370 research outputs found
IMPACTS OF HOUSEHOLD COMPOSITION ON CONVENIENCE AND NONCONVENIENCE FOOD EXPENDITURES IN THE SOUTH
Consumer/Household Economics,
Spatial Analyses of the Flow of Slaughter Livestock in 1955 and 1960
In this study attention is focused on the spatial aspects of slaughter livestock movements from production to slaughtering. Given the regional levels of production, slaughtering and the costs of moving one unit of various types of slaughter livestock from any one region to another region, this study is concerned with ascertaining the regional price differentials, and the volume and direction of regional imports and exports that are consistent with minimizing the total cost of moving the livestock from production to slaughter. In addition, questions about the consequences of changes in the existing structure of the livestock economy may be evaluated with regard to their impact on regional prices and slaughter livestock flows
Joint Spatial Analysis of Regional Slaughter and the Flows and Pricing of Livestock and Meat
The purpose of this study is to (1) develop a model to handle the simultaneous solution for the processing and flow problem, (2) develop estimates of slaughtering capacity for cattle and hogs in each region, and (3) apply the model using estimates of regional levels of production, regional levels of consumption, regional slaughtering capacities, and transportation costs of live slaughter animals and meats. Attention is focused at determining what regional levels of slaughter and directions and levels of interregional livestock and meat flows satisfy the regional production consumption, and capacity constraints and make the total cost of transportation of live slaughter animals and meat a minimum. The analysis is broadened to also obtain the impacts of alternative regional slaughter capacity restrictions and .regional differences in the labor cost of slaughtering livestock
Spatial Analyses of the Meat Marketing Sector in 1955 and 1960
The livestock products sector is a complex composed of the activities of production, farm marketing, slaughtering, distribution and consumption. The level of each of these activities varies spatially and thus regional imbalances are generated which make necessary product flows between the geographical areas. Within this setting this study is concerned with an interregional analysis of the livestock meat sector of the U. S. economy. Thus, spatial slaughter-consumption relations will be basic observations for this analysis. In this study regional demands are reflected by price dependent demand relations or specific estimates of consumption. Regional supplies are dressed carcass weights of livestock slaughter within the regions. In particular for the beef, pork, veal, and lamb and mutton sectors for the years 1955 and 1960 answers will be sought to the following questions: 1. What are the levels of regional demand for each of these meat products? 2. What are the levels of regional supply for each of these products? 3. What is the aggregate interregional trade for each meat product for each year? 4. For each commodity and for each year, what regions import, export or do neither? 5. What are the levels of regional exports and imports for each region, commodity and year? 6. What is the optimum volume and direction of trade between all possible pairs of regions for each commodity and each year? 7. What are the optimum price differentials between regions for each commodity and year? 8. What is the total transport cost for the aggregate trade of each commodity and year? 9. What is the impact of alternative ways of estimating regional meat consumption on the interregional flows and price differentials? In the following pages the results that are generated by these questions will be given and the implications and uses of the results will be discussed
Projective Ring Line of a Specific Qudit
A very particular connection between the commutation relations of the
elements of the generalized Pauli group of a -dimensional qudit, being a
product of distinct primes, and the structure of the projective line over the
(modular) ring \bZ_{d} is established, where the integer exponents of the
generating shift () and clock () operators are associated with submodules
of \bZ^{2}_{d}. Under this correspondence, the set of operators commuting
with a given one -- a perp-set -- represents a \bZ_{d}-submodule of
\bZ^{2}_{d}. A crucial novel feature here is that the operators are also
represented by {\it non}-admissible pairs of \bZ^{2}_{d}. This additional
degree of freedom makes it possible to view any perp-set as a {\it
set-theoretic} union of the corresponding points of the associated projective
line
Finite Projective Spaces, Geometric Spreads of Lines and Multi-Qubits
Given a (2N - 1)-dimensional projective space over GF(2), PG(2N - 1, 2), and
its geometric spread of lines, there exists a remarkable mapping of this space
onto PG(N - 1, 4) where the lines of the spread correspond to the points and
subspaces spanned by pairs of lines to the lines of PG(N - 1, 4). Under such
mapping, a non-degenerate quadric surface of the former space has for its image
a non-singular Hermitian variety in the latter space, this quadric being {\it
hyperbolic} or {\it elliptic} in dependence on N being {\it even} or {\it odd},
respectively. We employ this property to show that generalized Pauli groups of
N-qubits also form two distinct families according to the parity of N and to
put the role of symmetric operators into a new perspective. The N=4 case is
taken to illustrate the issue.Comment: 3 pages, no figures/tables; V2 - short introductory paragraph added;
V3 - to appear in Int. J. Mod. Phys.
A variant of Peres-Mermin proof for testing noncontextual realist models
For any state in four-dimensional system, the quantum violation of an
inequality based on the Peres-Mermin proof for testing noncontextual realist
models has experimentally been corroborated. In the Peres-Mermin proof, an
array of nine holistic observables for two two-qubit system was used. We, in
this letter, present a new symmetric set of observables for the same system
which also provides a contradiction of quantum mechanics with noncontextual
realist models in a state-independent way. The whole argument can also be cast
in the form of a new inequality that can be empirically tested.Comment: 3 pages, To be published in Euro. Phys. Let
Finite-precision measurement does not nullify the Kochen-Specker theorem
It is proven that any hidden variable theory of the type proposed by Meyer
[Phys. Rev. Lett. {\bf 83}, 3751 (1999)], Kent [{\em ibid.} {\bf 83}, 3755
(1999)], and Clifton and Kent [Proc. R. Soc. London, Ser. A {\bf 456}, 2101
(2000)] leads to experimentally testable predictions that are in contradiction
with those of quantum mechanics. Therefore, it is argued that the existence of
dense Kochen-Specker-colorable sets must not be interpreted as a nullification
of the physical impact of the Kochen-Specker theorem once the finite precision
of real measurements is taken into account.Comment: REVTeX4, 5 page
The Clumping Transition in Niche Competition: a Robust Critical Phenomenon
We show analytically and numerically that the appearance of lumps and gaps in
the distribution of n competing species along a niche axis is a robust
phenomenon whenever the finiteness of the niche space is taken into account. In
this case depending if the niche width of the species is above or
below a threshold , which for large n coincides with 2/n, there are
two different regimes. For the lumpy pattern emerges
directly from the dominant eigenvector of the competition matrix because its
corresponding eigenvalue becomes negative. For the lumpy
pattern disappears. Furthermore, this clumping transition exhibits critical
slowing down as is approached from above. We also find that the number
of lumps of species vs. displays a stair-step structure. The positions
of these steps are distributed according to a power-law. It is thus
straightforward to predict the number of groups that can be packed along a
niche axis and it coincides with field measurements for a wide range of the
model parameters.Comment: 16 pages, 7 figures;
http://iopscience.iop.org/1742-5468/2010/05/P0500
Kochen-Specker Theorem for Finite Precision Spin One Measurements
Unsharp spin 1 observables arise from the fact that a residual uncertainty
about the actual orientation of the measurement device remains. If the
uncertainty is below a certain level, and if the distribution of measurement
errors is covariant under rotations, a Kochen-Specker theorem for the unsharp
spin observables follows: There are finite sets of directions such that not all
the unsharp spin observables in these directions can consistently be assigned
approximate truth-values in a non-contextual way.Comment: 4 page
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