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Modeling and simulation of correlated random variables are important for evaluating operating characteristics of experimental designs in various applications, of which clinical trials with multiple endpoints provide an important e...
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Modeling and simulation of correlated random variables are important for evaluating operating characteristics of experimental designs in various applications, of which clinical trials with multiple endpoints provide an important example. There exist efficient algorithms to address the problem of generatingmultivariate distributions with given marginals and correlation structure. For model fitting as well as for simulation,it is important to know the feasible range of pairwise correlations, which can be much narrower than the interval [- 1,+1].We provide closed-form expressions for extreme correlations for several classes of bivariate distributions that involve both discrete and continuous endpoints, as well as an algorithm for the construction of such distributions in the discrete case.
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Fifty clones of saffron (Crocus sativus L.) were planted in a randomized bock design with three replications at Saffron Research Station, Pampore, SKUAST-Kashmir during 2010. Observations were recorded on 10 randomly selected and ...
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Fifty clones of saffron (Crocus sativus L.) were planted in a randomized bock design with three replications at Saffron Research Station, Pampore, SKUAST-Kashmir during 2010. Observations were recorded on 10 randomly selected and tagged competitive plants for 11 morphological, physiological, floral and corm attributes. The estimates of genotypic correlation coefficients were higher in magnitude through similar in direction for all the traits. The results have further revealed that the number of flowers corm"' exhibited a strong significant positive association with all the traits. The fresh pistil weight, an important yield attributing character revealed a strong positive association with all the floral attributes except number of radical leaves planf' and number of flowers corm '. Similarly, stomatal frequency also recorded significant positive association with all the traits. The average weight of daughter corms showed significant positive association with stomatal size and positive association with chlorophyll content. The average weight of daughter corms shows significant positive association with stomatal size and positive association with chlorophyll content. A significant positive association of average weight of daughter corms with numberof daughter corms was observed both at phenotypic and genotypic levels, indicating that an increase in number of daughter corms results in proportional decline in average corm weight. Identification of five elite genotypes with distinct superiority in yield and corm attributes could be a source for further improvement and development of high yielding varieties.
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The behavior of the spatial two-particle correlation function is surveyed in detail for a uniform one-dimensional Bose gas with repulsive contact interactions at finite temperatures. Long-, medium-, and short-range effects are inv...
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The behavior of the spatial two-particle correlation function is surveyed in detail for a uniform one-dimensional Bose gas with repulsive contact interactions at finite temperatures. Long-, medium-, and short-range effects are investigated. The results span the entire range of physical regimes from ideal gas to stronglyinteracting and from zero temperature to high temperature (Gross-Pitaevskii) and strongly interacting (Tonks-Girardeau) gases. We present perturbative analytic methods, available at strong and weak couplings, andfirst-principles numerical results using imaginary time simulations with the gauge-P representation in regimeswhere perturbative methods are invalid. Nontrivial effects are observed from the interplay of thermally inducedbunching behavior versus interaction induced antibunching.
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More than half of a century has passed since the free energy of classical fluids defined by second Legendre transform was derived as a functional of density-density correlation function. It is now becoming an increasingly signific...
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More than half of a century has passed since the free energy of classical fluids defined by second Legendre transform was derived as a functional of density-density correlation function. It is now becoming an increasingly significant issue to develop the correlation functional theory that encompasses the liquid state theory, especially for glassy systems where out of equilibrium correlation fields are to be investigated. Here, we have formulated a field theoretic perturbation theory that incorporates two-body fields (both of density-density correlation field and its dual field playing the role of two-body interaction potential) into a density functional integral representation of the Helmholtz free energy. Quadratic density fluctuations are only considered in the saddle-point approximation of two-body fields as well as the density field. We have obtained a set of self-consistent field equations with respect to these fields, which simply reads a modified mean-field equation of density field where the bare interaction potential in the thermal energy unit is replaced by minus the direct correlation function given in the mean spherical approximation. Such replacement of the interaction potential in the mean-field equation belongs to the same category as the local molecular field theory proposed by Weeks and co-workers in a series of papers [e.g., Rodgers et al., Phys. Rev. Lett. 97, 097801 (2006); Remsing et al., Proc. Natl. Acad. Sci. USA 113, 2819 (2016)]. Notably, it has been shown that even the mean-field part of the free energy functional given by the self-consistent field theory includes information on short-range correlations between fluid particles, similar to the formulation of the local molecular field theory. The advantage of our field theoretic approach is not only that the modified mean-field equation can be improved systematically, but also that fluctuations of two-body fields in nonuniform fluids may be considered, which would be relevant especially for g
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We investigate the total effect of correlations on photoionization of atomic states with nonzero orbitalmomentum in the nonrelativistic high-energy asymptotic limit, considering the exclusive case of the dominantfinal state of an ...
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We investigate the total effect of correlations on photoionization of atomic states with nonzero orbitalmomentum in the nonrelativistic high-energy asymptotic limit, considering the exclusive case of the dominantfinal state of an initial neutral atom. We find that the substantial cancellation of the dominant intrashellcorrelations, which had been reported earlier, can be understood utilizing the closure properties satisfied by theeigenfunctions of the nonrelativistic Hamiltonian. Considering the sum of correlations with all states, occupiedor not, we show that complete sum is equal to the contribution of the high-energy part of the continuum.Consequently there is a total cancellation between the contributions of the bound states (occupied and unoc-cupied) and the low-energy part of the continuum states. This means that the real correlations in the physicalatom due to the sum rule over the occupied states can be also obtained as the negative of the sum ofcontributions of low-energy bound and continuum unoccupied states. We calculate this in the framework of thequantum-defect model. As we would expect, the results are close to those obtained earlier in particular cases bydirect summation over the occupied states. However this approach also allows us to see that the sum ofcorrelations over the occupied states is smaller than the dominant intrashell correlation. Hence, there is a partialcancellation between correlations with the occupied states. We can also obtain some limits on the correlationeffects by considering calculations with the screened Coulomb functions. The role of correlations in theexclusive photoionization processes, also the modification of correlations in the case of atomic ions, isdiscussed.
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The method of correlation mapping on the full sphere is used to study the properties of the ILC map, as well as the dust and synchrotron background components. An anomalous correlation of the components with the ILC map in the mai...
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The method of correlation mapping on the full sphere is used to study the properties of the ILC map, as well as the dust and synchrotron background components. An anomalous correlation of the components with the ILC map in the main plane and in the poles of the ecliptic and equatorial coordinate systems was discovered. Apart from the bias, a dominant quadrupole contribution in the power spectrum of the mosaic correlation maps was found in the pixel correlation histogram. Various causes of the anomalous signal are discussed.
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In this paper we study one-dimensional sections of the maps of WMAP ILC and of the NVSSsurvey on scale lengths of 0.75, 3, 4.5, and 6.75 degrees and analyze the correlation properties of thesections. On these maps we identify the ...
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In this paper we study one-dimensional sections of the maps of WMAP ILC and of the NVSSsurvey on scale lengths of 0.75, 3, 4.5, and 6.75 degrees and analyze the correlation properties of thesections. On these maps we identify the domains where the absolute value of the correlation coefficientexceeds 0.5. The catalog of such domains is presented. It is shown that the number of the domains agreeswith the number of such domains on simulated maps and this fact may be indicative of just statisticalagreement of the arrangement of the domains considered.
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Thirty six okra genotypes were evaluated for different agro-morphological and biochemical traits at Melkas-sa Agricultural Research Center, Ethiopia during 2018 main season using 6x6 simple lattice design. The objectives were to a...
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Thirty six okra genotypes were evaluated for different agro-morphological and biochemical traits at Melkas-sa Agricultural Research Center, Ethiopia during 2018 main season using 6x6 simple lattice design. The objectives were to assess the correlationof agro-morphological and biochemical traits with fruit yield and to partition the correlation in to direct and indirect effects through path analysis. The genotypic correlation was positive and significant for fruit yield per hectare with stem diameter, plant height, leaf length, leaf width, peduncle length, fruit length, fresh fruit mass, hundred seed mass, seed yield per hectare and ash content. The phenotypic correlation was positive and significant for fruit yield per hectare with stem diameter, plant height, number of branches, leaf length, leaf width, peduncle length, fruit length, fresh fruit mass, number of fruits per plant, hundred seed mass, seed yield per hectare, ash, fat and protein content. Path coefficient analysis indicated fresh fruit mass and seed yield per hectare had positive direct effects on fruit yield per hectare at phenotypic and genotypic levels. These traits also exerted high to low positive indirect effects through other traits on fruit yield at genotypic and phenotypic level. In conclusion, this study showed the presence of association of traits with fruit yield indicating that the prime importance of these traits while selecting higher yield okra genotypes.
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Correlation and heritability estimates of the yield and the fiber or lint quality were determined using 15 F, cotton hybrids obtained from a diallel cross made in the Werer Agricultural Research Center, in Ethiopia, in 2003. The r...
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Correlation and heritability estimates of the yield and the fiber or lint quality were determined using 15 F, cotton hybrids obtained from a diallel cross made in the Werer Agricultural Research Center, in Ethiopia, in 2003. The results indicated that the seed cotton yield was highly genetically correlated to boll weight (r = 0.99~(**)), lint yield (r = 0.88~(**)) and lint index (r = 0.96~(**)). The lint yield was highly correlated to lint percentage (r = 0.94~(**)) and the number of seeds per boll (r = 0.96~(**)). The results illustrated that a high lint percentage, more bolls per plant and a small seed size were positively correlated to high cotton lint yield.
Fiber strength was highly correlated to all fiber quality parameters and positive correlations were found between staple length 2.5% (r = 0.99~(**)) staple length 50% (r = 0.64~(**)) and fiber strength. A positive correlation was also found between the fineness indicator (micronaire) and the uniformity ratio (r = 0.61~(**)). However negative correlations were observed between fiber length and the fineness indicator (micronaire) (r = -0.86~(**)), short fiber index (r = -0.85~(**)) and uniformity ratio (r = -0.99~(**)).
Negative genetic correlation coefficients of lint percentage and lint yield with fiber strength were quite high (r = -0.99 and r = -0.96~(**), respectively), but they had a positive correlation with the fiber-fineness indicator or micronaire (r=0.99~(**) and 0.79~(**), respectively). The broad-sense heritability estimates of the yield and yield components were high for lint percentage (h~2 = 97%), lint yield (h~2 = 72%), lint index (h~2 - 79%) and seed index (h~2 = 86%). As they also had a strong relationship with other fiber quality parameters as well, they could be considered as indicators of the yield and fiber quality improvement in cotton.
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In a recent study, Saha et al. (2019, https://doi.org/10.1029/2018JD030082) examine the correlation between boreal summer seasonal mean rainfall over India and rainfall variance as a function of subseasonal time scale and find tha...
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In a recent study, Saha et al. (2019, https://doi.org/10.1029/2018JD030082) examine the correlation between boreal summer seasonal mean rainfall over India and rainfall variance as a function of subseasonal time scale and find that the correlation has a local maximum (exceeding a value of 0.6) for synoptic time scales (2-5 day periods). They claim these results to be a major advancement in understanding monsoon predictability but do not provide a clear physical explanation. Here we examine the sensitivity of this relationship to the details of the analysis and only consider the observed correlation identified by Saha et al. (2019, https://doi.org/10.1029/2018JD030082). There is large sensitivity in the correlation maximum between spatially averaged seasonal mean rainfall and synoptic scale rainfall variance averaged over the same domain. The correlation maximum is weaker over the longer period of 1901-2015, and more notably it is highly sensitive to the domain of prior averaging. A correlation peak is not found outside central India and is neither found within central India when averaging over a smaller domain. Averaging over a larger domain results in a disproportionate reduction in synoptic variance (that is of most interest). The peak in correlation between seasonal mean and 2-5 day variance only emerges after first averaging over a sufficiently large region; thus, the maximum appears to be an artifact of spatial averaging. It is further pointed out that a positive mean-variance relationship is an intrinsic property of rainfall, and thus, its existence alone does not necessarily imply any physical, causal, and/or predictive connection between time scales.
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