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Although convergence to stability is typically a complex and irregular process, the Kullback distance provides a measure that moves consistently to 0 as a population becomes stable. The roots of the Kullback distance are in information theory, but it is a meaningful demographic quantity. It reflects a population's log momentum, or the amount of growth built(More)
  • Y J Kim
  • 1987
A general and complete exposition of the dynamics of populations with changing vital rates is given in the discrete time formulation. Results obtained are stronger than Lopez's or Hajnal's. In addition to the proof of existence of limits, an explicit expression for the age distribution is obtained by considering forward products of population projection(More)
The shovel is a basic tool that has undergone only nominal systematic design changes. Although previous studies found shovel-weight and blade-size effects of shovelling, the exact trade-off between the two has not been quantified. Energy expenditure, heart rate, ratings of perceived exertion and shovelling performance were measured on five subjects using(More)
Differential scanning calorimetry (DSC) was used to determine the thermodynamic functions of the undercooled liquid and the amorphous phase with respect to the crystalline state of the ~41.2Ti13.8CU125Nilo.OBe22.5 bulk mltallic glass forming alloy. The specific heat capacities of this alloy. in the undercooled liquid, the amorphous state and the crystal(More)
We report a neutron scattering study on the tetragonal compound Sr2Cu3O4Cl2, which has two-dimensional (2D) interpenetrating CuI and CuII subsystems, each forming a S = 1/2 square lattice quantum Heisenberg antiferromagnet (SLQHA). The mean-field ground state is degenerate, since the inter-subsystem interactions are geometrically frustrated. Magnetic(More)
Starting with a sinusoidal birth function, we derive an explicit expression for the associated wave of net maternity (R(t)). The phase shift and relative amplification of R(t) depend heavily on the cycle length of oscillation (T) relative to the mean age of net maternity (mu) and on the amplitude of oscillation of the birth function. For short cycle lengths(More)
This paper investigates the simplest multistate population model, a one-age-group, two-living-state model with constant rates of birth, death, and interstate movement. A general solution for the model is presented, and special attention is given to the process of convergence to stability and its relationship to spatial population momentum. The constant(More)
Atmospheric Chemistry and Physics Discussions This discussion paper is/has been under review for the journal Atmospheric Chemistry and Physics (ACP). Please refer to the corresponding final paper in ACP if available. Abstract In situ measurements of the mass concentration of elemental carbon (EC) and mixing ratios of carbon monoxide (CO) and carbon dioxide(More)
Three kinds of Bi-based solder powders with different chemical compositions of binary Bi–Sn, ternary Bi–Sn–In, and quaternary Bi–Sn–In–Ga were prepared using a gas atomization process and subsequently ball-milled for smaller-size fabrication. In particular, only the quaternary Bi–Sn–In–Ga solder powders were severely broken to the size of less than 10 µm in(More)
By restricting the number of age groups to two and by introducing continued fractions, the dynamics of populations with deterministically changing vital rates are completely specified at all times. Explicit expressions for the sequence of the product of population projection matrices are given. From these, relative age distribution and reproductive values(More)
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