systems and control approaches. We demonstrate the proposed framework for human activity classification, and for time series forecasting/anomaly detection in power grid application.
Influence of satellite-derived photolysis rates and NOx emissions on Texas ozone modeling
Tang, W.; Cohan, D. S.; Pour-Biazar, A.; Lamsal, L. N.; White, A. T.; Xiao, X.; Zhou, W.; Henderson, B. H.; Lash, B. F.
2015-02-01
Uncertain photolysis rates and emission inventory impair the accuracy of state-level ozone (O3) regulatory modeling. Past studies have separately used satellite-observed clouds to correct the model-predicted photolysis rates, or satellite-constrained top-down NOx emissions to identify and reduce uncertainties in bottom-up NOx emissions. However, the joint application of multiple satellite-derived model inputs to improve O3 state implementation plan (SIP) modeling has rarely been explored. In this study, Geostationary Operational Environmental Satellite (GOES) observations of clouds are applied to derive the photolysis rates, replacing those used in Texas SIP modeling. This changes modeled O3 concentrations by up to 80 ppb and improves O3 simulations by reducing modeled normalized mean bias (NMB) and normalized mean error (NME) by up to 0.1. A sector-based discrete Kalman filter (DKF) inversion approach is incorporated with the Comprehensive Air Quality Model with extensions (CAMx)-decoupled direct method (DDM) model to adjust Texas NOx emissions using a high-resolution Ozone Monitoring Instrument (OMI) NO2 product. The discrepancy between OMI and CAMx NO2 vertical column densities (VCDs) is further reduced by increasing modeled NOx lifetime and adding an artificial amount of NO2 in the upper troposphere. The region-based DKF inversion suggests increasing NOx emissions by 10-50% in most regions, deteriorating the model performance in predicting ground NO2 and O3, while the sector-based DKF inversion tends to scale down area and nonroad NOx emissions by 50%, leading to a 2-5 ppb decrease in ground 8 h O3 predictions. Model performance in simulating ground NO2 and O3 are improved using sector-based inversion-constrained NOx emissions, with 0.25 and 0.04 reductions in NMBs and 0.13 and 0.04 reductions in NMEs, respectively. Using both GOES-derived photolysis rates and OMI-constrained NOx emissions together reduces modeled NMB and NME by 0.05, increases the model
Categorical model of structural operational semantics for imperative language
Directory of Open Access Journals (Sweden)
William Steingartner
2016-12-01
Full Text Available Definition of programming languages consists of the formal definition of syntax and semantics. One of the most popular semantic methods used in various stages of software engineering is structural operational semantics. It describes program behavior in the form of state changes after execution of elementary steps of program. This feature makes structural operational semantics useful for implementation of programming languages and also for verification purposes. In our paper we present a new approach to structural operational semantics. We model behavior of programs in category of states, where objects are states, an abstraction of computer memory and morphisms model state changes, execution of a program in elementary steps. The advantage of using categorical model is its exact mathematical structure with many useful proved properties and its graphical illustration of program behavior as a path, i.e. a composition of morphisms. Our approach is able to accentuate dynamics of structural operational semantics. For simplicity, we assume that data are intuitively typed. Visualization and facility of our model is not only a new model of structural operational semantics of imperative programming languages but it can also serve for education purposes.
VERIFICATION OF GEAR DYNAMIC MODEL IN DIFFERENT OPERATING CONDITIONS
Directory of Open Access Journals (Sweden)
Grzegorz PERUŃ
2014-09-01
Full Text Available The article presents the results of verification of the drive system dynamic model with gear. Tests were carried out on the real object in different operating conditions. For the same assumed conditions were also carried out simulation studies. Comparison of the results obtained from those two series of tests helped determine the suitability of the model and verify the possibility of replacing experimental research by simulations with use of dynamic model.
Tourism Operator Sustainability Predictive Model in Marine Park
Mohamad, Zaleha; Ramli, Nurhafizah; Muslim, Aidy Mohamed Shawal M.; Hii, Yii Siang
2017-01-01
Sustainable tourism is the concept of visiting a place as a tourist and trying to make only a positive impact on the environment, society and economy. Tourism can involve primary transportation to the general location, local transportation, accommodations, entertainment, recreation, nourishment and shopping. In this context, the research study tourism is operator towards recreational. This study analyzed the sustainability tourism predictive model towards operator in marine park. The research...
Designing visual displays and system models for safe reactor operations
International Nuclear Information System (INIS)
Brown-VanHoozer, S.A.
1995-01-01
The material presented in this paper is based on two studies involving the design of visual displays and the user's prospective model of a system. The studies involve a methodology known as Neuro-Linguistic Programming and its use in expanding design choices from the operator's perspective image. The contents of this paper focuses on the studies and how they are applicable to the safety of operating reactors
Model of environmental life cycle assessment for coal mining operations
Energy Technology Data Exchange (ETDEWEB)
Burchart-Korol, Dorota, E-mail: dburchart@gig.eu; Fugiel, Agata, E-mail: afugiel@gig.eu; Czaplicka-Kolarz, Krystyna, E-mail: kczaplicka@gig.eu; Turek, Marian, E-mail: mturek@gig.eu
2016-08-15
This paper presents a novel approach to environmental assessment of coal mining operations, which enables assessment of the factors that are both directly and indirectly affecting the environment and are associated with the production of raw materials and energy used in processes. The primary novelty of the paper is the development of a computational environmental life cycle assessment (LCA) model for coal mining operations and the application of the model for coal mining operations in Poland. The LCA model enables the assessment of environmental indicators for all identified unit processes in hard coal mines with the life cycle approach. The proposed model enables the assessment of greenhouse gas emissions (GHGs) based on the IPCC method and the assessment of damage categories, such as human health, ecosystems and resources based on the ReCiPe method. The model enables the assessment of GHGs for hard coal mining operations in three time frames: 20, 100 and 500 years. The model was used to evaluate the coal mines in Poland. It was demonstrated that the largest environmental impacts in damage categories were associated with the use of fossil fuels, methane emissions and the use of electricity, processing of wastes, heat, and steel supports. It was concluded that an environmental assessment of coal mining operations, apart from direct influence from processing waste, methane emissions and drainage water, should include the use of electricity, heat and steel, particularly for steel supports. Because the model allows the comparison of environmental impact assessment for various unit processes, it can be used for all hard coal mines, not only in Poland but also in the world. This development is an important step forward in the study of the impacts of fossil fuels on the environment with the potential to mitigate the impact of the coal industry on the environment. - Highlights: • A computational LCA model for assessment of coal mining operations • Identification of
Model of environmental life cycle assessment for coal mining operations
International Nuclear Information System (INIS)
Burchart-Korol, Dorota; Fugiel, Agata; Czaplicka-Kolarz, Krystyna; Turek, Marian
2016-01-01
This paper presents a novel approach to environmental assessment of coal mining operations, which enables assessment of the factors that are both directly and indirectly affecting the environment and are associated with the production of raw materials and energy used in processes. The primary novelty of the paper is the development of a computational environmental life cycle assessment (LCA) model for coal mining operations and the application of the model for coal mining operations in Poland. The LCA model enables the assessment of environmental indicators for all identified unit processes in hard coal mines with the life cycle approach. The proposed model enables the assessment of greenhouse gas emissions (GHGs) based on the IPCC method and the assessment of damage categories, such as human health, ecosystems and resources based on the ReCiPe method. The model enables the assessment of GHGs for hard coal mining operations in three time frames: 20, 100 and 500 years. The model was used to evaluate the coal mines in Poland. It was demonstrated that the largest environmental impacts in damage categories were associated with the use of fossil fuels, methane emissions and the use of electricity, processing of wastes, heat, and steel supports. It was concluded that an environmental assessment of coal mining operations, apart from direct influence from processing waste, methane emissions and drainage water, should include the use of electricity, heat and steel, particularly for steel supports. Because the model allows the comparison of environmental impact assessment for various unit processes, it can be used for all hard coal mines, not only in Poland but also in the world. This development is an important step forward in the study of the impacts of fossil fuels on the environment with the potential to mitigate the impact of the coal industry on the environment. - Highlights: • A computational LCA model for assessment of coal mining operations • Identification of
Hysteresis modeling based on saturation operator without constraints
International Nuclear Information System (INIS)
Park, Y.W.; Seok, Y.T.; Park, H.J.; Chung, J.Y.
2007-01-01
This paper proposes a simple way to model complex hysteresis in a magnetostrictive actuator by employing the saturation operators without constraints. Having no constraints causes a singularity problem, i.e. the inverse matrix cannot be obtained during calculating the weights. To overcome it, a pseudoinverse concept is introduced. Simulation results are compared with the experimental data, based on a Terfenol-D actuator. It is clear that the proposed model is much closer to the experimental data than the modified PI model. The relative error is calculated as 12% and less than 1% with the modified PI Model and proposed model, respectively
Gravity field models derived from Swarm GPS data
Teixeira da Encarnação, João; Arnold, Daniel; Bezděk, Aleš; Dahle, Christoph; Doornbos, Eelco; van den IJssel, Jose; Jäggi, Adrian; Mayer-Gürr, Torsten; Sebera, Josef; Visser, Pieter; Zehentner, Norbert
2017-04-01
The Swarm satellites, with primary mission to measure Earth's Magnetic Field, continue to provide high-quality hl-SST data. We use these data to derive the time-varying gravity field of the Earth up to Spherical Harmonic degree and order 12, on a monthly basis since December 2013. We combine the gravity field solutions computed with the data of all three satellites, as provided by a number of institutes, namely at the Astronomical Institute (ASU) of the Czech Academy of Sciences (Bezděk et al., 2016), the Astronomical Institute of the University of Bern (AIUB, Jäggi et al., 2016) and the Institute of Geodesy (IfG) of the Graz University of Technology (Zehentner et al., 2015) and demonstrate that this uninterrupted time series of gravity field models are in good agreement with the temporal variations observed by the GRACE satellites. Therefore, these data can be used to study large-scale mass changes globally, e.g. i) in the context of low-latency applications, such as the European Gravity Service for Improved Emergency Management project (http://egsiem.eu), ii) in those months where GRACE solutions are not available, and iii) as an important source of independent information for mitigating the GRACE/GRACE Follow-On gap.
Hossain, Mokarram; Steinmann, Paul
2013-06-01
Rubber-like materials can deform largely and nonlinearly upon loading, and they return to the initial configuration when the load is removed. Such rubber elasticity is achieved due to very flexible long-chain molecules and a three-dimensional network structure that is formed via cross-linking or entanglements between molecules. Over the years, to model the mechanical behavior of such randomly oriented microstructures, several phenomenological and micromechanically motivated network models for nearly incompressible hyperelastic polymeric materials have been proposed in the literature. To implement these models for polymeric material (undoubtedly with widespread engineering applications) in the finite element framework for solving a boundary value problem, one would require two important ingredients, i.e., the stress tensor and the consistent fourth-order tangent operator, where the latter is the result of linearization of the former. In our previous work, 14 such material models are reviewed by deriving the accurate stress tensors and tangent operators from a group of phenomenological and micromechanical models at large deformations. The current contribution will supplement some further important models that were not included in the previous work. For comparison of all selected models in reproducing the well-known Treloar data, the analytical expressions for the three homogeneous defomation modes, i.e., uniaxial tension, equibiaxial tension, and pure shear, have been derived and the performances of the models are analyzed.
The Fréchet Derivative of an Analytic Function of a Bounded Operator with Some Applications
Directory of Open Access Journals (Sweden)
D. S. Gilliam
2009-01-01
analytic function of a bounded operator, tangentially to the space of all bounded operators. Some applied problems from statistics and numerical analysis are included as a motivation for this study. The perturbation operator (increment is not of any special form and is not supposed to commute with the operator at which the derivative is evaluated. This generality is important for the applications. In the Hermitian case, moreover, some results on perturbation of an isolated eigenvalue, its eigenprojection, and its eigenvector if the eigenvalue is simple, are also included. Although these results are known in principle, they are not in general formulated in terms of arbitrary perturbations as required for the applications. Moreover, these results are presented as corollaries to the main theorem, so that this paper also provides a short, essentially self-contained review of these aspects of perturbation theory.
Nadiri, Ata Allah; Sedghi, Zahra; Khatibi, Rahman; Gharekhani, Maryam
2017-09-01
Driven by contamination risks, mapping Vulnerability Indices (VI) of multiple aquifers (both unconfined and confined) is investigated by integrating the basic DRASTIC framework with multiple models overarched by Artificial Neural Networks (ANN). The DRASTIC framework is a proactive tool to assess VI values using the data from the hydrosphere, lithosphere and anthroposphere. However, a research case arises for the application of multiple models on the ground of poor determination coefficients between the VI values and non-point anthropogenic contaminants. The paper formulates SCFL models, which are derived from the multiple model philosophy of Supervised Committee (SC) machines and Fuzzy Logic (FL) and hence SCFL as their integration. The Fuzzy Logic-based (FL) models include: Sugeno Fuzzy Logic (SFL), Mamdani Fuzzy Logic (MFL), Larsen Fuzzy Logic (LFL) models. The basic DRASTIC framework uses prescribed rating and weighting values based on expert judgment but the four FL-based models (SFL, MFL, LFL and SCFL) derive their values as per internal strategy within these models. The paper reports that FL and multiple models improve considerably on the correlation between the modeled vulnerability indices and observed nitrate-N values and as such it provides evidence that the SCFL multiple models can be an alternative to the basic framework even for multiple aquifers. The study area with multiple aquifers is in Varzeqan plain, East Azerbaijan, northwest Iran. Copyright © 2017 Elsevier B.V. All rights reserved.
Modelling the basic error tendencies of human operators
International Nuclear Information System (INIS)
Reason, J.
1988-01-01
The paper outlines the primary structural features of human cognition: a limited, serial workspace interacting with a parallel distributed knowledge base. It is argued that the essential computational features of human cognition - to be captured by an adequate operator model - reside in the mechanisms by which stored knowledge structures are selected and brought into play. Two such computational 'primitives' are identified: similarity-matching and frequency-gambling. These two retrieval heuristics, it is argued, shape both the overall character of human performance (i.e. its heavy reliance on pattern-matching) and its basic error tendencies ('strong-but-wrong' responses, confirmation, similarity and frequency biases, and cognitive 'lock-up'). The various features of human cognition are integrated with a dynamic operator model capable of being represented in software form. This computer model, when run repeatedly with a variety of problem configurations, should produce a distribution of behaviours which, in total, simulate the general character of operator performance. (author)
Modelling the basic error tendencies of human operators
International Nuclear Information System (INIS)
Reason, James
1988-01-01
The paper outlines the primary structural features of human cognition: a limited, serial workspace interacting with a parallel distributed knowledge base. It is argued that the essential computational features of human cognition - to be captured by an adequate operator model - reside in the mechanisms by which stored knowledge structures are selected and brought into play. Two such computational 'primitives' are identified: similarity-matching and frequency-gambling. These two retrieval heuristics, it is argued, shape both the overall character of human performance (i.e. its heavy reliance on pattern-matching) and its basic error tendencies ('strong-but-wrong' responses, confirmation, similarity and frequency biases, and cognitive 'lock-up'). The various features of human cognition are integrated with a dynamic operator model capable of being represented in software form. This computer model, when run repeatedly with a variety of problem configurations, should produce a distribution of behaviours which, in toto, simulate the general character of operator performance. (author)
Marine Vessel Models in Changing Operational Conditions - A Tutorial
DEFF Research Database (Denmark)
Perez, Tristan; Sørensen, Asgeir; Blanke, Mogens
2006-01-01
conditions (VOC). However, since marine systems operate in changing VOCs, there is a need to adapt the models. To date, there is no theory available to describe a general model valid across different VOCs due to the complexity of the hydrodynamic involved. It is believed that system identification could......This tutorial paper provides an introduction, from a systems perspective, to the topic of ship motion dynamics of surface ships. It presents a classification of parametric models currently used for monitoring and control of marine vessels. These models are valid for certain vessel operational...... provide a significant contribution towards obtaining such a general model. Therefore, the main aim of the paper is to highlight the essential characteristics of marine system dynamics so as to provide a background for practitioners who would attempt future application of system identification techniques...
Development of a Model for Dynamic Recrystallization Consistent with the Second Derivative Criterion
Directory of Open Access Journals (Sweden)
Muhammad Imran
2017-11-01
Full Text Available Dynamic recrystallization (DRX processes are widely used in industrial hot working operations, not only to keep the forming forces low but also to control the microstructure and final properties of the workpiece. According to the second derivative criterion (SDC by Poliak and Jonas, the onset of DRX can be detected from an inflection point in the strain-hardening rate as a function of flow stress. Various models are available that can predict the evolution of flow stress from incipient plastic flow up to steady-state deformation in the presence of DRX. Some of these models have been implemented into finite element codes and are widely used for the design of metal forming processes, but their consistency with the SDC has not been investigated. This work identifies three sources of inconsistencies that models for DRX may exhibit. For a consistent modeling of the DRX kinetics, a new strain-hardening model for the hardening stages III to IV is proposed and combined with consistent recrystallization kinetics. The model is devised in the Kocks-Mecking space based on characteristic transition in the strain-hardening rate. A linear variation of the transition and inflection points is observed for alloy 800H at all tested temperatures and strain rates. The comparison of experimental and model results shows that the model is able to follow the course of the strain-hardening rate very precisely, such that highly accurate flow stress predictions are obtained.
Imran, Muhammad; Kühbach, Markus; Roters, Franz; Bambach, Markus
2017-11-02
Dynamic recrystallization (DRX) processes are widely used in industrial hot working operations, not only to keep the forming forces low but also to control the microstructure and final properties of the workpiece. According to the second derivative criterion (SDC) by Poliak and Jonas, the onset of DRX can be detected from an inflection point in the strain-hardening rate as a function of flow stress. Various models are available that can predict the evolution of flow stress from incipient plastic flow up to steady-state deformation in the presence of DRX. Some of these models have been implemented into finite element codes and are widely used for the design of metal forming processes, but their consistency with the SDC has not been investigated. This work identifies three sources of inconsistencies that models for DRX may exhibit. For a consistent modeling of the DRX kinetics, a new strain-hardening model for the hardening stages III to IV is proposed and combined with consistent recrystallization kinetics. The model is devised in the Kocks-Mecking space based on characteristic transition in the strain-hardening rate. A linear variation of the transition and inflection points is observed for alloy 800H at all tested temperatures and strain rates. The comparison of experimental and model results shows that the model is able to follow the course of the strain-hardening rate very precisely, such that highly accurate flow stress predictions are obtained.
Deriving albedo maps for HAPEX-Sahel from ASAS data using kernel-driven BRDF models
Directory of Open Access Journals (Sweden)
P. Lewis
1999-01-01
Full Text Available This paper describes the application and testing of a method for deriving spatial estimates of albedo from multi-angle remote sensing data. Linear kernel-driven models of surface bi-directional reflectance have been inverted against high spatial resolution multi-angular, multi- spectral airborne data of the principal cover types within the HAPEX-Sahel study site in Niger, West Africa. The airborne data are obtained from the NASA Airborne Solid-state Imaging Spectrometer (ASAS instrument, flown in Niger in September and October 1992. The maps of model parameters produced are used to estimate integrated reflectance properties related to spectral albedo. Broadband albedo has been estimated from this by weighting the spectral albedo for each pixel within the map as a function of the appropriate spectral solar irradiance and proportion of direct and diffuse illumination. Partial validation of the results was performed by comparing ASAS reflectance and derived directional-hemispherical reflectance with simulations of a millet canopy made with a complex geometric canopy reflectance model, the Botanical Plant Modelling System (BPMS. Both were found to agree well in magnitude. Broadband albedo values derived from the ASAS data were compared with ground-based (point sample albedo measurements and found to agree extremely well. These results indicate that the linear kernel-driven modelling approach, which is to be used operationally to produce global 16 day, 1 km albedo maps from forthcoming NASA Earth Observing System spaceborne data, is both sound and practical for the estimation of angle-integrated spectral reflectance quantities related to albedo. Results for broadband albedo are dependent on spectral sampling and on obtaining the correct spectral weigthings.
Currents, HF Radio-derived, SF Bay Outlet, Normal Model, Zonal, EXPERIMENTAL
National Oceanic and Atmospheric Administration, Department of Commerce — The data is the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements, with missing values filled in by a normal model....
Currents, HF Radio-derived, Ano Nuevo, Normal Model, Zonal, EXPERIMENTAL
National Oceanic and Atmospheric Administration, Department of Commerce — The data is the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements, with missing values filled in by a normal model....
Currents, HF Radio-derived, Monterey Bay, Normal Model, Zonal, EXPERIMENTAL
National Oceanic and Atmospheric Administration, Department of Commerce — The data is the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements, with missing values filled in by a normal model....
Directory of Open Access Journals (Sweden)
Ya-Juan Hao
2013-01-01
Full Text Available The main object of this paper is to investigate the Helmholtz and diffusion equations on the Cantor sets involving local fractional derivative operators. The Cantor-type cylindrical-coordinate method is applied to handle the corresponding local fractional differential equations. Two illustrative examples for the Helmholtz and diffusion equations on the Cantor sets are shown by making use of the Cantorian and Cantor-type cylindrical coordinates.
Model of environmental life cycle assessment for coal mining operations.
Burchart-Korol, Dorota; Fugiel, Agata; Czaplicka-Kolarz, Krystyna; Turek, Marian
2016-08-15
This paper presents a novel approach to environmental assessment of coal mining operations, which enables assessment of the factors that are both directly and indirectly affecting the environment and are associated with the production of raw materials and energy used in processes. The primary novelty of the paper is the development of a computational environmental life cycle assessment (LCA) model for coal mining operations and the application of the model for coal mining operations in Poland. The LCA model enables the assessment of environmental indicators for all identified unit processes in hard coal mines with the life cycle approach. The proposed model enables the assessment of greenhouse gas emissions (GHGs) based on the IPCC method and the assessment of damage categories, such as human health, ecosystems and resources based on the ReCiPe method. The model enables the assessment of GHGs for hard coal mining operations in three time frames: 20, 100 and 500years. The model was used to evaluate the coal mines in Poland. It was demonstrated that the largest environmental impacts in damage categories were associated with the use of fossil fuels, methane emissions and the use of electricity, processing of wastes, heat, and steel supports. It was concluded that an environmental assessment of coal mining operations, apart from direct influence from processing waste, methane emissions and drainage water, should include the use of electricity, heat and steel, particularly for steel supports. Because the model allows the comparison of environmental impact assessment for various unit processes, it can be used for all hard coal mines, not only in Poland but also in the world. This development is an important step forward in the study of the impacts of fossil fuels on the environment with the potential to mitigate the impact of the coal industry on the environment. Copyright © 2016 Elsevier B.V. All rights reserved.
Modelling safety of gantry crane operations using Petri nets.
Singh, Karmveer; Raj, Navneet; Sahu, S K; Behera, R K; Sarkar, Sobhan; Maiti, J
2017-03-01
Being a powerful tool in modelling industrial and service operations, Petri net (PN) has been extremely used in different domains, but its application in safety study is limited. In this study, we model the gantry crane operations used for industrial activities using generalized stochastic PNs. The complete cycle of operations of the gantry crane is split into three parts namely inspection and loading, movement of load, and unloading of load. PN models are developed for all three parts and the whole system as well. The developed PN models have captured the safety issues through reachability tree. The hazardous states are identified and how they ultimately lead to some unwanted accidents is demonstrated. The possibility of falling of load and failure of hook, sling, attachment and hoist rope are identified. Possible suggestions based on the study are presented for redesign of the system. For example, mechanical stoppage of operations in case of loosely connected load, and warning system for use of wrong buttons is tested using modified models.
Modeling of reservoir operation in UNH global hydrological model
Shiklomanov, Alexander; Prusevich, Alexander; Frolking, Steve; Glidden, Stanley; Lammers, Richard; Wisser, Dominik
2015-04-01
Climate is changing and river flow is an integrated characteristic reflecting numerous environmental processes and their changes aggregated over large areas. Anthropogenic impacts on the river flow, however, can significantly exceed the changes associated with climate variability. Besides of irrigation, reservoirs and dams are one of major anthropogenic factor affecting streamflow. They distort hydrological regime of many rivers by trapping of freshwater runoff, modifying timing of river discharge and increasing the evaporation rate. Thus, reservoirs is an integral part of the global hydrological system and their impacts on rivers have to be taken into account for better quantification and understanding of hydrological changes. We developed a new technique, which was incorporated into WBM-TrANS model (Water Balance Model-Transport from Anthropogenic and Natural Systems) to simulate river routing through large reservoirs and natural lakes based on information available from freely accessible databases such as GRanD (the Global Reservoir and Dam database) or NID (National Inventory of Dams for US). Different formulations were applied for unregulated spillway dams and lakes, and for 4 types of regulated reservoirs, which were subdivided based on main purpose including generic (multipurpose), hydropower generation, irrigation and water supply, and flood control. We also incorporated rules for reservoir fill up and draining at the times of construction and decommission based on available data. The model were tested for many reservoirs of different size and types located in various climatic conditions using several gridded meteorological data sets as model input and observed daily and monthly discharge data from GRDC (Global Runoff Data Center), USGS Water Data (US Geological Survey), and UNH archives. The best results with Nash-Sutcliffe model efficiency coefficient in the range of 0.5-0.9 were obtained for temperate zone of Northern Hemisphere where most of large
Operational policy for disposal of land-derived wastewater to the ...
African Journals Online (AJOL)
Basic Principles, providing the broad reference framework or direction of the policy • Ground Rules, providing more specific rules, derived within the broader context of the Basic Principles • Management Framework, providing a generic, structured approach within which to implement the policy. This paper is to provide an ...
Operational policy for disposal of land-derived wastewater to the ...
African Journals Online (AJOL)
2006-10-04
Oct 4, 2006 ... mined by pipeline length and bathymetry) and dilution (diffuser design). Specific Ground Rules stipulated in terms of scientific and engineering assessment studies are as follows: • A licence application for the disposal of land-derived waste- water to the marine environment will only be considered where a ...
Validation of Fatigue Modeling Predictions in Aviation Operations
Gregory, Kevin; Martinez, Siera; Flynn-Evans, Erin
2017-01-01
Bio-mathematical fatigue models that predict levels of alertness and performance are one potential tool for use within integrated fatigue risk management approaches. A number of models have been developed that provide predictions based on acute and chronic sleep loss, circadian desynchronization, and sleep inertia. Some are publicly available and gaining traction in settings such as commercial aviation as a means of evaluating flight crew schedules for potential fatigue-related risks. Yet, most models have not been rigorously evaluated and independently validated for the operations to which they are being applied and many users are not fully aware of the limitations in which model results should be interpreted and applied.
Integrating hydrodynamic models and COSMO-SkyMed derived products for flood damage assessment
Giuffra, Flavio; Boni, Giorgio; Pulvirenti, Luca; Pierdicca, Nazzareno; Rudari, Roberto; Fiorini, Mattia
2015-04-01
Floods are the most frequent weather disasters in the world and probably the most costly in terms of social and economic losses. They may have a strong impact on infrastructures and health because the range of possible damages includes casualties, loss of housing and destruction of crops. Presently, the most common approach for remotely sensing floods is the use of synthetic aperture radar (SAR) images. Key features of SAR data for inundation mapping are the synoptic view, the capability to operate even in cloudy conditions and during both day and night time and the sensitivity of the microwave radiation to water. The launch of a new generation of instruments, such as TerraSAR-X and COSMO-SkyMed (CSK) allows producing near real time flood maps having a spatial resolution in the order of 1-5 m. Moreover, the present (CSK) and upcoming (Sentinel-1) constellations permit the acquisition of radar data characterized by a short revisit time (in the order of some hours for CSK), so that the production of frequent inundation maps can be envisaged. Nonetheless, gaps might be present in the SAR-derived flood maps because of the limited area imaged by SAR; moreover, the detection of floodwater may be complicated by the presence of very dense vegetation or urban settlements. Hence the need to complement SAR-derived flood maps with the outputs of physical models. Physical models allow delivering to end users very useful information for a complete flood damage assessment, such as data on water depths and flow directions, which cannot be directly derived from satellite remote sensing images. In addition, the flood extent predictions of hydraulic models can be compared to SAR-derived inundation maps to calibrate the models, or to fill the aforementioned gaps that can be present in the SAR-derived maps. Finally, physical models enable the construction of risk scenarios useful for emergency managers to take their decisions and for programming additional SAR acquisitions in order to
A High-Speed Train Operation Plan Inspection Simulation Model
Directory of Open Access Journals (Sweden)
Yang Rui
2018-01-01
Full Text Available We developed a train operation simulation tool to inspect a train operation plan. In applying an improved Petri Net, the train was regarded as a token, and the line and station were regarded as places, respectively, in accordance with the high-speed train operation characteristics and network function. Location change and running information transfer of the high-speed train were realized by customizing a variety of transitions. The model was built based on the concept of component combination, considering the random disturbance in the process of train running. The simulation framework can be generated quickly and the system operation can be completed according to the different test requirements and the required network data. We tested the simulation tool when used for the real-world Wuhan to Guangzhou high-speed line. The results showed that the proposed model can be developed, the simulation results basically coincide with the objective reality, and it can not only test the feasibility of the high-speed train operation plan, but also be used as a support model to develop the simulation platform with more capabilities.
Dynamic and adaptive policy models for coalition operations
Verma, Dinesh; Calo, Seraphin; Chakraborty, Supriyo; Bertino, Elisa; Williams, Chris; Tucker, Jeremy; Rivera, Brian; de Mel, Geeth R.
2017-05-01
It is envisioned that the success of future military operations depends on the better integration, organizationally and operationally, among allies, coalition members, inter-agency partners, and so forth. However, this leads to a challenging and complex environment where the heterogeneity and dynamism in the operating environment intertwines with the evolving situational factors that affect the decision-making life cycle of the war fighter. Therefore, the users in such environments need secure, accessible, and resilient information infrastructures where policy-based mechanisms adopt the behaviours of the systems to meet end user goals. By specifying and enforcing a policy based model and framework for operations and security which accommodates heterogeneous coalitions, high levels of agility can be enabled to allow rapid assembly and restructuring of system and information resources. However, current prevalent policy models (e.g., rule based event-condition-action model and its variants) are not sufficient to deal with the highly dynamic and plausibly non-deterministic nature of these environments. Therefore, to address the above challenges, in this paper, we present a new approach for policies which enables managed systems to take more autonomic decisions regarding their operations.
A model for acoustic absorbent materials derived from coconut fiber
Directory of Open Access Journals (Sweden)
Ramis, J.
2014-03-01
Full Text Available In the present paper, a methodology is proposed for obtaining empirical equations describing the sound absorption characteristics of an absorbing material obtained from natural fibers, specifically from coconut. The method, which was previously applied to other materials, requires performing measurements of air-flow resistivity and of acoustic impedance for samples of the material under study. The equations that govern the acoustic behavior of the material are then derived by means of a least-squares fit of the acoustic impedance and of the propagation constant. These results can be useful since they allow the empirically obtained analytical equations to be easily incorporated in prediction and simulation models of acoustic systems for noise control that incorporate the studied materials.En este trabajo se describe el proceso seguido para obtener ecuaciones empíricas del comportamiento acústico de un material absorbente obtenido a partir de fibras naturales, concretamente el coco. El procedimiento, que ha sido ensayado con éxito en otros materiales, implica la realización de medidas de impedancia y resistencia al flujo de muestras del material bajo estudio. Las ecuaciones que gobiernan el comportamiento desde el punto de vista acústico del material se obtienen a partir del ajuste de ecuaciones de comportamiento de la impedancia acústica y la constante de propagación del material. Los resultados son útiles ya que, al disponer de ecuaciones analíticas obtenidas empíricamente, facilitan la incorporación de estos materiales en predicciones mediante métodos numéricos del comportamiento cuando son instalados formando parte de dispositivos para el control del ruido.
Modeling and Simulating Airport Surface Operations with Gate Conflicts
Zelinski, Shannon; Windhorst, Robert
2017-01-01
The Surface Operations Simulator and Scheduler (SOSS) is a fast-time simulation platform used to develop and test future surface scheduling concepts such as NASAs Air Traffic Demonstration 2 of time-based surface metering at Charlotte Douglas International Airport (CLT). Challenges associated with CLT surface operations have driven much of SOSS development. Recently, SOSS functionality for modeling hardstand operations was developed to address gate conflicts, which occur when an arrival and departure wish to occupy the same gate at the same time. Because surface metering concepts such as ATD2 have the potential to increase gates conflicts as departure are held at their gates, it is important to study the interaction between surface metering and gate conflict management. Several approaches to managing gate conflicts with and without the use of hardstands were simulated and their effects on surface operations and scheduler performance compared.
Comparison of operation optimization methods in energy system modelling
DEFF Research Database (Denmark)
Ommen, Torben Schmidt; Markussen, Wiebke Brix; Elmegaard, Brian
2013-01-01
In areas with large shares of Combined Heat and Power (CHP) production, significant introduction of intermittent renewable power production may lead to an increased number of operational constraints. As the operation pattern of each utility plant is determined by optimization of economics......, possibilities for decoupling production constraints may be valuable. Introduction of heat pumps in the district heating network may pose this ability. In order to evaluate if the introduction of heat pumps is economically viable, we develop calculation methods for the operation patterns of each of the used...... operation constraints, while the third approach uses nonlinear programming. In the present case the non-linearity occurs in the boiler efficiency of power plants and the cv-value of an extraction plant. The linear programming model is used as a benchmark, as this type is frequently used, and has the lowest...
Model and Adaptive Operations of an Adaptive Component
Wei, Le; Zhao, Qiuyun; Shu, Hongping
In order to keep up with the dynamical and open internet environment and in terms of component, an adaptive component model which is based on event mechanism and policy binding is proposed. Components of the model can sense external changes and give the explicit description of the external environment. According to preset policy, component also can take adaptive operations such as adding, deleting, replacing and updating when necessary, and adjust the behavior and structure of the internetware to provide better services.
Cognitive model of the power unit operator activity
International Nuclear Information System (INIS)
Chachko, S.A.
1992-01-01
Basic notions making it possible to study and simulate the peculiarities of man-operator activity, in particular his way of thiking, are considered. Special attention is paid to cognitive models based on concept of decisive role of knowledge (its acquisition, storage and application) in the man mental processes and activity. The models are based on three basic notions, which are the professional world image, activity strategy and spontaneous decisions
MAESTRO -- A Model and Expert System Tuning Resource for Operators
International Nuclear Information System (INIS)
Lager, D.L.; Brand, H.R.; Maurer, W.J.; Coffield, F.E.; Chambers, F.
1989-01-01
We have developed MAESTRO, a Model And Expert System Tuning Resource for Operators. It provides a unified software environment for optimizing the performance of large, complex machines, in particular the Advanced Test Accelerator and Experimental Test Accelerator at Lawrence Livermore National Laboratory. The system incorporates three approaches to tuning: a mouse-based manual interface to select and control magnets and to view displays of machine performance; an automation based on ''cloning the operator'' by implementing the strategies and reasoning used by the operator; an automation based on a simulator model which, when accurately matched to the machine, allows downloading of optimal sets of parameters and permits diagnosing errors in the beamline. The latter two approaches are based on the Artificial Intelligence technique known as Expert Systems. 4 refs., 4 figs
Automated particulate sampler field test model operations guide
Energy Technology Data Exchange (ETDEWEB)
Bowyer, S.M.; Miley, H.S.
1996-10-01
The Automated Particulate Sampler Field Test Model Operations Guide is a collection of documents which provides a complete picture of the Automated Particulate Sampler (APS) and the Field Test in which it was evaluated. The Pacific Northwest National Laboratory (PNNL) Automated Particulate Sampler was developed for the purpose of radionuclide particulate monitoring for use under the Comprehensive Test Ban Treaty (CTBT). Its design was directed by anticipated requirements of small size, low power consumption, low noise level, fully automatic operation, and most predominantly the sensitivity requirements of the Conference on Disarmament Working Paper 224 (CDWP224). This guide is intended to serve as both a reference document for the APS and to provide detailed instructions on how to operate the sampler. This document provides a complete description of the APS Field Test Model and all the activity related to its evaluation and progression.
Mathematical modelling of unglazed solar collectors under extreme operating conditions
DEFF Research Database (Denmark)
Bunea, M.; Perers, Bengt; Eicher, S.
2015-01-01
average temperature levels at the evaporator. Simulation of these systems requires a collector model that can take into account operation at very low temperatures (below freezing) and under various weather conditions, particularly operation without solar irradiation.A solar collector mathematical model......Combined heat pumps and solar collectors got a renewed interest on the heating system market worldwide. Connected to the heat pump evaporator, unglazed solar collectors can considerably increase their efficiency, but they also raise the coefficient of performance of the heat pump with higher...... was found due to the condensation phenomenon and up to 40% due to frost under no solar irradiation. This work also points out the influence of the operating conditions on the collector's characteristics.Based on experiments carried out at a test facility, every heat flux on the absorber was separately...
Finite BRST Mapping in Higher-Derivative Models
Moshin, Pavel Yu.; Upadhyay, Sudhaker; Castro, Ricardo A.
2017-08-01
We continue the study of finite field-dependent BRST (FFBRST) symmetry in the quantum theory of gauge fields. An expression for the Jacobian of path integral measure is presented, depending on a finite field-dependent parameter, and the FFBRST symmetry is then applied to a number of well-established quantum gauge theories in a form which incudes higher-derivative terms. Specifically, we examine the corresponding versions of the Maxwell theory, non-Abelian vector field theory, and gravitation theory. We present a systematic mapping between different forms of gauge-fixing, including those with higher-derivative terms, for which these theories have better renormalization properties. In doing so, we also provide the independence of the S-matrix from a particular gauge-fixing with higher derivatives. Following this method, a higher-derivative quantum action can be constructed for any gauge theory in the FFBRST framework.
Water operator partnerships as a model to achieve the Millenium ...
African Journals Online (AJOL)
In the void left by the declining popularity of public-private partnerships, the concept of 'water operator partnerships' (WOPs) has increasingly been promoted as an alternative for improving water services provision in developing countries. This paper assesses the potential of such partnerships as a 'model' for contributing to ...
Dynamic modeling of temperature change in outdoor operated tubular photobioreactors.
Androga, Dominic Deo; Uyar, Basar; Koku, Harun; Eroglu, Inci
2017-07-01
In this study, a one-dimensional transient model was developed to analyze the temperature variation of tubular photobioreactors operated outdoors and the validity of the model was tested by comparing the predictions of the model with the experimental data. The model included the effects of convection and radiative heat exchange on the reactor temperature throughout the day. The temperatures in the reactors increased with increasing solar radiation and air temperatures, and the predicted reactor temperatures corresponded well to the measured experimental values. The heat transferred to the reactor was mainly through radiation: the radiative heat absorbed by the reactor medium, ground radiation, air radiation, and solar (direct and diffuse) radiation, while heat loss was mainly through the heat transfer to the cooling water and forced convection. The amount of heat transferred by reflected radiation and metabolic activities of the bacteria and pump work was negligible. Counter-current cooling was more effective in controlling reactor temperature than co-current cooling. The model developed identifies major heat transfer mechanisms in outdoor operated tubular photobioreactors, and accurately predicts temperature changes in these systems. This is useful in determining cooling duty under transient conditions and scaling up photobioreactors. The photobioreactor design and the thermal modeling were carried out and experimental results obtained for the case study of photofermentative hydrogen production by Rhodobacter capsulatus, but the approach is applicable to photobiological systems that are to be operated under outdoor conditions with significant cooling demands.
Modeling operational risks of the nuclear industry with Bayesian networks
International Nuclear Information System (INIS)
Wieland, Patricia; Lustosa, Leonardo J.
2009-01-01
Basically, planning a new industrial plant requires information on the industrial management, regulations, site selection, definition of initial and planned capacity, and on the estimation of the potential demand. However, this is far from enough to assure the success of an industrial enterprise. Unexpected and extremely damaging events may occur that deviates from the original plan. The so-called operational risks are not only in the system, equipment, process or human (technical or managerial) failures. They are also in intentional events such as frauds and sabotage, or extreme events like terrorist attacks or radiological accidents and even on public reaction to perceived environmental or future generation impacts. For the nuclear industry, it is a challenge to identify and to assess the operational risks and their various sources. Early identification of operational risks can help in preparing contingency plans, to delay the decision to invest or to approve a project that can, at an extreme, affect the public perception of the nuclear energy. A major problem in modeling operational risk losses is the lack of internal data that are essential, for example, to apply the loss distribution approach. As an alternative, methods that consider qualitative and subjective information can be applied, for example, fuzzy logic, neural networks, system dynamic or Bayesian networks. An advantage of applying Bayesian networks to model operational risk is the possibility to include expert opinions and variables of interest, to structure the model via causal dependencies among these variables, and to specify subjective prior and conditional probabilities distributions at each step or network node. This paper suggests a classification of operational risks in industry and discusses the benefits and obstacles of the Bayesian networks approach to model those risks. (author)
International Nuclear Information System (INIS)
2017-01-01
This publication provides selected default OIL values, together with a detailed description of the methodology for their derivation, as well as practical tools and recommendations for their use. The tools and default OIL values provided here may be directly integrated into national emergency arrangements or reviewed and modified as necessary to meet the specific emergency preparedness and response arrangements of the country in which they will be applied.
DUVAS (derivative uv-absorption spectrometer): instrument description and operating manual
International Nuclear Information System (INIS)
Hawthorne, A.R.; Dougherty, J.M.; Metcalfe, C.E.
1980-11-01
DUVAS is a real-time, field-portable spectrometer capable of monitoring a variety of aromatic organic vapors and inorganic gases at sub-ppM concentrations. The instrument is a prototype, microcomputer-controlled, derivative ultraviolet (UV) absorption spectrometer (DUVAS) developed primarily for area monitoring at coal conversion facilities, although other important occupational and environmental monitoring applications for compounds such as SO 2 , NO/sub x/, NH 3 , and HCHO are also being pursued
DUVAS (derivative uv-absorption spectrometer): instrument description and operating manual
Energy Technology Data Exchange (ETDEWEB)
Hawthorne, A.R.; Dougherty, J.M.; Metcalfe, C.E.
1980-11-01
DUVAS is a real-time, field-portable spectrometer capable of monitoring a variety of aromatic organic vapors and inorganic gases at sub-ppM concentrations. The instrument is a prototype, microcomputer-controlled, derivative ultraviolet (UV) absorption spectrometer (DUVAS) developed primarily for area monitoring at coal conversion facilities, although other important occupational and environmental monitoring applications for compounds such as SO/sub 2/, NO/sub x/, NH/sub 3/, and HCHO are also being pursued.
Modelling security properties in a grid-based operating system with anti-goals
Arenas, A.; Aziz, Benjamin; Bicarregui, J.; Matthews, B.; Yang, E.
2008-01-01
In this paper, we discuss the use of formal requirements-engineering techniques in capturing security requirements for a Grid-based operating system. We use KAOS goal model to represent two security goals for Grid systems, namely authorisation and single-sign on authentication. We apply goal-refinement to derive security requirements for these two security goals and we develop a model of antigoals and show how system vulnerabilities and threats to the security goals can arise from such anti-m...
Predicting third molar surgery operative time: a validated model.
Susarla, Srinivas M; Dodson, Thomas B
2013-01-01
The purpose of the present study was to develop and validate a statistical model to predict third molar (M3) operative time. This was a prospective cohort study consisting of a sample of subjects presenting for M3 removal. The demographic, anatomic, and operative variables were recorded for each subject. Using an index sample of randomly selected subjects, a multiple linear regression model was generated to predict the operating time. A nonoverlapping group of randomly selected subjects (validation sample) was used to assess model accuracy. P≤.05 was considered significant. The sample was composed of 150 subjects (n) who had 450 (k) M3s removed. The index sample (n=100 subjects, k=313 M3s extracted) had a mean age of 25.4±10.0 years. The mean extraction time was 6.4±7.0 minutes. The multiple linear regression model included M3 location, Winter's classification, tooth morphology, number of teeth extracted, procedure type, and surgical experience (R2=0.58). No statistically significant differences were seen between the index sample and the validation sample (n=50, k=137) for any of the study variables. Compared with the index model, the β-coefficients of the validation model were similar in direction and magnitude for most variables. Compared with the observed extraction time for all teeth in the sample, the predicted extraction time was not significantly different (P=.16). Fair agreement was seen between the β-coefficients for our multiple models in the index and validation populations, with no significant difference in the predicted and observed operating times. Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.
Modeling the Environmental Impact of Air Traffic Operations
Chen, Neil
2011-01-01
There is increased interest to understand and mitigate the impacts of air traffic on the climate, since greenhouse gases, nitrogen oxides, and contrails generated by air traffic can have adverse impacts on the climate. The models described in this presentation are useful for quantifying these impacts and for studying alternative environmentally aware operational concepts. These models have been developed by leveraging and building upon existing simulation and optimization techniques developed for the design of efficient traffic flow management strategies. Specific enhancements to the existing simulation and optimization techniques include new models that simulate aircraft fuel flow, emissions and contrails. To ensure that these new models are beneficial to the larger climate research community, the outputs of these new models are compatible with existing global climate modeling tools like the FAA's Aviation Environmental Design Tool.
Directory of Open Access Journals (Sweden)
Hossein Jafari
2016-04-01
Full Text Available The non-differentiable solution of the linear and non-linear partial differential equations on Cantor sets is implemented in this article. The reduced differential transform method is considered in the local fractional operator sense. The four illustrative examples are given to show the efficiency and accuracy features of the presented technique to solve local fractional partial differential equations.
Hossein Jafari; Hassan K Jassim; Seithuti P Moshokoa; Vernon M Ariyan; Fairouz Tchier
2016-01-01
The non-differentiable solution of the linear and non-linear partial differential equations on Cantor sets is implemented in this article. The reduced differential transform method is considered in the local fractional operator sense. The four illustrative examples are given to show the efficiency and accuracy features of the presented technique to solve local fractional partial differential equations.
eWaterCycle: A global operational hydrological forecasting model
van de Giesen, Nick; Bierkens, Marc; Donchyts, Gennadii; Drost, Niels; Hut, Rolf; Sutanudjaja, Edwin
2015-04-01
Development of an operational hyper-resolution hydrological global model is a central goal of the eWaterCycle project (www.ewatercycle.org). This operational model includes ensemble forecasts (14 days) to predict water related stress around the globe. Assimilation of near-real time satellite data is part of the intended product that will be launched at EGU 2015. The challenges come from several directions. First, there are challenges that are mainly computer science oriented but have direct practical hydrological implications. For example, we aim to make use as much as possible of existing standards and open-source software. For example, different parts of our system are coupled through the Basic Model Interface (BMI) developed in the framework of the Community Surface Dynamics Modeling System (CSDMS). The PCR-GLOBWB model, built by Utrecht University, is the basic hydrological model that is the engine of the eWaterCycle project. Re-engineering of parts of the software was needed for it to run efficiently in a High Performance Computing (HPC) environment, and to be able to interface using BMI, and run on multiple compute nodes in parallel. The final aim is to have a spatial resolution of 1km x 1km, which is currently 10 x 10km. This high resolution is computationally not too demanding but very memory intensive. The memory bottleneck becomes especially apparent for data assimilation, for which we use OpenDA. OpenDa allows for different data assimilation techniques without the need to build these from scratch. We have developed a BMI adaptor for OpenDA, allowing OpenDA to use any BMI compatible model. To circumvent memory shortages which would result from standard applications of the Ensemble Kalman Filter, we have developed a variant that does not need to keep all ensemble members in working memory. At EGU, we will present this variant and how it fits well in HPC environments. An important step in the eWaterCycle project was the coupling between the hydrological and
Directory of Open Access Journals (Sweden)
Sérgio Roberto da Silva
2016-06-01
Full Text Available Colombia has been one of the first countries to introduce electronic billing process on a voluntary basis, from a traditional to a digital version. In this context, the article analyzes the electronic billing process implemented in Colombia and the advantages. Methodological research is applied, qualitative, descriptive and documentary; where the regulatory framework and the conceptualization of the model is identified; the process of adoption of electronic billing is analyzed, and finally the advantages and disadvantages of its implementation is analyzed. The findings indicate that the model applied in Colombia to issue an electronic billing in sending and receiving process, is not complex, but it requires a small adequate infrastructure and trained personnel to reach all sectors, especially the micro and business which is the largest business network in the country.
Sol-Terra - AN Operational Space Weather Forecasting Model Framework
Bisi, M. M.; Lawrence, G.; Pidgeon, A.; Reid, S.; Hapgood, M. A.; Bogdanova, Y.; Byrne, J.; Marsh, M. S.; Jackson, D.; Gibbs, M.
2015-12-01
The SOL-TERRA project is a collaboration between RHEA Tech, the Met Office, and RAL Space funded by the UK Space Agency. The goal of the SOL-TERRA project is to produce a Roadmap for a future coupled Sun-to-Earth operational space weather forecasting system covering domains from the Sun down to the magnetosphere-ionosphere-thermosphere and neutral atmosphere. The first stage of SOL-TERRA is underway and involves reviewing current models that could potentially contribute to such a system. Within a given domain, the various space weather models will be assessed how they could contribute to such a coupled system. This will be done both by reviewing peer reviewed papers, and via direct input from the model developers to provide further insight. Once the models have been reviewed then the optimal set of models for use in support of forecast-based SWE modelling will be selected, and a Roadmap for the implementation of an operational forecast-based SWE modelling framework will be prepared. The Roadmap will address the current modelling capability, knowledge gaps and further work required, and also the implementation and maintenance of the overall architecture and environment that the models will operate within. The SOL-TERRA project will engage with external stakeholders in order to ensure independently that the project remains on track to meet its original objectives. A group of key external stakeholders have been invited to provide their domain-specific expertise in reviewing the SOL-TERRA project at critical stages of Roadmap preparation; namely at the Mid-Term Review, and prior to submission of the Final Report. This stakeholder input will ensure that the SOL-TERRA Roadmap will be enhanced directly through the input of modellers and end-users. The overall goal of the SOL-TERRA project is to develop a Roadmap for an operational forecast-based SWE modelling framework with can be implemented within a larger subsequent activity. The SOL-TERRA project is supported within
Nuclear power plant safety and reliability improvements derived from operational experience analysis
International Nuclear Information System (INIS)
Zebroski, E.L.; Rosen, S.L.
1983-01-01
The frequency and distribution of significant events at operating nuclear power plants can be used as one of several indices to obtain a preliminary indication of unit and/or utility performance in the development and implementation of improvements aimed at reducing the probability or consequences of troublesome events. Initial data of this type are presented along with qualifications on the validity of such indicators. Planned further steps to improve this as a performance indicator are noted
A Stochastic Operational Planning Model for Smart Power Systems
Directory of Open Access Journals (Sweden)
Sh. Jadid
2014-12-01
Full Text Available Smart Grids are result of utilizing novel technologies such as distributed energy resources, and communication technologies in power system to compensate some of its defects. Various power resources provide some benefits for operation domain however, power system operator should use a powerful methodology to manage them. Renewable resources and load add uncertainty to the problem. So, independent system operator should use a stochastic method to manage them. A Stochastic unit commitment is presented in this paper to schedule various power resources such as distributed generation units, conventional thermal generation units, wind and PV farms, and demand response resources. Demand response resources, interruptible loads, distributed generation units, and conventional thermal generation units are used to provide required reserve for compensating stochastic nature of various resources and loads. In the presented model, resources connected to distribution network can participate in wholesale market through aggregators. Moreover, a novel three-program model which can be used by aggregators is presented in this article. Loads and distributed generation can contract with aggregators by these programs. A three-bus test system and the IEEE RTS are used to illustrate usefulness of the presented model. The results show that ISO can manage the system effectively by using this model
Preliminary Exploration of Adaptive State Predictor Based Human Operator Modeling
Trujillo, Anna C.; Gregory, Irene M.
2012-01-01
Control-theoretic modeling of the human operator dynamic behavior in manual control tasks has a long and rich history. In the last two decades, there has been a renewed interest in modeling the human operator. There has also been significant work on techniques used to identify the pilot model of a given structure. The purpose of this research is to attempt to go beyond pilot identification based on collected experimental data and to develop a predictor of pilot behavior. An experiment was conducted to quantify the effects of changing aircraft dynamics on an operator s ability to track a signal in order to eventually model a pilot adapting to changing aircraft dynamics. A gradient descent estimator and a least squares estimator with exponential forgetting used these data to predict pilot stick input. The results indicate that individual pilot characteristics and vehicle dynamics did not affect the accuracy of either estimator method to estimate pilot stick input. These methods also were able to predict pilot stick input during changing aircraft dynamics and they may have the capability to detect a change in a subject due to workload, engagement, etc., or the effects of changes in vehicle dynamics on the pilot.
Optimizing Biorefinery Design and Operations via Linear Programming Models
Energy Technology Data Exchange (ETDEWEB)
Talmadge, Michael; Batan, Liaw; Lamers, Patrick; Hartley, Damon; Biddy, Mary; Tao, Ling; Tan, Eric
2017-03-28
The ability to assess and optimize economics of biomass resource utilization for the production of fuels, chemicals and power is essential for the ultimate success of a bioenergy industry. The team of authors, consisting of members from the National Renewable Energy Laboratory (NREL) and the Idaho National Laboratory (INL), has developed simple biorefinery linear programming (LP) models to enable the optimization of theoretical or existing biorefineries. The goal of this analysis is to demonstrate how such models can benefit the developing biorefining industry. It focuses on a theoretical multi-pathway, thermochemical biorefinery configuration and demonstrates how the biorefinery can use LP models for operations planning and optimization in comparable ways to the petroleum refining industry. Using LP modeling tools developed under U.S. Department of Energy's Bioenergy Technologies Office (DOE-BETO) funded efforts, the authors investigate optimization challenges for the theoretical biorefineries such as (1) optimal feedstock slate based on available biomass and prices, (2) breakeven price analysis for available feedstocks, (3) impact analysis for changes in feedstock costs and product prices, (4) optimal biorefinery operations during unit shutdowns / turnarounds, and (5) incentives for increased processing capacity. These biorefinery examples are comparable to crude oil purchasing and operational optimization studies that petroleum refiners perform routinely using LPs and other optimization models. It is important to note that the analyses presented in this article are strictly theoretical and they are not based on current energy market prices. The pricing structure assigned for this demonstrative analysis is consistent with $4 per gallon gasoline, which clearly assumes an economic environment that would favor the construction and operation of biorefineries. The analysis approach and examples provide valuable insights into the usefulness of analysis tools for
Application of online modeling to the operation of SLC
International Nuclear Information System (INIS)
Woodley, M.D.; Sanchez-Chopitea, L.; Shoaee, H.
1987-01-01
Online computer models of first order beam optics have been developed for the commissioning, control and operation of the entire SLC including Damping Rings, Linac, Positron Return Line and Collider Arcs. A generalized online environment utilizing these models provides the capability for interactive selection of a desire optics configuration and for the study of its properties. Automated procedures have been developed which calculate and load beamline component set-points and which can scale magnet strengths to achieve desired beam properties for any Linac energy profile. Graphic displays facilitate comparison of design, desired and actual optical characteristics of the beamlines. Measured beam properties, such as beam emittance and dispersion, can be incorporated interactively into the models and used for beam matching and optimization of injection and extraction efficiencies and beam transmissions. The online optics modeling facility also serves as the foundation for many model-driven applications such as autosteering, calculation of beam launch parameters, emittance measurement and dispersion correction
A model technology transfer program for independent operators
Energy Technology Data Exchange (ETDEWEB)
Schoeling, L.G.
1996-08-01
In August 1992, the Energy Research Center (ERC) at the University of Kansas was awarded a contract by the US Department of Energy (DOE) to develop a technology transfer regional model. This report describes the development and testing of the Kansas Technology Transfer Model (KTTM) which is to be utilized as a regional model for the development of other technology transfer programs for independent operators throughout oil-producing regions in the US. It describes the linkage of the regional model with a proposed national technology transfer plan, an evaluation technique for improving and assessing the model, and the methodology which makes it adaptable on a regional basis. The report also describes management concepts helpful in managing a technology transfer program.
International Nuclear Information System (INIS)
Bishop, Peter; Povyakalo, Andrey
2017-01-01
Reliability testing is typically used in demand-based systems (such as protection systems) to derive a confidence bound for a specific operational profile. To be realistic, the number of tests for each class of demand should be proportional to the demand frequency of the class. In practice, however, the actual operational profile may differ from that used during testing. This paper provides a means for estimating the confidence bound when the test profile differs from the profile used in actual operation. Based on this analysis the paper examines what bound can be claimed for different types of profile uncertainty and options for dealing with this uncertainty. We also show that the same conservative bound estimation equations can be applied to cases where different measures of software test coverage and operational profile are used. - Highlights: • Calculation of a new confidence bound when the operational profile changes. • The bound formula is an analytic approximation that is always conservative. • Formula can be used to optimise testing to allow for profile uncertainty. • Formulated for demand based systems with different demand classes. • But formulae can be generalised (e.g. to continuous time systems).
Classical mapping for Hubbard operators: Application to the double-Anderson model
International Nuclear Information System (INIS)
Li, Bin; Miller, William H.; Levy, Tal J.; Rabani, Eran
2014-01-01
A classical Cartesian mapping for Hubbard operators is developed to describe the nonequilibrium transport of an open quantum system with many electrons. The mapping of the Hubbard operators representing the many-body Hamiltonian is derived by using analogies from classical mappings of boson creation and annihilation operators vis-à-vis a coherent state representation. The approach provides qualitative results for a double quantum dot array (double Anderson impurity model) coupled to fermionic leads for a range of bias voltages, Coulomb couplings, and hopping terms. While the width and height of the conduction peaks show deviations from the master equation approach considered to be accurate in the limit of weak system-leads couplings and high temperatures, the Hubbard mapping captures all transport channels involving transition between many electron states, some of which are not captured by approximate nonequilibrium Green function closures
Nickel, Stefan; Schröder, Winfried
2017-05-01
Atmospheric deposition of heavy metals (HM) can be determined by use of numeric models, technical devices and biomonitors. Mainly focussing on Germany, this paper aims at evaluating data from deposition modelling and biomonitoring programmes. The model LOTOS-EUROS (LE) yielded data on HM deposition at a spatial resolution of 25 km by 25 km throughout Europe. The European Monitoring and Evaluation Programme (EMEP) provided model calculations on 50 km by 50 km grids. Corresponding data on HM concentration in moss, leaves and needles and soil were derived from the European Moss Survey (EMS), the German Environmental Specimen Bank (ESB) and the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (iCP Forests). The modelled HM deposition and respective concentrations in moss (EMS), leaves and needles (ESB, iCP Forests) and soil (iCP Forests) were investigated for their statistical relationships. Regression equations were applied on geostatistical surface estimations of HM concentration in moss and then the residuals were interpolated by use of kriging interpolation. Both maps were summed up to a map of cadmium (Cd) and lead (Pb) deposition across Germany. Biomonitoring data were strongly correlated to LE than to EMEP. For HM concentrations in moss, the highest correlations were found for the association between geostatistical surface estimations of HM concentration in moss and deposition (LE).
Directory of Open Access Journals (Sweden)
Luzango Pangani Mfupe
2014-12-01
Full Text Available Advances in technology have enabled network-less mobile voice over internet protocol operator (MVoIPO to offer data services (i.e. voice, text and video to mobile network operator's (MNO's subscribers through an application enabled on subscriber's user equipment using MNO's packet-based cellular network infrastructure. However, this raises the problem of how to handle interconnection settlements between the two types of operators, particularly how to deal with users who now have the ability to make ‘free’ on-net MVoIP calls among themselves within the MNO's network. This study proposes a service level agreement-based transparent settlement model (TSM to solve this problem. The model is based on concepts of achievement and reward, not violation and punishment. The TSM calculates the MVoIPO's throughput distribution by monitoring the variations of peaks and troughs at the edge of a network. This facilitates the determination of conformance and non-conformance levels to the pre-set throughput thresholds and, subsequently, the issuing of compensation to the MVoIPO by the MNO as a result of generating an economically acceptable volume of data traffic.
Standard model baryogenesis through four-fermion operators in braneworlds
International Nuclear Information System (INIS)
Chung, Daniel J.H.; Dent, Thomas
2002-01-01
We study a new baryogenesis scenario in a class of braneworld models with low fundamental scale, which typically have difficulty with baryogenesis. The scenario is characterized by its minimal nature: the field content is that of the standard model and all interactions consistent with the gauge symmetry are admitted. Baryon number is violated via a dimension-6 proton decay operator, suppressed today by the mechanism of quark-lepton separation in extra dimensions; we assume that this operator was unsuppressed in the early Universe due to a time-dependent quark-lepton separation. The source of CP violation is the CKM matrix, in combination with the dimension-6 operators. We find that almost independently of cosmology, sufficient baryogenesis is nearly impossible in such a scenario if the fundamental scale is above 100 TeV, as required by an unsuppressed neutron-antineutron oscillation operator. The only exception producing sufficient baryon asymmetry is a scenario involving out-of-equilibrium c quarks interacting with equilibrium b quarks
Plant-derived extracts in the neuroscience of anxiety on animal models: biases and comments.
Chirumbolo, Salvatore
2012-04-01
Generalized anxiety disorders probably represent one of the world's biggest mental health problems. A large number of studies have also shown that anxiety disorders and depression are often associated with quality of life impairments. As anxiety represents a big concern in public health, a substantial literature supports clinically important associations between psychiatric illness and chronic medical conditions. Actually, most research focuses on depression, finding that depression can adversely affect self-care and increase the risk of incident medical illness, complications, and mortality. Anxiety disorders are less well studied, but robust epidemiological and clinical evidences show that they play an equally important role. Recent reported articles have raised a debate about the effectiveness of some plant-derived extracts in anxiety-like models in mice. Biases about several aspects related with experimental setting, animal selection, environments, operators and investigators, selection and performance of behavioral tests, controls, results managing, and statistics are here discussed.
Refuse-derived fuel as a secondary energy in Taiwan - Using Hotelling space allocation model
International Nuclear Information System (INIS)
Kwodong Wey; Sheueching Hong
2006-01-01
Most Taiwanese farmers usually blend rice straws into the soil after harvest. However, rice straws possess great thermal energy, which can be used to produce refuse-derived fuel (RDF-5). As Taiwan faces energy shortage, the development benefits of the RDF-5 industry are tempting. This study employs the Hotelling model to design the locations and the optimal numbers of RDF-5 plants. From the technology and material supply point of view, turning waste rice straws into RDF-5 is feasible in Taiwan. Nevertheless, from the business operation perspective, even if the RDF-5 plant is willing to lower its profit rate, its selling price is still hard to compete with imported RDF-5. If the Taiwanese government decides to pursue RDF-5 as an alternative energy, they might need to take a step further to subsidize entrepreneurs or provide appropriate tax benefits. Otherwise, the RDF-5 industry is hard to survive in Taiwan. (Author)
Analysis of Operating Principles with S-system Models
Lee, Yun; Chen, Po-Wei; Voit, Eberhard O.
2011-01-01
Operating principles address general questions regarding the response dynamics of biological systems as we observe or hypothesize them, in comparison to a priori equally valid alternatives. In analogy to design principles, the question arises: Why are some operating strategies encountered more frequently than others and in what sense might they be superior? It is at this point impossible to study operation principles in complete generality, but the work here discusses the important situation where a biological system must shift operation from its normal steady state to a new steady state. This situation is quite common and includes many stress responses. We present two distinct methods for determining different solutions to this task of achieving a new target steady state. Both methods utilize the property of S-system models within Biochemical Systems Theory (BST) that steady-states can be explicitly represented as systems of linear algebraic equations. The first method uses matrix inversion, a pseudo-inverse, or regression to characterize the entire admissible solution space. Operations on the basis of the solution space permit modest alterations of the transients toward the target steady state. The second method uses standard or mixed integer linear programming to determine admissible solutions that satisfy criteria of functional effectiveness, which are specified beforehand. As an illustration, we use both methods to characterize alternative response patterns of yeast subjected to heat stress, and compare them with observations from the literature. PMID:21377479
A practical guide for operational validation of discrete simulation models
Directory of Open Access Journals (Sweden)
Fabiano Leal
2011-04-01
Full Text Available As the number of simulation experiments increases, the necessity for validation and verification of these models demands special attention on the part of the simulation practitioners. By analyzing the current scientific literature, it is observed that the operational validation description presented in many papers does not agree on the importance designated to this process and about its applied techniques, subjective or objective. With the expectation of orienting professionals, researchers and students in simulation, this article aims to elaborate a practical guide through the compilation of statistical techniques in the operational validation of discrete simulation models. Finally, the guide's applicability was evaluated by using two study objects, which represent two manufacturing cells, one from the automobile industry and the other from a Brazilian tech company. For each application, the guide identified distinct steps, due to the different aspects that characterize the analyzed distributions
Fires involving radioactive materials : transference model; operative recommendations
International Nuclear Information System (INIS)
Rodriguez, C.E.; Puntarulo, L.J.; Canibano, J.A.
1988-01-01
In all aspects related to the nuclear activity, the occurrence of an explosion, fire or burst type accident, with or without victims, is directly related to the characteristics of the site. The present work analyses the different parameters involved, describing a transference model and recommendations for evaluation and control of the radiological risk for firemen. Special emphasis is placed on the measurement of the variables existing in this kind of operations
Modelling of innovative SANEX process mal-operations
Energy Technology Data Exchange (ETDEWEB)
McLachlan, F. [National Nuclear Laboratory, Building D5, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom); Taylor, R.; Whittaker, D.; Woodhead, D. [National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, Cumbria CA20 1PG (United Kingdom); Geist, A. [Karlsruhe Institute of Technology - KIT, 76021, Karlsruhe (Germany)
2016-07-01
The innovative (i-) SANEX process for the separation of minor actinides from PUREX highly active raffinate is expected to employ a solvent phase comprising 0.2 M TODGA with 5 v/v% 1-octanol in an inert diluent. An initial extract / scrub section would be used to extract trivalent actinides and lanthanides from the feed whilst leaving other fission products in the aqueous phase, before the loaded solvent is contacted with a low acidity aqueous phase containing a sulphonated bis-triazinyl pyridine ligand (BTP) to effect a selective strip of the actinides, so yielding separate actinide (An) and lanthanide (Ln) product streams. This process has been demonstrated in lab scale trials at Juelich (FZJ). The SACSESS (Safety of Actinide Separation processes) project is focused on the evaluation and improvement of the safety of such future systems. A key element of this is the development of an understanding of the response of a process to upsets (mal-operations). It is only practical to study a small subset of possible mal-operations experimentally and consideration of the majority of mal-operations entails the use of a validated dynamic model of the process. Distribution algorithms for HNO{sub 3}, Am, Cm and the lanthanides have been developed and incorporated into a dynamic flowsheet model that has, so far, been configured to correspond to the extract-scrub section of the i-SANEX flowsheet trial undertaken at FZJ in 2013. Comparison is made between the steady state model results and experimental results. Results from modelling of low acidity and high temperature mal-operations are presented. (authors)
Directory of Open Access Journals (Sweden)
Waleed M. Abd-Elhameed
2016-09-01
Full Text Available Herein, two numerical algorithms for solving some linear and nonlinear fractional-order differential equations are presented and analyzed. For this purpose, a novel operational matrix of fractional-order derivatives of Fibonacci polynomials was constructed and employed along with the application of the tau and collocation spectral methods. The convergence and error analysis of the suggested Fibonacci expansion were carefully investigated. Some numerical examples with comparisons are presented to ensure the efficiency, applicability and high accuracy of the proposed algorithms. Two accurate semi-analytic polynomial solutions for linear and nonlinear fractional differential equations are the result.
Data Envelopment Analysis (DEA) Model in Operation Management
Malik, Meilisa; Efendi, Syahril; Zarlis, Muhammad
2018-01-01
Quality management is an effective system in operation management to develops, maintains, and improves quality from groups of companies that allow marketing, production, and service at the most economycal level as well as ensuring customer satisfication. Many companies are practicing quality management to improve their bussiness performance. One of performance measurement is through measurement of efficiency. One of the tools can be used to assess efficiency of companies performance is Data Envelopment Analysis (DEA). The aim of this paper is using Data Envelopment Analysis (DEA) model to assess efficiency of quality management. In this paper will be explained CCR, BCC, and SBM models to assess efficiency of quality management.
International Nuclear Information System (INIS)
Niccoli, G.
2009-12-01
In an earlier paper (G. Niccoli and J. Teschner, 2009), the spectrum (eigenvalues and eigenstates) of a lattice regularizations of the Sine-Gordon model has been completely characterized in terms of polynomial solutions with certain properties of the Baxter equation. This characterization for cyclic representations has been derived by the use of the Separation of Variables (SOV) method of Sklyanin and by the direct construction of the Baxter Q-operator family. Here, we reconstruct the Baxter Q-operator and the same characterization of the spectrum by only using the SOV method. This analysis allows us to deduce the main features required for the extension to cyclic representations of other integrable quantum models of this kind of spectrum characterization. (orig.)
Antitumor Activity of Fascaplysin Derivatives on Glioblastoma Model In Vitro.
Lyakhova, I A; Bryukhovetsky, I S; Kudryavtsev, I V; Khotimchenko, Yu S; Zhidkov, M E; Kantemirov, A V
2018-03-01
Antitumor efficiency of fascaplysin synthetic derivatives (7-phenylfascaplysin, 3-chlorofascaplysin, 3-bromofascaplysin, and 10-bromofascaplysin) was compared out in vitro on C6 glioma cells. The cytotoxic efficiency of all tested compounds was higher than that of unsubstituted fascaplysin; 3-bromofascaplysin and 7-phenylfascaplysin exhibited the best capacity to kill glioma C6 cells. Apoptosis was the main mechanism of glioma cell death. The cytotoxic activity of these compounds increased with prolongation of exposure to the substance and increase of its concentration. Fascaplysin derivatives modified all phases of glioma cell vital cycle. The count of viable tumor cell in G0 phase remained minimum by the end of experiment under the effects of 3-bromofascaplysin and 7-phenylfascaplysin.
Communicating Sustainability: An Operational Model for Evaluating Corporate Websites
Directory of Open Access Journals (Sweden)
Alfonso Siano
2016-09-01
Full Text Available The interest in corporate sustainability has increased rapidly in recent years and has encouraged organizations to adopt appropriate digital communication strategies, in which the corporate website plays a key role. Despite this growing attention in both the academic and business communities, models for the analysis and evaluation of online sustainability communication have not been developed to date. This paper aims to develop an operational model to identify and assess the requirements of sustainability communication in corporate websites. It has been developed from a literature review on corporate sustainability and digital communication and the analysis of the websites of the organizations included in the “Global CSR RepTrak 2015” by the Reputation Institute. The model identifies the core dimensions of online sustainability communication (orientation, structure, ergonomics, content—OSEC, sub-dimensions, such as stakeholder engagement and governance tools, communication principles, and measurable items (e.g., presence of the materiality matrix, interactive graphs. A pilot study on the websites of the energy and utilities companies included in the Dow Jones Sustainability World Index 2015 confirms the applicability of the OSEC framework. Thus, the model can provide managers and digital communication consultants with an operational tool that is useful for developing an industry ranking and assessing the best practices. The model can also help practitioners to identify corrective actions in the critical areas of digital sustainability communication and avoid greenwashing.
Stability of the matrix model in operator interpretation
Directory of Open Access Journals (Sweden)
Katsuta Sakai
2017-12-01
Full Text Available The IIB matrix model is one of the candidates for nonperturbative formulation of string theory, and it is believed that the model contains gravitational degrees of freedom in some manner. In some preceding works, it was proposed that the matrix model describes the curved space where the matrices represent differential operators that are defined on a principal bundle. In this paper, we study the dynamics of the model in this interpretation, and point out the necessity of the principal bundle from the viewpoint of the stability and diffeomorphism invariance. We also compute the one-loop correction which yields a mass term for each field due to the principal bundle. We find that the stability is not violated.
International Nuclear Information System (INIS)
Dufresne, Alice
2014-01-01
The zirconium-hydrogen system is of nuclear safety interest, as the hydride precipitation leads to the cladding embrittlement, which is made of zirconium-based alloys. The cladding is the first safety barrier confining the radioactive products: its integrity shall be kept during the entire fuel-assemblies life, in reactor, including accidental situation, and post-operation (transport and storage). Many uncertainties remain regarding the hydrides precipitation kinetics and the local stress impact on their precipitation. The atomic scale modeling of this system would bring clarifications on the relevant mechanisms. The usual atomistic modeling methods are based on thermo-statistic approaches, whose precision and reliability depend on the interatomic potential used. However, there was no potential allowing a rigorous study of the Zr-H system. The present work has indeed addressed this issue: a new tight-binding potential for zirconium hydrides modeling is now available. Moreover, this thesis provides a detailed manual for deriving such potentials accounting for spd hybridization, and fitted here on DFT results. This guidebook has be written in light of modeling a pure transition metal followed by a metal-covalent coupling (metallic carbides, nitrides and silicides). (author)
Yanqing solar field: Dynamic optical model and operational safety analysis
International Nuclear Information System (INIS)
Zhao, Dongming; Wang, Zhifeng; Xu, Ershu; Zhu, Lingzhi; Lei, Dongqiang; Xu, Li; Yuan, Guofeng
2017-01-01
Highlights: • A dynamic optical model of the Yanqing solar field was built. • Tracking angle characteristics were studied with different SCA layouts and time. • The average energy flux was simulated across four clear days. • Influences of defocus angles for energy flux were analyzed. - Abstract: A dynamic optical model was established for the Yanqing solar field at the parabolic trough solar thermal power plant and a simulation was conducted on four separate days of clear weather (March 3rd, June 2nd, September 25th, December 17th). The solar collector assembly (SCA) was comprised of a North-South and East-West layout. The model consisted of the following modules: DNI, SCA operational, and SCA optical. The tracking angle characteristics were analyzed and the results showed that the East-West layout of the tracking system was the most viable. The average energy flux was simulated for a given time period and different SCA layouts, yielding an average flux of 6 kW/m 2 , which was then used as the design and operational standards of the Yanqing parabolic trough plant. The mass flow of North-South layout was relatively stable. The influences of the defocus angles on both the average energy flux and the circumferential flux distribution were also studied. The results provided a theoretical basis for the following components: solar field design, mass flow control of the heat transfer fluid, design and operation of the tracking system, operational safety of SCAs, and power production prediction in the Yanqing 1 MW parabolic trough plant.
Projected metastable Markov processes and their estimation with observable operator models
International Nuclear Information System (INIS)
Wu, Hao; Prinz, Jan-Hendrik; Noé, Frank
2015-01-01
The determination of kinetics of high-dimensional dynamical systems, such as macromolecules, polymers, or spin systems, is a difficult and generally unsolved problem — both in simulation, where the optimal reaction coordinate(s) are generally unknown and are difficult to compute, and in experimental measurements, where only specific coordinates are observable. Markov models, or Markov state models, are widely used but suffer from the fact that the dynamics on a coarsely discretized state spaced are no longer Markovian, even if the dynamics in the full phase space are. The recently proposed projected Markov models (PMMs) are a formulation that provides a description of the kinetics on a low-dimensional projection without making the Markovianity assumption. However, as yet no general way of estimating PMMs from data has been available. Here, we show that the observed dynamics of a PMM can be exactly described by an observable operator model (OOM) and derive a PMM estimator based on the OOM learning
Mixing height derived from the DMI-HIRLAM NWP model, and used for ETEX dispersion modelling
Energy Technology Data Exchange (ETDEWEB)
Soerensen, J.H.; Rasmussen, A. [Danish Meteorological Inst., Copenhagen (Denmark)
1997-10-01
For atmospheric dispersion modelling it is of great significance to estimate the mixing height well. Mesoscale and long-range diffusion models using output from numerical weather prediction (NWP) models may well use NWP model profiles of wind, temperature and humidity in computation of the mixing height. This is dynamically consistent, and enables calculation of the mixing height for predicted states of the atmosphere. In autumn 1994, the European Tracer Experiment (ETEX) was carried out with the objective to validate atmospheric dispersion models. The Danish Meteorological Institute (DMI) participates in the model evaluations with the Danish Emergency Response Model of the Atmosphere (DERMA) using NWP model data from the DMI version of the High Resolution Limited Area Model (HIRLAM) as well as from the global model of the European Centre for Medium-Range Weather Forecast (ECMWF). In DERMA, calculation of mixing heights are performed based on a bulk Richardson number approach. Comparing with tracer gas measurements for the first ETEX experiment, a sensitivity study is performed for DERMA. Using DMI-HIRLAM data, the study shows that optimum values of the critical bulk Richardson number in the range 0.15-0.35 are adequate. These results are in agreement with recent mixing height verification studies against radiosonde data. The fairly large range of adequate critical values is a signature of the robustness of the method. Direct verification results against observed missing heights from operational radio-sondes released under the ETEX plume are presented. (au) 10 refs.
Operational cooling tower model (CTTOOL V1.0)
Energy Technology Data Exchange (ETDEWEB)
Aleman, S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); LocalDomainServers, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Garrett, A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2015-01-01
Mechanical draft cooling towers (MDCT’s) are widely used to remove waste heat from industrial processes, including suspected proliferators of weapons of mass destruction (WMD). The temperature of the air being exhausted from the MDCT is proportional to the amount of thermal energy being removed from the process cooling water, although ambient weather conditions and cooling water flow rate must be known or estimated to calculate the rate of thermal energy dissipation (Q). It is theoretically possible to derive MDCT air exhaust temperatures from thermal images taken from a remote sensor. A numerical model of a MDCT is required to translate the air exhaust temperature to a Q. This report describes the MDCT model developed by the Problem Centered Integrated Analysis (PCIA) program that was designed to perform those computational tasks. The PCIA program is a collaborative effort between the Savannah River National Laboratory (SRNL), the Northrop-Grumman Corporation (NG) and the Aerospace Corporation (AERO).
Physically-Derived Dynamical Cores in Atmospheric General Circulation Models
Rood, Richard B.; Lin, Shian-Kiann
1999-01-01
The algorithm chosen to represent the advection in atmospheric models is often used as the primary attribute to classify the model. Meteorological models are generally classified as spectral or grid point, with the term grid point implying discretization using finite differences. These traditional approaches have a number of shortcomings that render them non-physical. That is, they provide approximate solutions to the conservation equations that do not obey the fundamental laws of physics. The most commonly discussed shortcomings are overshoots and undershoots which manifest themselves most overtly in the constituent continuity equation. For this reason many climate models have special algorithms to model water vapor advection. This talk focuses on the development of an atmospheric general circulation model which uses a consistent physically-based advection algorithm in all aspects of the model formulation. The shallow-water model of Lin and Rood (QJRMS, 1997) is generalized to three dimensions and combined with the physics parameterizations of NCAR's Community Climate Model. The scientific motivation for the development is to increase the integrity of the underlying fluid dynamics so that the physics terms can be more effectively isolated, examined, and improved. The expected benefits of the new model are discussed and results from the initial integrations will be presented.
Operator realization of the SU(2) WZNW model
International Nuclear Information System (INIS)
Furlan, P.; Todorov, I.T.
1995-12-01
Decoupling the chiral dynamics in the canonical approach to the WZNW model requires an extended phase space that includes left and right monodromy variables M and M-bar. Earlier work on the subject, which traced back the quantum group symmetry of the model to the Lie-Poisson symmetry of the chiral symplectic form, left some open questions: How to reconcile the necessity to set M M-bar -1 = 1 (in order to recover the monodromy invariance of the local 2D group valued field g = uu-bar) with the fact the M and M-bar obey different exchange relations? What is the status of the quantum symmetry in the 2D theory in which the chiral fields u(x-t) and u-bar(x+t) commute? Is there a consistent operator formalism in the chiral (and the extended 2D) theory in the continuum limit? We propose a constructive affirmative answer to these questions for G = SU(2) by presenting the quantum field u and u-bar as sums of products of chiral vertex operators and q Bose creation and annihilation operators. (author). 17 refs
Cost Model for Risk Assessment of Company Operation in Audit
Directory of Open Access Journals (Sweden)
S. V.
2017-12-01
Full Text Available This article explores the approach to assessing the risk of company activities termination by building a cost model. This model gives auditors information on managers’ understanding of factors influencing change in the value of assets and liabilities, and the methods to identify it in more effective and reliable ways. Based on this information, the auditor can assess the adequacy of use of the assumption on continuity of company operation by management personnel when preparing financial statements. Financial uncertainty entails real manifestations of factors creating risks of the occurrence of costs, revenue losses due their manifestations, which in the long run can be a reason for termination of company operation, and, therefore, need to be foreseen in the auditor’s assessment of the adequacy of use of the continuity assumption when preparing financial statements by company management. The purpose of the study is to explore and develop a methodology for use of cost models to assess the risk of termination of company operation in audit. The issue of methodology for assessing the audit risk through analyzing methods for company valuation has not been dealt with. The review of methodologies for assessing the risks of termination of company operation in course of audit gives grounds for the conclusion that use of cost models can be an effective methodology for identification and assessment of such risks. The analysis of the above methods gives understanding of the existing system for company valuation, integrated into the management system, and the consequences of its use, i. e. comparison of the asset price data with the accounting data and the market value of the asset data. Overvalued or undervalued company assets may be a sign of future sale or liquidation of a company, which may signal on high probability of termination of company operation. A wrong choice or application of valuation methods can be indicative of the risk of non
Best Approximation of the Fractional Semi-Derivative Operator by Exponential Series
Directory of Open Access Journals (Sweden)
Vladimir D. Zakharchenko
2018-01-01
Full Text Available A significant reduction in the time required to obtain an estimate of the mean frequency of the spectrum of Doppler signals when seeking to measure the instantaneous velocity of dangerous near-Earth cosmic objects (NEO is an important task being developed to counter the threat from asteroids. Spectral analysis methods have shown that the coordinate of the centroid of the Doppler signal spectrum can be found by using operations in the time domain without spectral processing. At the same time, an increase in the speed of resolving the algorithm for estimating the mean frequency of the spectrum is achieved by using fractional differentiation without spectral processing. Thus, an accurate estimate of location of the centroid for the spectrum of Doppler signals can be obtained in the time domain as the signal arrives. This paper considers the implementation of a fractional-differentiating filter of the order of ½ by a set of automation astatic transfer elements, which greatly simplifies practical implementation. Real technical devices have the ultimate time delay, albeit small in comparison with the duration of the signal. As a result, the real filter will process the signal with some error. In accordance with this, this paper introduces and uses the concept of a “pre-derivative” of ½ of magnitude. An optimal algorithm for realizing the structure of the filter is proposed based on the criterion of minimum mean square error. Relations are obtained for the quadrature coefficients that determine the structure of the filter.
Turner, Sean; Galelli, Stefano; Wilcox, Karen
2015-04-01
to both the El Niño Southern Oscillation and the Indian Ocean Dipole influence local hydro-meteorological processes; statistically significant lag correlations have already been established. Simulation of the derived operating policies, which are benchmarked against standard policies conditioned on the reservoir storage and the antecedent inflow, demonstrates the potential of the proposed approach. Future research will further develop the model for sensitivity analysis and regional studies examining the economic value of incorporating long range forecasts into reservoir operation.
Fuzzy expert systems models for operations research and management science
Turksen, I. B.
1993-12-01
Fuzzy expert systems can be developed for the effective use of management within the domains of concern associated with Operations Research and Management Science. These models are designed with: (1) expressive powers of representation embedded in linguistic variables and their linguistic values in natural language expressions, and (2) improved methods of interference based on fuzzy logic which is a generalization of multi-valued logic with fuzzy quantifiers. The results of these fuzzy expert system models are either (1) approximately good in comparison with their classical counterparts, or (2) much better than their counterparts. Moreover, for fuzzy expert systems models, it is only necessary to obtain ordinal scale data. Whereas for their classical counterparts, it is generally required that data be at least on ratio and absolute scale in order to guarantee the additivity and multiplicativity assumptions.
Groundwater flow modelling of the excavation and operational phases - Laxemar
Energy Technology Data Exchange (ETDEWEB)
Svensson, Urban (Computer-aided Fluid Engineering AB, Lyckeby (Sweden)); Rhen, Ingvar (SWECO Environment AB, Falun (Sweden))
2010-12-15
As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. The modelling study reported here presents calculated inflow rates, drawdown of the groundwater table and upconing of deep saline water for different levels of grouting efficiency during the excavation and operational phases of a final repository at Laxemar. The inflow calculations were accompanied by a sensitivity study, which among other matters handled the impact of different deposition hole rejection criteria. The report also presents tentative modelling results for the duration of the saturation phase, which starts once the used parts of the repository are being backfilled
Ergonomic evaluation model of operational room based on team performance
Directory of Open Access Journals (Sweden)
YANG Zhiyi
2017-05-01
Full Text Available A theoretical calculation model based on the ergonomic evaluation of team performance was proposed in order to carry out the ergonomic evaluation of the layout design schemes of the action station in a multitasking operational room. This model was constructed in order to calculate and compare the theoretical value of team performance in multiple layout schemes by considering such substantial influential factors as frequency of communication, distance, angle, importance, human cognitive characteristics and so on. An experiment was finally conducted to verify the proposed model under the criteria of completion time and accuracy rating. As illustrated by the experiment results,the proposed approach is conductive to the prediction and ergonomic evaluation of the layout design schemes of the action station during early design stages,and provides a new theoretical method for the ergonomic evaluation,selection and optimization design of layout design schemes.
Using Whole-House Field Tests to Empirically Derive Moisture Buffering Model Inputs
Energy Technology Data Exchange (ETDEWEB)
Woods, J.; Winkler, J.; Christensen, D.; Hancock, E.
2014-08-01
Building energy simulations can be used to predict a building's interior conditions, along with the energy use associated with keeping these conditions comfortable. These models simulate the loads on the building (e.g., internal gains, envelope heat transfer), determine the operation of the space conditioning equipment, and then calculate the building's temperature and humidity throughout the year. The indoor temperature and humidity are affected not only by the loads and the space conditioning equipment, but also by the capacitance of the building materials, which buffer changes in temperature and humidity. This research developed an empirical method to extract whole-house model inputs for use with a more accurate moisture capacitance model (the effective moisture penetration depth model). The experimental approach was to subject the materials in the house to a square-wave relative humidity profile, measure all of the moisture transfer terms (e.g., infiltration, air conditioner condensate) and calculate the only unmeasured term: the moisture absorption into the materials. After validating the method with laboratory measurements, we performed the tests in a field house. A least-squares fit of an analytical solution to the measured moisture absorption curves was used to determine the three independent model parameters representing the moisture buffering potential of this house and its furnishings. Follow on tests with realistic latent and sensible loads showed good agreement with the derived parameters, especially compared to the commonly-used effective capacitance approach. These results show that the EMPD model, once the inputs are known, is an accurate moisture buffering model.
An operational phenological model for numerical pollen prediction
Scheifinger, Helfried
2010-05-01
The general prevalence of seasonal allergic rhinitis is estimated to be about 15% in Europe, and still increasing. Pre-emptive measures require both the reliable assessment of production and release of various pollen species and the forecasting of their atmospheric dispersion. For this purpose numerical pollen prediction schemes are being developed by a number of European weather services in order to supplement and improve the qualitative pollen prediction systems by state of the art instruments. Pollen emission is spatially and temporally highly variable throughout the vegetation period and not directly observed, which precludes a straightforward application of dispersion models to simulate pollen transport. Even the beginning and end of flowering, which indicates the time period of potential pollen emission, is not (yet) available in real time. One way to create a proxy for the beginning, the course and the end of the pollen emission is its simulation as function of real time temperature observations. In this work the European phenological data set of the COST725 initiative forms the basis of modelling the beginning of flowering of 15 species, some of which emit allergic pollen. In order to keep the problem as simple as possible for the sake of spatial interpolation, a 3 parameter temperature sum model was implemented in a real time operational procedure, which calculates the spatial distribution of the entry dates for the current day and 24, 48 and 72 hours in advance. As stand alone phenological model and combined with back trajectories it is thought to support the qualitative pollen prediction scheme at the Austrian national weather service. Apart from that it is planned to incorporate it in a numerical pollen dispersion model. More details, open questions and first results of the operation phenological model will be discussed and presented.
International Nuclear Information System (INIS)
Zhao, Yibo; Jiang, Yi; Feng, Jiuchao; Wu, Lifu
2016-01-01
Highlights: • A novel nonlinear Wiener adaptive filters based on the backslash operator are proposed. • The identification approach to the memristor-based chaotic systems using the proposed adaptive filters. • The weight update algorithm and convergence characteristics for the proposed adaptive filters are derived. - Abstract: Memristor-based chaotic systems have complex dynamical behaviors, which are characterized as nonlinear and hysteresis characteristics. Modeling and identification of their nonlinear model is an important premise for analyzing the dynamical behavior of the memristor-based chaotic systems. This paper presents a novel nonlinear Wiener adaptive filtering identification approach to the memristor-based chaotic systems. The linear part of Wiener model consists of the linear transversal adaptive filters, the nonlinear part consists of nonlinear adaptive filters based on the backslash operator for the hysteresis characteristics of the memristor. The weight update algorithms for the linear and nonlinear adaptive filters are derived. Final computer simulation results show the effectiveness as well as fast convergence characteristics. Comparing with the adaptive nonlinear polynomial filters, the proposed nonlinear adaptive filters have less identification error.
UV Stellar Distribution Model for the Derivation of Payload
Directory of Open Access Journals (Sweden)
Young-Jun Choi
1999-12-01
Full Text Available We present the results of a model calculation of the stellar distribution in a UV and centered at 2175Å corresponding to the well-known bump in the interstellar extinction curve. The stellar distribution model used here is based on the Bahcall-Soneira galaxy model (1980. The source code for model calculation was designed by Brosch (1991 and modified to investigate various designing factors for UV satellite payload. The model predicts UV stellar densities in different sky directions, and its results are compared with the TD-1 star counts for a number of sky regions. From this study, we can determine the field of view, size of optics, angular resolution, and number of stars in one orbit. There will provide the basic constrains in designing a satellite payload for UV observations.
Lagerloef, G.
1 and diagnose model errors. Another immediate application of these data relates to fisheries management and ma- rine wildlife research in the region. Movements of several species of sea turtle in the tropical region are being tracked by satellite with System Argos. Results show that some turtle tracks follow meandering portions of the North Equatorial Current and North Equatorial Counter Current. The surface current data allow researchers to exam- ine the oceanography of the habitat these turtles are using, for example, and evaluate to what extent they are using the equatorial currents and regions of surface convergence. Findings indicate that different species/stocks use different habitats. Some forage at or near the surface at convergences and others forage sub-surface away from currents (Polovina et al., 2002). References: Bonjean, F. and G.S.E. Lagerloef, 2002: Diagnostic model and analysis of the surface currents in the Tropical Pacific Ocean, J. Phys. Oceanogr., In press. Lagerloef,G.S.E., G.Mitchum, R.Lukas and P.Niiler, 1999: Tropical Pacific near sur- face currents estimated from altimeter, wind and drifter data, J. Geophys. Res., 104, 23,313-23,326. Polovina, J. J., G. H. Balazs, E. A Howell, D. M. Parker, M. P. Seki, and P. H. Dutton, 2002. Forage and migration habitat of loggerhead (Caretta caretta) and olive ridley (Lepidochelys olivacea) sea turtles in the central North Pacific Ocean. Fish. Oceanogr., In Review.
A Final Approach Trajectory Model for Current Operations
Gong, Chester; Sadovsky, Alexander
2010-01-01
Predicting accurate trajectories with limited intent information is a challenge faced by air traffic management decision support tools in operation today. One such tool is the FAA's Terminal Proximity Alert system which is intended to assist controllers in maintaining safe separation of arrival aircraft during final approach. In an effort to improve the performance of such tools, two final approach trajectory models are proposed; one based on polynomial interpolation, the other on the Fourier transform. These models were tested against actual traffic data and used to study effects of the key final approach trajectory modeling parameters of wind, aircraft type, and weight class, on trajectory prediction accuracy. Using only the limited intent data available to today's ATM system, both the polynomial interpolation and Fourier transform models showed improved trajectory prediction accuracy over a baseline dead reckoning model. Analysis of actual arrival traffic showed that this improved trajectory prediction accuracy leads to improved inter-arrival separation prediction accuracy for longer look ahead times. The difference in mean inter-arrival separation prediction error between the Fourier transform and dead reckoning models was 0.2 nmi for a look ahead time of 120 sec, a 33 percent improvement, with a corresponding 32 percent improvement in standard deviation.
Modeling Characteristics of an Operational Probabilistic Safety Assessment (PSA)
International Nuclear Information System (INIS)
Anoba, Richard C.; Khalil, Yehia; Fluehr, J.J. III; Kellogg, Richard; Hackerott, Alan
2002-01-01
Probabilistic Safety Assessments (PSAs) are increasingly being used as a tool for supporting the acceptability of design, procurement, construction, operation, and maintenance activities at nuclear power plants. Since the issuance of Generic Letter 88-20 and subsequent Individual Plant Examinations (IPEs)/Individual Plant Examinations for External Events (IPEEEs), the NRC has issued several Regulatory Guides such as RG 1.182 to describe the use of PSA in risk informed regulation activities. The PSA models developed for the IPEs were typically based on a 'snapshot' of the the risk profile at the nuclear power plant. The IPE models contain implicit assumptions and simplifications that limit the ability to realistically assess current issues. For example, IPE modeling assumptions related to plant configuration limit the ability to perform online equipment out-of-service assessments. The lack of model symmetry results in skewed risk results. IPE model simplifications related to initiating events have resulted in non-conservative estimates of risk impacts when equipment is removed from service. The IPE models also do not explicitly address all external events that are potentially risk significant as equipment is removed from service. (authors)
Derivation of Distributed Models of Atomic Polarizability for Molecular Simulations.
Soteras, Ignacio; Curutchet, Carles; Bidon-Chanal, Axel; Dehez, François; Ángyán, János G; Orozco, Modesto; Chipot, Christophe; Luque, F Javier
2007-11-01
The main thrust of this investigation is the development of models of distributed atomic polarizabilities for the treatment of induction effects in molecular mechanics simulations. The models are obtained within the framework of the induced dipole theory by fitting the induction energies computed via a fast but accurate MP2/Sadlej-adjusted perturbational approach in a grid of points surrounding the molecule. Particular care is paid in the examination of the atomic quantities obtained from models of implicitly and explicitly interacting polarizabilities. Appropriateness and accuracy of the distributed models are assessed by comparing the molecular polarizabilities recovered from the models and those obtained experimentally and from MP2/Sadlej calculations. The behavior of the models is further explored by computing the polarization energy for aromatic compounds in the context of cation-π interactions and for selected neutral compounds in a TIP3P aqueous environment. The present results suggest that the computational strategy described here constitutes a very effective tool for the development of distributed models of atomic polarizabilities and can be used in the generation of new polarizable force fields.
Rigorous theoretical derivation of lumped models to transmission line systems
International Nuclear Information System (INIS)
Zhao Jixiang
2012-01-01
By virtue of the negative electric parameter concept, i.e. negative lumped resistance, inductance, conductance and capacitance (N-RLGC), the lumped equivalent models of transmission line systems, including the circuit model, two-port π-network and T-network, are given. We start from the N-segment-ladder-like equivalent networks composed distributed parameters, and achieve the input impedance in the form of a continued fraction. Utilizing the continued fraction theory, the expressions of input impedance are obtained under three kinds of extreme cases, i.e. the load impedances are equal to zero, infinity and characteristic impedance, respectively. When the number of segment N is limited to infinity, they are transformed to lumped elements. Comparison between the distributed model and lumped model of transmission lines, the expression of tanh γd, which is the key term in the transmission line equations, are obtained by RLGC, furthermore, according to input admittance, admittance matrix and ABCD matrix of transmission lines, the lumped equivalent circuit models, π-networks and T-networks have been given. The models are verified in the frequency and time domain, respectively, showing that the models are accurate and efficient. (semiconductor integrated circuits)
Object-oriented process dose modeling for glovebox operations
International Nuclear Information System (INIS)
Boerigter, S.T.; Fasel, J.H.; Kornreich, D.E.
1999-01-01
The Plutonium Facility at Los Alamos National Laboratory supports several defense and nondefense-related missions for the country by performing fabrication, surveillance, and research and development for materials and components that contain plutonium. Most operations occur in rooms with one or more arrays of gloveboxes connected to each other via trolley gloveboxes. Minimizing the effective dose equivalent (EDE) is a growing concern as a result of steadily declining allowable dose limits being imposed and a growing general awareness of safety in the workplace. In general, the authors discriminate three components of a worker's total EDE: the primary EDE, the secondary EDE, and background EDE. A particular background source of interest is the nuclear materials vault. The distinction between sources inside and outside of a particular room is arbitrary with the underlying assumption that building walls and floors provide significant shielding to justify including sources in other rooms in the background category. Los Alamos has developed the Process Modeling System (ProMoS) primarily for performing process analyses of nuclear operations. ProMoS is an object-oriented, discrete-event simulation package that has been used to analyze operations at Los Alamos and proposed facilities such as the new fabrication facilities for the Complex-21 effort. In the past, crude estimates of the process dose (the EDE received when a particular process occurred), room dose (the EDE received when a particular process occurred in a given room), and facility dose (the EDE received when a particular process occurred in the facility) were used to obtain an integrated EDE for a given process. Modifications to the ProMoS package were made to utilize secondary dose information to use dose modeling to enhance the process modeling efforts
Towards assimilation of InSAR data in operational weather models
Mulder, Gert; van Leijen, Freek; Barkmeijer, Jan; de Haan, Siebren; Hanssen, Ramon
2017-04-01
InSAR signal delays due to the varying atmospheric refractivity are a potential data source to improve weather models [1]. Especially with the launch of the new Sentinel-1 satellites, which increases data coverage, latency and accessibility, it may become possible to operationalize the assimilation of differential integrated refractivity (DIR) values in numerical weather models. Although studies exist on comparison between InSAR data and weather models [2], the impact of assimilation of DIR values in an operational weather model has never been assessed. In this study we present different ways to assimilate DIR values in an operational weather model and show the first forecast results. There are different possibilities to assimilate InSAR-data in a weather model. For example, (i) absolute DIR values can be derived using additional GNSS zenith or slant delay values, (ii) DIR values can be converted to water vapor pressures, or (iii) water vapor pressures can be derived for different heights by combining GNSS and InSAR data. However, an increasing number of assumptions in these processing steps will increase the uncertainty in the final results. Therefore, we chose to insert the InSAR derived DIR values after minimal additional processing. In this study we use the HARMONIE model [3], which is a spectral, non-hydrostatic model with a resolution of about 2.5 km. Currently, this is the operational model in 11 European countries and based on the AROME model [4]. To assimilate the DIR values in the weather model we use a simple adjustment of the weather parameters over the full slant column to match the DIR values. This is a first step towards a more sophisticated approach based on the 3D-VAR or 4D-VAR schemes [5]. Where both assimilation schemes can correct for different weather parameters simultaneously, and 4D-VAR allow us to assimilate DIR values at the exact moment of satellite overpass instead of the start of the forecast window. The approach will be demonstrated
DEFF Research Database (Denmark)
King, Alexander Weider; Agerkvist, Finn T.
2017-01-01
Commonly used models of moving-coil loudspeaker voice coils, which include effects from eddy current losses, are either inaccurate or contain an abundance of parameters, and are difficult to extend to the nonlinear domain. On the contrary, fractional derivative models accurately describe...... order derivative approaches a value of 1, corresponding to an ideal inductance, when the voice coil is completely outside the magnetic system. Finally, the developed model reveals details about the effect of conductive voice coil formers...
Generic UAV Modeling to Obtain Its Aerodynamic and Control Derivatives
National Research Council Canada - National Science Library
Chua, Choon S
2008-01-01
...). These data has a dual application. Firstly, it is required in the Mathworks Simulink 6-degree-of-freedom model of a generic unmanned air vehicle to develop a robust controller and do a variety of trade-offs...
A Consistent Pricing Model for Index Options and Volatility Derivatives
DEFF Research Database (Denmark)
Cont, Rama; Kokholm, Thomas
We propose and study a flexible modeling framework for the joint dynamics of an index and a set of forward variance swap rates written on this index, allowing options on forward variance swaps and options on the underlying index to be priced consistently. Our model reproduces various empirically...... observed properties of variance swap dynamics and allows for jumps in volatility and returns. An affine specification using L´evy processes as building blocks leads to analytically tractable pricing formulas for options on variance swaps as well as efficient numerical methods for pricing of European...... options on the underlying asset. The model has the convenient feature of decoupling the vanilla skews from spot/volatility correlations and allowing for different conditional correlations in large and small spot/volatility moves. We show that our model can simultaneously fit prices of European options...
Modeling neurodegenerative diseases with patient-derived induced pluripotent cells
DEFF Research Database (Denmark)
Poon, Anna; Zhang, Yu; Chandrasekaran, Abinaya
2017-01-01
The rising prevalence of progressive neurodegenerative diseases coupled with increasing longevity poses an economic burden at individual and societal levels. There is currently no effective cure for the majority of neurodegenerative diseases and disease-affected tissues from patients have been...... the opportunity to model disease development, uncover novel mechanisms and test potential therapeutics. Here we review findings from iPSC-based modeling of selected neurodegenerative diseases, including Alzheimer's disease, frontotemporal dementia and spinocerebellar ataxia. Furthermore, we discuss...
Modeling ramp-hold indentation measurements based on Kelvin-Voigt fractional derivative model
Zhang, Hongmei; zhe Zhang, Qing; Ruan, Litao; Duan, Junbo; Wan, Mingxi; Insana, Michael F.
2018-03-01
Interpretation of experimental data from micro- and nano-scale indentation testing is highly dependent on the constitutive model selected to relate measurements to mechanical properties. The Kelvin-Voigt fractional derivative model (KVFD) offers a compact set of viscoelastic features appropriate for characterizing soft biological materials. This paper provides a set of KVFD solutions for converting indentation testing data acquired for different geometries and scales into viscoelastic properties of soft materials. These solutions, which are mostly in closed-form, apply to ramp-hold relaxation, load-unload and ramp-load creep-testing protocols. We report on applications of these model solutions to macro- and nano-indentation testing of hydrogels, gastric cancer cells and ex vivo breast tissue samples using an atomic force microscope (AFM). We also applied KVFD models to clinical ultrasonic breast data using a compression plate as required for elasticity imaging. Together the results show that KVFD models fit a broad range of experimental data with a correlation coefficient typically R 2 > 0.99. For hydrogel samples, estimation of KVFD model parameters from test data using spherical indentation versus plate compression as well as ramp relaxation versus load-unload compression all agree within one standard deviation. Results from measurements made using macro- and nano-scale indentation agree in trend. For gastric cell and ex vivo breast tissue measurements, KVFD moduli are, respectively, 1/3-1/2 and 1/6 of the elasticity modulus found from the Sneddon model. In vivo breast tissue measurements yield model parameters consistent with literature results. The consistency of results found for a broad range of experimental parameters suggest the KVFD model is a reliable tool for exploring intrinsic features of the cell/tissue microenvironments.
The phantom derivative method when a structure model is available: about its theoretical basis.
Burla, Maria Cristina; Cascarano, Giovanni Luca; Giacovazzo, Carmelo; Polidori, Giampiero
2017-05-01
This study clarifies why, in the phantom derivative (PhD) approach, randomly created structures can help in refining phases obtained by other methods. For this purpose the joint probability distribution of target, model, ancil and phantom derivative structure factors and its conditional distributions have been studied. Since PhD may use n phantom derivatives, with n ≥ 1, a more general distribution taking into account all the ancil and derivative structure factors has been considered, from which the conditional distribution of the target phase has been derived. The corresponding conclusive formula contains two components. The first is the classical Srinivasan & Ramachandran term, relating the phases of the target structure with the model phases. The second arises from the combination of two correlations: that between model and derivative (the first is a component of the second) and that between derivative and target. The second component mathematically codifies the information on the target phase arising from model and derivative electron-density maps. The result is new, and explains why a random structure, uncorrelated with the target structure, adds useful information on the target phases, provided a model structure is known. Some experimental tests aimed at checking if the second component really provides information on ϕ (the target phase) were performed; the favourable results confirm the correctness of the theoretical calculations and of the corresponding analysis.
Modeling spot markets for electricity and pricing electricity derivatives
Ning, Yumei
Spot prices for electricity have been very volatile with dramatic price spikes occurring in restructured market. The task of forecasting electricity prices and managing price risk presents a new challenge for market players. The objectives of this dissertation are: (1) to develop a stochastic model of price behavior and predict price spikes; (2) to examine the effect of weather forecasts on forecasted prices; (3) to price electricity options and value generation capacity. The volatile behavior of prices can be represented by a stochastic regime-switching model. In the model, the means of the high-price and low-price regimes and the probabilities of switching from one regime to the other are specified as functions of daily peak load. The probability of switching to the high-price regime is positively related to load, but is still not high enough at the highest loads to predict price spikes accurately. An application of this model shows how the structure of the Pennsylvania-New Jersey-Maryland market changed when market-based offers were allowed, resulting in higher price spikes. An ARIMA model including temperature, seasonal, and weekly effects is estimated to forecast daily peak load. Forecasts of load under different assumptions about weather patterns are used to predict changes of price behavior given the regime-switching model of prices. Results show that the range of temperature forecasts from a normal summer to an extremely warm summer cause relatively small increases in temperature (+1.5%) and load (+3.0%). In contrast, the increases in prices are large (+20%). The conclusion is that the seasonal outlook forecasts provided by NOAA are potentially valuable for predicting prices in electricity markets. The traditional option models, based on Geometric Brownian Motion are not appropriate for electricity prices. An option model using the regime-switching framework is developed to value a European call option. The model includes volatility risk and allows changes
Comparing pharmacophore models derived from crystallography and NMR ensembles
Ghanakota, Phani; Carlson, Heather A.
2017-11-01
NMR and X-ray crystallography are the two most widely used methods for determining protein structures. Our previous study examining NMR versus X-Ray sources of protein conformations showed improved performance with NMR structures when used in our Multiple Protein Structures (MPS) method for receptor-based pharmacophores (Damm, Carlson, J Am Chem Soc 129:8225-8235, 2007). However, that work was based on a single test case, HIV-1 protease, because of the rich data available for that system. New data for more systems are available now, which calls for further examination of the effect of different sources of protein conformations. The MPS technique was applied to Growth factor receptor bound protein 2 (Grb2), Src SH2 homology domain (Src-SH2), FK506-binding protein 1A (FKBP12), and Peroxisome proliferator-activated receptor-γ (PPAR-γ). Pharmacophore models from both crystal and NMR ensembles were able to discriminate between high-affinity, low-affinity, and decoy molecules. As we found in our original study, NMR models showed optimal performance when all elements were used. The crystal models had more pharmacophore elements compared to their NMR counterparts. The crystal-based models exhibited optimum performance only when pharmacophore elements were dropped. This supports our assertion that the higher flexibility in NMR ensembles helps focus the models on the most essential interactions with the protein. Our studies suggest that the "extra" pharmacophore elements seen at the periphery in X-ray models arise as a result of decreased protein flexibility and make very little contribution to model performance.
Integration of field data into operational snowmelt-runoff models
International Nuclear Information System (INIS)
Brandt, M.; Bergström, S.
1994-01-01
Conceptual runoff models have become standard tools for operational hydrological forecasting in Scandinavia. These models are normally based on observations from the national climatological networks, but in mountainous areas the stations are few and sometimes not representative. Due to the great economic importance of good hydrological forecasts for the hydro-power industry attempts have been made to improve the model simulations by support from field observations of the snowpack. The snowpack has been mapped by several methods; airborne gamma-spectrometry, airborne georadars, satellites and by conventional snow courses. The studies cover more than ten years of work in Sweden. The conclusion is that field observations of the snow cover have a potential for improvement of the forecasts of inflow to the reservoirs in the mountainous part of the country, where the climatological data coverages is poor. This is pronounced during years with unusual snow distribution. The potential for model improvement is smaller in the climatologically more homogeneous forested lowlands, where the climatological network is denser. The costs of introduction of airborne observations into the modelling procedure are high and can only be justified in areas of great hydropower potential. (author)
Deduction of reservoir operating rules for application in global hydrological models
Directory of Open Access Journals (Sweden)
H. M. Coerver
2018-01-01
Full Text Available A big challenge in constructing global hydrological models is the inclusion of anthropogenic impacts on the water cycle, such as caused by dams. Dam operators make decisions based on experience and often uncertain information. In this study information generally available to dam operators, like inflow into the reservoir and storage levels, was used to derive fuzzy rules describing the way a reservoir is operated. Using an artificial neural network capable of mimicking fuzzy logic, called the ANFIS adaptive-network-based fuzzy inference system, fuzzy rules linking inflow and storage with reservoir release were determined for 11 reservoirs in central Asia, the US and Vietnam. By varying the input variables of the neural network, different configurations of fuzzy rules were created and tested. It was found that the release from relatively large reservoirs was significantly dependent on information concerning recent storage levels, while release from smaller reservoirs was more dependent on reservoir inflows. Subsequently, the derived rules were used to simulate reservoir release with an average Nash–Sutcliffe coefficient of 0.81.
Deduction of reservoir operating rules for application in global hydrological models
Coerver, Hubertus M.; Rutten, Martine M.; van de Giesen, Nick C.
2018-01-01
A big challenge in constructing global hydrological models is the inclusion of anthropogenic impacts on the water cycle, such as caused by dams. Dam operators make decisions based on experience and often uncertain information. In this study information generally available to dam operators, like inflow into the reservoir and storage levels, was used to derive fuzzy rules describing the way a reservoir is operated. Using an artificial neural network capable of mimicking fuzzy logic, called the ANFIS adaptive-network-based fuzzy inference system, fuzzy rules linking inflow and storage with reservoir release were determined for 11 reservoirs in central Asia, the US and Vietnam. By varying the input variables of the neural network, different configurations of fuzzy rules were created and tested. It was found that the release from relatively large reservoirs was significantly dependent on information concerning recent storage levels, while release from smaller reservoirs was more dependent on reservoir inflows. Subsequently, the derived rules were used to simulate reservoir release with an average Nash-Sutcliffe coefficient of 0.81.
Operational modal analysis modeling, Bayesian inference, uncertainty laws
Au, Siu-Kui
2017-01-01
This book presents operational modal analysis (OMA), employing a coherent and comprehensive Bayesian framework for modal identification and covering stochastic modeling, theoretical formulations, computational algorithms, and practical applications. Mathematical similarities and philosophical differences between Bayesian and classical statistical approaches to system identification are discussed, allowing their mathematical tools to be shared and their results correctly interpreted. Many chapters can be used as lecture notes for the general topic they cover beyond the OMA context. After an introductory chapter (1), Chapters 2–7 present the general theory of stochastic modeling and analysis of ambient vibrations. Readers are first introduced to the spectral analysis of deterministic time series (2) and structural dynamics (3), which do not require the use of probability concepts. The concepts and techniques in these chapters are subsequently extended to a probabilistic context in Chapter 4 (on stochastic pro...
Operational Testing of Satellite based Hydrological Model (SHM)
Gaur, Srishti; Paul, Pranesh Kumar; Singh, Rajendra; Mishra, Ashok; Gupta, Praveen Kumar; Singh, Raghavendra P.
2017-04-01
Incorporation of the concept of transposability in model testing is one of the prominent ways to check the credibility of a hydrological model. Successful testing ensures ability of hydrological models to deal with changing conditions, along with its extrapolation capacity. For a newly developed model, a number of contradictions arises regarding its applicability, therefore testing of credibility of model is essential to proficiently assess its strength and limitations. This concept emphasizes to perform 'Hierarchical Operational Testing' of Satellite based Hydrological Model (SHM), a newly developed surface water-groundwater coupled model, under PRACRITI-2 program initiated by Space Application Centre (SAC), Ahmedabad. SHM aims at sustainable water resources management using remote sensing data from Indian satellites. It consists of grid cells of 5km x 5km resolution and comprises of five modules namely: Surface Water (SW), Forest (F), Snow (S), Groundwater (GW) and Routing (ROU). SW module (functions in the grid cells with land cover other than forest and snow) deals with estimation of surface runoff, soil moisture and evapotranspiration by using NRCS-CN method, water balance and Hragreaves method, respectively. The hydrology of F module is dependent entirely on sub-surface processes and water balance is calculated based on it. GW module generates baseflow (depending on water table variation with the level of water in streams) using Boussinesq equation. ROU module is grounded on a cell-to-cell routing technique based on the principle of Time Variant Spatially Distributed Direct Runoff Hydrograph (SDDH) to route the generated runoff and baseflow by different modules up to the outlet. For this study Subarnarekha river basin, flood prone zone of eastern India, has been chosen for hierarchical operational testing scheme which includes tests under stationary as well as transitory conditions. For this the basin has been divided into three sub-basins using three flow
Metric versus observable operator representation, higher spin models
Fring, Andreas; Frith, Thomas
2018-02-01
We elaborate further on the metric representation that is obtained by transferring the time-dependence from a Hermitian Hamiltonian to the metric operator in a related non-Hermitian system. We provide further insight into the procedure on how to employ the time-dependent Dyson relation and the quasi-Hermiticity relation to solve time-dependent Hermitian Hamiltonian systems. By solving both equations separately we argue here that it is in general easier to solve the former. We solve the mutually related time-dependent Schrödinger equation for a Hermitian and non-Hermitian spin 1/2, 1 and 3/2 model with time-independent and time-dependent metric, respectively. In all models the overdetermined coupled system of equations for the Dyson map can be decoupled algebraic manipulations and reduces to simple linear differential equations and an equation that can be converted into the non-linear Ermakov-Pinney equation.
Directory of Open Access Journals (Sweden)
Mauricio Arriagada-Benítez
2017-10-01
Full Text Available Configurable process models are frequently used to represent business workflows and other discrete event systems among different branches of large organizations: they unify commonalities shared by all branches and describe their differences, at the same time. The configuration of such models is usually done manually, which is challenging. On the one hand, when the number of configurable nodes in the configurable process model grows, the size of the search space increases exponentially. On the other hand, the person performing the configuration may lack the holistic perspective to make the right choice for all configurable nodes at the same time, since choices influence each other. Nowadays, information systems that support the execution of business processes create event data reflecting how processes are performed. In this article, we propose three strategies (based on exhaustive search, genetic algorithms and a greedy heuristic that use event data to automatically derive a process model from a configurable process model that better represents the characteristics of the process in a specific branch. These strategies have been implemented in our proposed framework and tested in both business-like event logs as recorded in a higher educational enterprise resource planning system and a real case scenario involving a set of Dutch municipalities.
Modeling of crushed ore agglomeration for heap leach operations
Dhawan, Nikhil
agglomeration, specifically crushed ore agglomeration. The experimental difficulties and how to overcome them are described. An empirical model that is readily useful for plant heap leach operations is shown in detail. The analysis of constituent particles within agglomerate size class is done with a partition model. The guest and host nature of particles, thus delineated, helps one to anticipate the nature of agglomerates that would be formed with a given ore size distribution. Thus, all aspects of batch agglomeration are addressed in this work.
A fractal derivative constitutive model for three stages in granite creep
Directory of Open Access Journals (Sweden)
R. Wang
Full Text Available In this paper, by replacing the Newtonian dashpot with the fractal dashpot and considering damage effect, a new constitutive model is proposed in terms of time fractal derivative to describe the full creep regions of granite. The analytic solutions of the fractal derivative creep constitutive equation are derived via scaling transform. The conventional triaxial compression creep tests are performed on MTS 815 rock mechanics test system to verify the efficiency of the new model. The granite specimen is taken from Beishan site, the most potential area for the China’s high-level radioactive waste repository. It is shown that the proposed fractal model can characterize the creep behavior of granite especially in accelerating stage which the classical models cannot predict. The parametric sensitivity analysis is also conducted to investigate the effects of model parameters on the creep strain of granite. Keywords: Beishan granite, Fractal derivative, Damage evolution, Scaling transformation
Calculus for cognitive scientists derivatives, integrals and models
Peterson, James K
2016-01-01
This book provides a self-study program on how mathematics, computer science and science can be usefully and seamlessly intertwined. Learning to use ideas from mathematics and computation is essential for understanding approaches to cognitive and biological science. As such the book covers calculus on one variable and two variables and works through a number of interesting first-order ODE models. It clearly uses MatLab in computational exercises where the models cannot be solved by hand, and also helps readers to understand that approximations cause errors – a fact that must always be kept in mind.
Understanding forest-derived biomass supply with GIS modelling
DEFF Research Database (Denmark)
Hock, B. K.; Blomqvist, L.; Hall, P.
2012-01-01
distribution, and the cost of delivery as forests are frequently remote from energy users. A GIS-based model was developed to predict supply curves of forest biomass material for a site or group of sites, both now and in the future. The GIS biomass supply model was used to assist the New Zealand Energy...... Efficiency and Conservation Authority's development of a national target for biomass use for industrial heat production, to determine potential forest residue volumes for industrial heat and their delivery costs for 19 processing plants of the dairy company Fonterra, and towards investigating options...
Modelling operator cognitive interactions in nuclear power plant safety evaluation
International Nuclear Information System (INIS)
Senders, J.W.; Moray, N.; Smiley, A.; Sellen, A.
1985-08-01
The overall objectives of the study were to review methods which are applicable to the analysis of control room operator cognitive interactions in nuclear plant safety evaluations and to indicate where future research effort in this area should be directed. This report is based on an exhaustive search and review of the literature on NPP (Nuclear Power Plant) operator error, human error, human cognitive function, and on human performance. A number of methods which have been proposed for the estimation of data for probabilistic risk analysis have been examined and have been found wanting. None addresses the problem of diagnosis error per se. Virtually all are concerned with the more easily detected and identified errors of action. None addresses underlying cause and mechanism. It is these mechanisms which must be understood if diagnosis errors and other cognitive errors are to be controlled and predicted. We have attempted to overcome the deficiencies of earlier work and have constructed a model/taxonomy, EXHUME, which we consider to be exhaustive. This construct has proved to be fruitful in organizing our thinking about the kinds of error that can occur and the nature of self-correcting mechanisms, and has guided our thinking in suggesting a research program which can provide the data needed for quantification of cognitive error rates and of the effects of mitigating efforts. In addition a preliminary outline of EMBED, a causal model of error, is given based on general behavioural research into perception, attention, memory, and decision making. 184 refs
Verification of the NWP models operated at ICM, Poland
Melonek, Malgorzata
2010-05-01
Interdisciplinary Centre for Mathematical and Computational Modelling, University of Warsaw (ICM) started its activity in the field of NWP in May 1997. Since this time the numerical weather forecasts covering Central Europe have been routinely published on our publicly available website. First NWP model used in ICM was hydrostatic Unified Model developed by the UK Meteorological Office. It was a mesoscale version with horizontal resolution of 17 km and 31 levels in vertical. At present two NWP non-hydrostatic models are running in quasi-operational regime. The main new UM model with 4 km horizontal resolution, 38 levels in vertical and forecats range of 48 hours is running four times a day. Second, the COAMPS model (Coupled Ocean/Atmosphere Mesoscale Prediction System) developed by the US Naval Research Laboratory, configured with the three nested grids (with coresponding resolutions of 39km, 13km and 4.3km, 30 vertical levels) are running twice a day (for 00 and 12 UTC). The second grid covers Central Europe and has forecast range of 84 hours. Results of the both NWP models, ie. COAMPS computed on 13km mesh resolution and UM, are verified against observations from the Polish synoptic stations. Verification uses surface observations and nearest grid point forcasts. Following meteorological elements are verified: air temperature at 2m, mean sea level pressure, wind speed and wind direction at 10 m and 12 hours accumulated precipitation. There are presented different statistical indices. For continous variables Mean Error(ME), Mean Absolute Error (MAE) and Root Mean Squared Error (RMSE) in 6 hours intervals are computed. In case of precipitation the contingency tables for different thresholds are computed and some of the verification scores such as FBI, ETS, POD, FAR are graphically presented. The verification sample covers nearly one year.
Using statistical compatibility to derive advanced probabilistic fatigue models
Czech Academy of Sciences Publication Activity Database
Fernández-Canteli, A.; Castillo, E.; López-Aenlle, M.; Seitl, Stanislav
2010-01-01
Roč. 2, č. 1 (2010), s. 1131-1140 E-ISSN 1877-7058. [Fatigue 2010. Praha, 06.06.2010-11.06.2010] Institutional research plan: CEZ:AV0Z20410507 Keywords : Fatigue models * Statistical compatibility * Functional equations Subject RIV: JL - Materials Fatigue, Friction Mechanics
Derivation of Monotone Decision Models from Non-Monotone Data
Daniëls, H.A.M.; Velikova, M.V.
2003-01-01
The objective of data mining is the extraction of knowledge from databases. In practice, one often encounters difficulties with models that are constructed purely by search, without incorporation of knowledge about the domain of application.In economic decision making such as credit loan approval or
Barnes-Holmes, Dermot; Regan, Donal; Barnes-Holmes, Yvonne; Commins, Sean; Walsh, Derek; Stewart, Ian; Smeets, Paul M.; Whelan, Robert; Dymond, Simon
2005-01-01
The current study aimed to test a Relational Frame Theory (RFT) model of analogical reasoning based on the relating of derived same and derived difference relations. Experiment 1 recorded reaction time measures of similar-similar (e.g., "apple is to orange as dog is to cat") versus different-different (e.g., "he is to his brother as…
Simple Entropic Derivation of a Generalized Black-Scholes Option Pricing Model
Directory of Open Access Journals (Sweden)
Michael J. Stutzer
2000-04-01
Full Text Available Abstract: A straightforward derivation of the celebrated Black-Scholes Option Pricing model is obtained by solution of a simple constrained minimization of relative entropy. The derivation leads to a natural generalization of it, which is consistent with some evidence from stock index option markets.
Nisbet, R.M.; Martin, B.T.; de Roos, A.M.
2016-01-01
Two contrasting approaches are widely used to derive population dynamics as an emergent property deriving from the physiology and behavior of individual organisms. "Individual-based models" (IBMs) are computer simulations where the "state" (e.g., age, size) of each individual in a population is fol-
Proposal for operator's mental model using the concept of multilevel flow modeling
International Nuclear Information System (INIS)
Yoshimura, Seiichi; Takano, Kenichi; Sasou, Kunihide
1995-01-01
It is necessary to analyze an operator's thinking process and a operator team's intension forming process for preventing human errors in a highly advanced huge system like a nuclear power plant. Central Research Institute of Electric Power Industry is promoting a research project to establish human error prevention countermeasures by modeling the thinking and intension forming process. The important is the future prediction and the cause identification when abnormal situations occur in a nuclear power plant. The concept of Multilevel Flow Modeling (MFM) seems to be effective as an operator's mental model which performs the future prediction and the cause identification. MFM is a concept which qualitatively describes the plant functions by energy and mass flows and also describes the plant status by breaking down the targets in a hierarchical manner which a plant should achieve. In this paper, an operator's mental model using the concept of MFM was proposed and a nuclear power plant diagnosis support system using MFM was developed. The system evaluation test by personnel who have operational experience in nuclear power plants revealed that MFM was superior in the future prediction and the cause identification to a traditional nuclear power plant status display system which used mimics and trends. MFM proved to be useful as an operator's mental model by the test. (author)
Deriving dynamic marketing effectiveness from econometric time series models
Horváth, C.; Franses, Ph.H.B.F.
2003-01-01
textabstractTo understand the relevance of marketing efforts, it has become standard practice to estimate the long-run and short-run effects of the marketing-mix, using, say, weekly scanner data. A common vehicle for this purpose is an econometric time series model. Issues that are addressed in the literature are unit roots, cointegration, structural breaks and impulse response functions. In this paper we summarize the most important concepts by reviewing all possible empirical cases that can...
An Emprical Point Error Model for Tls Derived Point Clouds
Ozendi, Mustafa; Akca, Devrim; Topan, Hüseyin
2016-06-01
The random error pattern of point clouds has significant effect on the quality of final 3D model. The magnitude and distribution of random errors should be modelled numerically. This work aims at developing such an anisotropic point error model, specifically for the terrestrial laser scanner (TLS) acquired 3D point clouds. A priori precisions of basic TLS observations, which are the range, horizontal angle and vertical angle, are determined by predefined and practical measurement configurations, performed at real-world test environments. A priori precision of horizontal (𝜎𝜃) and vertical (𝜎𝛼) angles are constant for each point of a data set, and can directly be determined through the repetitive scanning of the same environment. In our practical tests, precisions of the horizontal and vertical angles were found as 𝜎𝜃=±36.6𝑐𝑐 and 𝜎𝛼=±17.8𝑐𝑐, respectively. On the other hand, a priori precision of the range observation (𝜎𝜌) is assumed to be a function of range, incidence angle of the incoming laser ray, and reflectivity of object surface. Hence, it is a variable, and computed for each point individually by employing an empirically developed formula varying as 𝜎𝜌=±2-12 𝑚𝑚 for a FARO Focus X330 laser scanner. This procedure was followed by the computation of error ellipsoids of each point using the law of variance-covariance propagation. The direction and size of the error ellipsoids were computed by the principal components transformation. The usability and feasibility of the model was investigated in real world scenarios. These investigations validated the suitability and practicality of the proposed method.
Rifalazil and derivative compounds show potent efficacy in a mouse model of H. pylori colonization.
Rothstein, David M; Mullin, Steve; Sirokman, Klari; Söndergaard, Karen L; Johnson, Starrla; Gwathmey, Judith K; van Duzer, John; Murphy, Christopher K
2008-08-01
The rifamycin rifalazil (RFZ), and derivatives (NCEs) were efficacious in a mouse model of Helicobacter pylori colonization. Select NCEs were more active in vitro and showed greater efficacy than RFZ. A systemic component contributes to efficacy.
Experimentally derived model to predict permeability behavior of mudstones
Schneider, J.; Flemings, P. B.; Day-Stirrat, R.; Germaine, J. T.
2010-12-01
We use uniaxial consolidation experiments to analyze the permeability evolution during consolidation for mudstones with varying composition to develop a predictive permeability model for mudstones. We admixed silt-sized silica to dry, natural Boston Blue Clay (BBC) powder in five different mass ratios. The result is mixtures of silty clay and clayey silt with percentages of clay-sized particles varying between 36 % and 57 %. To recreate natural conditions yet remove variability and soil disturbance, we resedimented all mixtures to a total stress of 100 kPa. We then loaded them to a vertical effective stress of 2.4 MPa in an uniaxial, constant-rate-of-strain consolidation device. We show that vertical permeability increases exponentially with void ratio and decreasing clay content. There is an order of magnitude difference in permeability at a given void ratio for clay contents varying from 36 % to 57 % (by mass). We developed a model that predicts the permeability of silt-clay mixtures based on knowledge of the composition and void ratio alone. The model assumes that flow occurs through the clay-matrix. Thus, the effective permeability is controlled by the void ratio of the clay fraction. At a given stress level, the clay void ratio increases with silt content: large pores are preserved in silty samples due to stress-bridging which does not allow the clay particles to consolidate. Mudstones are important to practical and fundamental programs. They are a key cap rock for subsurface hydrocarbons and geologic storage of CO2. Over the last decade, large amounts of natural gas have been produced from mudstone (shale) gas fields.
A critical view on temperature modelling for application in weather derivatives markets
International Nuclear Information System (INIS)
Šaltytė Benth, Jūratė; Benth, Fred Espen
2012-01-01
In this paper we present a stochastic model for daily average temperature. The model contains seasonality, a low-order autoregressive component and a variance describing the heteroskedastic residuals. The model is estimated on daily average temperature records from Stockholm (Sweden). By comparing the proposed model with the popular model of Campbell and Diebold (2005), we point out some important issues to be addressed when modelling the temperature for application in weather derivatives market. - Highlights: ► We present a stochastic model for daily average temperature, containing seasonality, a low-order autoregressive component and a variance describing the heteroskedastic residuals. ► We compare the proposed model with the popular model of Campbell and Diebold (2005). ► Some important issues to be addressed when modelling the temperature for application in weather derivatives market are pointed out.
Modeling and simulation of the USAVRE network and radiology operations
Martinez, Ralph; Bradford, Daniel Q.; Hatch, Jay; Sochan, John; Chimiak, William J.
1998-07-01
. There are three levels to the model: (1) Network model of the Cable Bundling Initiative (CBI) network and base networks (CUITIN), (2) Protocol model, including network, transport, and middleware protocols, such TCP/IP and Common Object Request Broker Architecture (CORBA) protocols, and (3) USAVRE Application layer model, including database archive systems, acquisition equipment, viewing workstations, and operations and management. The Network layer of the model contains the ATM-based backbone network provided by the CBI, interfaces into the RMC regional networks and the PACS networks at the medical centers and RMC sites. The CBI network currently is a DS-3 (45 Mbps) backbone consisting of three major hubs, at Ft. Leavenworth, KS, Ft. Belvoir, VA, and Ft. McPherson, GA. The medical center PACS networks are 100 Mbps and 1 Gbps networks. The RMC site networks are 100 Mbps speeds. The model is very beneficial in studying the multimedia transfer and operations characteristics of the USAVRE before it is completely built and deployed.
Chiral condensate in the Schwinger model with matrix product operators
Energy Technology Data Exchange (ETDEWEB)
Banuls, Mari Carmen [Max-Planck-Institut fuer Quantenoptik (MPQ), Garching (Germany); Cichy, Krzysztof [Frankfurt Univ. (Germany). Inst. fuer Theoretische Physik; Poznan Univ. (Poland). Faculty of Physics; Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Saito, Hana [Tsukuba Univ. (Japan). Center for Computational Sciences
2016-03-15
Tensor network (TN) methods, in particular the Matrix Product States (MPS) ansatz, have proven to be a useful tool in analyzing the properties of lattice gauge theories. They allow for a very good precision, much better than standard Monte Carlo (MC) techniques for the models that have been studied so far, due to the possibility of reaching much smaller lattice spacings. The real reason for the interest in the TN approach, however, is its ability, shown so far in several condensed matter models, to deal with theories which exhibit the notorious sign problem in MC simulations. This makes it prospective for dealing with the non-zero chemical potential in QCD and other lattice gauge theories, as well as with real-time simulations. In this paper, using matrix product operators, we extend our analysis of the Schwinger model at zero temperature to show the feasibility of this approach also at finite temperature. This is an important step on the way to deal with the sign problem of QCD. We analyze in detail the chiral symmetry breaking in the massless and massive cases and show that the method works very well and gives good control over a broad range of temperatures, essentially from zero to infinite temperature.
Groundwater flow modelling of the excavation and operational phases - Forsmark
International Nuclear Information System (INIS)
Svensson, Urban; Follin, Sven
2010-07-01
As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different climate conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. The modelling study reported here presents calculated inflow rates, drawdown of the groundwater table and upconing of deep saline water for different levels of grouting efficiency during the excavation and operational phases of a final repository at Forsmark. The inflow calculations are accompanied by a sensitivity study, which among other matters handles the impact of parameter heterogeneity, different deposition hole rejection criteria, and the SFR facility (the repository for short-lived radioactive waste located approximately 1 km to the north of the investigated candidate area for a final repository at Forsmark). The report also presents tentative modelling results for the duration of the saturation phase, which starts once the used parts of the repository are being backfilled
Groundwater flow modelling of the excavation and operational phases - Forsmark
Energy Technology Data Exchange (ETDEWEB)
Svensson, Urban (Computer-aided Fluid Engineering AB, Lyckeby (Sweden)); Follin, Sven (SF GeoLogic AB, Taeby (Sweden))
2010-07-15
As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different climate conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. The modelling study reported here presents calculated inflow rates, drawdown of the groundwater table and upconing of deep saline water for different levels of grouting efficiency during the excavation and operational phases of a final repository at Forsmark. The inflow calculations are accompanied by a sensitivity study, which among other matters handles the impact of parameter heterogeneity, different deposition hole rejection criteria, and the SFR facility (the repository for short-lived radioactive waste located approximately 1 km to the north of the investigated candidate area for a final repository at Forsmark). The report also presents tentative modelling results for the duration of the saturation phase, which starts once the used parts of the repository are being backfilled.
A nonlinear fractional derivative model of impulse motion for viscoelastic materials
International Nuclear Information System (INIS)
Fukunaga, Masataka; Shimizu, Nobuyuki; Nasuno, Hiroshi
2009-01-01
Generally, force can be described as a function of displacement in the mechanical model. A nonlinear fractional derivative model with respect to displacement is proposed to describe force for a viscoelastic material based on the measured data of impulsive motion. In the model, the nonlinearity is assumed to appear in the term of the fractional derivative. Three types of nonlinearity in the fractional derivative term are considered as candidates for a suitable model for reproducing the impulsive responses of the measured data. The first one is the case where the nonlinearity appears in the coefficient of the fractional derivative and the second in the fractionally differentiated term. The third one is the case where the nonlinearity appears as the combination of the above two types. The equation of motion and the initial conditions are derived by employing the above nonlinear models for head-on collisions of a rigid body onto the viscoelastic material. The property of the impulsive responses for the system that is derived above is characterized by the time when the acceleration shows its maximum. The symmetry property of increasing and decreasing acceleration response about the time of maximum acceleration is also considered. The second-type nonlinearity in the model seems to be adequate for reproducing the measured response.
Making Risk Models Operational for Situational Awareness and Decision Support
Energy Technology Data Exchange (ETDEWEB)
Paulson, Patrick R.; Coles, Garill A.; Shoemaker, Steven V.
2012-06-12
Modernization of nuclear power operations control systems, in particular the move to digital control systems, creates an opportunity to modernize existing legacy infrastructure and extend plant life. We describe here decision support tools that allow the assessment of different facets of risk and support the optimization of available resources to reduce risk as plants are upgraded and maintained. This methodology could become an integrated part of the design review process and a part of the operations management systems. The methodology can be applied to the design of new reactors such as small nuclear reactors (SMR), and be helpful in assessing the risks of different configurations of the reactors. Our tool provides a low cost evaluation of alternative configurations and provides an expanded safety analysis by considering scenarios while early in the implementation cycle where cost impacts can be minimized. The effects of failures can be modeled and thoroughly vetted to understand their potential impact on risk. The process and tools presented here allow for an integrated assessment of risk by supporting traditional defense in depth approaches while taking into consideration the insertion of new digital instrument and control systems.
Thermal evolution of the Schwinger model with matrix product operators
Energy Technology Data Exchange (ETDEWEB)
Banuls, M.C.; Cirac, J.I. [Max-Planck-Institut fuer Quantenoptik, Garching (Germany); Cichy, K. [Frankfurt am Main Univ. (Germany). Inst. fuer Theoretische Physik; Poznan Univ. (Poland). Faculty of Physics; DESY Zeuthen (Germany). John von Neumann-Institut fuer Computing (NIC); Jansen, K.; Saito, H. [DESY Zeuthen (Germany). John von Neumann-Institut fuer Computing (NIC)
2015-10-15
We demonstrate the suitability of tensor network techniques for describing the thermal evolution of lattice gauge theories. As a benchmark case, we have studied the temperature dependence of the chiral condensate in the Schwinger model, using matrix product operators to approximate the thermal equilibrium states for finite system sizes with non-zero lattice spacings. We show how these techniques allow for reliable extrapolations in bond dimension, step width, system size and lattice spacing, and for a systematic estimation and control of all error sources involved in the calculation. The reached values of the lattice spacing are small enough to capture the most challenging region of high temperatures and the final results are consistent with the analytical prediction by Sachs and Wipf over a broad temperature range.
New empirically-derived solar radiation pressure model for GPS satellites
Bar-Sever, Y.; Kuang, D.
2003-04-01
We derive a new and improved GPS solar pressure model by estimating model parameters using least square approximation to four and a half years of GPS precise orbit data. The new solar radiation model for Block IIR satellites provides 90% improvement over to the best pre-launch model, as measured by orbit fits and orbit prediction quality. The new model of Block II/IIA realizes a more modest improvement of the previous JPL empirical model. The empirical model is constructed as a set of Fourier functions of the Earth-Probe-Sun angle, to represent the solar radiation pressure forces in the coordinate system tied to the nominal solar panel surface orientation. The model derivation reveals a number of systematic patterns, some of which can be explained in terms of properties of the GPS attitude control system, and some are yet to be explained. Finally, we will discuss the overall orbit determination improvements using the new models.
On a business cycle model with fractional derivative under narrow-band random excitation
International Nuclear Information System (INIS)
Lin, Zifei; Li, Jiaorui; Li, Shuang
2016-01-01
This paper analyzes the dynamics of a business cycle model with fractional derivative of order α (0 < α < 1) subject to narrow-band random excitation, in which fractional derivative describes the memory property of the economic variables. Stochastic dynamical system concepts are integrated into the business cycle model for understanding the economic fluctuation. Firstly, the method of multiple scales is applied to derive the model to obtain the approximate analytical solution. Secondly, the effect of economic policy with fractional derivative on the amplitude of the economic fluctuation and the effect on stationary probability density are studied. The results show macroeconomic regulation and control can lower the stable amplitude of economic fluctuation. While in the process of equilibrium state, the amplitude is magnified. Also, the macroeconomic regulation and control improves the stability of the equilibrium state. Thirdly, how externally stochastic perturbation affects the dynamics of the economy system is investigated.
Preventive effects of tonsil-derived mesenchymal stem cells on osteoradionecrosis in a rat model.
Park, Hae Sang; Lee, Jihae; Kim, Jin-Woo; Kim, Ha Young; Jung, Soo Yeon; Lee, Sung Min; Park, Chan Hum; Kim, Han Su
2018-03-01
The purpose of this study was to investigate the effects of tonsil-derived mesenchymal stem cells (MSCs) on osteoradionecrosis (ORN). We generated a mandibular ORN rat model using a combination of 20-Gy single-dose irradiation and tooth extraction. Study groups were negative control (tooth extraction only), ORN group (irradiation, tooth extraction), Matrigel-1 group (Matrigel; BD Biosciences, San Jose, CA; irradiation, Matrigel application immediately after tooth extraction), tonsil-derived MSC-1 group (irradiation, tonsil-derived MSC application immediately after tooth extraction), Matrigel-4 group (irradiation, Matrigel application 4 weeks after tooth extraction), and tonsil-derived MSC-4 group (irradiation, tonsil-derived MSC application 4 weeks after tooth extraction). Bone mineral density was significantly lower in the ORN group than in the negative control group. The tonsil-derived MSC-1 group showed significantly higher bone mineral density than did the ORN and tonsil-derived MSC-4 groups. A single 20-Gy dose of irradiation combined with tooth extraction successfully generated ORN in the rat model. The tonsil-derived MSCs can be effective for bone regeneration in ORN, particularly when applied immediately after dentoalveolar trauma or surgery. © 2017 Wiley Periodicals, Inc.
CHAOS-2-a geomagnetic field model derived from one decade of continuous satellite data
DEFF Research Database (Denmark)
Olsen, Nils; Mandea, M.; Sabaka, T.J.
2009-01-01
We have derived a model of the near-Earth's magnetic field using more than 10 yr of high-precision geomagnetic measurements from the three satellites Orsted, CHAMP and SAC-C. This model is an update of the two previous models, CHAOS (Olsen et al. 2006) and xCHAOS (Olsen & Mandea 2008). Data...... coefficients up to n = 20 are described by order 5 splines (with 6-month knot spacing) spanning the years from 1997.0 to 2009.5. Compared to its predecessors, the temporal regularization of the CHAOS-2 model is also modified. Indeed, second and higher order time derivatives of the core field are damped...... by minimizing the second time derivative of the squared magnetic field intensity at the core-mantle boundary. The CHAOS-2 model describes rapid time changes, as monitored by the ground magnetic observatories, much better than its predecessors....
EMMA model: an advanced operational mesoscale air quality model for urban and regional environments
International Nuclear Information System (INIS)
Jose, R.S.; Rodriguez, M.A.; Cortes, E.; Gonzalez, R.M.
1999-01-01
Mesoscale air quality models are an important tool to forecast and analyse the air quality in regional and urban areas. In recent years an increased interest has been shown by decision makers in these types of software tools. The complexity of such a model has grown exponentially with the increase of computer power. Nowadays, medium workstations can run operational versions of these modelling systems successfully. Presents a complex mesoscale air quality model which has been installed in the Environmental Office of the Madrid community (Spain) in order to forecast accurately the ozone, nitrogen dioxide and sulphur dioxide air concentrations in a 3D domain centred on Madrid city. Describes the challenging scientific matters to be solved in order to develop an operational version of the atmospheric mesoscale numerical pollution model for urban and regional areas (ANA). Some encouraging results have been achieved in the attempts to improve the accuracy of the predictions made by the version already installed. (Author)
2016-07-13
AFRL-RH-WP-TR-2016-0075 Evaluation of Physiologically – Based Artificial Neural Network Models to Detect Operator Workload in Remotely...16 Interim Report 1 August 2015 – 8 July 2016 4. TITLE AND SUBTITLE Evaluation of Physiologically – Based Artificial Neural Network Models to...One proposal to accomplish this is to allow operators to control multiple aircraft simultaneously (Rose, Arnold, & Howse, 2013). However, piloting
Anatomy of a Rescue: What Makes Hostage Rescue Operations Successful?
National Research Council Canada - National Science Library
Perez, Carlos
2004-01-01
...: surprise, intelligence, operator's skill, and deception. These principles are derived from planning models used in special operations, personal experience, and an analysis of six historical case studies...
Modeling of a dependence between human operators in advanced main control rooms
International Nuclear Information System (INIS)
Lee, Seung Jun; Kim, Jaewhan; Jang, Seung-Cheol; Shin, Yeong Cheol
2009-01-01
For the human reliability analysis of main control room (MCR) operations, not only parameters such as the given situation and capability of the operators but also the dependence between the actions of the operators should be considered because MCR operations are team operations. The dependence between operators might be more prevalent in an advanced MCR in which operators share the same information using a computerized monitoring system or a computerized procedure system. Therefore, this work focused on the computerized operation environment of advanced MCRs and proposed a model to consider the dependence representing the recovery possibility of an operator error by another operator. The proposed model estimates human error probability values by considering adjustment values for a situation and dependence values for operators during the same operation using independent event trees. This work can be used to quantitatively calculate a more reliable operation failure probability for an advanced MCR. (author)
Remote Sensing and Modeling for Improving Operational Aquatic Plant Management
Bubenheim, Dave
2016-01-01
The California Sacramento-San Joaquin River Delta is the hub for California’s water supply, conveying water from Northern to Southern California agriculture and communities while supporting important ecosystem services, agriculture, and communities in the Delta. Changes in climate, long-term drought, water quality changes, and expansion of invasive aquatic plants threatens ecosystems, impedes ecosystem restoration, and is economically, environmentally, and sociologically detrimental to the San Francisco Bay/California Delta complex. NASA Ames Research Center and the USDA-ARS partnered with the State of California and local governments to develop science-based, adaptive-management strategies for the Sacramento-San Joaquin Delta. The project combines science, operations, and economics related to integrated management scenarios for aquatic weeds to help land and waterway managers make science-informed decisions regarding management and outcomes. The team provides a comprehensive understanding of agricultural and urban land use in the Delta and the major water sheds (San Joaquin/Sacramento) supplying the Delta and interaction with drought and climate impacts on the environment, water quality, and weed growth. The team recommends conservation and modified land-use practices and aids local Delta stakeholders in developing management strategies. New remote sensing tools have been developed to enhance ability to assess conditions, inform decision support tools, and monitor management practices. Science gaps in understanding how native and invasive plants respond to altered environmental conditions are being filled and provide critical biological response parameters for Delta-SWAT simulation modeling. Operational agencies such as the California Department of Boating and Waterways provide testing and act as initial adopter of decision support tools. Methods developed by the project can become routine land and water management tools in complex river delta systems.
A new electron density model of the plasmasphere for operational applications and services
Jakowski, Norbert; Hoque, Mohammed Mainul
2018-03-01
The Earth's plasmasphere contributes essentially to total electron content (TEC) measurements from ground or satellite platforms. Furthermore, as an integral part of space weather, associated plasmaspheric phenomena must be addressed in conjunction with ionosphere weather monitoring by operational space weather services. For supporting space weather services and mitigation of propagation errors in Global Navigation Satellite Systems (GNSS) applications we have developed the empirical Neustrelitz plasmasphere model (NPSM). The model consists of an upper L shell dependent part and a lower altitude dependent part, both described by specific exponential decays. Here the McIllwain parameter L defines the geomagnetic field lines in a centered dipole model for the geomagnetic field. The coefficients of the developed approaches are successfully fitted to numerous electron density data derived from dual frequency GPS measurements on-board the CHAMP satellite mission from 2000 to 2005. The data are utilized for fitting up to the L shell L = 3 because a previous validation has shown a good agreement with IMAGE/RPI measurements up to this value. Using the solar radio flux index F10.7 as the only external parameter, the operation of the model is robust, with 40 coefficients fast and sufficiently accurate to be used as a background model for estimating TEC or electron density profiles in near real time GNSS applications and services. In addition to this, the model approach is sensitive to ionospheric coupling resulting in anomalies such as the Nighttime Winter Anomaly and the related Mid-Summer Nighttime Anomaly and even shows a slight plasmasphere compression of the dayside plasmasphere due to solar wind pressure. Modelled electron density and TEC values agree with estimates reported in the literature in similar cases.
Modeling Operating Modes for the Monju Nuclear Power Plant
DEFF Research Database (Denmark)
Lind, Morten; Yoshikawa, Hidekazu; Jørgensen, Sten Bay
2012-01-01
The specification of supervision and control tasks in complex processes requires definition of plant states on various levels of abstraction related to plant operation in start-up, normal operation and shut-down. Modes of plant operation are often specified in relation to a plant decomposition in...
Zhou, Tong; Chen, Dong; Liu, Weining
2018-03-01
Based on the full velocity difference and acceleration car-following model, an extended car-following model is proposed by considering the vehicle’s acceleration derivative. The stability condition is given by applying the control theory. Considering some typical traffic environments, the results of theoretical analysis and numerical simulation show the extended model has a more actual acceleration of string vehicles than that of the previous models in starting process, stopping process and sudden brake. Meanwhile, the traffic jams more easily occur when the coefficient of vehicle’s acceleration derivative increases, which is presented by space-time evolution. The results confirm that the vehicle’s acceleration derivative plays an important role in the traffic jamming transition and the evolution of traffic congestion.
Cuppens, Tine; Depreeuw, Jeroen; Annibali, Daniela; Thomas, Debby; Hermans, Els; Gommé, Ellen; Trinh, Xuan Bich; Debruyne, David; Moerman, Philippe; Lambrechts, Diether; Amant, Frédéric
2017-01-01
Uterine sarcomas (US) and carcinosarcomas (CS) are rare, aggressive cancers. The lack of reliable preclinical models hampers the search for new treatment strategies and predictive biomarkers. To this end, we established and characterized US and CS patient-derived xenograft (PDX) models. Tumor
Patient-Derived Xenograft Models : An Emerging Platform for Translational Cancer Research
Hidalgo, Manuel; Amant, Frederic; Biankin, Andrew V.; Budinska, Eva; Byrne, Annette T.; Caldas, Carlos; Clarke, Robert B.; de Jong, Steven; Jonkers, Jos; Maelandsmo, Gunhild Mari; Roman-Roman, Sergio; Seoane, Joan; Trusolino, Livio; Villanueva, Alberto
Recently, there has been an increasing interest in the development and characterization of patient-derived tumor xenograft (PDX) models for cancer research. PDX models mostly retain the principal histologic and genetic characteristics of their donor tumor and remain stable across passages. These
Relational Understanding of the Derivative Concept through Mathematical Modeling: A Case Study
Sahin, Zulal; Aydogan Yenmez, Arzu; Erbas, Ayhan Kursat
2015-01-01
The purpose of this study was to investigate three second-year graduate students' awareness and understanding of the relationships among the "big ideas" that underlie the concept of derivative through modeling tasks and Skemp's distinction between relational and instrumental understanding. The modeling tasks consisting of warm-up,…
A direct derivation of the exact Fisther information matrix of Gaussian vector state space models
Klein, A.A.B.; Neudecker, H.
2000-01-01
This paper deals with a direct derivation of Fisher's information matrix of vector state space models for the general case, by which is meant the establishment of the matrix as a whole and not element by element. The method to be used is matrix differentiation, see [4]. We assume the model to be
Straub, Annette; Beck, Christoph; Breitner, Susanne; Cyrys, Josef; Geruschkat, Uta; Jacobeit, Jucundus; Kühlbach, Benjamin; Kusch, Thomas; Richter, Katja; Schneider, Alexandra; Umminger, Robin; Wolf, Kathrin
2017-04-01
Frequently spatial variations of air temperature of considerable magnitude occur within urban areas. They correspond to varying land use/land cover characteristics and vary with season, time of day and synoptic conditions. These temperature differences have an impact on human health and comfort directly by inducing thermal stress as well as indirectly by means of affecting air quality. Therefore, knowledge of the spatial patterns of air temperature in cities and the factors causing them is of great importance, e.g. for urban planners. A multitude of studies have shown statistical modelling to be a suitable tool for generating spatial air temperature patterns. This contribution presents a comparison of different statistical modelling approaches for deriving spatial air temperature patterns in the urban environment of Augsburg, Southern Germany. In Augsburg there exists a measurement network for air temperature and humidity currently comprising 48 stations in the city and its rural surroundings (corporately operated by the Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health and the Institute of Geography, University of Augsburg). Using different datasets for land surface characteristics (Open Street Map, Urban Atlas) area percentages of different types of land cover were calculated for quadratic buffer zones of different size (25, 50, 100, 250, 500 m) around the stations as well for source regions of advective air flow and used as predictors together with additional variables such as sky view factor, ground level and distance from the city centre. Multiple Linear Regression and Random Forest models for different situations taking into account season, time of day and weather condition were applied utilizing selected subsets of these predictors in order to model spatial distributions of mean hourly and daily air temperature deviations from a rural reference station. Furthermore, the different model setups were
Directory of Open Access Journals (Sweden)
Cong Guan
2015-06-01
Full Text Available In this article, the operation of a large two-stroke marine diesel engine including various cases with turbocharger cut-out was thoroughly investigated by using a modular zero-dimensional engine model built in MATLAB/Simulink environment. The model was developed by using as a basis an in-house modular mean value engine model, in which the existing cylinder block was replaced by a more detailed one that is capable of representing the scavenging ports-cylinder-exhaust valve processes. Simulation of the engine operation at steady state conditions was performed and the derived engine performance parameters were compared with the respective values obtained by the engine shop trials. The investigation of engine operation under turbocharger cut-out conditions in the region from 10% to 50% load was carried out and the influence of turbocharger cut-out on engine performance including the in-cylinder parameters was comprehensively studied. The recommended schedule for the combination of the turbocharger cut-out and blower activation was discussed for the engine operation under part load conditions. Finally, the influence of engine operating strategies on the annual fuel savings, CO2 emissions reduction and blower operating hours for a Panamax container ship operating at slow steaming conditions is presented and discussed.
Interaction of hematoporphyrin derivative, light, and ionizing radiation in a rat glioma model
International Nuclear Information System (INIS)
Kostron, H.; Swartz, M.R.; Miller, D.C.; Martuza, R.L.
1986-01-01
The effects of hematoporphyrin derivative, light, and cobalt 60 ( 60 Co) irradiation were studied in a rat glioma model using an in vivo and an in vitro clonogenic assay. There was no effect on tumor growth by visible light or by a single dose of 60 Co irradiation at 4 Gy or 8 Gy, whereas 16 Gy inhibited tumor growth to 40% versus the control. Hematoporphyrin derivative alone slightly stimulated growth (P less than 0.1). Light in the presence of 10 mg hematoporphyrin derivative/kg inhibited tumor growth to 32%. 60 Co irradiation in the presence of hematoporphyrin derivative produced a significant tumor growth inhibition (P less than 0.02). This growth inhibition was directly related to the concentration of hematoporphyrin derivative. The addition of 60 Co to light in the presence of hematoporphyrin derivative produced a greater growth inhibition than light or 60 Co irradiation alone. This effect was most pronounced when light was applied 30 minutes before 60 Co irradiation. Our experiments in a subcutaneous rat glioma model suggest a radiosensitizing effect of hematoporphyrin derivative. Furthermore, the photodynamic inactivation is enhanced by the addition of 60 Co irradiation. These findings may be of importance in planning new treatment modalities in malignant brain tumors
Analysis of the Keller–Segel Model with a Fractional Derivative without Singular Kernel
Directory of Open Access Journals (Sweden)
Abdon Atangana
2015-06-01
Full Text Available Using some investigations based on information theory, the model proposed by Keller and Segel was extended to the concept of fractional derivative using the derivative with fractional order without singular kernel recently proposed by Caputo and Fabrizio. We present in detail the existence of the coupled-solutions using the fixed-point theorem. A detailed analysis of the uniqueness of the coupled-solutions is also presented. Using an iterative approach, we derive special coupled-solutions of the modified system and we present some numerical simulations to see the effect of the fractional order.
Variables influencing the use of derivatives in South Africa – the development of a conceptual model
Directory of Open Access Journals (Sweden)
Stefan Schwegler
2011-03-01
Full Text Available This paper, which is the first in a two-part series, sets out the development of a conceptual model on the variables influencing investors’ decisions to use derivatives in their portfolios. Investor-specific variables include: the investor’s needs, goals and return expectations, the investor’s knowledge of financial markets, familiarity with different asset classes including derivative instruments, and the investor’s level of wealth and level of risk tolerance. Market-specific variables include: the level of volatility, standardisation, regulation and liquidity in a market, the level of information available on derivatives, the transparency of price determination, taxes, brokerage costs and product availability.
Liang, Yingjie; Ye, Allen Q.; Chen, Wen; Gatto, Rodolfo G.; Colon-Perez, Luis; Mareci, Thomas H.; Magin, Richard L.
2016-10-01
Non-Gaussian (anomalous) diffusion is wide spread in biological tissues where its effects modulate chemical reactions and membrane transport. When viewed using magnetic resonance imaging (MRI), anomalous diffusion is characterized by a persistent or 'long tail' behavior in the decay of the diffusion signal. Recent MRI studies have used the fractional derivative to describe diffusion dynamics in normal and post-mortem tissue by connecting the order of the derivative with changes in tissue composition, structure and complexity. In this study we consider an alternative approach by introducing fractal time and space derivatives into Fick's second law of diffusion. This provides a more natural way to link sub-voxel tissue composition with the observed MRI diffusion signal decay following the application of a diffusion-sensitive pulse sequence. Unlike previous studies using fractional order derivatives, here the fractal derivative order is directly connected to the Hausdorff fractal dimension of the diffusion trajectory. The result is a simpler, computationally faster, and more direct way to incorporate tissue complexity and microstructure into the diffusional dynamics. Furthermore, the results are readily expressed in terms of spectral entropy, which provides a quantitative measure of the overall complexity of the heterogeneous and multi-scale structure of biological tissues. As an example, we apply this new model for the characterization of diffusion in fixed samples of the mouse brain. These results are compared with those obtained using the mono-exponential, the stretched exponential, the fractional derivative, and the diffusion kurtosis models. Overall, we find that the order of the fractal time derivative, the diffusion coefficient, and the spectral entropy are potential biomarkers to differentiate between the microstructure of white and gray matter. In addition, we note that the fractal derivative model has practical advantages over the existing models from the
Directory of Open Access Journals (Sweden)
Yang Xiao-Jun
2017-01-01
Full Text Available In this paper, we address a class of the fractional derivatives of constant and variable orders for the first time. Fractional-order relaxation equations of constants and variable orders in the sense of Caputo type are modeled from mathematical view of point. The comparative results of the anomalous relaxation among the various fractional derivatives are also given. They are very efficient in description of the complex phenomenon arising in heat transfer.
An Executable Architecture Tool for the Modeling and Simulation of Operational Process Models
2015-03-16
network-based fuzzy logic control and decision system,” IEEE Trans. Comput., vol. 40, no. 12, pp. 1320–1336, 1991. [16] M. Beale, M. Hagan, and H...such as models based on neural networks [14]–[16], or genetic algorithms [17] to represent activities in the process flow. Furthermore, since the model...particularly relevant to experiments and exercises. The operational views provide a logical description of the activities and information exchanged
Application of a procedure oriented crew model to modelling nuclear plant operation
International Nuclear Information System (INIS)
Baron, S.
1986-01-01
PROCRU (PROCEDURE-ORIENTED CREW MODEL) is a model developed to analyze flight crew procedures in a commercial ILS approach-to-landing. The model builds on earlier, validated control-theoretic models for human estimation and control behavior, but incorporates features appropriate to analyzing supervisory control in multi-task environments. In this paper, the basic ideas underlying the PROCRU model, and the generalization of these ideas to provide a supervisory control model of wider applicability are discussed. The potential application of this supervisory control model to nuclear power plant operations is considered. The range of problems that can be addressed, the kinds of data that will be needed and the nature of the results that might be expected from such an application are indicated
Artificial Systems and Models for Risk Covering Operations
Directory of Open Access Journals (Sweden)
Laurenţiu Mihai Treapăt
2017-04-01
Full Text Available Mainly, this paper focuses on the roles of artificial intelligence based systems and especially on risk-covering operations. In this context, the paper comes with theoretical explanations on real-life based examples and applications. From a general perspective, the paper enriches its value with a wide discussion on the related subject. The paper aims to revise the volatilities’ estimation models and the correlations between the various time series and also by presenting the Risk Metrics methodology, as explained is a case study. The advantages that the VaR estimation offers, consist of its ability to quantitatively and numerically express the risk level of a portfolio, at a certain moment in time and also the risk of on open position (in titles, in FX, commodities or granted loans, belonging to an economic agent or even individual; hence, its role in a more efficient capital allocation, in the assumed risk delimitation, and also as a performance measurement instrument. In this paper and the study case that completes our work, we aim to prove how we can prevent considerable losses and even bankruptcies if VaR is known and applied accordingly. For this reason, the universities inRomaniashould include or increase their curricula with the study of the VaR model as an artificial intelligence tool. The simplicity of the presented case study, most probably, is the strongest argument of the current work because it can be understood also by the readers that are not necessarily very experienced in the risk management field.
Bassil, Alfred; Rubod, Chrystèle; Borghesi, Yves; Kerbage, Yohan; Schreiber, Elie Servan; Azaïs, Henri; Garabedian, Charles
2017-04-01
Hysteroscopy is one of the most common gynaecological procedure. Training for diagnostic and operative hysteroscopy can be achieved through numerous previously described models like animal models or virtual reality simulation. We present our novel combined model associating virtual reality and bovine uteruses and bladders. End year residents in obstetrics and gynaecology attended a full day workshop. The workshop was divided in theoretical courses from senior surgeons and hands-on training in operative hysteroscopy and virtual reality Essure ® procedures using the EssureSim™ and Pelvicsim™ simulators with multiple scenarios. Theoretical and operative knowledge was evaluated before and after the workshop and General Points Averages (GPAs) were calculated and compared using a Student's T test. GPAs were significantly higher after the workshop was completed. The biggest difference was observed in operative knowledge (0,28 GPA before workshop versus 0,55 after workshop, pvirtual reality simulation is an efficient model not described before. Copyright © 2017 Elsevier B.V. All rights reserved.
Model Structure Analysis of Model-based Operation of Petroleum Reservoirs
Van Doren, J.F.M.
2010-01-01
The demand for petroleum is expected to increase in the coming decades, while the production of petroleum from subsurface reservoirs is becoming increasingly complex. To meet the demand petroleum reservoirs should be operated more efficiently. Physics-based petroleum reservoir models that describe
Ogawa, Ken-ichiro; Miyake, Yoshihiro
2011-03-01
Many conventional models have used the positional information hypothesis to explain each elementary process of morphogenesis during the development of multicellular organisms. Their models assume that the steady concentration patterns of morphogens formed in an extracellular environment have an important property of positional information, so-called "robustness". However, recent experiments reported that a steady morphogen pattern, the concentration gradient of the Bicoid protein, during early Drosophila embryonic development is not robust for embryo-to-embryo variability. These reports encourage a reconsideration of a long-standing problem in systematic cell differentiation: what is the entity of positional information for cells? And, what is the origin of the robust boundary of gene expression? To address these problems at a cellular level, in this article we pay attention to the re-generative phenomena that show another important property of positional information, "size invariance". In view of regenerative phenomena, we propose a new mathematical model to describe the generation mechanism of a spatial pattern of positional values. In this model, the positional values are defined as the values into which differentiable cells transform a spatial pattern providing positional information. The model is mathematically described as an associative algebra composed of various terms, each of which is the multiplication of some fundamental operators under the assumption that the operators are derived from the remarkable properties of cell differentiation on an amputation surface in regenerative phenomena. We apply this model to the concentration pattern of the Bicoid protein during the anterior-posterior axis formation in Drosophila, and consider the conditions needed to establish the robust boundary of the expression of the hunchback gene. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.
An equilibrium pricing model for weather derivatives in a multi-commodity setting
International Nuclear Information System (INIS)
Lee, Yongheon; Oren, Shmuel S.
2009-01-01
Many industries are exposed to weather risk. Weather derivatives can play a key role in hedging and diversifying such risk because the uncertainty in a company's profit function can be correlated to weather condition which affects diverse industry sectors differently. Unfortunately the weather derivatives market is a classical example of an incomplete market that is not amenable to standard methodologies used for derivative pricing in complete markets. In this paper, we develop an equilibrium pricing model for weather derivatives in a multi-commodity setting. The model is constructed in the context of a stylized economy where agents optimize their hedging portfolios which include weather derivatives that are issued in a fixed quantity by a financial underwriter. The supply and demand resulting from hedging activities and the supply by the underwriter are combined in an equilibrium pricing model under the assumption that all agents maximize some risk averse utility function. We analyze the gains due to the inclusion of weather derivatives in hedging portfolios and examine the components of that gain attributable to hedging and to risk sharing. (author)
Naughton, B J; Mylotte, J M; Tayara, A
2000-10-01
To derive a prediction model of 30 day mortality for nursing home-acquired pneumonia (NHAP) based on factors that can be readily identified by nursing home staff at the time of diagnosis and to apply the model to management issues related to NHAP including clarifying the importance of prepneumonia functional status as a predictor of outcome of NHAP. This was a retrospective chart review of 378 episodes of NHAP treated in the nursing home or hospital during two periods: November 1997 to April 1998 and November 1998 to April 1999. Eleven nursing homes in the greater Buffalo, NY region. Nursing home residents with radiographically proven pneumonia who had at least one of the following signs/symptoms: cough, fever, purulent sputum, respiratory rate > or =25 breaths/minute, localized auscultatory findings, or pleuritic pain. Status (alive or dead) of each resident at 30 days (30 day mortality) after diagnosis of NHAP was the dependent variable. Factors predicting 30 day mortality were identified by logistic regression analysis. A scoring system was developed based on the results of the logistic model. Each episode of NHAP in the derivation cohort was scored using the model and the cohort was stratified by the model score into six categories or risk for mortality (0-5). The predictability of the model in the derivation cohort was measured using receiver operator characteristics curve analysis. Of 378 episodes of NHAP, 74% were treated initially in the nursing home and 26% were hospitalized initially for treatment. The overall 30 day mortality was 21.4%; however, the mortality rate was significantly higher for those treated initially in the hospital (29.6% vs 16.6%; P = .012). Logistic regression analysis identified four predictors of 30 day mortality: (1) respiratory rate >30 breaths/minute (2 points), (2) pulse > 125 beats/minute (1 point), (3) altered mental status (1 point), and (4) a history of dementia (1 point). Applying the scoring system to each episode in the
Thermodynamic and kinetic modelling of fuel oxidation behaviour in operating defective fuel
International Nuclear Information System (INIS)
Lewis, B.J.; Thompson, W.T.; Akbari, F.; Thompson, D.M.; Thurgood, C.; Higgs, J.
2004-01-01
A theoretical treatment has been developed to predict the fuel oxidation behaviour in operating defective nuclear fuel elements. The equilibrium stoichiometry deviation in the hyper-stoichiometric fuel has been derived from thermodynamic considerations using a self-consistent set of thermodynamic properties for the U-O system, which emphasizes replication of solubilities and three-phase invariant conditions displayed in the U-O binary phase diagram. The kinetics model accounts for multi-phase transport including interstitial oxygen diffusion in the solid and gas-phase transport of hydrogen and steam in the fuel cracks. The fuel oxidation model is further coupled to a heat conduction model to account for the feedback effect of a reduced thermal conductivity in the hyper-stoichiometric fuel. A numerical solution has been developed using a finite-element technique with the FEMLAB software package. The model has been compared to available data from several in-reactor X-2 loop experiments with defective fuel conducted at the Chalk River Laboratories. The model has also been benchmarked against an O/U profile measurement for a spent defective fuel element discharged from a commercial reactor
How to derive and validate clinical prediction models for use in intensive care medicine.
Labarère, José; Renaud, Bertrand; Bertrand, Renaud; Fine, Michael J
2014-04-01
Clinical prediction models are formal combinations of historical, physical examination and laboratory or radiographic test data elements designed to accurately estimate the probability that a specific illness is present (diagnostic model), will respond to a form of treatment (therapeutic model) or will have a well-defined outcome (prognostic model) in an individual patient. They are derived and validated using empirical data and used to assist physicians in their clinical decision-making that requires a quantitative assessment of diagnostic, therapeutic or prognostic probabilities at the bedside. To provide intensivists with a comprehensive overview of the empirical development and testing phases that a clinical prediction model must satisfy before its implementation into clinical practice. The development of a clinical prediction model encompasses three consecutive phases, namely derivation, (external) validation and impact analysis. The derivation phase consists of building a multivariable model, estimating its apparent predictive performance in terms of both calibration and discrimination, and assessing the potential for statistical over-fitting using internal validation techniques (i.e. split-sampling, cross-validation or bootstrapping). External validation consists of testing the predictive performance of a model by assessing its calibration and discrimination in different but plausibly related patients. Impact analysis involves comparative research [i.e. (cluster) randomized trials] to determine whether clinical use of a prediction model affects physician practices, patient outcomes or the cost of healthcare delivery. This narrative review introduces a checklist of 19 items designed to help intensivists develop and transparently report valid clinical prediction models.
Modeling and Control for Islanding Operation of Active Distribution Systems
DEFF Research Database (Denmark)
Cha, Seung-Tae; Wu, Qiuwei; Saleem, Arshad
2011-01-01
Along with the increasing penetration of distributed generation (DG) in distribution systems, there are more resources for system operators to improve the operation and control of the whole system and enhance the reliability of electricity supply to customers. The distribution systems with DG...... are able to operate in is-landing operation mode intentionally or unintentionally. In order to smooth the transition from grid connected operation to islanding operation for distribution systems with DG, a multi-agent based controller is proposed to utilize different re-sources in the distribution systems...... to stabilize the frequency. Different agents are defined to represent different resources in the distribution systems. A test platform with a real time digital simulator (RTDS), an OPen Connectivity (OPC) protocol server and the multi-agent based intelligent controller is established to test the proposed multi...
Operations model for utilities using wind-generator arrays
Schlueter, R. A.; Park, G. L.; Dorsey, J.; Lotfalian, M.; Shayanfar, A.
1981-05-01
The effects that various combinations of wind regime, array configuration and penetrations, and system characteristics have on system variables such as area control error, frequency, interchange power and spinning reserve are discussed. The characteristics of the combinations causing system operating stress or operating problems are denoted and methods for estimating effects on a simplified and on a detailed simulation basis are reported. Methods for reducing operating problems are suggested and involve array configurations, penetration, unit commitment and dispatch changes, and wind generator controls.
Optimizing Warehouse Logistics Operations Through Site Selection Models: Istanbul, Turkey
National Research Council Canada - National Science Library
Erdemir, Ugur
2003-01-01
.... Given the dynamic environment surrounding the military operations, logistic sustainability requirements, rapid information technology developments, and budget-constrained Turkish DoD acquisition...
Grbac, Zorana; Scherer, Matthias; Zagst, Rudi
2016-01-01
This book presents 20 peer-reviewed chapters on current aspects of derivatives markets and derivative pricing. The contributions, written by leading researchers in the field as well as experienced authors from the financial industry, present the state of the art in: • Modeling counterparty credit risk: credit valuation adjustment, debit valuation adjustment, funding valuation adjustment, and wrong way risk. • Pricing and hedging in fixed-income markets and multi-curve interest-rate modeling. • Recent developments concerning contingent convertible bonds, the measuring of basis spreads, and the modeling of implied correlations. The recent financial crisis has cast tremendous doubts on the classical view on derivative pricing. Now, counterparty credit risk and liquidity issues are integral aspects of a prudent valuation procedure and the reference interest rates are represented by a multitude of curves according to their different periods and maturities. A panel discussion included in the book (featuring D...
DEFF Research Database (Denmark)
King, Alexander Weider; Agerkvist, Finn T.
2017-01-01
Commonly used models of moving-coil loudspeaker voice coils, which include effects from eddy current losses, are either inaccurate or contain an abundance of parameters, and are difficult to extend to the nonlinear domain. On the contrary, fractional derivative models accurately describe the freq......Commonly used models of moving-coil loudspeaker voice coils, which include effects from eddy current losses, are either inaccurate or contain an abundance of parameters, and are difficult to extend to the nonlinear domain. On the contrary, fractional derivative models accurately describe...... the frequency and position dependence of the lossy inductance, with meaningful connections to the underlying physics, while keeping the number of parameters low. These fractional derivatives are also compatible with state-space polynomial methods of modeling nonlinear behavior. It is shown that the fractional...... order derivative approaches a value of 1, corresponding to an ideal inductance, when the voice coil is completely outside the magnetic system. Finally, the developed model reveals details about the effect of conductive voice coil formers...
Modeling Neurodegenerative Microenvironment Using Cortical Organoids Derived from Human Stem Cells.
Yan, Yuanwei; Song, Liqing; Bejoy, Julie; Zhao, Jing; Kanekiyo, Takahisa; Bu, Guojun; Zhou, Yi; Li, Yan
2018-02-27
Alzheimer's disease (AD) is one of the most common neurodegenerative disorders and causes cognitive impairment and memory deficits of the patients. The mechanism of AD is not well known, due to lack of human brain models. Recently, mini-brain tissues called organoids have been derived from human induced pluripotent stem cells (hiPSCs) for modeling human brain development and neurological diseases. Thus, the objective of this research is to model and characterize neural degeneration microenvironment using three-dimensional (3D) forebrain cortical organoids derived from hiPSCs and study the response to the drug treatment. It is hypothesized that the 3D forebrain organoids derived from hiPSCs with AD-associated genetic background may partially recapitulate the extracellular microenvironment in neural degeneration. To test this hypothesis, AD-patient derived hiPSCs with presenilin-1 mutation were used for cortical organoid generation. AD-related inflammatory responses, matrix remodeling and the responses to DAPT, heparin (completes with heparan sulfate proteoglycans [HSPGs] to bind Aβ42), and heparinase (digests HSPGs) treatments were investigated. The results indicate that the cortical organoids derived from AD-associated hiPSCs exhibit a high level of Aβ42 comparing with healthy control. In addition, the AD-derived organoids result in an elevated gene expression of proinflammatory cytokines interleukin-6 and tumor necrosis factor-α, upregulate syndecan-3, and alter matrix remodeling protein expression. Our study demonstrates the capacity of hiPSC-derived organoids for modeling the changes of extracellular microenvironment and provides a potential approach for AD-related drug screening.
Modeling Operating Modes for the Monju Nuclear Power Plant
DEFF Research Database (Denmark)
Lind, Morten; Yoshikawa, H.; Jørgensen, Sten Bay
2012-01-01
of the process plant, its function and its structural elements. The paper explains how the means-end concepts of MFM can be used to provide formalized definitions of plant operation modes. The paper will introduce the mode types defined by MFM and show how selected operation modes can be represented...
Incorporating Worker-Specific Factors in Operations Management Models
J.A. Larco Martinelli (Jose)
2010-01-01
textabstractTo add value, manufacturing and service operations depend on workers to do the job. As a result, the performance of these operations is ultimately dependent on the performance of individual workers. Simultaneously, workers are major stakeholders of the firm. Workers spend a
Simulation of nuclear plant operation into a stochastic energy production model
International Nuclear Information System (INIS)
Pacheco, R.L.
1983-04-01
A simulation model of nuclear plant operation is developed to fit into a stochastic energy production model. In order to improve the stochastic model used, and also reduce its computational time burdened by the aggregation of the model of nuclear plant operation, a study of tail truncation of the unsupplied demand distribution function has been performed. (E.G.) [pt
International Nuclear Information System (INIS)
Dufo-López, Rodolfo; Fernández-Jiménez, L. Alfredo; Ramírez-Rosado, Ignacio J.; Artal-Sevil, J. Sergio; Domínguez-Navarro, José A.; Bernal-Agustín, José L.
2017-01-01
Highlights: • Method for optimising the daily operation of photovoltaic-wind-diesel-battery systems. • Weather forecasts of hourly wind speed, irradiation, temperature and load are used. • Each day five control variables are optimised for the control of the system. • Operating cost includes real ageing of the batteries and the diesel generator. • Results show that the optimal control strategy used for each day led to cost savings. - Abstract: This article presents a method for optimising the daily operation (minimising the total operating cost) of a hybrid photovoltaic-wind-diesel-battery system using model predictive control. The model uses actual weather forecasts of hourly values of wind speed, irradiation, temperature and load. Five control variables are optimised, and thus their optimal set points values determine the optimal control strategy for each day. This involves the use of an accurate model for estimating the degradation of the batteries by considering the capacity loss due to corrosion and degradation. The model considers the extra costs of maintaining and replacing the diesel generator due to running out of its optimal conditions. The optimisation is carried out by means of genetic algorithms. An example of application compares the total operating cost obtained using the optimal control strategy for each day with the cost of using the optimal control strategy found for the whole year, obtaining savings of up to 7.8%. Also the comparison with the cost of using the “load following” control strategy is analysed, obtaining savings of up to 37.7%.
Lauro, Figueroa-Valverde; Francisco, Díaz-Cedillo; Elodia, García-Cervera; Eduardo, Pool-Gómez; Maria, López-Ramos; Marcela, Rosas-Nexticapa; Lenin, Hau-Heredia; Betty, Sarabia-Alcocer; Monica, Velázquez-Sarabia Betty
2014-01-01
Some reports indicate that several steroid derivatives have activity at cardiovascular level; nevertheless, there is scarce information about the activity exerted by the testosterone derivatives on cardiac injury caused by ischemia/reperfusion (I/R). Analyzing these data, in this study, a new testosterone derivative was synthetized with the objective of evaluating its effect on myocardial injury using an ischemia/reperfusion model. In addition, perfusion pressure and coronary resistance were evaluated in isolated rat hearts using the Langendorff technique. Additionally, molecular mechanism involved in the activity exerted by the testosterone derivative on perfusion pressure and coronary resistance was evaluated by measuring left ventricular pressure in the absence or presence of the following compounds: flutamide, prazosin, metoprolol, nifedipine, indomethacin, and PINANE TXA2. The results showed that the testosterone derivative significantly increases (P = 0.05) the perfusion pressure and coronary resistance in isolated heart. Other data indicate that the testosterone derivative increases left ventricular pressure in a dose-dependent manner (0.001–100 nM); however, this phenomenon was significantly inhibited (P = 0.06) by indomethacin and PINANE-TXA2 (P = 0.05) at a dose of 1 nM. In conclusion, these data suggest that testosterone derivative induces changes in the left ventricular pressure levels through thromboxane receptor activation. PMID:24839599
DEFF Research Database (Denmark)
Hilson, Mary
2017-01-01
the Pellervo Society, to promote rural cooperation, in 1899. He noted that Ireland’s ‘tragic history’, its struggle for national self-determination and the introduction of co-operative dairies to tackle rural poverty, seemed to offer a useful example for Finnish reformers. This article explores the exchanges...... that even before the First World War it was Finland, not Ireland, that had begun to be regarded as ‘a model co-operative country’....
Sibonga, J. D.; Feiveson, A. H.
2014-01-01
This work was accomplished in support of the Finite Element [FE] Strength Task Group, NASA Johnson Space Center [JSC], Houston, TX. This group was charged with the task of developing rules for using finite-element [FE] bone-strength measures to construct operating bands for bone health that are relevant to astronauts following exposure to spaceflight. FE modeling is a computational tool used by engineers to estimate the failure loads of complex structures. Recently, some engineers have used this tool to characterize the failure loads of the hip in population studies that also monitored fracture outcomes. A Directed Research Task was authorized in July, 2012 to investigate FE data from these population studies to derive these proposed standards of bone health as a function of age and gender. The proposed standards make use of an FE-based index that integrates multiple contributors to bone strength, an expanded evaluation that is critical after an astronaut is exposed to spaceflight. The current index of bone health used by NASA is the measurement of areal BMD. There was a concern voiced by a research and clinical advisory panel that the sole use of areal BMD would be insufficient to fully evaluate the effects of spaceflight on the hip. Hence, NASA may not have a full understanding of fracture risk, both during and after a mission, and may be poorly estimating in-flight countermeasure efficacy. The FE Strength Task Group - composed of principal investigators of the aforementioned population studies and of FE modelers -donated some of its population QCT data to estimate of hip bone strength by FE modeling for this specific purpose. Consequently, Human Health Countermeasures [HHC] has compiled a dataset of FE hip strengths, generated by a single FE modeling approach, from human subjects (approx.1060) with ages covering the age range of the astronauts. The dataset has been analyzed to generate a set of FE strength cutoffs for the following scenarios: a) Qualify an
Potta, Thrimoorthy; Zhen, Zhuo; Grandhi, Taraka Sai Pavan; Christensen, Matthew D.; Ramos, James; Breneman, Curt M.; Rege, Kaushal
2014-01-01
We describe the combinatorial synthesis and cheminformatics modeling of aminoglycoside antibiotics-derived polymers for transgene delivery and expression. Fifty-six polymers were synthesized by polymerizing aminoglycosides with diglycidyl ether cross-linkers. Parallel screening resulted in identification of several lead polymers that resulted in high transgene expression levels in cells. The role of polymer physicochemical properties in determining efficacy of transgene expression was investigated using Quantitative Structure-Activity Relationship (QSAR) cheminformatics models based on Support Vector Regression (SVR) and ‘building block’ polymer structures. The QSAR model exhibited high predictive ability, and investigation of descriptors in the model, using molecular visualization and correlation plots, indicated that physicochemical attributes related to both, aminoglycosides and diglycidyl ethers facilitated transgene expression. This work synergistically combines combinatorial synthesis and parallel screening with cheminformatics-based QSAR models for discovery and physicochemical elucidation of effective antibiotics-derived polymers for transgene delivery in medicine and biotechnology. PMID:24331709
Potta, Thrimoorthy; Zhen, Zhuo; Grandhi, Taraka Sai Pavan; Christensen, Matthew D; Ramos, James; Breneman, Curt M; Rege, Kaushal
2014-02-01
We describe the combinatorial synthesis and cheminformatics modeling of aminoglycoside antibiotics-derived polymers for transgene delivery and expression. Fifty-six polymers were synthesized by polymerizing aminoglycosides with diglycidyl ether cross-linkers. Parallel screening resulted in identification of several lead polymers that resulted in high transgene expression levels in cells. The role of polymer physicochemical properties in determining efficacy of transgene expression was investigated using Quantitative Structure-Activity Relationship (QSAR) cheminformatics models based on Support Vector Regression (SVR) and 'building block' polymer structures. The QSAR model exhibited high predictive ability, and investigation of descriptors in the model, using molecular visualization and correlation plots, indicated that physicochemical attributes related to both, aminoglycosides and diglycidyl ethers facilitated transgene expression. This work synergistically combines combinatorial synthesis and parallel screening with cheminformatics-based QSAR models for discovery and physicochemical elucidation of effective antibiotics-derived polymers for transgene delivery in medicine and biotechnology. Copyright © 2013 Elsevier Ltd. All rights reserved.
A model for the derivation of new transport limits for non-fixed contamination
Energy Technology Data Exchange (ETDEWEB)
Thierfeldt, S. [Brenk Systemplanung GmbH, Aachen (Germany); Lorenz, B. [GNS Gesellschaft fuer Nuklearservice, Essen (Germany); Hesse, J. [RWE Power AG, Essen (Germany)
2004-07-01
The IAEA Regulations for the Safe Transport of Radioactive Material contain requirements for contamination limits on packages and conveyances used for the transport of radioactive material. Current contamination limits for packages and conveyances under routine transport conditions have been derived from a model proposed by Fairbairn more than 40 years ago. This model has proven effective if used with pragmatism, but is based on very conservative as well as extremely simple assumptions which is in no way appropriate any more and which is not compatible with ICRP recommendations regarding radiation protection standards. Therefore, a new model has now been developed which reflects all steps of the transport process. The derivation of this model has been fostered by the IAEA by initiating a Co-ordinated Research Project. The results of the calculations using this model could be directly applied as new nuclide specific transport limits for the non-fixed contamination.
A model for the derivation of new transport limits for non-fixed contamination
International Nuclear Information System (INIS)
Thierfeldt, S.; Lorenz, B.; Hesse, J.
2004-01-01
The IAEA Regulations for the Safe Transport of Radioactive Material contain requirements for contamination limits on packages and conveyances used for the transport of radioactive material. Current contamination limits for packages and conveyances under routine transport conditions have been derived from a model proposed by Fairbairn more than 40 years ago. This model has proven effective if used with pragmatism, but is based on very conservative as well as extremely simple assumptions which is in no way appropriate any more and which is not compatible with ICRP recommendations regarding radiation protection standards. Therefore, a new model has now been developed which reflects all steps of the transport process. The derivation of this model has been fostered by the IAEA by initiating a Co-ordinated Research Project. The results of the calculations using this model could be directly applied as new nuclide specific transport limits for the non-fixed contamination
Jorgensen, Palle E T
1987-01-01
Historically, operator theory and representation theory both originated with the advent of quantum mechanics. The interplay between the subjects has been and still is active in a variety of areas.This volume focuses on representations of the universal enveloping algebra, covariant representations in general, and infinite-dimensional Lie algebras in particular. It also provides new applications of recent results on integrability of finite-dimensional Lie algebras. As a central theme, it is shown that a number of recent developments in operator algebras may be handled in a particularly e
Hydrologic Derivatives for Modeling and Analysis—A new global high-resolution database
Verdin, Kristine L.
2017-07-17
The U.S. Geological Survey has developed a new global high-resolution hydrologic derivative database. Loosely modeled on the HYDRO1k database, this new database, entitled Hydrologic Derivatives for Modeling and Analysis, provides comprehensive and consistent global coverage of topographically derived raster layers (digital elevation model data, flow direction, flow accumulation, slope, and compound topographic index) and vector layers (streams and catchment boundaries). The coverage of the data is global, and the underlying digital elevation model is a hybrid of three datasets: HydroSHEDS (Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales), GMTED2010 (Global Multi-resolution Terrain Elevation Data 2010), and the SRTM (Shuttle Radar Topography Mission). For most of the globe south of 60°N., the raster resolution of the data is 3 arc-seconds, corresponding to the resolution of the SRTM. For the areas north of 60°N., the resolution is 7.5 arc-seconds (the highest resolution of the GMTED2010 dataset) except for Greenland, where the resolution is 30 arc-seconds. The streams and catchments are attributed with Pfafstetter codes, based on a hierarchical numbering system, that carry important topological information. This database is appropriate for use in continental-scale modeling efforts. The work described in this report was conducted by the U.S. Geological Survey in cooperation with the National Aeronautics and Space Administration Goddard Space Flight Center.
International Nuclear Information System (INIS)
Goan, Hsi-Sheng; Jian, Chung-Chin; Chen, Po-Wen
2010-01-01
We evaluate the non-Markovian finite-temperature two-time correlation functions (CF's) of system operators of a pure-dephasing spin-boson model in two different ways, one by the direct exact operator technique and the other by the recently derived evolution equations, valid to second order in the system-environment interaction Hamiltonian. This pure-dephasing spin-boson model that is exactly solvable has been extensively studied as a simple decoherence model. However, its exact non-Markovian finite-temperature two-time system operator CF's, to our knowledge, have not been presented in the literature. This may be mainly due to the fact, illustrated in this article, that in contrast to the Markovian case, the time evolution of the reduced density matrix of the system (or the reduced quantum master equation) alone is not sufficient to calculate the two-time system operator CF's of non-Markovian open systems. The two-time CF's obtained using the recently derived evolution equations in the weak system-environment coupling case for this non-Markovian pure-dephasing model happen to be the same as those obtained from the exact evaluation. However, these results significantly differ from the non-Markovian two-time CF's obtained by wrongly directly applying the quantum regression theorem (QRT), a useful procedure to calculate the two-time CF's for weak-coupling Markovian open systems. This demonstrates clearly that the recently derived evolution equations generalize correctly the QRT to non-Markovian finite-temperature cases. It is believed that these evolution equations will have applications in many different branches of physics.
Goan, Hsi-Sheng; Jian, Chung-Chin; Chen, Po-Wen
2010-07-01
We evaluate the non-Markovian finite-temperature two-time correlation functions (CF’s) of system operators of a pure-dephasing spin-boson model in two different ways, one by the direct exact operator technique and the other by the recently derived evolution equations, valid to second order in the system-environment interaction Hamiltonian. This pure-dephasing spin-boson model that is exactly solvable has been extensively studied as a simple decoherence model. However, its exact non-Markovian finite-temperature two-time system operator CF’s, to our knowledge, have not been presented in the literature. This may be mainly due to the fact, illustrated in this article, that in contrast to the Markovian case, the time evolution of the reduced density matrix of the system (or the reduced quantum master equation) alone is not sufficient to calculate the two-time system operator CF’s of non-Markovian open systems. The two-time CF’s obtained using the recently derived evolution equations in the weak system-environment coupling case for this non-Markovian pure-dephasing model happen to be the same as those obtained from the exact evaluation. However, these results significantly differ from the non-Markovian two-time CF’s obtained by wrongly directly applying the quantum regression theorem (QRT), a useful procedure to calculate the two-time CF’s for weak-coupling Markovian open systems. This demonstrates clearly that the recently derived evolution equations generalize correctly the QRT to non-Markovian finite-temperature cases. It is believed that these evolution equations will have applications in many different branches of physics.
Cut-HDMR-based fully equivalent operational model for analysis of ...
Indian Academy of Sciences (India)
Abstract. Mesoscale models are highly competent for understanding behaviour of unreinforced masonry structures. Their only limitation is large computational expense. Fully Equivalent Operational Model forms an equivalent mathematical model to represent a particular phenomenon where explicit relationship between.
Simulation modelers increasingly require greater flexibility for model implementation on diverse operating systems, and they demand high computational speed for efficient iterative simulations. Additionally, model users may differ in preference for proprietary versus open-source software environment...
Bhattacharyay, A.
2018-03-01
An alternative equilibrium stochastic dynamics for a Brownian particle in inhomogeneous space is derived. Such a dynamics can model the motion of a complex molecule in its conformation space when in equilibrium with a uniform heat bath. The derivation is done by a simple generalization of the formulation due to Zwanzig for a Brownian particle in homogeneous heat bath. We show that, if the system couples to different number of bath degrees of freedom at different conformations then the alternative model gets derived. We discuss results of an experiment by Faucheux and Libchaber which probably has indicated possible limitation of the Boltzmann distribution as equilibrium distribution of a Brownian particle in inhomogeneous space and propose experimental verification of the present theory using similar methods.
Collective operations in a file system based execution model
Shinde, Pravin; Van Hensbergen, Eric
2013-02-19
A mechanism is provided for group communications using a MULTI-PIPE synthetic file system. A master application creates a multi-pipe synthetic file in the MULTI-PIPE synthetic file system, the master application indicating a multi-pipe operation to be performed. The master application then writes a header-control block of the multi-pipe synthetic file specifying at least one of a multi-pipe synthetic file system name, a message type, a message size, a specific destination, or a specification of the multi-pipe operation. Any other application participating in the group communications then opens the same multi-pipe synthetic file. A MULTI-PIPE file system module then implements the multi-pipe operation as identified by the master application. The master application and the other applications then either read or write operation messages to the multi-pipe synthetic file and the MULTI-PIPE synthetic file system module performs appropriate actions.
Technology Reference Model (TRM) Reports: Technology/Operating System Report
Department of Veterans Affairs — The One VA Enterprise Architecture (OneVA EA) is a comprehensive picture of the Department of Veterans Affairs' (VA) operations, capabilities and services and the...
Optimizing warehouse logistics operations through site selection models : Istanbul, Turkey
Erdemir, Ugur
2003-01-01
Approved for public release; distribution is unlimited This thesis makes a cost benefit analysis of relocating the outdated and earthquake damaged supply distribution center of the Turkish Navy. Given the dynamic environment surrounding the military operations, logistic sustainability requirements, rapid information technology developments, and budget-constrained Turkish DoD acquisition environment, the site selection of a supply distribution center is critical to the future operations and...
Preliminary Hybrid Modeling of the Panama Canal: Operations and Salinity Diffusion
Directory of Open Access Journals (Sweden)
Luis Rabelo
2012-01-01
Full Text Available This paper deals with the initial modeling of water salinity and its diffusion into the lakes during lock operation on the Panama Canal. A hybrid operational model was implemented using the AnyLogic software simulation environment. This was accomplished by generating an operational discrete-event simulation model and a continuous simulation model based on differential equations, which modeled the salinity diffusion in the lakes. This paper presents that unique application and includes the effective integration of lock operations and its impact on the environment.
Directory of Open Access Journals (Sweden)
Delel Dridi
2016-01-01
Full Text Available New chalcones derived from coumarines were synthesized and tested as CDC25 phosphatase inhibitors. Molecular modeling of these new compounds was also presented in aim to study the mode of compounds orientation within CDC25 A and B. The reversibility of compounds 3, 4 and 5 was confirmed by application of MALDI–TOFMS technique.
Deboeck, Pascal R.; Nicholson, Jody; Kouros, Chrystyna; Little, Todd D.; Garber, Judy
2015-01-01
Matching theories about growth, development, and change to appropriate statistical models can present a challenge, which can result in misuse, misinterpretation, and underutilization of different analytical approaches. We discuss the use of "derivatives": the change of a construct with respect to the change in another construct.…
Equity and Foreign Exchange Hybrid Models for Pricing Long-Maturity Financial Derivatives
Grzelak, L.A.
2011-01-01
Modelling derivative products in Finance usually starts with the specification of a system of Stochastic Differential Equations (SDEs), that corresponds to state variables like stock, interest rate, Foreign Exchange (FX) rate and volatility. By correlating the SDEs for the different asset classes
Arabic Language Modeling with Stem-Derived Morphemes for Automatic Speech Recognition
Heintz, Ilana
2010-01-01
The goal of this dissertation is to introduce a method for deriving morphemes from Arabic words using stem patterns, a feature of Arabic morphology. The motivations are three-fold: modeling with morphemes rather than words should help address the out-of-vocabulary problem; working with stem patterns should prove to be a cross-dialectally valid…
Evaluation of MSG-derived global radiation estimates for application in a regional crop model
Roerink, G.J.; Bojanowski, J.S.; Wit, de A.J.W.; Eerens, H.; Supit, I.; Leo, O.; Boogaard, H.L.
2012-01-01
Crop monitoring systems that rely on agrometeorologic models require estimates of global radiation. These estimates are difficult to obtain due to the limited number of weather stations that measure this variable. In the present study, we validated the global radiation estimates derived from
A generalized one-factor term structure model and pricing of interest rate derivative securities
Jiang, George J.
1997-01-01
The purpose of this paper is to propose a nonparametric interest rate term structure model and investigate its implications on term structure dynamics and prices of interest rate derivative securities. The nonparametric spot interest rate process is estimated from the observed short-term interest
Market segment derivation and profiling via a finite mixture model framework
Wedel, M; Desarbo, WS
The Marketing literature has shown how difficult it is to profile market segments derived with finite mixture models. especially using traditional descriptor variables (e.g., demographics). Such profiling is critical for the proper implementation of segmentation strategy. we propose a new finite
Pathway computation in models derived from bio-science text sources
DEFF Research Database (Denmark)
Andreasen, Troels; Bulskov, Henrik; Jensen, Per Anker
2017-01-01
This paper outlines a system, OntoScape, serving to accomplish complex inference tasks on knowledge bases and bio-models derived from life-science text corpora. The system applies so-called natural logic, a form of logic which is readable for humans. This logic affords ontological representations...
Computing Pathways in Bio-Models Derived from Bio-Science Text Sources
DEFF Research Database (Denmark)
Andreasen, Troels; Bulskov, Henrik; Nilsson, Jørgen Fischer
2015-01-01
This paper outlines a system, OntoScape, serving to accomplish complex inference tasks on knowledge bases and bio-models derived from life-science text corpora. The system applies so-called natural logic, a form of logic which is readable for humans. This logic affords ontological representations...
Directory of Open Access Journals (Sweden)
Yang Xiao-Jun
2016-01-01
Full Text Available In this article we propose a new fractional derivative without singular kernel. We consider the potential application for modeling the steady heat-conduction problem. The analytical solution of the fractional-order heat flow is also obtained by means of the Laplace transform.
Polling models with renewal arrivals: a new method to derive heavy-traffic asymptotics
van der Mei, R.D.; Winands, E.M.M.
2008-01-01
We consider asymmetric cyclic polling systems with an arbitrary number of queues, general service-time distributions, zero switch-over times, gated service at each queue, and with general renewal arrival processes at each of the queues. For this classical model, we propose a new method to derive
Measurements on 3D models of human skulls derived from two different cone beam CT scanners
van Vlijmen, Olivier J. C.; Rangel, Frits A.; Bergé, Stefaan J.; Bronkhorst, Ewald M.; Becking, Alfred G.; Kuijpers-Jagtman, Anne Marie
2011-01-01
The aims of this study were to compare measurements on three-dimensional (3D) models of human skulls derived from two different cone beam CT scanners (CBCT) and to evaluate if the used hardware can influence the performed measurements. CBCT scans of 40 dry human skulls with both the i-CAT and the
Operation of the computer model for microenvironment atomic oxygen exposure
Bourassa, R. J.; Gillis, J. R.; Gruenbaum, P. E.
1995-01-01
A computer model for microenvironment atomic oxygen exposure has been developed to extend atomic oxygen modeling capability to include shadowing and reflections. The model uses average exposure conditions established by the direct exposure model and extends the application of these conditions to treat surfaces of arbitrary shape and orientation.
Precise troposphere delay model for Egypt, as derived from radiosonde data
Directory of Open Access Journals (Sweden)
M.A. Abdelfatah
2015-06-01
Real GPS data of six stations in 8-day period were used for the assessment of zenith part of PTD model against the available international models. These international models include Saastamoinen, Hopfield, and the local Egyptian dry model proposed by Mousa & El-Fiky. The data were processed using Bernese software version 5.0. The closure error results indicate that the PTD model is the best model in all session, but when the available radiosonde stations are less, the accuracy of PTD model is near to classic models. As radiosonde data for all ten stations are not available every session, it is recommended to use one of the regularization techniques for database to overcome missing data and derive consistent tropospheric delay information.
Evaluating measurement of dynamic constructs: defining a measurement model of derivatives.
Estabrook, Ryne
2015-03-01
While measurement evaluation has been embraced as an important step in psychological research, evaluating measurement structures with longitudinal data is fraught with limitations. This article defines and tests a measurement model of derivatives (MMOD), which is designed to assess the measurement structure of latent constructs both for analyses of between-person differences and for the analysis of change. Simulation results indicate that MMOD outperforms existing models for multivariate analysis and provides equivalent fit to data generation models. Additional simulations show MMOD capable of detecting differences in between-person and within-person factor structures. Model features, applications, and future directions are discussed. (c) 2015 APA, all rights reserved).
Patient Derived Xenograft Models: An Emerging Platform for Translational Cancer Research
Hidalgo, Manuel; Amant, Frederic; Biankin, Andrew V.; Budinská, Eva; Byrne, Annette T.; Caldas, Carlos; Clarke, Robert B.; de Jong, Steven; Jonkers, Jos; Mælandsmo, Gunhild Mari; Roman-Roman, Sergio; Seoane, Joan; Trusolino, Livio; Villanueva, Alberto
2014-01-01
Recently, there has been increasing interest in the development and characterization of patient derived tumor xenograft (PDX) models for cancer research. PDX models mostly retain the principal histological and genetic characteristics of their donor tumor and remain stable across passages. These models have been shown to be predictive of clinical outcomes and are being used for preclinical drug evaluation, biomarker identification, biological studies, and personalized medicine strategies. This paper summarizes the current state of the art in this field including methodological issues, available collections, practical applications, challenges and shortcoming, and future directions, and introduces a European consortium of PDX models. PMID:25185190
Duplication in a model of rock fracture with fractional derivative without singular kernel
Goufo Emile F. Doungmo; Pene Morgan Kamga; Mwambakana Jeanine N.
2015-01-01
We provide a mathematical analysis of a break-up model with the newly developed Caputo-Fabrizio fractional order derivative with no singular kernel, modeling rock fracture in the ecosystem. Recall that rock fractures play an important role in ecological and geological events, such as groundwater contamination, earthquakes and volcanic eruptions. Hence, in the theory of rock division, especially in eco-geology, open problems like phenomenon of shattering, which remains partially un...
Modeling the diurnal tide with dissipation derived from UARS/HRDI measurements
Directory of Open Access Journals (Sweden)
M. A. Geller
1997-09-01
Full Text Available This paper uses dissipation values derived from UARS/HRDI observations in a recently published diurnal-tide model. These model structures compare quite well with the UARS/HRDI observations with respect to the annual variation of the diurnal tidal amplitudes and the size of the amplitudes themselves. It is suggested that the annual variation of atmospheric dissipation in the mesosphere-lower thermosphere is a major controlling factor in determining the annual variation of the diurnal tide.
Modeling of the influence of transparency of the derivatives market on financial depth
Directory of Open Access Journals (Sweden)
Irina Burdenko
2016-07-01
Full Text Available The market of derivative tools becomes an integral part of the financial market, the functions which are carrying out in it peculiar only to it: hedging, distribution of risks, ensuring liquidity of basic assets, information support of future movement of the prices, decrease in asymmetry of information in the financial markets. However, the insufficiency or lack of transparent information can lead to emergence of the crisis phenomena, shocks in the financial market and growth of system risk. Emergence of need for strengthening of information function of the market of derivatives changes of requirements to transparency of information had been caused by financial crisis of 2008-2009. In this article the attempt of an assessment of influence was made by means of autoregressive models the change of requirements to standard transparency, such as qualitative characteristic of the derivatives market, on quantitative indices of the financial market, in particular financial depth. The results of research demonstrate that reforming of the legislation concerning strengthening of transparency in the derivatives market positively influences the growth of financial depth. The research of this question will promote the best understanding of importance of reforming of regulation of the derivatives market, in particular strengthening of requirements to transparency. Recommendations of the further researches concern the needs of input of reforms of financial regulation in the derivatives market in Ukraine, and, thus, to provide the corresponding conditions for his development
Zhou, H. W.; Yi, H. Y.; Mishnaevsky, L.; Wang, R.; Duan, Z. Q.; Chen, Q.
2017-05-01
A modeling approach to time-dependent property of Glass Fiber Reinforced Polymers (GFRP) composites is of special interest for quantitative description of long-term behavior. An electronic creep machine is employed to investigate the time-dependent deformation of four specimens of dog-bond-shaped GFRP composites at various stress level. A negative exponent function based on structural changes is introduced to describe the damage evolution of material properties in the process of creep test. Accordingly, a new creep constitutive equation, referred to fractional derivative Maxwell model, is suggested to characterize the time-dependent behavior of GFRP composites by replacing Newtonian dashpot with the Abel dashpot in the classical Maxwell model. The analytic solution for the fractional derivative Maxwell model is given and the relative parameters are determined. The results estimated by the fractional derivative Maxwell model proposed in the paper are in a good agreement with the experimental data. It is shown that the new creep constitutive model proposed in the paper needs few parameters to represent various time-dependent behaviors.
International Nuclear Information System (INIS)
Smidts, C.; Shen, S.H.; Mosleh, A.
1997-01-01
This paper is the first of a series of papers describing IDA which is a cognitive model for analysing the behaviour of nuclear power plant operators under accident conditions. The domain of applicability of the model is a relatively constrained environment where behaviour is significantly influenced by high levels of training and explicit requirement to follow written procedures. IDA consists of a model for individual operator behaviour and a model for control room operating crew expanded from the individual model. The model and its derivatives such as an error taxonomy and data collection approach has been designed with ultimate objective of becoming a quantitative method for human reliability analysis (HRA) in probabilistic risk assessment (PRA). The present paper gives a description of the main components of IDA such as memory structure, goals, and problem solving and decision making strategies. It also identifies factors that are at the origin of transitions between goals or between strategies. These factors cover the effects of external conditions and psychological state of the operator. The description is generic at first and then made specific to the nuclear power plant environment and more precisely to abnormal conditions
Ding, Weimin; Zhang, Sheng; Zhu, Meixuan; Wang, Shaoming; Xu, Tao; Qu, Haijing; Yu, Tao; Yan, Xiufeng; Wang, Yang
2017-01-01
Betulinic acid is a lupane-type triterpene firstly extracted from the bark of white birch. It has displayed anti-inflammatory, antioxidant, anti-HIV and selective cytotoxicity. To understand the structure- anti-tumor activity relationship of betulinic acid and betulin derivatives and to synthesize novel anti-tumor derivatives of betulinic acid and betulin. The 3D-QSAR methods including CoMFA and CoMSIA methods were performed to study the structureanti- tumor activity relationship of betulinic acid (BA) and betulin (BE) derivatives. According to the models, near the C-3 site, non-bulky, negatively charged electron-donating, hydrophobic, non-hydrogen-bond-donating and hydrogen-bond-accepting groups are favored to the activity. Around the C-28 site, the bulky, positively charged electron-withdrawing and hydrophobic groups are favored, whereas hydrophilic groups may be introduced at the terminal of the side chain. Based on the models, BA and BE were esterified with substituted amino acid derivatives achieving novel derivatives for the modeling validation. The experimental results verified the modeling rules, and showed when different rules may apply to the new structures, the steric effects might be more important. The synthesized derivatives were showed promising cytotoxicity against tested cancer cell lines. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
Modeling of biopharmaceutical processes. Part 2: Process chromatography unit operation
DEFF Research Database (Denmark)
Kaltenbrunner, Oliver; McCue, Justin; Engel, Philip
2008-01-01
Process modeling can be a useful tool to aid in process development, process optimization, and process scale-up. When modeling a chromatography process, one must first select the appropriate models that describe the mass transfer and adsorption that occurs within the porous adsorbent. The theoret......Process modeling can be a useful tool to aid in process development, process optimization, and process scale-up. When modeling a chromatography process, one must first select the appropriate models that describe the mass transfer and adsorption that occurs within the porous adsorbent...
Modeling the wind-fields of accidental releases with an operational regional forecast model
International Nuclear Information System (INIS)
Albritton, J.R.; Lee, R.L.; Sugiyama, G.
1995-01-01
The Atmospheric Release Advisory Capability (ARAC) is an operational emergency preparedness and response organization supported primarily by the Departments of Energy and Defense. ARAC can provide real-time assessments of atmospheric releases of radioactive materials at any location in the world. ARAC uses robust three-dimensional atmospheric transport and dispersion models, extensive geophysical and dose-factor databases, meteorological data-acquisition systems, and an experienced staff. Although it was originally conceived and developed as an emergency response and assessment service for nuclear accidents, the ARAC system has been adapted to also simulate non-radiological hazardous releases. For example, in 1991 ARAC responded to three major events: the oil fires in Kuwait, the eruption of Mt. Pinatubo in the Philippines, and the herbicide spill into the upper Sacramento River in California. ARAC's operational simulation system, includes two three-dimensional finite-difference models: a diagnostic wind-field scheme, and a Lagrangian particle-in-cell transport and dispersion scheme. The meteorological component of ARAC's real-time response system employs models using real-time data from all available stations near the accident site to generate a wind-field for input to the transport and dispersion model. Here we report on simulation studies of past and potential release sites to show that even in the absence of local meteorological observational data, readily available gridded analysis and forecast data and a prognostic model, the Navy Operational Regional Atmospheric Prediction System, applied at an appropriate grid resolution can successfully simulate complex local flows
High Altitude Venus Operations Concept Trajectory Design, Modeling and Simulation
Lugo, Rafael A.; Ozoroski, Thomas A.; Van Norman, John W.; Arney, Dale C.; Dec, John A.; Jones, Christopher A.; Zumwalt, Carlie H.
2015-01-01
A trajectory design and analysis that describes aerocapture, entry, descent, and inflation of manned and unmanned High Altitude Venus Operation Concept (HAVOC) lighter-than-air missions is presented. Mission motivation, concept of operations, and notional entry vehicle designs are presented. The initial trajectory design space is analyzed and discussed before investigating specific trajectories that are deemed representative of a feasible Venus mission. Under the project assumptions, while the high-mass crewed mission will require further research into aerodynamic decelerator technology, it was determined that the unmanned robotic mission is feasible using current technology.
Weak Memory Models with Matching Axiomatic and Operational Definitions
Zhang, Sizhuo; Vijayaraghavan, Muralidaran; Lustig, Dan; Arvind
2017-01-01
Memory consistency models are notorious for being difficult to define precisely, to reason about, and to verify. More than a decade of effort has gone into nailing down the definitions of the ARM and IBM Power memory models, and yet there still remain aspects of those models which (perhaps surprisingly) remain unresolved to this day. In response to these complexities, there has been somewhat of a recent trend in the (general-purpose) architecture community to limit new memory models to being ...
A new visco-elasto-plastic model via time-space fractional derivative
Hei, X.; Chen, W.; Pang, G.; Xiao, R.; Zhang, C.
2018-02-01
To characterize the visco-elasto-plastic behavior of metals and alloys we propose a new constitutive equation based on a time-space fractional derivative. The rheological representative of the model can be analogous to that of the Bingham-Maxwell model, while the dashpot element and sliding friction element are replaced by the corresponding fractional elements. The model is applied to describe the constant strain rate, stress relaxation and creep tests of different metals and alloys. The results suggest that the proposed simple model can describe the main characteristics of the experimental observations. More importantly, the model can also provide more accurate predictions than the classic Bingham-Maxwell model and the Bingham-Norton model.
Optimal Operational Monetary Policy Rules in an Endogenous Growth Model: a calibrated analysis
Arato, Hiroki
2009-01-01
This paper constructs an endogenous growth New Keynesian model and considers growth and welfare effect of Taylor-type (operational) monetary policy rules. The Ramsey equilibrium and optimal operational monetary policy rule is also computed. In the calibrated model, the Ramseyoptimal volatility of inflation rate is smaller than that in standard exogenous growth New Keynesian model with physical capital accumulation. Optimal operational monetary policy rule makes nominal interest rate respond s...
2016-01-05
Computer-aided transformation of PDE models: languages, representations, and a calculus of operations A domain-specific embedded language called...languages, representations, and a calculus of operations Report Title A domain-specific embedded language called ibvp was developed to model initial...Computer-aided transformation of PDE models: languages, representations, and a calculus of operations 1 Vision and background Physical and engineered systems
Human iPS cell-derived dopaminergic neurons function in a primate Parkinson's disease model.
Kikuchi, Tetsuhiro; Morizane, Asuka; Doi, Daisuke; Magotani, Hiroaki; Onoe, Hirotaka; Hayashi, Takuya; Mizuma, Hiroshi; Takara, Sayuki; Takahashi, Ryosuke; Inoue, Haruhisa; Morita, Satoshi; Yamamoto, Michio; Okita, Keisuke; Nakagawa, Masato; Parmar, Malin; Takahashi, Jun
2017-08-30
Induced pluripotent stem cells (iPS cells) are a promising source for a cell-based therapy to treat Parkinson's disease (PD), in which midbrain dopaminergic neurons progressively degenerate. However, long-term analysis of human iPS cell-derived dopaminergic neurons in primate PD models has never been performed to our knowledge. Here we show that human iPS cell-derived dopaminergic progenitor cells survived and functioned as midbrain dopaminergic neurons in a primate model of PD (Macaca fascicularis) treated with the neurotoxin MPTP. Score-based and video-recording analyses revealed an increase in spontaneous movement of the monkeys after transplantation. Histological studies showed that the mature dopaminergic neurons extended dense neurites into the host striatum; this effect was consistent regardless of whether the cells were derived from patients with PD or from healthy individuals. Cells sorted by the floor plate marker CORIN did not form any tumours in the brains for at least two years. Finally, magnetic resonance imaging and positron emission tomography were used to monitor the survival, expansion and function of the grafted cells as well as the immune response in the host brain. Thus, this preclinical study using a primate model indicates that human iPS cell-derived dopaminergic progenitors are clinically applicable for the treatment of patients with PD.
Transplantation of human stem cell-derived hepatocytes in an animal model of acute liver failure.
Ramanathan, Rajesh; Pettinato, Giuseppe; Beeston, John T; Lee, David D; Wen, Xuejun; Mangino, Martin J; Fisher, Robert A
2015-08-01
Hepatocyte cell transplantation can be life-saving in patients with acute liver failure (ALF); however, primary human hepatocyte transplantation is limited by the scarcity of donor hepatocytes. We investigated the effect of stem cell-derived, hepatocyte-like cells in an animal xenotransplant model of ALF. Intraperitoneal d-galactosamine was used to develop a lethal model of ALF in the rat. Human induced pluripotent stem cells (iPSC), human mesenchymal stem cells, and human iPSC combined with human endothelial cells (iPSC + EC) were differentiated into hepatocyte-like cells and transplanted into the spleens of athymic nude rats with ALF. A reproducible lethal model of ALF was achieved with nearly 90% death within 3 days. Compared with negative controls, rats transplanted with stem cell-derived, hepatocyte-like cells were associated with increased survival. Human albumin was detected in the rat serum 3 days after transplantation in more than one-half the animals transplanted with hepatocyte-like cells. Only animals transplanted with iPSC + EC-derived hepatocytes had serum human albumin at 14 days posttransplant. Transplanted hepatocyte-like cells homed to the injured rat liver, whereas the ECs were only detected in the spleen. Transplantation of stem cell-derived, hepatocyte-like cells improved survival with evidence of in vivo human albumin production. Combining ECs may prolong cell function after transplantation. Copyright © 2015 Elsevier Inc. All rights reserved.
Drainage Structure Datasets and Effects on LiDAR-Derived Surface Flow Modeling
Directory of Open Access Journals (Sweden)
Ruopu Li
2013-12-01
Full Text Available With extraordinary resolution and accuracy, Light Detection and Ranging (LiDAR-derived digital elevation models (DEMs have been increasingly used for watershed analyses and modeling by hydrologists, planners and engineers. Such high-accuracy DEMs have demonstrated their effectiveness in delineating watershed and drainage patterns at fine scales in low-relief terrains. However, these high-resolution datasets are usually only available as topographic DEMs rather than hydrologic DEMs, presenting greater land roughness that can affect natural flow accumulation. Specifically, locations of drainage structures such as road culverts and bridges were simulated as barriers to the passage of drainage. This paper proposed a geospatial method for producing LiDAR-derived hydrologic DEMs, which incorporates data collection of drainage structures (i.e., culverts and bridges, data preprocessing and burning of the drainage structures into DEMs. A case study of GIS-based watershed modeling in South Central Nebraska showed improved simulated surface water derivatives after the drainage structures were burned into the LiDAR-derived topographic DEMs. The paper culminates in a proposal and discussion of establishing a national or statewide drainage structure dataset.
Operational numerical wind-wave model for the Black Sea
Directory of Open Access Journals (Sweden)
A. KORTCHEVA
2000-06-01
Full Text Available In this paper the discrete spectral shallow water wave model named VAGBUHL1 is presented. This model is used for real-time Black Sea state forecasting. The model was verified against satellite ERS-2 altimeter wave height data.
Modeling of biopharmaceutical processes. Part 2: Process chromatography unit operation
DEFF Research Database (Denmark)
Kaltenbrunner, Oliver; McCue, Justin; Engel, Philip
2008-01-01
Process modeling can be a useful tool to aid in process development, process optimization, and process scale-up. When modeling a chromatography process, one must first select the appropriate models that describe the mass transfer and adsorption that occurs within the porous adsorbent. The theoret...
Dobeš, Josef; Grábner, Martin; Puričer, Pavel; Vejražka, František; Míchal, Jan; Popp, Jakub
2017-05-01
Nowadays, there exist relatively precise pHEMT models available for computer-aided design, and they are frequently compared to each other. However, such comparisons are mostly based on absolute errors of drain-current equations and their derivatives. In the paper, a novel method is suggested based on relative root-mean-square errors of both drain current and its derivatives up to the third order. Moreover, the relative errors are subsequently relativized to the best model in each category to further clarify obtained accuracies of both drain current and its derivatives. Furthermore, one our older and two newly suggested models are also included in comparison with the traditionally precise Ahmed, TOM-2 and Materka ones. The assessment is performed using measured characteristics of a pHEMT operating up to 110 GHz. Finally, a usability of the proposed models including the higher-order derivatives is illustrated using s-parameters analysis and measurement at more operating points as well as computation and measurement of IP3 points of a low-noise amplifier of a multi-constellation satellite navigation receiver with ATF-54143 pHEMT.
Modeling and Management of Variation in the Operating Theatre
P.S. Stepaniak (Pieter)
2010-01-01
textabstractAfter having worked in the profit industry, I continued my career in 2004 as a manager of operating rooms (ORs) in a large general teaching hospital in Rotterdam. My experiences in industry management taught me to work efficiently, effectively and to excel in service to every customer
Models, algorithms and performance analysis for adaptive operating room scheduling
G. Xiao (Guanlian); W.L. van Jaarsveld (Willem); M. Dong (Ming); J.J. van de Klundert (Joris)
2017-01-01
textabstractThe complex optimisation problems arising in the scheduling of operating rooms have received considerable attention in recent scientific literature because of their impact on costs, revenues and patient health. For an important part, the complexity stems from the stochastic nature of the
A Dynamic Pricing Model for Coordinated Sales and Operations
M. Fleischmann (Moritz); J.M. Hall (Joseph); D.F. Pyke (David)
2005-01-01
textabstractRecent years have seen advances in research and management practice in the area of pricing, and particularly in dynamic pricing and revenue management. At the same time, researchers and managers have made dramatic improvements in operations and supply chain management. The interactions
Modeling motive activation in the Operant Motives Test
DEFF Research Database (Denmark)
Runge, J. Malte; Lang, Jonas W. B.; Engeser, Stefan
2016-01-01
The Operant Motive Test (OMT) is a picture-based procedure that asks respondents to generate imaginative verbal behavior that is later coded for the presence of affiliation, power, and achievement-related motive content by trained coders. The OMT uses a larger number of pictures and asks...
Model-based Optimization of Oil Recovery : Robust Operational Strategies
Van Essen, G.M.
2015-01-01
The process of depleting an oil reservoir can be poured into an optimal control problem with the objective to maximize economic performance over the life of the ?eld. Despite its large potential, life-cycle optimization has not yet found its way into operational environments. The objective of this
Steam boilers : Process models for improved operation and design
Ahnert, F.
2007-01-01
Biomass combustion can be an economic way to contribute to the reduction of CO2 emissions, which are a main suspect of the so-called greenhouse effect. In order to promote a widespread utilization of biomass combustion, operational problems like fuel treatment, slagging, fouling and corrosion have
TECHNOLOGICAL PROCESS MODELING AIMING TO IMPROVE ITS OPERATIONS MANAGEMENT
Directory of Open Access Journals (Sweden)
Ivan Mihajlović
2011-11-01
Full Text Available This paper presents the modeling procedure of one real technological system. In this study, thecopper extraction from the copper flotation waste generated at the Bor Copper Mine (Serbia, werethe object of modeling. Sufficient data base for statistical modeling was constructed using theorthogonal factorial design of the experiments. Mathematical model of investigated system wasdeveloped using the combination of linear and multiple linear statistical analysis approach. Thepurpose of such a model is obtaining optimal states of the system that enable efficient operationsmanagement. Besides technological and economical, ecological parameters of the process wereconsidered as crucial input variables.
Operational Semantics of a Weak Memory Model inspired by Go
Fava, Daniel Schnetzer; Stolz, Volker; Valle, Stian
2017-01-01
A memory model dictates which values may be returned when reading from memory. In a parallel computing setting, the memory model affects how processes communicate through shared memory. The design of a proper memory model is a balancing act. On one hand, memory models must be lax enough to allow common hardware and compiler optimizations. On the other, the more lax the model, the harder it is for developers to reason about their programs. In order to alleviate the burden on programmers, a wea...
Directory of Open Access Journals (Sweden)
Renée El-Gabalawy
2017-08-01
Full Text Available Introduction: Risk assessment for post-operative delirium (POD is poorly developed. Improved metrics could greatly facilitate peri-operative care as costs associated with POD are staggering. In this preliminary study, we develop a novel stress-diathesis model based on comprehensive pre-operative psychiatric and neuropsychological testing, a blood oxygenation level-dependent (BOLD magnetic resonance imaging (MRI carbon dioxide (CO2 stress test, and high fidelity measures of intra-operative parameters that may interact facilitating POD.Methods: The study was approved by the ethics board at the University of Manitoba and registered at clinicaltrials.gov as NCT02126215. Twelve patients were studied. Pre-operative psychiatric symptom measures and neuropsychological testing preceded MRI featuring a BOLD MRI CO2 stress test whereby BOLD scans were conducted while exposing participants to a rigorously controlled CO2 stimulus. During surgery the patient had hemodynamics and end-tidal gases downloaded at 0.5 hz. Post-operatively, the presence of POD and POD severity was comprehensively assessed using the Confusion Assessment Measure –Severity (CAM-S scoring instrument on days 0 (surgery through post-operative day 5, and patients were followed up at least 1 month post-operatively.Results: Six of 12 patients had no evidence of POD (non-POD. Three patients had POD and 3 had clinically significant confusional states (referred as subthreshold POD; ST-POD (score ≥ 5/19 on the CAM-S. Average severity for delirium was 1.3 in the non-POD group, 3.2 in ST-POD, and 6.1 in POD (F-statistic = 15.4, p < 0.001. Depressive symptoms, and cognitive measures of semantic fluency and executive functioning/processing speed were significantly associated with POD. Second level analysis revealed an increased inverse BOLD responsiveness to CO2 pre-operatively in ST-POD and marked increase in the POD groups when compared to the non-POD group. An association was also noted for
Directory of Open Access Journals (Sweden)
Koca Ilknur
2017-01-01
Full Text Available Recently Hristov using the concept of a relaxation kernel with no singularity developed a new model of elastic heat diffusion equation based on the Caputo-Fabrizio fractional derivative as an extended version of Cattaneo model of heat diffusion equation. In the present article, we solve exactly the Cattaneo-Hristov model and extend it by the concept of a derivative with non-local and non-singular kernel by using the new Atangana-Baleanu derivative. The Cattaneo-Hristov model with the extended derivative is solved analytically with the Laplace transform, and numerically using the Crank-Nicholson scheme.
A constitutive rheological model for agglomerating blood derived from nonequilibrium thermodynamics
Tsimouri, Ioanna Ch.; Stephanou, Pavlos S.; Mavrantzas, Vlasis G.
2018-03-01
Red blood cells tend to aggregate in the presence of plasma proteins, forming structures known as rouleaux. Here, we derive a constitutive rheological model for human blood which accounts for the formation and dissociation of rouleaux using the generalized bracket formulation of nonequilibrium thermodynamics. Similar to the model derived by Owens and co-workers ["A non-homogeneous constitutive model for human blood. Part 1. Model derivation and steady flow," J. Fluid Mech. 617, 327-354 (2008)] through polymer network theory, each rouleau in our model is represented as a dumbbell; the corresponding structural variable is the conformation tensor of the dumbbell. The kinetics of rouleau formation and dissociation is treated as in the work of Germann et al. ["Nonequilibrium thermodynamic modeling of the structure and rheology of concentrated wormlike micellar solutions," J. Non-Newton. Fluid Mech. 196, 51-57 (2013)] by assuming a set of reversible reactions, each characterized by a forward and a reverse rate constant. The final set of evolution equations for the microstructure of each rouleau and the expression for the stress tensor turn out to be very similar to those of Owens and co-workers. However, by explicitly considering a mechanism for the formation and breakage of rouleaux, our model further provides expressions for the aggregation and disaggregation rates appearing in the final transport equations, which in the kinetic theory-based network model of Owens were absent and had to be specified separately. Despite this, the two models are found to provide similar descriptions of experimental data on the size distribution of rouleaux.
Directory of Open Access Journals (Sweden)
Shiqian Nie
2017-01-01
Full Text Available The fractional advection-diffusion equation (fADE model is a new approach to describe the vertical distribution of suspended sediment concentration in steady turbulent flow. However, the advantages and parameter definition of the fADE model in describing the sediment suspension distribution are still unclear. To address this knowledge gap, this study first reviews seven models, including the fADE model, for the vertical distribution of suspended sediment concentration in steady turbulent flow. The fADE model, among others, describes both Fickian and non-Fickian diffusive characteristics of suspended sediment, while the other six models assume that the vertical diffusion of suspended sediment follows Fick’s first law. Second, this study explores the sensitivity of the fractional index of the fADE model to the variation of particle sizes and sediment settling velocities, based on experimental data collected from the literatures. Finally, empirical formulas are developed to relate the fractional derivative order to particle size and sediment settling velocity. These formulas offer river engineers a substitutive way to estimate the fractional derivative order in the fADE model.
Ability of silybin and its derivatives to prevent protein oxidation in different model systems
DEFF Research Database (Denmark)
Purchartová, K.; Baron, C.P.; Křen, V.
2013-01-01
to prevent activation of hemoglobin (Hb) to highly reactive hypervalent heme protein species (ferrylHb and perferrylHb) was examined. Indeed, Hb cytotoxicity has been associated with the generation of protein radicals, which are formed when the ferric iron of Hb (Fe3+) is oxidised by H2O2 to (Fe4+) to form...... perferrylHb and ferrylHb, with the later also bearing a radical on its protein. The relationship between the structural properties of silybin and its derivatives and their ability to prevent oxidation of Hb was investigated in model system in the presence or the absence of lipids. The antioxidant activities...... of silybin, dehydrosilybin, 23-O-butanoyl and 23-O-palmitoyl silybin derivatives were correlated with their interaction with Hb species. Results are discussed in relation to the potential of dehydrosilybin, silybin and C4 and C16 derivates to prevent activation of Hb to hypevalent heme protein species....
The Impact of Microwave-Derived Surface Soil Moisture on Watershed Hydrological Modeling
ONeill, P. E.; Hsu, A. Y.; Jackson, T. J.; Wood, E. F.; Zion, M.
1997-01-01
The usefulness of incorporating microwave-derived soil moisture information in a semi-distributed hydrological model was demonstrated for the Washita '92 experiment in the Little Washita River watershed in Oklahoma. Initializing the hydrological model with surface soil moisture fields from the ESTAR airborne L-band microwave radiometer on a single wet day at the start of the study period produced more accurate model predictions of soil moisture than a standard hydrological initialization with streamflow data over an eight-day soil moisture drydown.
International Nuclear Information System (INIS)
Chang, Y.H.J.; Mosleh, A.
2007-01-01
This is the fourth in a series of five papers describing the Information, Decision, and Action in Crew context (IDAC) operator response model for human reliability analysis. An example application of this modeling technique is also discussed in this series. The model has been developed to probabilistically predicts the responses of a nuclear power plant control room operating crew in accident conditions. The operator response spectrum includes cognitive, emotional, and physical activities during the course of an accident. This paper assesses the effects of the performance-influencing factors (PIFs) affecting the operators' problem-solving responses including information pre-processing (I), diagnosis and decision making (D), and action execution (A). Literature support and justifications are provided for the assessment on the influences of PIFs
What should a 'good' model of the NPP operator contain
International Nuclear Information System (INIS)
Bainbridge, L.
1986-01-01
Much of human factors design is done without reference to models. A 'scientific' cognitive model contains multi-level goal-oriented top-down processing, in which behaviour choice depends on working memory, mental and environmental constraints, and expected results. Simpler models are more practical for supporting 0 behaviour, or predicting performance limits. Many types of reason make numerical predictions of cognitive behaviour non trivial
Intelligent decision-making models for production and retail operations
Guo, Zhaoxia
2016-01-01
This book provides an overview of intelligent decision-making techniques and discusses their application in production and retail operations. Manufacturing and retail enterprises have stringent standards for using advanced and reliable techniques to improve decision-making processes, since these processes have significant effects on the performance of relevant operations and the entire supply chain. In recent years, researchers have been increasingly focusing attention on using intelligent techniques to solve various decision-making problems. The opening chapters provide an introduction to several commonly used intelligent techniques, such as genetic algorithm, harmony search, neural network and extreme learning machine. The book then explores the use of these techniques for handling various production and retail decision-making problems, such as production planning and scheduling, assembly line balancing, and sales forecasting.
Böttcher, N.; Nagel, T.; Goerke, U.; Khaledi, K.; Lins, Y.; König, D.; Schanz, T.; Köhn, D.; Attia, S.; Rabbel, W.; Bauer, S.; Kolditz, O.
2013-12-01
In the course of the Energy Transition in Germany, the focus of the country's energy sources is shifting from fossil to renewable and sustainable energy carriers. Since renewable energy sources, such as wind and solar power, are subjected to annual, seasonal, and diurnal fluctuations, the development and extension of energy storage capacities is a priority in German R&D programs. Common methods of energy storage are the utilization of subsurface caverns as a reservoir for natural or artificial fuel gases, such as hydrogen, methane, or the storage of compressed air. The construction of caverns in salt rock is inexpensive in comparison to solid rock formations due to the possibility of solution mining. Another advantage of evaporite as a host material is the self-healing capacity of salt rock. Gas caverns are capable of short-term energy storage (hours to days), so the operating pressures inside the caverns are fluctuating periodically with a high number of cycles. This work investigates the influence of fluctuating operation pressures on the stability of the host rock of gas storage caverns utilizing numerical models. Therefore, we developed a coupled Thermo-Hydro-Mechanical (THM) model based on the finite element method utilizing the open-source software platform OpenGeoSys. Our simulations include the thermodynamic behaviour of the gas during the loading/ unloading of the cavern. This provides information on the transient pressure and temperature distribution on the cavern boundary to calculate the deformation of its geometry. Non-linear material models are used for the mechanical analysis, which describe the creep and self-healing behavior of the salt rock under fluctuating loading pressures. In order to identify the necessary material parameters, we perform experimental studies on the mechanical behaviour of salt rock under varying pressure and temperature conditions. Based on the numerical results, we further derive concepts for monitoring THM quantities in the
No-ghost theorem for the fourth-order derivative Pais-Uhlenbeck oscillator model.
Bender, Carl M; Mannheim, Philip D
2008-03-21
A new realization of the fourth-order derivative Pais-Uhlenbeck oscillator is constructed. This realization possesses no states of negative norm and has a real energy spectrum that is bounded below. The key to this construction is the recognition that in this realization the Hamiltonian is not Dirac Hermitian. However, the Hamiltonian is symmetric under combined space reflection P and time reversal T. The Hilbert space that is appropriate for this PT-symmetric Hamiltonian is identified and it is found to have a positive-definite inner product. Furthermore, the time-evolution operator is unitary.
Rapid screening of operational freshwater availability using global models
Straatsma, M.W.; Vermeulen, P.; Kuijper, Marijn; Bonte, Matthijs; Niele, Frank; Bierkens, M.F.P.
2016-01-01
Freshwater shortage already affects large parts of the world, and is expected to increase rapidly over the coming decades as a result of increased water demands and the impacts of climate change. Global-scale water risk or stress maps are available online, but these lack quantitative information on local freshwater availability, rendering them unsuitable for water risk assessment from an operational perspective, i.e. when comparing water availability to a specific quantified water demand (in ...
Operational results from a physical power prediction model
Energy Technology Data Exchange (ETDEWEB)
Landberg, L. [Risoe National Lab., Meteorology and Wind Energy Dept., Roskilde (Denmark)
1999-03-01
This paper will describe a prediction system which predicts the expected power output of a number of wind farms. The system is automatic and operates on-line. The paper will quantify the accuracy of the predictions and will also give examples of the performance for specific storm events. An actual implementation of the system will be described and the robustness demonstrated. (au) 11 refs.
Using Multiple Satellite-derived Water Levels to Inform Hydrodynamic Model in Sparsely Gauged Areas
Pham, H. T.; Marshall, L. A.; Johnson, F.; Sharma, A.
2017-12-01
Satellite radar altimetry from different orbits such as ENVISAT (35-day), Jason-2 (10-day), or CryoSat-2 (369-day) have been used as input data in hydrodynamic models for calibration, parameter estimation, or data assimilation. Due to coarse temporal resolutions, satellite altimeters are usually combined with in-situ data to improve their temporal resolutions and thereby improve model outputs. However, in sparsely gauged areas, using only low temporal resolution satellite altimeters without any complementation of in-situ river heights causes poor model performances. To improve hydrodynamic models in such areas, a method is required to complement high frequent satellite altimeters without using in-situ data. Here we propose a method to supplement 10-day Jason-2 satellite altimetry to produce daily water levels using multiple remotely sensed datasets rather than using in-situ data. A simple seasonal linear regression model is developed of the relationship between Jason-2 satellite altimetry to the difference in day and night land surface temperature (ΔLST) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua land surface temperature products, satellite precipitation obtained from the Global Satellite Mapping of Precipitation (GSMAP) product, and satellite soil moisture retrieved from the Soil Moisture and Ocean Salinity (SMOS) product. The main aims of this study are (1) to evaluate the applicability of the daily multiple satellite-derived water levels in hydrodynamic models, and (2) to assess the propagation of uncertainty of multiple satellite datasets to model outputs. A Monte Carlo approach is used to incorporate the errors from multiple satellite input datasets. We apply the methodology at several locations to ensure that the proposed method is robust and reliable. The results indicate the potential of using multiple satellite-derived water levels for hydrodynamic models and other applications in sparsely gauged areas.
The effect of dietary fatty acids on post-operative inflammatory response in a porcine model
DEFF Research Database (Denmark)
Langerhuus, Sine Nygaard; Jensen, Karin Hjelholt; Tønnesen, Else Kirstine
2012-01-01
), sunflower oil (SO, n 28), or animal fat (AF, n 28) was evaluated with respect to post-operative responses in inflammatory markers in a porcine model on aortic vascular prosthetic graft infection. In the early post-operative period (0 ...-operative response in a number of inflammatory markers was affected by FO, and this was most apparent compared with SO....
Operating Comfort Prediction Model of Human-Machine Interface Layout for Cabin Based on GEP.
Deng, Li; Wang, Guohua; Chen, Bo
2015-01-01
In view of the evaluation and decision-making problem of human-machine interface layout design for cabin, the operating comfort prediction model is proposed based on GEP (Gene Expression Programming), using operating comfort to evaluate layout scheme. Through joint angles to describe operating posture of upper limb, the joint angles are taken as independent variables to establish the comfort model of operating posture. Factor analysis is adopted to decrease the variable dimension; the model's input variables are reduced from 16 joint angles to 4 comfort impact factors, and the output variable is operating comfort score. The Chinese virtual human body model is built by CATIA software, which will be used to simulate and evaluate the operators' operating comfort. With 22 groups of evaluation data as training sample and validation sample, GEP algorithm is used to obtain the best fitting function between the joint angles and the operating comfort; then, operating comfort can be predicted quantitatively. The operating comfort prediction result of human-machine interface layout of driller control room shows that operating comfort prediction model based on GEP is fast and efficient, it has good prediction effect, and it can improve the design efficiency.
Mint3 in bone marrow-derived cells promotes lung metastasis in breast cancer model mice.
Hara, Toshiro; Murakami, Yoshinori; Seiki, Motoharu; Sakamoto, Takeharu
2017-08-26
Breast cancer is one of the most common cancers in women in the world. Although breast cancer is well treatable at the early stage, patients with distant metastases show a poor prognosis. Data from recent studies using transplantation models indicate that Mint3/APBA3 might promote breast cancer malignancy. However, whether Mint3 indeed contributes to tumor development, progression, or metastasis in vivo remains unclear. To address this, here we examined whether Mint3 depletion affects tumor malignancy in MMTV-PyMT breast cancer model mice. In MMTV-PyMT mice, Mint3 depletion did not affect tumor onset and tumor growth, but attenuated lung metastases. Experimental lung metastasis of breast cancer Met-1 cells derived from MMTV-PyMT mice also decreased in Mint3-depleted mice, indicating that host Mint3 expression affected lung metastasis of MMTV-PyMT-derived breast cancer cells. Further bone marrow transplant experiments revealed that Mint3 in bone marrow-derived cells promoted lung metastasis in MMTV-PyMT mice. Thus, targeting Mint3 in bone marrow-derived cells might be a good strategy for preventing metastasis and improving the prognosis of breast cancer patients. Copyright © 2017 Elsevier Inc. All rights reserved.
Human primary liver cancer-derived organoid cultures for disease modeling and drug screening.
Broutier, Laura; Mastrogiovanni, Gianmarco; Verstegen, Monique Ma; Francies, Hayley E; Gavarró, Lena Morrill; Bradshaw, Charles R; Allen, George E; Arnes-Benito, Robert; Sidorova, Olga; Gaspersz, Marcia P; Georgakopoulos, Nikitas; Koo, Bon-Kyoung; Dietmann, Sabine; Davies, Susan E; Praseedom, Raaj K; Lieshout, Ruby; IJzermans, Jan N M; Wigmore, Stephen J; Saeb-Parsy, Kourosh; Garnett, Mathew J; van der Laan, Luc Jw; Huch, Meritxell
2017-12-01
Human liver cancer research currently lacks in vitro models that can faithfully recapitulate the pathophysiology of the original tumor. We recently described a novel, near-physiological organoid culture system, wherein primary human healthy liver cells form long-term expanding organoids that retain liver tissue function and genetic stability. Here we extend this culture system to the propagation of primary liver cancer (PLC) organoids from three of the most common PLC subtypes: hepatocellular carcinoma (HCC), cholangiocarcinoma (CC) and combined HCC/CC (CHC) tumors. PLC-derived organoid cultures preserve the histological architecture, gene expression and genomic landscape of the original tumor, allowing for discrimination between different tumor tissues and subtypes, even after long-term expansion in culture in the same medium conditions. Xenograft studies demonstrate that the tumorogenic potential, histological features and metastatic properties of PLC-derived organoids are preserved in vivo. PLC-derived organoids are amenable for biomarker identification and drug-screening testing and led to the identification of the ERK inhibitor SCH772984 as a potential therapeutic agent for primary liver cancer. We thus demonstrate the wide-ranging biomedical utilities of PLC-derived organoid models in furthering the understanding of liver cancer biology and in developing personalized-medicine approaches for the disease.
Barnes-Holmes, Dermot; Regan, Donal; Barnes-Holmes, Yvonne; Commins, Sean; Walsh, Derek; Stewart, Ian; Smeets, Paul M; Whelan, Robert; Dymond, Simon
2005-11-01
The current study aimed to test a Relational Frame Theory (RFT) model of analogical reasoning based on the relating of derived same and derived difference relations. Experiment 1 recorded reaction time measures of similar-similar (e.g., "apple is to orange as dog is to cat") versus different-different (e.g., "he is to his brother as chalk is to cheese") derived relational responding, in both speed-contingent and speed-noncontingent conditions. Experiment 2 examined the event-related potentials (ERPs) associated with these two response patterns. Both experiments showed similar-similar responding to be significantly faster than different-different responding. Experiment 2 revealed significant differences between the waveforms of the two response patterns in the left-hemispheric prefrontal regions; different-different waveforms were significantly more negative than similar-similar waveforms. The behavioral and neurophysiological data support the RFT prediction that, all things being equal, similar-similar responding is relationally "simpler" than, and functionally distinct from, different-different analogical responding. The ERP data were fully consistent with findings in the neurocognitive literature on analogy. These findings strengthen the validity of the RFT model of analogical reasoning and supplement the behavior-analytic approach to analogy based on the relating of derived relations.
Liang, Yingjie; Chen, Wen
2018-03-01
Ultraslow diffusion has been observed in numerous complicated systems. Its mean squared displacement (MSD) is not a power law function of time, but instead a logarithmic function, and in some cases grows even more slowly than the logarithmic rate. The distributed-order fractional diffusion equation model simply does not work for the general ultraslow diffusion. Recent study has used the local structural derivative to describe ultraslow diffusion dynamics by using the inverse Mittag-Leffler function as the structural function, in which the MSD is a function of inverse Mittag-Leffler function. In this study, a new stretched logarithmic diffusion law and its underlying non-local structural derivative diffusion model are proposed to characterize the ultraslow diffusion in aging dense colloidal glass at both the short and long waiting times. It is observed that the aging dynamics of dense colloids is a class of the stretched logarithmic ultraslow diffusion processes. Compared with the power, the logarithmic, and the inverse Mittag-Leffler diffusion laws, the stretched logarithmic diffusion law has better precision in fitting the MSD of the colloidal particles at high densities. The corresponding non-local structural derivative diffusion equation manifests clear physical mechanism, and its structural function is equivalent to the first-order derivative of the MSD.
Directory of Open Access Journals (Sweden)
Abdon Atangana
2014-01-01
Full Text Available The notion of uncertainty in groundwater hydrology is of great importance as it is known to result in misleading output when neglected or not properly accounted for. In this paper we examine this effect in groundwater flow models. To achieve this, we first introduce the uncertainties functions u as function of time and space. The function u accounts for the lack of knowledge or variability of the geological formations in which flow occur (aquifer in time and space. We next make use of Riemann-Liouville fractional derivatives that were introduced by Kobelev and Romano in 2000 and its approximation to modify the standard version of groundwater flow equation. Some properties of the modified Riemann-Liouville fractional derivative approximation are presented. The classical model for groundwater flow, in the case of density-independent flow in a uniform homogeneous aquifer is reformulated by replacing the classical derivative by the Riemann-Liouville fractional derivatives approximations. The modified equation is solved via the technique of green function and the variational iteration method.
Modeling contractor and company employee behavior in high hazard operation
Lin, P.H.; Hanea, D.; Ale, B.J.M.
2013-01-01
The recent blow-out and subsequent environmental disaster in the Gulf of Mexico have highlighted a number of serious problems in scientific thinking about safety. Risk models have generally concentrated on technical failures, which are easier to model and for which there are more concrete data.
A Modified Model to Estimate Building Rental Multipiers Accounting for Advalorem Operating Expenses
Directory of Open Access Journals (Sweden)
Smolyak S.A.
2016-09-01
Full Text Available To develop ideas on building element valuation contained in the first article on the subject published in REMV, we propose an elaboration of the approach accounting for ad valorem expenses incidental to property management, such as land taxes, income/capital gains tax, and insurance premium costs; all such costs, being of an ad valorem nature in the first instance, cause circularity in the logic of the model, which, however, is not intractable under the proposed approach. The resulting formulas for carrying out practical estimation of building rental multipliers and, in consequence, of building values, turn out to be somewhat modified, and we demonstrate the sensitivity of the developed approach to the impact of these ad valorem factors. On the other hand, it is demonstrated that (accounting for building depreciation charges, which should seemingly be included among the considered ad valorem factors, cancel out and do not have any impact on the resulting estimates. However, treating the depreciation of buildings in quantifiable economic terms as a reduction in derivable operating benefits over time (instead of mere physical indications, such as age, we also demonstrate that the approach has implications for estimating the economic service lives of buildings and can be practical when used in conjunction with the market-related approach to valuation – from which the requisite model inputs can be extracted as shown in the final part of the paper.
Modeling the operational risk in Iranian commercial banks: case study of a private bank
Momen, Omid; Kimiagari, Alimohammad; Noorbakhsh, Eaman
2012-08-01
The Basel Committee on Banking Supervision from the Bank for International Settlement classifies banking risks into three main categories including credit risk, market risk, and operational risk. The focus of this study is on the operational risk measurement in Iranian banks. Therefore, issues arising when trying to implement operational risk models in Iran are discussed, and then, some solutions are recommended. Moreover, all steps of operational risk measurement based on Loss Distribution Approach with Iran's specific modifications are presented. We employed the approach of this study to model the operational risk of an Iranian private bank. The results are quite reasonable, comparing the scale of bank and other risk categories.
Overall feature of EAST operation space by using simple Core-SOL-Divertor model
International Nuclear Information System (INIS)
Hiwatari, R.; Hatayama, A.; Zhu, S.; Takizuka, T.; Tomita, Y.
2005-01-01
We have developed a simple Core-SOL-Divertor (C-S-D) model to investigate qualitatively the overall features of the operational space for the integrated core and edge plasma. To construct the simple C-S-D model, a simple core plasma model of ITER physics guidelines and a two-point SOL-divertor model are used. The simple C-S-D model is applied to the study of the EAST operational space with lower hybrid current drive experiments under various kinds of trade-off for the basic plasma parameters. Effective methods for extending the operation space are also presented. As shown by this study for the EAST operation space, it is evident that the C-S-D model is a useful tool to understand qualitatively the overall features of the plasma operation space. (author)
Energy Technology Data Exchange (ETDEWEB)
Schoeling, L.G.
1993-09-01
This report describes the development and testing of the Kansas Technology Transfer Model (KTTM) which is to be utilized as a regional model for the development of other technology transfer programs for independent operators throughout oil-producing regions in the US. It describes the linkage of the regional model with a proposed national technology transfer plan, an evaluation technique for improving and assessing the model, and the methodology which makes it adaptable on a regional basis. The report also describes management concepts helpful in managing a technology transfer program. The original Tertiary Oil Recovery Project (TORP) activities, upon which the KTTM is based, were developed and tested for Kansas and have proved to be effective in assisting independent operators in utilizing technology. Through joint activities of TORP and the Kansas Geological Survey (KGS), the KTTM was developed and documented for application in other oil-producing regions. During the course of developing this model, twelve documents describing the implementation of the KTTM were developed as deliverables to DOE. These include: (1) a problem identification (PI) manual describing the format and results of six PI workshops conducted in different areas of Kansas, (2) three technology workshop participant manuals on advanced waterflooding, reservoir description, and personal computer applications, (3) three technology workshop instructor manuals which provides instructor material for all three workshops, (4) three technologies were documented as demonstration projects which included reservoir management, permeability modification, and utilization of a liquid-level acoustic measuring device, (5) a bibliography of all literature utilized in the documents, and (6) a document which describes the KTTM.
Czech Academy of Sciences Publication Activity Database
Pivokonský, Radek; Filip, Petr; Zelenková, Jana
2015-01-01
Roč. 4, č. 293 (2015), s. 1227-1236 ISSN 0303-402X Institutional support: RVO:67985874 Keywords : constitutive model * Gordon-Schowalter derivative * PTT model * PTT-XPP model * shear flow * elongational flow Subject RIV: BK - Fluid Dynamics Impact factor: 1.890, year: 2015 http://download.springer.com/ static /pdf/707/art%253A10.1007%252Fs00396-015-3498-7.pdf?auth66=1426682430_7112efb47b46fdc0a8ab81568fe83505&ext=.pdf
EDM - A model for optimising the short-term power operation of a complex hydroelectric network
International Nuclear Information System (INIS)
Tremblay, M.; Guillaud, C.
1996-01-01
In order to optimize the short-term power operation of a complex hydroelectric network, a new model called EDM was added to PROSPER, a water management analysis system developed by SNC-Lavalin. PROSPER is now divided into three parts: an optimization model (DDDP), a simulation model (ESOLIN), and an economic dispatch model (EDM) for the short-term operation. The operation of the KSEB hydroelectric system (located in southern India) with PROSPER was described. The long-term analysis with monthly time steps is assisted by the DDDP, and the daily analysis with hourly or half-hourly time steps is performed with the EDM model. 3 figs
Testing sensitivity of the LISFLOOD subgrid hydraulic model to SAR image derived information
Wood, Melissa; Bates, Paul; Neal, Jeff; Hostache, Renaud; Matgen, Patrick; Chini, Marco; Giustarini, Laura
2013-04-01
There has been much interest in the use of Synthetic Aperture Radar (SAR) images to indirectly estimate flood extent and flood elevation to aid the understanding of fluvial flood inundation processes. SAR remote sensing satellites are capable of all-weather day/night observations that can discriminate between land and smooth open water surfaces over large scales. By combining SAR derived information with 2D hydraulic models and terrain data, the mechanisms of flooding can be better simulated therefore enabling more accurate and reliable flood forecasting. The objective of this study is to test the sensitivity of a LISFLOOD subgrid 2D model to its main parameters (i.e. roughness coefficient, river bathymetry) using SAR derived flood extent maps. Because of SAR imaging techniques and processing steps used to derive the flood information, any SAR-derived flood extent image will contain inherent uncertainty. We therefore use the uncertainty of the SAR information to obtain a range of plausible parameters to test sensitivity of the hydraulic model. LISFLOOD is a distributed 2D model developed at the University of Bristol and designed for use with larger ungauged river catchments. The version used employs a subgrid procedure which allows any size of river channel below that of the grid resolution to be represented. This procedure has been shown to improve hydraulic connectivity within the modelled flooded area and thus improve flood prediction for data sparse areas. A hydrodynamic LISFLOOD subgrid model of the River Severn at Tewkesbury covering a domain area of 50x70km and including the confluence with a major tributary (the River Avon) will be utilised. A complete storm hydrograph will be used as inflow to the model to simulate the full flood event. Surveyed cross section and gauged daily flows are also available for the River Severn. Therefore, the model results using variable parameters can be compared against results obtained from ground observations to further
Matsuda, Sanae; Hisama, Masayoshi; Shibayama, Hiroharu; Itou, Norihiko; Iwaki, Masahiro
2009-05-01
We have developed the Rabbit Corneal Epithelial (RCE) Model to evaluate the in vitro eye irritation potential of chemicals including pharmaceuticals, cosmetics and their raw ingredients. In the model, a stratified culture of rabbit corneal epithelial cells is grown at the air-liquid interface on an amnion acting as a parabasal membrane. The alkaline exposure was restored each day in the presence of no irritants, although with the addition of sodium lauryl sulfate (SLS), which is a major irritant, the restoration of deficit was inhibited on the RCE model in a dose-dependent manner. The results of this test were comparable with those of the Draize test, and thus, this method using the RCE model may prove to be a useful and sensitive in vitro eye irritation test. The in vitro eye irritation potential of polyoxyethylene alkyl derivatives, polyoxyethylene lauryl ether (PLE), polyoxyethylene cetyl ether (PCE), polyoxyethylene stearyl ether (PSE), polyoxyethylene oleyl ether (POE), and polyoxyethylene behenyl ether (PBE) were evaluated using the RCE model containing an alkaline exposure. POE inhibited 90.2% of the restoration of deficit at a concentration of 0.5% on the 4th day after addition. Depending on the structure, an activity relationship was defined. The polyoxyethylene alkyl derivatives had distinctly different inhibitory potencies against the restoration of deficit, according to their substitution patterns. POE inhibited the restoration of deficit greater than other polyoxyethylene alkyl derivatives on the RCE model. These results indicated that the oleyl chain of POE is an important factor for inhibiting the restoration of deficit on the RCE model.
Operational Modelling of the Aerospace Propagation Environment. Volume II
1978-11-01
radiative transfer models are rarely available in a battlefield environment. tnly secondary ECNET parameters may be available. Hence, current modeling and...adopthe done lee traitements a 6tA de remplacer chaque valeur X4Dar son rang. Clest-h-diro quo Zj eet rermplacO pax Is nombre d’dohant~illons do X. qui...out uslub r -aItistial model relevant to thobe arcac If the Urt chooses a terraln typ- from the lIs- glvtn ,hov, a stetistlcol ’irregulal terr .’n
Cavazzoni, J.
System-level analyses for Advanced Life Support (ALS) require mathematical models for various processes, such as biomass production and waste management, which would ideally be integrated into overall system models. Explanatory models (also referred to as mechanistic or process models) would provide the basis for a more robust system model, as these would be based on an understanding of processes specific to ALS studies. However, integrating such models may not always be practicable because of their complexity, especially for initial system-level analyses where simple sub-models may be satisfactory. One way to address this is to capture important features of explanatory models in simple models that may be readily integrated for system-level analyses. In this paper, explanatory crop models were used to generate parameters and multi-variable polynomial equations for basic models that are suitable for estimating the direction and magnitude of daily changes in canopy gas-exchange, harvest index, and production scheduling due to off- nominal conditions for ALS system studies. The simplest variant of these models consists of only a few equations, and has been integrated into a top-level SIMULINK model for the Bioregenerative Planetary Life Support Systems Test Complex (BIO-Plex), a large-scale human-rated test facility under development at NASA Johnson Space Center. When included in systems studies, the simple crop models may help identify issues that need to be addressed using more detailed modeling studies and specific experiments. Similar modeling simplifications may also prove useful for other ALS sub-systems, as well as for Earth system applications.
Modelling and simulation of a dynamical system with the Atangana-Baleanu fractional derivative
Owolabi, Kolade M.
2018-01-01
In this paper, we model an ecological system consisting of a predator and two preys with the newly derived two-step fractional Adams-Bashforth method via the Atangana-Baleanu derivative in the Caputo sense. We analyze the dynamical system for correct choice of parameter values that are biologically meaningful. The local analysis of the main model is based on the application of qualitative theory for ordinary differential equations. By using the fixed point theorem idea, we establish the existence and uniqueness of the solutions. Convergence results of the new scheme are verified in both space and time. Dynamical wave phenomena of solutions are verified via some numerical results obtained for different values of the fractional index, which have some interesting ecological implications.
Shekhar, Karthik; Ruberman, Claire F; Ferguson, Andrew L; Barton, John P; Kardar, Mehran; Chakraborty, Arup K
2013-12-01
Mutational escape from vaccine-induced immune responses has thwarted the development of a successful vaccine against AIDS, whose causative agent is HIV, a highly mutable virus. Knowing the virus' fitness as a function of its proteomic sequence can enable rational design of potent vaccines, as this information can focus vaccine-induced immune responses to target mutational vulnerabilities of the virus. Spin models have been proposed as a means to infer intrinsic fitness landscapes of HIV proteins from patient-derived viral protein sequences. These sequences are the product of nonequilibrium viral evolution driven by patient-specific immune responses and are subject to phylogenetic constraints. How can such sequence data allow inference of intrinsic fitness landscapes? We combined computer simulations and variational theory á la Feynman to show that, in most circumstances, spin models inferred from patient-derived viral sequences reflect the correct rank order of the fitness of mutant viral strains. Our findings are relevant for diverse viruses.
Shekhar, Karthik; Ruberman, Claire F.; Ferguson, Andrew L.; Barton, John P.; Kardar, Mehran; Chakraborty, Arup K.
2013-12-01
Mutational escape from vaccine-induced immune responses has thwarted the development of a successful vaccine against AIDS, whose causative agent is HIV, a highly mutable virus. Knowing the virus' fitness as a function of its proteomic sequence can enable rational design of potent vaccines, as this information can focus vaccine-induced immune responses to target mutational vulnerabilities of the virus. Spin models have been proposed as a means to infer intrinsic fitness landscapes of HIV proteins from patient-derived viral protein sequences. These sequences are the product of nonequilibrium viral evolution driven by patient-specific immune responses and are subject to phylogenetic constraints. How can such sequence data allow inference of intrinsic fitness landscapes? We combined computer simulations and variational theory á la Feynman to show that, in most circumstances, spin models inferred from patient-derived viral sequences reflect the correct rank order of the fitness of mutant viral strains. Our findings are relevant for diverse viruses.
Dynamic Bayesian modeling for risk prediction in credit operations
DEFF Research Database (Denmark)
Borchani, Hanen; Martinez, Ana Maria; Masegosa, Andres
2015-01-01
Our goal is to do risk prediction in credit operations, and as data is collected continuously and reported on a monthly basis, this gives rise to a streaming data classification problem. Our analysis reveals some practical problems that have not previously been thoroughly analyzed in the context...... of streaming data analysis: the class labels are not immediately available and the relevant predictive features and entities under study (in this case the set of customers) may vary over time. In order to address these problems, we propose to use a dynamic classifier with a wrapper feature subset selection...
Extracting operative temperatures from temperatures of physical models with thermal inertia.
O'Connor
2000-10-01
Temperatures of operative temperature models, particularly those of thick-walled models of larger ectotherms, lag behind and are more restricted in range than the operative temperatures they estimate.Algorithms are provided to extract estimates of instantaneous operative temperatures from model temperatures.A simple deconvolution method can be used when wind speeds are constant.An iterative estimation method must be used when wind speed varies during the monitoring period.The iterative method is sensitive to measurement error, and so uses a smoothing filter to limit instabilities. The smoothing also limits the short-term fluctuations in the estimated operative temperature.Iterative estimates of operative temperature suggested time lags of up to 90 min between predicted operative temperatures and model temperatures for desert tortoises (mass=3 kg). Differences this large could affect estimates of time available for foraging.
Aerial Search Optimization Model (ASOM) for UAVs in Special Operations
National Research Council Canada - National Science Library
Kress, Moshe; Royset, Johannes O
2007-01-01
.... The goal is to detect the largest possible number of targets with the given resources. The model prescribes optimal deployment locations for the ground units and optimal time-phased search areas for the UAVs...
Modeling of Complex Adaptive Systems in Air Operations
National Research Council Canada - National Science Library
Busch, Timothy E; Trevisani, Dawn A
2006-01-01
.... Model predictive control theory provides the basis for this investigation. Given some set of objectives the military commander must devise a sequence of actions that transform the current state to the desired one...