BibSonomyburst/tag/mathematicalBibSonomy RSS feed for /tag/mathematical2012-02-15T23:20:17+01:00http://www.bibsonomy.org/bibtex/241d013af4ea6644fcf2ddcdcc4f60690/georges_pgeorges_p2011-12-22T11:51:38+01:00Basic Computer Conceptual Dialectics; Evolutionary Innovation Invention; Inventive Mathematical Patents Problem Standard TRIZ TRIZ; Trial aided algorithms; analysis; and error; frameworks; idea; inventions, operators; principles, problems; procedures; process; solving <span class="authorEditorList"><a href="/author/D.">Duran-Novoa R. Leon-Rovira N. Aguayo-Tellez H. Said D.</a> </span><em>Computers in Industry</em> <em>62(4):437-445</em> (<em>2011</em>)<em>cited By since 1996 0 . </em>Thu Dec 22 11:51:38 CET 2011Computers in Industrycited By (since 1996) 04437-445Inventive problem solving based on dialectical negation, using evolutionary algorithms and TRIZ heuristics622011Basic Computer Conceptual Dialectics; Evolutionary Innovation Invention; Inventive Mathematical Patents Problem Standard TRIZ TRIZ; Trial aided algorithms; analysis; and error; frameworks; idea; inventions, operators; principles, problems; procedures; process; solving The ability to solve inventive problems is at the core of the innovation process; however, the standard procedure to deal with them is to utilize random trial and error, despite the existence of several theories and methods. TRIZ and evolutionary algorithms (EA) have shown results that support the idea that inventiveness can be understood and developed systematically. This article presents a strategy based on dialectical negation in which both approaches converge, creating a new conceptual framework for enhancing computer-aided problem solving. Two basic ideas presented are the inversion of the traditional EA selection ("survival of the fittest"), and the incorporation of new dialectical negation operators in evolutionary algorithms based on TRIZ principles. Two case studies are the starting point to discuss what kind of results can be expected using this "Dialectical Negation Algorithm" (DNA). Β© 2010 Elsevier B.V. All rights reserved.http://www.bibsonomy.org/bibtex/2415c9e2a06ca332f3d5f2841ea2e5a27/toquetoque2011-11-16T22:33:57+01:00communication irhhu mathematical of theory <span class="authorEditorList"><a href="/author/Shannon">C E Shannon</a> </span><em>M.D. computing computers in medical practice.</em> <em>14(4):306-17</em> (<em>1963</em>)Wed Nov 16 22:33:57 CET 2011Secaucus, NJM.D. computing computers in medical practice.4306-17The mathematical theory of communication141963communication irhhu mathematical of theory http://www.bibsonomy.org/bibtex/2ae14b00b5489de8da6e4578ac3062bfc/bossatbossat2011-11-10T11:50:17+01:00analysis concept formal foundations mathematical <span class="authorEditorList"><a href="/author/Ganter">Bernhard Ganter</a>, and <a href="/author/Wille">Rudolf Wille</a> </span><em>Springer, </em><em>Berlin/Heidelberg, </em>(<em>1999</em>)Thu Nov 10 11:50:17 CET 2011Berlin/HeidelbergFormal Concept Analysis: Mathematical Foundations1999analysis concept formal foundations mathematical http://www.bibsonomy.org/bibtex/2cfbd4e1fa625f7ad865867a3335da417/procomunprocomun2011-09-01T13:26:03+02:00Solar arrays, blocking cells diodes, mathematical models, shadowed shunt, solar <span class="authorEditorList"><a href="/author/Rauschenbach">H. S. Rauschenbach</a> </span><em>IEEE Transactions on Electron Devices</em> (<em>1971</em>)Thu Sep 01 13:26:03 CEST 2011IEEE Transactions on Electron Devices8Electrical Output of Shadowed Solar Arrays181971Solar arrays, blocking cells diodes, mathematical models, shadowed shunt, solar The effects of shadows on the current-voltage characteristics of solar cell circuits are studied and used for the development of several mathematical models. These models descrciibrec uits of any geometry with or without shunt or blocking diodes. For efficient analyses of larger arrays the concept of the shadowing factor is developed. All models are useful in analyses performed by hand or digital computer, using theoretical or empirical input data.http://www.bibsonomy.org/bibtex/2d50f649875284bf1db9828f529ee649f/procomunprocomun2011-09-01T13:26:03+02:00Gauss-Newton, Newton-Raphson mathematical methods, <span class="authorEditorList"><a href="/author/Oviedo">J. M. Oviedo</a> </span>(<em>2006</em>)Thu Sep 01 13:26:03 CEST 2011Modelos No lineales: Gauss-Newton y Newton-Raphson. Implementaciones en Maple, Mathematica, Gauss, Matlab y Excel2006Gauss-Newton, Newton-Raphson mathematical methods, http://www.bibsonomy.org/bibtex/249857c0a7589f732d19045de0692471e/cocuscocus2011-03-27T19:35:34+02:00, character detection, document edge expressions, image image, mathematical processing, recognition, segmentation touching <span class="authorEditorList"><a href="/author/Nomura">A. Nomura</a>, <a href="/author/Michishita">K. Michishita</a>, <a href="/author/Uchida">S. Uchida</a>, and <a href="/author/Suzuki">M. Suzuki</a> </span><em>Proceedings of the Seventh International Conference on Document Analysis and Recognition, ICDAR2003, </em><em> 1, </em><em>page 126--130. </em><em>ieeeaddr, </em><em>ieee, </em>(<em>August 2003</em>)Sun Mar 27 19:35:34 CEST 2011ieeeaddrProceedings of the Seventh International Conference on Document Analysis and Recognition, (ICDAR2003)aug126--130Detection and segmentation of touching characters in mathematical expressions12003, character detection, document edge expressions, image image, mathematical processing, recognition, segmentation touching A technique for the detection and the segmentation of touching characters in mathematical expressions is presented. In the detection stage, a connected component initially recognized into some category is judged as a candidate of touched characters if its feature values deviate from the standard feature values of the category. In the segmentation stage, two component characters of the candidate are decided by the comparison with touching character images synthesized from two single character images. Experimental results showed the effectiveness on the accuracy improvement of the recognition of mathematical expressions.http://www.bibsonomy.org/bibtex/2bc51110f220c8fd5c68bbd1217298dca/chatpkchatpk2011-03-23T01:28:01+01:00competition group mathematical model social <span class="authorEditorList"><a href="/author/Abrams">Daniel M. Abrams</a>, <a href="/author/Yaple">Haley A. Yaple</a>, and <a href="/author/Wiener">Richard J. Wiener</a> </span>(<em>2010</em>)<em>cite arxiv:1012.1375 Comment: 5 pages, 4 figures with 6 pages and 7 figures of supplementary material . </em>Wed Mar 23 01:28:01 CET 2011cite arxiv:1012.1375 Comment: 5 pages, 4 figures (with 6 pages and 7 figures of supplementary material)A mathematical model of social group competition with application to the growth of religious non-affiliation2010competition group mathematical model social When groups compete for members, the resulting dynamics of human social activity may be understandable with simple mathematical models. Here, we apply techniques from dynamical systems and perturbation theory to analyze a theoretical framework for the growth and decline of competing social groups. We present a new treatment of the competition for adherents between religious and irreligious segments of modern secular societies and compile a new international data set tracking the growth of religious non-affiliation. Data suggest a particular case of our general growth law, leading to clear predictions about possible future trends in society. A mathematical model of social group competition with application to the growth of religious non-affiliationhttp://www.bibsonomy.org/bibtex/26cd78bac3cb1e2e4df4bfaef751b6edc/jmaiorajmaiora2011-03-11T12:21:24+01:00algorithm; analysis; hierarchical image mathematical morphology; reconstruction} segmentation; waterfall watershed; {image <span class="authorEditorList"><a href="/author/Beucher"> Beucher</a> </span><em>Mathematical Morphology And Its Applications To Image Processing, </em><em>volume 2 of Computational Imaging And Vision, </em><em>page 69-76. </em>(<em>1994</em>)Fri Mar 11 12:21:24 CET 2011{Mathematical Morphology And Its Applications To Image Processing}{69-76}{Computational Imaging And Vision}{Watershed, hierarchical segmentation and waterfall algorithm}{Proceedings Paper}{2}{1994}algorithm; analysis; hierarchical image mathematical morphology; reconstruction} segmentation; waterfall watershed; {image http://www.bibsonomy.org/bibtex/23a7098278b6a0bf5cc37dcf70f69ec65/grongron2011-01-26T09:49:19+01:00asynchronous benchmarks cache evaluation kernel locality loops mathematical tiling <span class="authorEditorList"><a href="/author/Liu">Lixia Liu</a>, and <a href="/author/Li">Zhiyuan Li</a> </span><em>Proceedings of the 15th ACM SIGPLAN symposium on Principles and practice of parallel programming, </em><em>page 213--222. </em><em>New York, NY, USA, </em><em>ACM, </em>(<em>2010</em>)Wed Jan 26 09:49:19 CET 2011New York, NY, USAProceedings of the 15th ACM SIGPLAN symposium on Principles and practice of parallel programming213--222PPoPP '10Improving parallelism and locality with asynchronous algorithms2010asynchronous benchmarks cache evaluation kernel locality loops mathematical tiling As multicore chips become the main building blocks for high performance computers, many numerical applications face a performance impediment due to the limited hardware capacity to move data between the CPU and the off-chip memory. This is especially true for large computing problems solved by iterative algorithms because of the large data set typically used. Loop tiling, also known as loop blocking, was shown previously to be an effective way to enhance data locality, and hence to reduce the memory bandwidth pressure, for a class of iterative algorithms executed on a single processor. Unfortunately, the tiled programs suffer from reduced parallelism because only the loop iterations within a single tile can be easily parallelized. In this work, we propose to use the asynchronous model to enable effective loop tiling such that both parallelism and locality can be attained simultaneously. Asynchronous algorithms were previously proposed to reduce the communication cost and synchronization overhead between processors. Our new discovery is that carefully controlled asynchrony and loop tiling can significantly improve the performance of parallel iterative algorithms on multicore processors due to simultaneously attained data locality and loop-level parallelism. We present supporting evidence from experiments with three well-known numerical kernels.Improving parallelism and locality with asynchronous algorithmshttp://www.bibsonomy.org/bibtex/236469c90e0a9615ea21f0056aa98353a/derikbderikb2011-01-20T17:30:31+01:00DiThe017 backward forward masking mathematical nachverdeckung theoretical vorverdeckung <span class="authorEditorList"><a href="/author/Zwicker">E. Zwicker</a> </span><em>Biol Cybern</em> (<em>June 1976</em>)Thu Jan 20 17:30:31 CET 2011Biol Cybernjun49--60{{A} model for predicting masking-period patterns}231976DiThe017 backward forward masking mathematical nachverdeckung theoretical vorverdeckung http://www.bibsonomy.org/bibtex/27ec6a73ed2f1b1cbcf6776c3718a60dc/yishyish2010-11-30T22:30:33+01:00attention cognition cognitive games gender girls haifa-games-course learning mathematical mental neuropsychology neuroscience neurosome psychology rotation skills spatial <span class="authorEditorList"><a href="/author/Feng">Jing Feng</a>, <a href="/author/Spence">Ian Spence</a>, and <a href="/author/Pratt">Jay Pratt</a> </span><em>Psychological Science</em> <em>18(10):850-855</em> (<em>2007</em>)Tue Nov 30 22:30:33 CET 2010Psychological Science10850-855Playing an Action Video Game Reduces Gender Difference in Spatial Cognition182007attention cognition cognitive games gender girls haifa-games-course learning mathematical mental neuropsychology neuroscience neurosome psychology rotation skills spatial We demonstrate a previously unknown gender difference in the distribution of spatial attention, a basic capacity that supports higher-level spatial cognition. More remarkably, we found that playing an action video game can virtually eliminate this gender difference in spatial attention and simultaneously decrease the gender disparity in mental rotation ability, a higher-level process in spatial cognition. After only 10 hr of training with an action video game, subjects realized substantial gains in both spatial attention and mental rotation, with women benefiting more than men. Control subjects who played a non-action game showed no improvement. Given that superior spatial skills are important in the mathematical and engineering sciences, these findings have practical implications for attracting men and women to these fields.http://www.bibsonomy.org/bibtex/243ab099ae01528ac949684571e9f6357/ra1602ra16022010-09-17T16:55:15+02:00Interferon-[gamma], Mathematical Pancreatic Rostock SBI cells, modelling, stellate {STAT1} <span class="authorEditorList"><a href="/author/Rateitschak">Katja Rateitschak</a>, <a href="/author/Karger">Anna Karger</a>, <a href="/author/Fitzner">Brit Fitzner</a>, <a href="/author/Lange">Falko Lange</a>, <a href="/author/Wolkenhauer">Olaf Wolkenhauer</a>, and <a href="/author/Jaster">Robert Jaster</a> </span><em>Cellular Signalling</em> <em>22(1):97--105</em> (<em>January 2010</em>)Fri Sep 17 16:55:15 CEST 2010Cellular Signallingjan197--105Mathematical modelling of interferon-[gamma] signalling in pancreatic stellate cells reflects and predicts the dynamics of {STAT1} pathway activity222010Interferon-[gamma], Mathematical Pancreatic Rostock SBI cells, modelling, stellate {STAT1} Signal transducer and activator of transcription {(STAT)} 1 is essentially involved in the mediation of antifibrotic interferon-[gamma] {(IFN[gamma])} effects in pancreatic stellate cells {(PSC).} Here, we have further analysed the activation of the {STAT1} pathway in a {PSC} line by combining quantitative data generation with mathematical modelling. At saturating concentrations of {IFN[gamma],} a triphasic pattern of {STAT1} activation was observed. An initial, rapid induction of {phospho-STAT1} was followed by a plateau phase and another, long-lasting phase of further increase. The late increase occurred despite enhanced expression of the feedback inhibitor {(SOCS1),} and corresponded to increased levels of total {STAT1} protein. If {IFN[gamma]} was applied at non-saturating concentrations, {phospho-STAT1} and {SOCS1} levels peaked and declined again over a 12 hour period, while {STAT1} protein levels remained high. The mathematical model, based on a system of ordinary differential equations, describes temporal changes of the network components as a function of interactions and transport processes. The model reproduced activation profiles of all components of the {STAT1} pathway that were experimentally analysed. Furthermore, it successfully predicted the dynamics of network components in additional experimental studies. Based on experimental findings and the results obtained from modelling, we suggest exhaustion of applied {IFN[gamma]} and {STAT1} dephosphorylation by tyrosine phosphatases as limiting factors of {STAT1} activation in {PSC.} In contrast, we did not obtain compelling evidence that {SOCS1} acts as an efficient feedback inhibitor in our experimental system. We believe that further investigations into mathematical modelling of the {STAT1} pathway will improve the understanding of the antifibrotic interferon action.http://www.bibsonomy.org/bibtex/27f326987a0acb8aca4d52dd79dbaca42/jomiralbjomiralb2010-09-05T22:59:08+02:00Ecuaciones Equacions; Equations; Estadística Mathematical matemàtica; matemática; statistics; <span class="authorEditorList"><a href="/author/Foguet">Joan Manuel Batista Foguet</a>, and <a href="/author/Gallart">Germà Coenders Gallart</a> </span><em>La Muralla, </em><em>Madrid, </em>(<em>2000</em>)<em>Joan Manuel Batista Foguet, Germà Coenders Gallart; :il., taules, quadres; Bibliografia p. 167- 173; Bibliografía p. 167- 173; Cuadernos de estadística <span class="info">...<div>Joan Manuel Batista Foguet, Germà Coenders Gallart; :il., taules, quadres; Bibliografia p. 167- 173; Bibliografía p. 167- 173; Cuadernos de estadística ;6</div></span> . </em>Sun Sep 05 22:59:08 CEST 2010MadridJoan Manuel Batista Foguet, Germà Coenders Gallart; :il., taules, quadres; Bibliografia p. [167]- 173; Bibliografía p. [167]- 173; Cuadernos de estadística ;6173Modelos de ecuaciones estructurales :modelos para el análisis de relaciones causales2000Ecuaciones Equacions; Equations; Estadística Mathematical matemàtica; matemática; statistics; http://www.bibsonomy.org/bibtex/2f61aa317dba1f6f78e3e7d07a2d8240a/jkmaccjkmacc2010-08-12T23:06:12+02:003225 8110 8159 9320 Altyn Asia Continental Geographic Geophysics: Location: Mathematical Numerical Rheology: Tagh Tectonophysics: analysis; and approximations continental crust deformation; fault; general; lithosphere; sheet; tectonics: thin viscous <span class="authorEditorList"><a href="/author/Dayem">Katherine E. Dayem</a>, <a href="/author/Houseman">Gregory A. Houseman</a>, and <a href="/author/Molnar">Peter Molnar</a> </span><em>Tectonics</em> (<em>May 2009</em>)Thu Aug 12 23:06:12 CEST 2010Tectonics053Localization of shear along a lithospheric strength discontinuity: Application of a continuous deformation model to the boundary between Tibet and the Tarim Basin2820093225 8110 8159 9320 Altyn Asia Continental Geographic Geophysics: Location: Mathematical Numerical Rheology: Tagh Tectonophysics: analysis; and approximations continental crust deformation; fault; general; lithosphere; sheet; tectonics: thin viscous A marked contrast in strength (or viscosity) within a continuously deforming zone can lead to concentration of shear strain in the weaker material adjacent to the boundary between them, but localization comparable to the width of the Altyn Tagh shear zone requires an additional weakening process. During numerical experiments on a thin viscous sheet indented by a rigid object, a shear zone develops adjacent to a strong region mimicking the Tarim Basin, when the boundary between the weak and strong regions is oblique to the orientation of convergence. The width of this shear zone narrows with increased strain, and for comparable penetration by the indenter, the strain is more concentrated for larger values of n, the exponent that relates strain rate to a power of stress, and for smaller values of the Argand number Ar, a measure of buoyancy-induced stress relative to viscous stress. Increasing concentration of shear occurs as the indentation develops without weakening because of a change in material properties. Additional localization develops with the inclusion of strain-dependent weakening associated with, for instance, a temperature increase due to shear heating. For such localization to scale to the width of the Altyn Tagh fault zone of Tibet, the initial temperature near the Moho must be relatively low (\&{\#}8764;600∞C), and a large value of n (\&{\#}8764;10) is required. This suggests that deformation there is described by a high-strength flow law, such as that proposed by Evans and Goetze (1979), in which the lithosphere would deform approximately plastically.http://www.bibsonomy.org/bibtex/27f5c49f729e0577953b3d94c7420ff52/jkmaccjkmacc2010-08-12T23:06:12+02:001219 3260 7205 7255 Continental Earth Geodesy Geophysics: Gravity Gravity: Inverse Mathematical Seismology: Surface and anomalies anomalies; crust; free gravity inversion; joint oscillations; structure; surface theory waves waves; <span class="authorEditorList"><a href="/author/Maceira">Monica Maceira</a>, and <a href="/author/Ammon">Charles J. Ammon</a> </span><em>J. Geophys. Res.</em> (<em>February 2009</em>)Thu Aug 12 23:06:12 CEST 2010J. Geophys. Res.02Joint inversion of surface wave velocity and gravity observations and its application to central Asian basins shear velocity structure11420091219 3260 7205 7255 Continental Earth Geodesy Geophysics: Gravity Gravity: Inverse Mathematical Seismology: Surface and anomalies anomalies; crust; free gravity inversion; joint oscillations; structure; surface theory waves waves; We implement and apply a method to the jointly inverted of surface wave group velocities and gravity anomalies observations. Surface wave dispersion measurements are sensitive to seismic shear wave velocities, and the gravity measurements supply constraints on rock density variations. Our goal is to obtain a self-consistent three-dimensional shear velocity‚{\"A}{\`\i}density model with increased resolution of shallow geologic structures. We apply the method to investigate the structure of the crust and upper mantle beneath two large central Asian sedimentary basins: the Tarim and Junggar. The basins have thick sediment sections that produce substantial regional gravity variations (up to several hundred milligals). We used gravity observations extracted from the global gravity model derived from the Gravity Recovery and Climate Experiment (GRACE) satellite mission. We combine the gravity anomalies with high-resolution surface wave slowness tomographic maps that provide group velocity dispersion values in the period range between 8 and 100 s for a grid of locations across central Asia. To integrate these data, we use a relationship between seismic velocity and density constructed through the combination of two empirical relations. One determined by Nafe and Drake, most appropriate for sedimentary rocks, and a linear Birch's law, more applicable to denser rocks (the basement). An iterative, damped least squares inversion including smoothing is used to jointly model both data sets, using shear velocity variations as the primary model parameters. Results show high upper mantle shear velocities beneath the Tarim basin and suggest differences in lower crust and upper mantle shear velocities between the eastern and western Tarim.http://www.bibsonomy.org/bibtex/20236ab9dc0265c54341901cf3592f2dc/joelotzjoelotz2010-06-23T08:39:21+02:003D analysis; attribute data domain;computational domain;data geometry;data grid grid;continuous histogram;continuous histogram;spatial mathematical model;interpolation;isosurface plot;discrete point;generic scatterplot;data statistical tetrahedral value variable;dense visualisation;interpolation;statistical visualization;discrete <span class="authorEditorList"><a href="/author/Bachthaler">S. Bachthaler</a>, and <a href="/author/Weiskopf">D. Weiskopf</a> </span><em>Visualization and Computer Graphics, IEEE Transactions on</em> <em>14(6):1428 -1435</em> (<em>November 2008</em>)Wed Jun 23 08:39:21 CEST 2010Visualization and Computer Graphics, IEEE Transactions onnov.-dec. 61428 -1435Continuous Scatterplots1420083D analysis; attribute data domain;computational domain;data geometry;data grid grid;continuous histogram;continuous histogram;spatial mathematical model;interpolation;isosurface plot;discrete point;generic scatterplot;data statistical tetrahedral value variable;dense visualisation;interpolation;statistical visualization;discrete Scatterplots are well established means of visualizing discrete data values with two data variables as a collection of discrete points. We aim at generalizing the concept of scatterplots to the visualization of spatially continuous input data by a continuous and dense plot. An example of a continuous input field is data defined on an n-D spatial grid with respective interpolation or reconstruction of in-between values. We propose a rigorous, accurate, and generic mathematical model of continuous scatterplots that considers an arbitrary density defined on an input field on an n-D domain and that maps this density to m-D scatterplots. Special cases are derived from this generic model and discussed in detail: scatterplots where the n-D spatial domain and the m-D data attribute domain have identical dimension, 1-D scatterplots as a way to define continuous histograms, and 2-D scatterplots of data on 3-D spatial grids. We show how continuous histograms are related to traditional discrete histograms and to the histograms of isosurface statistics. Based on the mathematical model of continuous scatterplots, respective visualization algorithms are derived, in particular for 2-D scatterplots of data from 3-D tetrahedral grids. For several visualization tasks, we show the applicability of continuous scatterplots. Since continuous scatterplots do not only sample data at grid points but interpolate data values within cells, a dense and complete visualization of the data set is achieved that scales well with increasing data set size. Especially for irregular grids with varying cell size, improved results are obtained when compared to conventional scatterplots. Therefore, continuous scatterplots are a suitable extension of a statistics visualization technique to be applied to typical data from scientific computation.http://www.bibsonomy.org/bibtex/2d64cbbff1420c510c33e7cbe834b7df2/jeijei2010-05-16T18:57:28+02:00coalitions democracy germany judeic mathematical parties theory wisrep10 <span class="authorEditorList"><a href="/author/Tangian">Andranik Tangian</a> </span><em>European Journal of Operational Research</em> <em>202(1):294-307</em> (<em>April 2010</em>)Sun May 16 18:57:28 CEST 2010European Journal of Operational ResearchApril1294-307Evaluation of German parties and coalitions by methods of the mathematical theory of democracy2022010coalitions democracy germany judeic mathematical parties theory wisrep10 The paper continues author’s studies on applications of the mathematical theory of democracy. Five German leading parties and their coalitions are evaluated with indices of popularity and universality to show how well they represent the electorate. The evaluation goes beyond the information on election results and uses an operational representation of party manifestos. It is shown that at the time of German parliamentary elections 2005 the most representative was the Social Democratic Party (SPD) which was however behind Christian Democratic Union (CDU) and the best coalition could be the coalition SPD/Green/Left-Party which failed because of disagreement between party leaders.http://www.bibsonomy.org/bibtex/23924014554036d1b4e23fe4f275e23d8/uvescouvesco2010-01-14T17:47:41+01:00Animals model AfricaSouthoftheSahara Tick-BorneDiseases epidemiology/parasitology/transmission mathematical CattleDiseases epidemiology/parasitology/transmission/veterinary Models Cattle veterinary Biological growth/&amp;/development TickInfestations Ticks <span class="authorEditorList"><a href="/author/Mwambi">Henry G Mwambi</a> </span><em>IMA Journal of Mathematics Applied In Medicine and Biology</em> <em>19(4):275--292</em> (<em>December 2002</em>)Thu Jan 14 17:47:41 CET 2010IMA Journal of Mathematics Applied In Medicine and BiologyDec4275--292Ticks and tick-borne diseases in Africa: a disease transmission model.192002Animals model AfricaSouthoftheSahara Tick-BorneDiseases epidemiology/parasitology/transmission mathematical CattleDiseases epidemiology/parasitology/transmission/veterinary Models Cattle veterinary Biological growth/&/development TickInfestations Ticks A general disease transmission model is developed for a tick-borne disease for cattle. Both the tick and cow are possible hosts for the disease parasite. The two species are therefore classified as infected or uninfected. The tick individual is further classified as sedentary (off-host) or feeding (on-host). First conditions for the persistence of the tick population are investigated. A threshold quantity for the disease is derived which is dependent on both the tick and host population parameters and the two transmission rates: from ticks to cattle and vice versa. From the analysis persistence and non-persistence conditions for both the tick population and the disease are investigated. The effect of the presence of a second host species is introduced as an additional feature in the analysis.http://www.bibsonomy.org/bibtex/2f99266cdeafb01590bbea8bc792fba9a/uvescouvesco2010-01-14T17:44:26+01:00Ixodes Animals model borrelia Tick-BorneDiseases mathematical MathematicalComputing PopulationDynamics epidemiology/transmission Italy Models Biological Seasons Ticks <span class="authorEditorList"><a href="/author/Ghosh">Mini Ghosh</a>, and <a href="/author/Pugliese">Andrea Pugliese</a> </span><em>Bulletin of Mathematical Biology</em> <em>66(6):1659--1684</em> (<em>November 2004</em>)<em>EFSA . </em>Thu Jan 14 17:44:26 CET 2010Bulletin of Mathematical BiologyNovEFSA61659--1684Seasonal population dynamics of ticks, and its influence on infection transmission: a semi-discrete approach.662004Ixodes Animals model borrelia Tick-BorneDiseases mathematical MathematicalComputing PopulationDynamics epidemiology/transmission Italy Models Biological Seasons Ticks In this paper, a simple semi-discrete (ticks' feeding is assumed to occur only during the summers of each year) model for tick population dynamics is presented. Conditions for existence, uniqueness, and stability of a positive equilibrium are found; the system is then studied numerically using parameter estimates calibrated for the tick Ixodes ricinus in Trentino, Italy, and the sensitivity to parameters is examined. Then, this model is extended to consider a tick-transmitted infection of one species of hosts, while other hosts are incompetent to the infection. Assuming, for simplicity, that the infection is not affecting the total number either of hosts or ticks, a threshold condition for infection persistence is obtained. The dependence of the equilibrium infection prevalence on parameters is studied numerically; in particular, we considered how infection prevalence depends on host densities. This analysis reveals that a 'dilution effect' occurs both for competent and for incompetent hosts; this means that, besides a lower threshold for host densities for infection to persist, there exists also an upper threshold: if host densities were higher than the upper threshold, the infection would go to extinction. Numerically, it is found that, for realistic parameter values, the upper threshold is not much higher than observed densities.http://www.bibsonomy.org/bibtex/2290eb8cc9d95633026f3f0becb9baa83/uvescouvesco2010-01-14T17:43:53+01:00Ixodes Animals model borrelia Pyrazoles Tick-BorneDiseases parasitology LymeDisease Humans mathematical PopulationDynamics pharmacology Italy Models growth/&amp;/development/microbiology microbiology/prevention/&amp;/control/transmission/veterinary NumericalAnalysis Insecticides Seasons Biological Computer-Assisted Deer <span class="authorEditorList"><a href="/author/Ding">Wandi Ding</a> </span><em>Mathematical Biosciences and Engineering</em> <em>4(4):633--659</em> (<em>October 2007</em>)<em>EFSA . </em>Thu Jan 14 17:43:53 CET 2010Mathematical Biosciences and EngineeringOctEFSA4633--659Optimal control on hybrid ode systems with application to a tick disease model.42007Ixodes Animals model borrelia Pyrazoles Tick-BorneDiseases parasitology LymeDisease Humans mathematical PopulationDynamics pharmacology Italy Models growth/&/development/microbiology microbiology/prevention/&/control/transmission/veterinary NumericalAnalysis Insecticides Seasons Biological Computer-Assisted Deer We are considering an optimal control problem for a type of hybrid system involving ordinary differential equations and a discrete time feature. One state variable has dynamics in only one season of the year and has a jump condition to obtain the initial condition for that corresponding season in the next year. The other state variable has continuous dynamics. Given a general objective functional, existence, necessary conditions and uniqueness for an optimal control are established. We apply our approach to a tick-transmitted disease model with age structure in which the tick dynamics changes seasonally while hosts have continuous dynamics. The goal is to maximize disease-free ticks and minimize infected ticks through an optimal control strategy of treatment with acaricide. Numerical examples are given to illustrate the results.