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Kinds of Results Available Selected AbstractsVisualization of the distant dipolar field: A numerical studyCONCEPTS IN MAGNETIC RESONANCE, Issue 6 2009Stefan Kirsch Abstract The magnetization of liquid water in an external field generates an intrinsic magnetic field in the sample called the distant dipolar field (DDF). To visualize the spatial distribution of the DDF a numerical study was performed for the case of liquid,state 1H NMR at 7 T. 2D maps of the frequency offset caused by the DDF in pure water were calculated for homogenously magnetized spherical and cylindrical samples as well as for the case of a spatially modulated magnetization distribution occurring e.g., in CRAZED (Cosy Revamped by Asymmetric Z-Gradient Echo Detection) experiments. The calculation yielded DDF induced frequency offsets in the range of 0.58 Hz to 10.24 Hz inside the homogeneously magnetized cylinders, while DDF-induced frequency offsets ,10,5 Hz were obtained inside the sphere. The calculated frequency offsets were in good agreement with analytical results available for a sphere and an infinitely long cylinder. In the case of a spatially modulated magnetization distribution, DDF-induced frequency offsets with maximum values of +0.83 Hz were obtained inside the sphere. The presented 2D maps of the DDF-induced frequency offset have tutorial character and may help to visualize this phenomenon in a direct manner. © 2009 Wiley Periodicals, Inc. Concepts Magn Reson Part A 34A:357,364, 2009. [source] A kinetic perspective on extracellular electron transfer by anode-respiring bacteriaFEMS MICROBIOLOGY REVIEWS, Issue 1 2010César I. Torres Abstract In microbial fuel cells and electrolysis cells (MXCs), anode-respiring bacteria (ARB) oxidize organic substrates to produce electrical current. In order to develop an electrical current, ARB must transfer electrons to a solid anode through extracellular electron transfer (EET). ARB use various EET mechanisms to transfer electrons to the anode, including direct contact through outer-membrane proteins, diffusion of soluble electron shuttles, and electron transport through solid components of the extracellular biofilm matrix. In this review, we perform a novel kinetic analysis of each EET mechanism by analyzing the results available in the literature. Our goal is to evaluate how well each EET mechanism can produce a high current density (>10 A m,2) without a large anode potential loss (less than a few hundred millivolts), which are feasibility goals of MXCs. Direct contact of ARB to the anode cannot achieve high current densities due to the limited number of cells that can come in direct contact with the anode. Slow diffusive flux of electron shuttles at commonly observed concentrations limits current generation and results in high potential losses, as has been observed experimentally. Only electron transport through a solid conductive matrix can explain observations of high current densities and low anode potential losses. Thus, a study of the biological components that create a solid conductive matrix is of critical importance for understanding the function of ARB. [source] Development of a finite element radiation model applied to two-dimensional participating mediaHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 6 2005Hong Qi Abstract A finite element method (FEM) for radiative heat transfer has been developed and it is applied to 2D problems with unstructured meshes. The present work provides a solution for temperature distribution in a rectangular enclosure with black or gray walls containing an absorbing, emitting, isotropically scattering medium. Compared with the results available from Monte Carlo simulation and finite volume method (FVM), the present FEM can predict the radiative heat transfer accurately. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(6): 386,395, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20076 [source] Numerical simulation of a dam break for an actual river terrain environmentHYDROLOGICAL PROCESSES, Issue 4 2007C. B. Liao Abstract A two-dimensional (2D) finite-difference shallow water model based on a second-order hybrid type of total variation diminishing (TVD) approximate solver with a MUSCL limiter function was developed to model flooding and inundation problems where the evolution of the drying and wetting interface is numerically challenging. Both a minimum positive depth (MPD) scheme and a non-MPD scheme were employed to handle the advancement of drying and wetting fronts. We used several model problems to verify the model, including a dam break in a slope channel, a dam break flooding over a triangular obstacle, an idealized circular dam-break, and a tide flow over a mound. Computed results agreed well with the experiment data and other numerical results available. The model was then applied to simulate the dam breaking and flooding of Hsindien Creek, Taiwan, with the detailed river basin topography. Computed flooding scenarios show reasonable flow characteristics. Though the average speed of flooding is 6,7 m s,1, which corresponds to the subcritical flow condition (Fr < 1), the local maximum speed of flooding is 14·12 m s,1, which corresponds to the supercritical flow condition (Fr , 1·31). It is necessary to conduct some kind of comparison of the numerical results with measurements/experiments in further studies. Nevertheless, the model exhibits its capability to capture the essential features of dam-break flows with drying and wetting fronts. It also exhibits the potential to provide the basis for computationally efficient flood routing and warning information. Copyright © 2006 John Wiley & Sons, Ltd. [source] Dynamic numerical simulations of void growth and coalescence with stress triaxiality maintained constant,Application to ductile solids with secondary voidsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 12 2008L. Siad Abstract Dynamic explicit finite element analysis is used to investigate void growth and plastic collapse of an axisymmetric unit cell model with a primary spherical void imbedded in a porous matrix material. The Gurson,Tvergaard,Needleman homogenized model is used to describe the plastic behaviour of the matrix material. The simulations are performed under large strain conditions for varying secondary void volume fractions and quasi-static loading controlled by constant stress triaxiality. The proposed accomplishment of constant stress triaxiality associated with dynamic explicit computations provides a method allowing to trace the collapse of the unit cell from the onset of coalescence to practically its final failure. Consistent with experimental and theoretical results available in the literature, the obtained results substantiate the sensitivity of coalescence to the presence of secondary voids. Copyright © 2008 John Wiley & Sons, Ltd. [source] Optimal shape of a grain or a fibre cross-section in a two-phase compositeINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 2 2005Vladislav Shenfeld Abstract The shape of grains or of cross-sections of fibres in a two-phase elastic material has an important influence on the overall mechanical behaviour of the composite. In this paper a numerical scheme is devised for determining the optimal shape of a two-dimensional grain or of a fibre's cross-section. The optimization problem is first posed mathematically, using a global objective function, and then solved numerically by the finite element method and a specially designed global optimization scheme. Excellent agreement is obtained with analytical results available for extreme cases. In addition, optimal shapes are obtained under more general conditions. Copyright © 2004 John Wiley & Sons, Ltd. [source] A-scalability and an integrated computational technology and framework for non-linear structural dynamics.INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 15 2003Part 2: Implementation aspects, parallel performance results Abstract An integrated framework and computational technology is described that addresses the issues to foster absolute scalability (A-scalability) of the entire transient duration of the simulations of implicit non-linear structural dynamics of large scale practical applications on a large number of parallel processors. Whereas the theoretical developments and parallel formulations were presented in Part 1, the implementation, validation and parallel performance assessments and results are presented here in Part 2 of the paper. Relatively simple numerical examples involving large deformation and elastic and elastoplastic non-linear dynamic behaviour are first presented via the proposed framework for demonstrating the comparative accuracy of methods in comparison to available experimental results and/or results available in the literature. For practical geometrically complex meshes, the A-scalability of non-linear implicit dynamic computations is then illustrated by employing scalable optimal dissipative zero-order displacement and velocity overshoot behaviour time operators which are a subset of the generalized framework in conjunction with numerically scalable spatial domain decomposition methods and scalable graph partitioning techniques. The constant run times of the entire simulation of ,fixed-memory-use-per-processor' scaling of complex finite element mesh geometries is demonstrated for large scale problems and large processor counts on at least 1024 processors. Copyright © 2003 John Wiley & Sons, Ltd. [source] A meshless method for Kirchhoff plate bending problemsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 10 2001Vitor M. A. Leitão Abstract In this work a meshless method for the analysis of bending of thin homogeneous plates is presented. This meshless method is based on the use of radial basis functions to build an approximation of the general solution of the partial differential equations governing the Kirchhoff plate bending problem. In order to obtain a symmetric and non-singular linear equation system the Hermite collocation method is used. To assess the formulation a series of plates with different boundary conditions are analysed. Comparisons are made with other results available in the literature. Copyright © 2001 John Wiley & Sons, Ltd. [source] Numerical simulation of the miscible displacement of radionuclides in a heterogeneous porous mediumINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 10 2005C.-H. Bruneau Abstract The aim of this paper is to model and simulate the displacement of radioactive elements in a saturated heterogeneous porous medium. New schemes are proposed to solve accurately the convection,diffusion,reaction equations including nonlinear terms in the time derivative. Numerical tests show the stability and robustness of these schemes through strong heterogeneities of the medium. Finally the COUPLEX 1 benchmark concerning the far field simulation of a polluted flow by a leak of a nuclear waste disposal is performed and compared with the results available in the literature. Copyright © 2005 John Wiley & Sons, Ltd. [source] Photoionization of C2F4 in the VUV regionINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 13 2006A. S. Dos Santos Abstract We report calculated cross sections and asymmetry parameters for photoionization out of the outermost valence orbital 2b2u of C2F4 for photon energies ranging from near-threshold to 19 eV. We also report asymmetry parameters for photoionization out of the eight outermost orbitals of C2F4 at the He I radiation energy (21.23 eV). The iterative Schwinger variational method at the exact static-exchange level is used to obtain the continuum photoelectron orbitals. Our calculated results are compared with experimental results available in the literature. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 [source] Neural models for coplanar waveguides with a finite dielectric thicknessINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 6 2003Celal Yildiz Abstract This article presents a new approach based on artificial neural networks (ANNs) to determine the characteristic parameters of symmetric and asymmetric coplanar waveguides with a finite dielectric thickness. ANNs are trained with the use of five training algorithms. The results obtained from neural models are in very good agreement with the theoritical and experimental results available in the literature. © 2003 Wiley Periodicals, Inc. Int J RF and Microwave CAE 13: 438,446, 2003. [source] The Liapunov's second method for continuous time difference equationsINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 15 2003P. PepeArticle first published online: 10 OCT 200 Abstract Among many other cases such as economic and lossless propagation models, continuous time difference equations are encountered as the internal dynamics in a class of non-linear time delay systems, when controlled by a suitable state feedback which drives the output exponentially to zero. The Liapunov's second method for these infinite dimensional systems has not been extensively investigated in the literature. This paper has the aim of filling this gap. Liapunov's second method theorems for checking the stability and the asymptotic stability of this class of infinite dimensional systems are built up, in both a finite and an infinite dimensional setting. In the finite dimensional setting, the Liapunov function is defined on finite dimensional sets. The conditions for stability are given as inequalities on continuous time. No derivatives are involved, as in the dynamics of the studied systems. In the infinite dimensional setting, the continuous time difference equation is transformed into a discrete time system evolving on an infinite dimensional space, and then the classical Liapunov theorem for the system in the new form is written. In this paper the very general case is considered, that is non-linear continuous time difference equations with multiple non commensurate delays are considered, and moreover the functions involved in the dynamics are allowed to be discontinuous, as well as the initial state. In order to study the stability of the internal dynamics in non-linear time delay feedback systems, an exogenous disturbance is added, which goes to zero exponentially as the time goes to infinity. An example is considered, from non-linear time delay feedback theory. While the results available in the literature are inconclusive as far as the stability of that example is concerned, such stability is proved to hold by the theorems developed in this paper, and is validated by simulation results. Copyright © 2003 John Wiley & Sons, Ltd. [source] A new absolute stability test for systems with state-dependent perturbationsINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 14 2002M. C. de Oliveira Abstract In this paper, a new test for the absolute stability of nonlinear systems with state-dependent nonlinearities is developed. Scalar nonlinearities are assumed to lie in sectors. Using a Lur'e function as a Lyapunov function, a linear matrix inequalities (LMI) stability condition is derived. The new condition lets one go from a pure integral (Persidskii) to a pure quadratic Lyapunov function in an unified framework. Several results available in the literature are generated as particular cases of the new test. An example shows that the proposed condition can be much less conservative than available diagonal stability and passivity based methods, as the circle and Popov criteria. Tests for infinite as well as finite nonlinearity sectors can be easily generated, since the parameters of the nonlinearity sectors appear in the LMI condition in a very convenient way. This feature can also provide optimization of the absolute stability sector through convex programming techniques. Copyright © 2002 John Wiley & Sons, Ltd. [source] Comparative analysis of the conformational profile of substance P using simulated annealing and molecular dynamicsJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 16 2004Francesc J. Corcho Abstract The present study describes an extensive conformational search of substance P using two different computational methods. On the one hand, the peptide was studied using the iterative simulated annealing, and on the other, molecular dynamics simulations at 300 and 400 K. With the former method, the peptide was studied in vacuo with a dielectric constant of 80, whereas using the latter study the peptide was studied in a box of TIP3P water molecules. Analysis of the results obtained using both methodologies was carried out using an in-house methodology using a cluster analysis method based on information theory. Comparison of the two sampling methodologies and the different environment used in the calculations is also analyzed. Finally, the conformational motifs that are characteristic of substance P in a hydrophilic environment are presented and compared with the experimental results available in the literature. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1937,1952, 2004 [source] Five years survival in metastatic non-small cell lung cancer patients treated with chemotherapy alone or chemotherapy and melatonin: a randomized trialJOURNAL OF PINEAL RESEARCH, Issue 1 2003P. Lissoni Abstract: Numerous experimental data have documented the oncostatic properties of melatonin. In addition to its potential direct antitumor activity, melatonin has proved to modulate the effects of cancer chemotherapy, by enhancing its therapeutic efficacy and reducing its toxicity. The increase in chemotherapeutic efficacy by melatonin may depend on two main mechanisms, namely prevention of chemotherapy-induced lymphocyte damage and its antioxidant effect, which has been proved to amplify cytotoxic actions of the chemotherapeutic agents against cancer cells. However, the clinical results available at present with melatonin and chemotherapy in the treatment of human neoplasms are generally limited to the evaluation of 1-year survival in patients with very advanced disease. Thus, the present study was performed to assess the 5-year survival results in metastatic non-small cell lung cancer patients obtained with a chemotherapeutic regimen consisting of cisplatin and etoposide, with or without the concomitant administration of melatonin (20 mg/day orally in the evening). The study included 100 consecutive patients who were randomized to receive chemotherapy alone or chemotherapy and melatonin. Both the overall tumor regression rate and the 5-year survival results were significantly higher in patients concomitantly treated with melatonin. In particular, no patient treated with chemotherapy alone was alive after 2 years, whereas a 5-year survival was achieved in three of 49 (6%) patients treated with chemotherapy and melatonin. Moreover, chemotherapy was better tolerated in patients treated with melatonin. This study confirms, in a considerable number of patients and for a long follow-up period, the possibility to improve the efficacy of chemotherapy in terms of both survival and quality of life by a concomitant administration of melatonin. This suggests a new biochemotherapeutic strategy in the treatment of human neoplasms. [source] A New Analytical Model for Estimation of Scratch-Induced Damage in Brittle SolidsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2007Xiaoning Jing Scratch tests are of fundamental interest both for understanding machining-induced damage and for evaluating the scratch resistance of brittle materials. An improved blister field model for the scratch process is proposed where the blister field strength is explicitly determined in terms of the material properties, loading conditions, and geometry of the scratch tool. Additionally, one new expanding cylindrical cavity model is implemented to estimate the plastic zone size surrounding the scratch groove. A quantitative evaluation of the damage zone size is conducted by combining the above two models. The predicted damage zone sizes are in good agreement with the results available elsewhere in literature. [source] Efficient organization of information processingMANAGERIAL AND DECISION ECONOMICS, Issue 1 2007Jacek Cukrowski The paper examines the application of the concept of economic efficiency to organizational issues of collective information processing in decision making. Information processing is modeled in the framework of the dynamic parallel processing model of associative computation with an endogenous setup cost of the processors. The model is extended to include the specific features of collective information processing in the team of decision makers which may lead to an error in data analysis. In such a model, the conditions for efficient organization of information processing are defined and the architecture of the efficient structures is considered. We show that specific features of collective decision making procedures require a broader framework for judging organizational efficiency than has traditionally been adopted. In particular, and contrary to the results available in economic literature, we show that there is no unique architecture for efficient information processing structures, but a number of various efficient forms. The results indicate that technological progress resulting in faster data processing (ceteris paribus) will lead to more regular information processing structures. However, if the relative cost of the delay in data analysis increases significantly, less regular structures could be efficient. Copyright © 2007 John Wiley & Sons, Ltd. [source] Semi-classical calculation of resonant states of a charged particle interacting with a metallic surfacePHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 10 2005John Jairo Zuluaga Abstract We assess the applicability of the semi-classical approach of Herman,Kluk with filter diagonalization to determine resonant states of either the electron-surface system or the ion-surface system. An effective potential model of the interaction of an electron with a ruthenium metallic surface is used. The evolution of the wave-function and the resonant states of this system are calculated. Analogous results for the interaction of the system formed by the H, and the ruthenium surface are presented. For the calculation of the resonances, the semi-classical wave-function is found, and the autocorrelation function between the initial and final wave-functions is calculated, from which the position and width of the resonances are extracted by using the harmonic inversion by filter diagonalization. The results are compared with results available in the literature for similar models obtained by quantum calculations using fast Fourier Transform. The positions of the lower-lying resonances found with the semi-classical and quantum approaches match closely, while the values of the widths of the resonances show larger discrepancies. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Leaf stomatal responses to vapour pressure deficit under current and CO2 -enriched atmosphere explained by the economics of gas exchangePLANT CELL & ENVIRONMENT, Issue 8 2009GABRIEL G. KATUL ABSTRACT Using the economics of gas exchange, early studies derived an expression of stomatal conductance (g) assuming that water cost per unit carbon is constant as the daily loss of water in transpiration (fe) is minimized for a given gain in photosynthesis (fc). Other studies reached identical results, yet assumed different forms for the underlying functions and defined the daily cost parameter as carbon cost per unit water. We demonstrated that the solution can be recovered when optimization is formulated at time scales commensurate with the response time of g to environmental stimuli. The optimization theory produced three emergent gas exchange responses that are consistent with observed behaviour: (1) the sensitivity of g to vapour pressure deficit (D) is similar to that obtained from a previous synthesis of more than 40 species showing g to scale as 1 , m log(D), where m ? [0.5,0.6], (2) the theory is consistent with the onset of an apparent ,feed-forward' mechanism in g, and (3) the emergent non-linear relationship between the ratio of intercellular to atmospheric [CO2] (ci/ca) and D agrees with the results available on this response. We extended the theory to diagnosing experimental results on the sensitivity of g to D under varying ca. [source] Estimation of the interaction energy between small molecules and a silica model as an approach for predicting the interaction order between elastomers and silicaPOLYMER INTERNATIONAL, Issue 7 2009León D Pérez Abstract BACKGROUND: Many elastomers are reinforced with fillers to improve their mechanical properties; good reinforcement requires favorable interactions between the elastomeric chains and the surfaces of the filler particles. A useful goal is the development of computational methods that estimate these interactions, and thereby guide choices of fillers for elastomers based on the structures of the two components in nanocomposites in general. RESULTS: Experimental results available from inverse gas chromatography rank nitriles, aromatics and 1-alkenes with regard to the magnitude of favorable interactions with silica reinforcing particles. Calculations using the Gaussian 03 package of computer programs were carried out, both with and without corrections for superposition errors. For the nitrile compounds, the formation of hydrogen bonds was predicted, and the interactions of the aromatic and 1-alkene compounds with silica were shown to be dependent on electron transfer from the silica to the tested molecules. CONCLUSION: The method developed should be useful for ranking polymer,filler combinations in general with regard to the interactions known to be conducive to good reinforcement. Copyright © 2009 Society of Chemical Industry [source] Serious Bacterial Infections in Febrile Outpatient Pediatric Heart Transplant RecipientsACADEMIC EMERGENCY MEDICINE, Issue 10 2009Shan Yin MD Abstract Objectives:, The purpose of this study was to describe the incidence of serious bacterial infections (SBIs) in febrile outpatient pediatric heart transplant recipients and to assess the utility of using white blood cell (WBC) indices to identify patients at low risk for bacteremia. Methods:, A retrospective study was conducted on all heart transplant recipients followed at a single children's hospital. All outpatient visits from January 1, 1995, to June 1, 2007, in which fever was evaluated were reviewed. Patients with history of a primary immunodeficiency, receiving concurrent chemotherapy, or having had a stem cell or small bowel transplant were excluded. Demographic, historical, physical examination, laboratory, and radiographic data were then recorded. Results:, Sixty-nine patients had 238 individual episodes of fever evaluation; of these, 217 (91.2%) had blood cultures drawn with results available in their initial evaluation. There were six (2.8%) true-positive blood cultures and eight (3.7%) false-positive cultures. Chest radiography was done in 185 evaluations (77.8%), and 44 episodes of pneumonia (23.8%) were diagnosed. Of 112 urine cultures done, one (0.9%) was positive. Neither of two lumbar punctures performed were positive. In non,ill-appearing children without indwelling central lines or focal bacterial infections (pneumonia, cellulitis), the incidence of bacteremia was 1.2%. In children with a focal bacterial infection, the rate of bacteremia was 6.3%. WBC indices were not significantly different between bacteremic and nonbacteremic patients. A band-to-neutrophil ratio (BNR) of ,0.25 and a published guideline for identifying low-risk infants using WBC indices identified all bacteremic patients, each with a sensitivity of 100% (95% confidence interval [CI] = 48% to 100% and 54% to 100%, respectively). Conclusions:, The incidence of bacteremia was low in febrile, outpatient pediatric heart transplant patients, especially in those who were not ill-appearing and did not have a focus of serious infection. Two different low-risk criteria performed well in identifying the bacteremic patients, although given the low number of true-positive cultures, the CIs for the sensitivities of these tests were extremely wide, and neither test could be reliably used at present. A prospective multicenter study is required to confirm the low incidence of bacteremia and low-risk criteria in this population. [source] A model for the dynamic behavior of a commercial scale slurry bubble column reactor applied for the Fischer,Tropch synthesisASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2010Samira Ghasemi Abstract Fischer-Tropsch synthesis (FTS) is an important chemical process for the production of liquid fuels. In the present study, a dynamic model for a commercial size slurry bubble column reactor (SBCR) operating under heterogeneous flow regime and dealing with the FTS has been developed. In such a model a detailed kinetics expressions for the FTS and water gas shift (WGS) reactions have been considered. A selectivity model combined with SBCR hydrodynamics and the multicomponent VLE scheme have been applied to estimate the distribution of olefins and paraffins in the products. In addition, the effects of catalyst deactivation on reactor performance and product distribution under transient conditions may be predicted from this model. The data calculated from the model have been correlated with the experimental results available in the literature. It seems that the present model could be applied to estimate the main characteristics of the reactor's dynamic behavior. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Artificial neural network modeling of O2 separation from air in a hollow fiber membrane moduleASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 4 2008S. S. Madaeni Abstract In this study artificial neural network (ANN) modeling of a hollow fiber membrane module for separation of oxygen from air was conducted. Feed rates, transmembrane pressure, membrane surface area, and membrane permeability for the present constituents in the feed were network input data. Output data were rate of permeate from the membrane, the amount of N2 in the remaining flow, and the amount of O2 in the permeate flow. Experimental data were obtained from software developed by Research Institute of Petroleum Industry (RIPI). A part of the data generated by this software was confirmed by experimental results available in literature. Two third of the data were employed for training ANNs. Based on different training algorithms, radial basis function (RBF) was found as the best network with minimum training error. Generalization capability of best RBF networks was checked by one third of unseen data. The network was able to properly predict new data that incorporate excellent performance of the network. The developed model can be used for optimization and online control. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Testing a Partial Ordering of Population Means with Application to Inference about Growth Habits of Cowpea GenotypesBIOMETRICS, Issue 4 2007Daniel R. Jeske Summary Using general results available in the literature, we derive the likelihood ratio test for a particular partial ordering of means that naturally arises in a biological context. We then show that the conceptual and computational complexity of the derivation can be substantially reduced by equivalently deriving the test using the intersection-union principle for decomposing a complex null hypothesis into elemental forms. A Monte Carlo algorithm for obtaining the p -value of the test is proposed. The test procedure is illustrated with a data set of the competitive ability of several cowpea genotypes, where previous experiments have indicated the proposed partial order of the means. A simulation study is used to examine the power of the test. [source] | |||||||||||||||||||||||||