bluuebunny/crossref_metadata_2025_split huggingface dataset:
An example of a superproportional graph
Authors: Kärrman Jan 
Published: May 2007

AbstractIn the theory of random graphs, several classes of graphs occur that are exceptional cases in limit theorems for subgraph counts. The purpose of this article is to show the existence of graphs in one of these classes, by providing an explicit, computer generated, example. We also show that the class is closed under complementation. © 1994 John Wiley & Sons, Inc.
On the number of subtrees for almost all graphs
Authors: Tomescu Ioan 
Published: May 2007

AbstractIn this article it is shown that the number of common edges of two random subtrees of Kn having r and s vertices, respectively, has a Poisson distribution with expectation 2λμ if \documentclass{article}\pagestyle{empty}\begin{document}$\mathop {\lim }\limits_{n \to \infty } r/n = \lambda$\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$\mathop {\lim }\limits_{n \to \infty } s/n = \mu$\end{document}. Also, some estimations of the number of subtrees for almost all graphs are made by using Chebycheff's inequality. © 1994 John Wiley & Sons, Inc.
Infinitary queries and their asymptotic probabilities. II. Properties definable in least fixed point logic
Authors: Tyszkiewicz Jerzy 
Published: May 2007

AbstractWe develop an almost complete theory for existence of asymptotic probabilities of least fixed point and partial fixed pint definable properties, and for the complexity of the associated almost sure theory. Our method works for any randomized class of finite structures. © 1994 John Wiley & Sons, Inc.
Adaptive power control for satellite to ground laser communication
Authors: Gubergrits Michael , Goot Roman E. , Mahlab Uri , Arnon Shlomi 
Published: May 2007

AbstractWe develop an adaptive power control algorithm to facilitate satellite to ground laser communication through turbulence fading channels. Adaptive control is a powerful tool that improves energetic gain of the satellite laser. We use discrete laser transmitter intensity levels in our control algorithm. A novel recursive technique defines optimal laser transmitting intensity levels so that the laser‐transmitted power is adapted according to instant changes of the signal‐to‐noise ratio caused by channel fading. The algorithm's performance is first investigated in a general form suitable for any channel fading statistics. Then it is specified for a typical lognormal fading channel. The results indicate an improvement of up to 10dB in energetic gain. Copyright © 2007 John Wiley & Sons, Ltd.
Sustainable development in Rwanda: industry and government
Authors: Short Tim 
Published: May 2007

AbstractThis paper discusses the results of research carried out in Rwanda, in February 2005, through funding from the Royal Society. It investigates the methodologies and policies in use in Rwanda to promote and ensure sustainable industrial development and examines the Government's role in providing an appropriate framework. The paper considers the situation in Rwanda, following the 1994 genocide, and the part played by the Kigali Institute of Science, Technology and Management (KIST), formed with the specific remit of training a new generation of professionals to replace those lost in 1994. Finally it recognises similarities between manufacturing in the UK and in Rwanda, demonstrating how far Rwanda has come since the genocide. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
Parametric latent class joint model for a longitudinal biomarker and recurrent events
Authors: Han Jun , Slate Elizabeth H. , Peña Edsel A. 
Published: May 2007

AbstractA joint model for a longitudinal biomarker and recurrent events is proposed. This general model accommodates the effects of covariates on the biomarker and event processes, the effects of accumulating event occurrences, and effects caused by interventions after each event occurrence. Association between the biomarker and recurrent event processes is captured through a latent class structure, which also serves to handle an underlying heterogeneous population. We use the EM algorithm for maximum likelihood estimation of the model parameters and a penalized likelihood measure to determine the number of latent classes. This joint model is validated by simulation and illustrated with a data set from epileptic seizure study. Copyright © 2007 John Wiley & Sons, Ltd.
A model‐driven approach to automatic conversion of physical units
Authors: Cooper Jonathan , McKeever Steve 
Published: May 2007

AbstractWhen physical quantities are used in programs they are typically represented as raw numbers, with the units in which they were measured only being given in comments, if at all. This can lead to errors from the use of dimensionally inconsistent expressions, or the comparison of two quantities of the same dimension but measured in different units, which are not discovered until run time. Any program working with the physical world has this issue, with scientific modelling being a major application. Implementors of models have the time‐consuming and error‐prone task of adding in dynamic units checks and conversions manually. Most existing programming languages do not provide support for representing units explicitly (although extensions to some have been proposed). With the advent of domain‐specific modelling languages, incorporating code generation techniques, we propose checking physical units at the level of the modelling language, removing the need for such a support in the underlying implementation language. We present our work in the context of one such modelling language: CellML, developed at the
University of Auckland with a focus on modelling biological systems. We have developed an intuitive algorithm for performing automatic conversions between quantities measured in different units. It both requires fewer conversion operations than current approaches and makes more sensible choices about which quantities to convert. Uniquely, by using partial evaluation techniques it is also capable of dealing robustly with quantities raised to arbitrary powers, even where the exponent is given by an expression. We demonstrate our algorithm on various examples. Copyright © 2007 John Wiley & Sons, Ltd.
A comparison study of 12 paradigms for developing embodied agents
Authors: Bölöni Ladislau , Luotsinen Linus J. , Ekblad Joakim N. , Fitz‐Gibbon T. Ryan , Houchin Charles , Key Justin L. , Khan Majid Ali , Lyu Jin , Nguyen Johann , Oleson Rex , Stein Gary , Vander Weide Scott A. , Trinh Viet 
Published: May 2007

AbstractWe report on a study in which 12 different paradigms were used to implement agents acting in an environment which borrows elements from artificial life and multi‐player strategy games. In choosing the paradigms we strived to maintain a balance between high‐level, logic‐based approaches and low‐level, physics‐oriented models; between imperative programming, declarative approaches and ‘learning from basics’; between anthropomorphic or biologically inspired models on one hand and pragmatic, performance‐oriented approaches on the other. We have found that the choice of the paradigm determines the software development process and requires a different set of skills from the developers. In terms of raw performance, we found that the best performing paradigms were those which (a) allowed the knowledge of human experts to be explicitly transferred to the agent and (b) allowed the integration of well‐known, high‐performance algorithms. We have found that maintaining a commitment to the chosen paradigm can be difficult; there is a strong temptation to offer shallow fixes to perceived performance problems through a ‘flight into heuristics’. Our experience is that a development process without the discipline enforced by a central paradigm leads to agents which are a random collection of heuristics whose interactions are not clearly understood. Although far from providing a definitive verdict on the benefits of the different paradigms, our study provided a good insight into what kind of conceptual, technical or organizational problems would a development team face depending on their choice of agent paradigm. Copyright © 2007 John Wiley & Sons, Ltd.
Graphische Lösung der Hauptaufgabe der Luftphotogrammetrie im Sinne der Ausgleichsrechnung
Authors: Krames Josef 
Published: May 2007

AbstractFür die Wiederherstellung der gegenseitigen Lage zweier aus verschiedenen Luftstandpunkten aufgenommenen Geländebilder wird ein einfaches graphisches Verfahren abgeleitet. Dieses gründet sich auf die geometrische Theorie jener „gefährlichen”︁ Geländeflächen, für welche diese Aufgabe in der Praxis nur ungenau bestimmt ist.
Die Ausnutzung zusätzlicher Vorkenntnisse für die Einschließung von Eigenwerten beim Iterationsverfahren
Authors: Kreyszig E. 
Published: May 2007

AbstractIm Anschluß an eine frühere Arbeit [6]1) wird gezeigt, wie man mit Hilfe einer Theorie von Wielandt [1], [2] spezielle Vorkenntnisse, z. B. über eigenwertfreie Intervalle, etwa im Falle positiver Definitheit, über Schranken für gewisse Eigenwerte usw., für die Einschließung der Eigenwerte einer gegebenen hermiteschen Matrix A bei gegebener Iterationsfolge von Vektoren x0, x1 = A x0…, xs = Asx0 auswerten und dadurch die Einschließung verschärfen kann.
Beiträge zum Runge‐Kutta‐Verfahren
Authors: Albrecht Julius 
Published: May 2007

AbstractNach Diskussion eines allgemeinen Runge‐Kutta‐Ansatzes für y(n) = f (x, y, y', …, y(n—1)) werden für die spezielle Differentialgleichung y' = f(x, y) und die durch „Vordifferentiation”︁ in eine solche überführte Differentialgleichung y′ = g(x, y) neue Runge‐Kutta‐Vorschriften hergeleitet. Ferner werden „symmetrische”︁ Runge‐Kutta‐Formeln sowie Fehlerabschätzungen zu den Verfahren von Heun und Kutta für Differentialgleichungen 1. Ordnung angegeben.
Über die Randquerkräfte bei gestützten Platten
Authors: Kromm Alexander 
Published: May 2007

AbstractAm Beispiel einer allseitig momentenfrei gelagerten Platte mit gleichmäßig verteilter Belastung wird die Anwendung der verallgemeinerten Plattentheorie des Verfassers illustriert, die die Querschubverzerrungen der Platte berücksichtigt. Insbesondere wird die Verteilung der Randquerkräfte und die Frage der Eckkräfte untersucht, die die Rechnung nach der elementaren Plattentheorie liefert.
On the Role of Congestion in Transportation Problems
Authors: Prager William 
Published: May 2007

AbstractIn discussing the most efficient manner of distributing a product from several sources to numerous locations, Hitchcock [1] assumed that the specific transportation cost for a given shipping route was independent of the amount shipped over this route. In the present paper the problem is discussed under the assumption that the specific shipping cost for a route increases linearly with the amount shipped over this route. It is shown that the optimal shipping program then is unique and that it can be discussed either in terms of flows along the routes or in terms of accounting princes at the centers of production and consumption. A maximum principle is established for the accounting prices, which leads to a maximum characterization of the cost of the optimal program.
Berechnung einzelner Eigenwerte eines algebraischen linearen Eigenwertproblems durch „Störiteration”︁
Authors: Wittmeyer H. 
Published: May 2007

AbstractEine gegebene Näherungslösung λ(0), x(0) für einen gesuchten beliebigen einfachen Eigenwert λe und den zugehörigen Eigenvektor xe wird durch eine Störungsrechnung erster Ordnung verbessert. Dies Verfahren liefert, zu einer Iteration, der „Störiteration”︁, ausgebaut, die gleiche Folge von Näherungswerten wie die „gebrochene Iteration”︁ von Wielandt. Die Störiteration vermeidet jedoch die Auflösung von linearen Gleichungssystemen mit fast singulären Matrizen. Sie ist besonders geeignet zur Berechnung der Abhängigkeit einer Lösung λe, xe von einem in den Matrizen des Problemes enthaltenen Parameter.
Beitrag zu Walls Verfahren der getrennten Berechnung von Real‐ und Imaginärteilen der Nullstellen eines Polynoms
Authors: Occhini Luiz 
Published: May 2007

AbstractBei einem von Wall angegebenen Verfahren zur getrennten Bestimmung der Realteile und Imaginärteile der Nullstellen eines vorgegebenen Polynoms ist man zur Interpolation unglücklicherweise auf Werte einer gebrochen‐rationalen Funktion angewiesen. Ausgehend von dem Ansatz des “Halbsummenpolynoms”, der von Orlando zur Herleitung des Hurwitzschen Stabilitätskriteriums benützt wurde, gelangt man zwanglos zu einer dem Wallschen Vorgehen verwandten und dessen Vorzüge aufrechterhaltenden Methode, die jedoch nunmehr die Interpolation mittels der Werte eines Polynoms ‐ des Halbsummenpolynoms ‐ vorzunehmen gestattet.Die Vorzüge des Verfahrens kommen besonders bei Benützung programmgesteuerter Rechenanlagen zur Geltung.
Behandlung der Plattenaufgabe nach dem verbesserten Differenzenverfahren
Authors: Zurmühl Rudolf 
Published: May 2007

AbstractFür die Plattenaufgabe ΔΔu = p/K mit rechteckigen Rändern werden Differenzenformeln höherer Genauigkeit nach dem Mehrstellenverfahren entwickelt, die sowohl das Einarbeiten der Randbedingungen als auch die Berechnung der zweiten Ableitungen, also der Biegemomente mit hoher Genauigkeit ermöglichen. Die Verwendung der Formeln wird für die verschiedenen Lagerungsfälle angegeben und an einigen Zahlenbeispielen erläutert. Ein Vergleich mit bekannten strengen Lösungen zeigt die Güte des Verfahrens.
Beiträge zum Quellsenkenverfahren für die Berechnung von Überschallströmungen
Authors: Münch Johann 
Published: May 2007

AbstractIn der vorliegenden Arbeit werden die Quellsenkenverfahren eingehend untersucht und dahingehend verallgemeinert, daß sie auch auf Drehkörper mit Unstetigkeiten in den Ableitungen der Konturkurve anwendbar sind.
On the Pure Twist of a Thin Plate Containing an Infinite Row of Circular Holes
Authors: Yamashida T. 
Published: May 2007

AbstractThe problem of estimating the influence of an infinite series of equidistant circular holes of equal radius on the distribution of stress in an infinite plate under uniform twisting is treated according to the Poisson‐Kirchhoff theory of thin plates. The parametric coefficients included in the solution of this problem are determined by using the method of perturbation. For some special cases, numerical results are given.
Iterationen von beliebiger Ordnung
Authors: Berg Lothar 
Published: May 2007

AbstractEs wird ein Verfahren zur direkten Berechnung der Iterierten einer gegebenen Funktion von beliebiger reeller Ordnung angegeben, ohne den Umweg über die Abelsche Gleichung zu gehen. Das Verfahren liefert ein eindeutiges Ergebnis, das sich durch besondere Eigenschaften auszeichnet. Am Beispiel der Iterierten der Funktion ex−1 von der Ordnung 1/2 wird die Konvergenz des Verfahrens numerisch untersucht. Es zeigt sich, daß man die Ausgangsnäherung so wählen kann, daß mit verhältnismäßig wenig Rechenarbeit eine gewünschte Genauigkeit erzielt wird.
Geometrische Untersuchungen über Nomogramme für elliptische Integrale erster Gattung und Jacobische elliptische Funktionen I
Authors: Reutter F. 
Published: May 2007

AbstractDie vor kurzem in dieser Zeitschrift entwickelte Theorie der nomographischen Darstellbarkeit von Funktionensystemen [1]wird auf Funktionen eines komplexen Arguments angewandt. Insbesondere werden Nomogramme zur Ermittlung der Funktionswerte elliptischer Funktionen und Integrale entwickelt. Ihre geometrische Struktur und ihre zweckmäßige Formgebung werden eingehend untersucht.
Neue genauere Runge‐Kutta‐Formeln für Differentialgleichungen n‐ter Ordnung
Authors: Fehlberg Erwin 
Published: May 2007

AbstractDurch m‐malige Differentiation und Transformation der Differentalgleichung n‐ter Ordnung können Runge‐Kutta‐Formeln für die transformierte Differentialgleichung angegeben werden, die sowohl für die Lösungsfunktion als auch für deren Ableitungen noch die Glieder mit hm+5 der Taylor‐Reihe genau erfassen.Diese neuen und genaueren Runge‐Kutta‐Formeln erlauben eine Reduktion der Rechenzeit (auf einer elektronischen Rechenmaschine), da man die Integrationsschrittweite wesentlich vergrößern kann. Einige Beispiele werden gebracht, in denen die gleiche Genauigkeit wie beim üblichen Runge‐Kutta‐Verfahren mit unseren Formeln in 10% und weniger der Runge‐Kutta‐Rechenzeit erzielt wird (für m = 2, 3, 4).
Successive Approximations Process in Analog Solution of Partial Differential Equations by Difference Method
Authors: Matyáš Josef 
Published: May 2007

AbstractIn this paper a method of successive approximations in analog solution of partial differential equations is described. The convergence theorem for a wide class of boundary (or initial‐boundary) value problems is proved. A solution procedure is proposed to reach higher speed of the convergence of the successive approximations process and for estimating the accuracy of the solution. Analog computer solution is briefly discussed.
Selection of theoretical parameter characterizing scavenging activity of antioxidants on free radicals
Authors: Zhang Hong‐Yu 
Published: May 2007

AbstractSemiempirical quantum chemistry method Austin Model 1 (AM1) was employed to calculate the theoretical parameters of 15 antioxidants. Such parameters as bond order, bond length, and the difference of heat of formation (ΔHOF) between the antioxidant and its phenolic free radicals were obtained. Through correlating with previous experimental results ΔHOF was proven to be a proper parameter (r=0.9491) to characterize the free radical‐scavenging activity of antioxidants, but bond order and bond length were not able to represent the antioxidant's ability to scavenge free radicals. By comparing the results calculated by different semiempirical methods, including AM1, Modified Neglect of Diatomic Overlap, and Parametric Method 3, AM1 was found to be the best for calculating ΔHOF.
2‐thiobarbituric acid test for lipid oxidation in food: Synthesis and spectroscopic study of 2‐thiobarbituric acid‐malonaldehyde adduct
Authors: Guzmán‐Chozas Matías , Vicario‐Romero Isabel M. , Guillén‐Sans Remedios 
Published: May 2007

AbstractSynthesis, purification, elemental analysis, and spectroscopic studies were undertaken to characterize the structure of the red adduct 2:1 thiobarbituric acid (TBA)‐malonaldehyde involved in the evaluation of oxidative rancidity in fats and oils. Thin‐layer chromatography, infrared and ultravioletvisible absorption, 1H (1H NMR) and 13C nuclear magnetic resonance (NMR) spectra were used. A yield of 93% was obtained in the synthesis. The results of elemental analysis agree with the formula for the chloro‐monohydrated form, C11H11N4O5S2Cl. Three characteristic absorption maxima at 532, 310, and 245 nm, respectively, were shown in acid aqueous medium (pH 2.9). The characteristic vibrations assigned to the ‐NH, ‐OH, CαH (exocyclic) and ‐C=S groups were confirmed in the infrared spectra. There was no evidence of thioenolization. 1H NMR data at δ 5.10 (‐CONH‐ group, H2O and HCl molecules); δ 11.54 (‐OH group of keto‐enol tautomer, ‐NH group); and δ 176.4 (‐CONH‐ group) also were observed. The experimental results obtained were consistent with the existence of two spectral equivalent tautomeric structures. The colored adduct was compared with other TBA‐aldehyde compounds.
Optimization of fatty acid extraction from Phaeodactylum tricornutum UTEX 640 biomass
Authors: IbáɁez González M. J. , Robles Medina A. , Grima E. Molina , Giménez A. Giménez , Carstens M. , Cerdán L. Esteban 
Published: May 2007

AbstractFatty acids in the microalga Phaeodactylum tricornutum were isolated using an optimized three‐step method: extraction of crude fatty acid potassium salts made by direct saponification of lipids in the microalgal biomass with KOH/ethanol (96%, vol/vol), separation of unsaponifiable lipids by extraction with hexane, and final purification of fatty acids by acidification of the alcoholic solution of potassium soaps followed by extraction of fatty acid into hexane. Direct saponification was carried out in ethanol (96%, vol/vol) using 2.09 mL ethanol (96%) per gram of wet biomass (10 mL/g of dry biomass) mixed with 0.4 g KOH/g of biomass. Under these conditions the fatty acid yield was 87%. The optimal water content of the alcoholic solution for extraction of the unsapononifiables was established as 40%, w/w. Data on equilibrium carotenoid distribution between the alcoholic (40%, w/w water) and hexane phases were determined. These data allow prediction of the carotenoid yields with different volumes of hexane in several extraction steps. The optimal pH of the alcoholic solution before extracting the purified fatty acid was established as pH 6, and the equilibrium fatty acid distribution between the alcoholic and hexane phases was determined. This optimized method permited a 20% reduction in the production costs of highly purified eicosapentaenoic acid (EPA) in the three‐step preparative process (extraction of fatty acid, concentration of polyunsaturated fatty acids by the urea method, and EPA fractionation through preparative high‐performance liquid chromatography) previously developed by the authors.
Pressure drop through in‐bulk flax seeds
Authors: Pagano A. M. , Crozza D. E. , Nolasco S. M. 
Published: May 2007

AbstractThe airflow resistance of in‐bulk flax seeds (Linum usitatissimum) and the effect of airflow rate, bed depth, type of packing, and presence of foreign material (“fines” and “chaff”) were studied. A good fit of the experimental data (R > 0.993) was obtained through the model DPL = cQ + dQ2 (where DPL is pressure drop per unit of bed depth, Pa/m; Q is airflow rate, m3/s‐m2; c and d are constants; and airflow range is 0.011–0.141 m3/s‐m2). The airflow resistance increases when bulk density and bed depth increase. In dense packing the pressure drop is 1.3 to 1.5 times the pressure drop in loose packing. The resistance increases with the increase of fines and decreases with the increase of chaff.
A simple method of preparation of methyl trans‐10,cis‐12‐ and cis‐9,trans‐11‐octadecadienoates from methyl linoleate
Authors: Berdeaux O. , Voinot L. , Angioni E. , Juanéda P. , Sébédio J. L. 
Published: May 2007

AbstractPure conjugated isomers of linoleic acid were prepared on a large scale by alkali‐isomerization of purified methyl linoleate. The methyl esters of alkali‐isomerized linoleic acid contained mainly the methyl cis‐9,trans‐11‐ and trans‐10,cis‐12‐octadecadienoates (44 and 47%, respectively). These two isomers were then separated and purified by a series of low‐temperature crystallizations from acetone. The isomeric purity obtained for the cis‐9,trans‐11‐octadecadienoate isomer was >90% and that of the trans‐10,cis‐12‐octadecadienoate isomer was 89 to 97%. The isolated yield of the two isomers corresponded to 18 and 25.7%, respectively, of the starting material. The structure of the two isomers was confirmed using partial hydrazine reduction, silver nitrate‐thin‐layer chromatography of the resulting monoenes and gas chromatography coupled with mass spectrometry of the 4,4‐dimethyloxazoline derivatives. Fourier transform infrared spectroscopy of the monoenes gave the confirmation of the geometry of each double bond.