59 research outputs found

    Involutive orbits of non-Noether symmetry groups

    Full text link
    We consider set of functions on Poisson manifold related by continues one-parameter group of transformations. Class of vector fields that produce involutive families of functions is investigated and relationship between these vector fields and non-Noether symmetries of Hamiltonian dynamical systems is outlined. Theory is illustrated with sample models: modified Boussinesq system and Broer-Kaup system.Comment: LaTeX 2e, 10 pages, no figure

    The Coupled Modified Korteweg-de Vries Equations

    Full text link
    Generalization of the modified KdV equation to a multi-component system, that is expressed by (ui)/(t)+6(j,k=0M1Cjkujuk)(ui)/(x)+(3ui)/(x3)=0,i=0,1,...,M1(\partial u_i)/(\partial t) + 6 (\sum_{j,k=0}^{M-1} C_{jk} u_j u_k) (\partial u_i)/(\partial x) + (\partial^3 u_{i})/(\partial x^3) = 0, i=0, 1, ..., M-1 , is studied. We apply a new extended version of the inverse scattering method to this system. It is shown that this system has an infinite number of conservation laws and multi-soliton solutions. Further, the initial value problem of the model is solved.Comment: 26 pages, LaTex209 file, uses jpsj.st

    Box-Cox Regression Method in Time Scaling

    Get PDF
    Hata terimi ile bağımlı değişkenin süreklilik ve normal dağılma varsayımıbozulduğu durumlarda λj, j = 1, 2, ..., k, kuvvet dönüşümü ile tanımlanan Box-Coxregresyon yöntemi kullanılmaktadır. Y'ler üzerindeki λj, j = 1, 2, ..., k, kuvvetdönüşümünün hangi λj değerinde Hata Kareler Toplamı (HKT)' nı minimum yaptığıdurum ele alınmaktadır. Box-Cox regresyon yöntemi, regresyon fonksiyonunundoğrusal olmayan durumu, sabit olmayan hata varyansları ve hata terimlerinindağılışlarının çarpıklığını düzeltmek için Y'nin üzerinde dönüşüm yapılması açısındanoldukça uygundur. Bu çalışmada fark ve diferansiyel analizin birlikte ele alındığızaman skalası türev kavramı kullanılarak Box-Cox regresyon yöntemi kullanmanınavantaj ve dezavantajları incelenmiştir. Box-Cox regression method with λj, for j = 1, 2, ..., k, power transformation can beused when dependent variable and error term of the linear regression model do notsatisfy the continuity and normality assumptions. The situation obtaining the smallestmean square error when optimum power λj, transformation for j = 1, 2, ..., k, of Y hasbeen discussed. Box-Cox regression method is especially appropriate to adjustexistence skewness or heteroscedasticity of error terms for a nonlinear functionalrelationship between dependent and explanatory variables. In this study, the advantageand disadvantage use of Box-Cox regression method have been discussed indifferentiation and differantial analysis of time scale concept

    Modelling UK house prices with structural breaks and conditional variance analysis

    Get PDF
    This paper differs from previous research by examining the existence of structural breaks in the UK regional house prices as well as in the prices of the different property types (flats, terraced, detached and semi-detached houses) in the UK as a whole, motivated by the uncertainty in the UK housing market and various financial events that may lead to structural changes within the housing market. Our paper enhances the conventional unit root tests by allowing for structural breaks, while including structural break tests strengthens our analysis. Our empirical results support the existence of structural breaks in the mean equation in seven out of thirteen regions of the UK as well as in three out of four property types, and in the variance equation in six regions and three property types. In addition, using a multivariate GARCH approach we examine both the behaviour of variances and covariances of the house price returns over time. Our results have significant implications for appropriate economic policy selection and investment management

    Reconciling the stratigraphy and depositional history of the Lycian orogen-top basins, SW Anatolia

    Get PDF
    Terrestrial fossil records from the SWAnatolian basins are crucial both for regional correlations and palaeoenvironmental reconstructions. By reassessing biostratigraphic constraints and incorporating new fossil data, we calibrated and reconstructed the late Neogene andQuaternary palaeoenvironments within a regional palaeogeographical framework. The culmination of the Taurides inSWAnatolia was followed by a regional crustal extension from the late Tortonian onwards that created a broad array of NE-trending orogen-top basins with synchronic associations of alluvial fan, fluvial and lacustrine deposits. The terrestrial basins are superimposed on the upper Burdigalian marine units with a c. 7 myr of hiatus that corresponds to a shift from regional shortening to extension. The initial infill of these basins is documented by a transition from marginal alluvial fans and axial fluvial systems into central shallow-perennial lakes coinciding with a climatic shift from warm/humid to arid conditions. The basal alluvial fan deposits abound in fossil macro-mammals of an early Turolian (MN11–12; late Tortonian) age. The Pliocene epoch in the region was punctuated by subhumid/humid conditions resulting in a rise of local base levels and expansion of lakes as evidenced by marsh-swamp deposits containing diverse fossilmammal assemblages indicating late Ruscinian (lateMN15; late Zanclean) ageWe are grateful for the support of the international bilateral project between The Scientific and Technological Research Council of Turkey (TUBITAK) and The Russian Scientific Foundation (RFBR) with grant a number of 111Y192. M.C.A. is grateful to the Turkish Academy of Sciences (TUBA) for a GEBIP (Young Scientist Award) grant. T.K. and S.M. are grateful to the Ege University Scientific Research Center for the TTM/002/2016 and TTM/001/2016 projects. M.C.A., H.A., S.M. and M.B. have obtained Martin and Temmick Fellowships at Naturalis Biodiversity Center (Leiden). F.A.D. is supported by a Mehmet Akif Ersoy University Scientific Research Grant. T.A.N. is supported by an Alexander-von-Humboldt Scholarship. L.H.O. received support from TUBITAK under the 2221 program for visiting scientists

    Experimental examination of effects of punch angle and clearance on shearing force and estimation of shearing force using fuzzy logic

    Get PDF
    A significant challenge faced when using blanking/piercing to machine sheet metal is the handling of the shearing force required for high strength and thick stock. Increased shearing forces lead to the requirement of higher performance expected from the pressing machine and result in increased wear on the punch tool and die. Clearance, employed to increase precision and quality in blanking/piercing operations, affects the shearing force as well. One of the techniques used to reduce the force required is the employment of a punch shear angle. In this study, the effects of punch shear angle and clearance on the forces required for blanking/piercing were examined on a grade of steel broadly used in the manufacturing industry, DC01. Experiments were carried out using five different punch shear angles, namely 0°, 2°, 4°, 8°, and 16°. Six matrices with varying clearance rates (0.4%t, 0.5%t, 0.6%t, 0.7%t, 0.8%t, and 0.9%t) were used in this study, and these clearances were altered by modular matrices on the die. This study shows that shearing forces can be reduced by 80% when 16° punch angle is used. The results of the experiments were transferred to a fuzzy logic model to obtain extrapolated results for intermediate values which had not been obtained from the experiments. The results obtained from the experiments and the output from the fuzzy logic model were compared and found to be highly similar. These results have showed that the model developed using fuzzy logic can be used to determine different shear angles and clearance values
    corecore