1,994 research outputs found
The relationship between work measurement and management accounting in small businesses
The research starts from the general premise that small firms could benefit from greater combined use of management techniques. Through analyses of the general concepts of two such techniques, management accounting and work measurement, theoretical links based on their various properties are established between them and their relevance to small businesses is assessed. The testing of a hypothesised relationship between the use of work measurement and beneficial output of management accounting information is carried out in small business units of the furniture and timber industry in the North of England. Measures are designed and applied to generate two sample groups of firms which are similar in their use of management accounting but are dichotomous in either using or not using work measurement. Differences between how useful the accounting information on direct labour activity is perceived by managers and supervisors from the two groups are measured. An assessment is made of whether this difference is associated mainly with the use of work measurement, or is influenced by the accounting system itself or by the behavioural aspects of the environment in which it operates. The results show clearly that in the cases researched, the management accounting information is perceived as being more useful by decision makers when it is based on the use of work measurement. Similar perceptions about the usefulness of information are held by accountants. Guide lines are suggested to aid small businesses in general who are not in the furniture and timber industry to assess the relevance of the research results to themselves
Propagation of Exchange Bias in CoFe/FeMn/CoFe Trilayers
CoFe/FeMn, FeMn/CoFe bilayers and CoFe/FeMn/CoFe trilayers were grown in
magnetic field and at room temperature. The exchange bias field
depends strongly on the order of depositions and is much higher at CoFe/FeMn
than at FeMn/CoFe interfaces. By combining the two bilayer structures into
symmetric CoFe/FeMn()/CoFe trilayers, and
of the top and bottom CoFe layers, respectively, are both enhanced.
Reducing of the trilayers also results in enhancements of
both and . These results evidence the propagation of
exchange bias between the two CoFe/FeMn and FeMn/CoFe interfaces mediated by
the FeMn antiferromagnetic order
On the equation of state of a dense columnar liquid crystal
An accurate description of a columnar liquid crystal of hard disks at high
packing fractions is presented using an improved free-volume theory. It is
shown that the orientational entropy of the disks in the one-dimensional fluid
direction leads to a different high-density scaling pressure compared to the
prediction from traditional cell theory. Excellent quantitative agreement is
found with recent Monte-Carlo simulation results for various thermodynamic and
structural properties of the columnar state.Comment: 4 pages, 2 figures, to appear in Phys. Rev. Let
Analysis of path integrals at low temperature : Box formula, occupation time and ergodic approximation
We study the low temperature behaviour of path integrals for a simple
one-dimensional model. Starting from the Feynman-Kac formula, we derive a new
functional representation of the density matrix at finite temperature, in terms
of the occupation times of Brownian motions constrained to stay within boxes
with finite sizes. From that representation, we infer a kind of ergodic
approximation, which only involves double ordinary integrals. As shown by its
applications to different confining potentials, the ergodic approximation turns
out to be quite efficient, especially in the low-temperature regime where other
usual approximations fail
BSE situation and establishment of Food Safety Commission in Japan
Eight major policies were implemented by Japanese Government since Oct. 2001, to deal with bovine spongiform encephalopathy (BSE). These are; 1) Surveillance in farm by veterinarian, 2) Prion test at healthy 1.3mi cows/yr, by veterinarian, 3) Elimination of specified risk material (SRM), 4) Ban of MBM for production, sale use, 5) Prion test for fallen stocks, 6) Transparent information and traceability, 7) New Measures such as Food Safety Basic Law, and 8) Establish of Food Safety Commission in the Cabinet Office. At this moment, the extent of SRM risk has only been indicated by several reports employing tests with a limited sensitivity. There is still a possibility that the items in the SRM list will increase in the future, and this indiscriminately applies to Japanese cattle as well. Although current practices of SRM elimination partially guarantee total food safety, additional latent problems and imminent issues remain as potential headaches to be addressed. If the index of SRM elimination cannot guarantee reliable food safety, we have but to resort to total elimination of tissues from high risk-bearing and BSE-infected animals. However, current BSE tests have their limitations and can not yet completely detect high-risk and/or infected animals. Under such circumstances, tissues/wastes and remains of diseased, affected fallen stocks and cohort animals have to be eliminated to prevent BSE invading the human food chain systems. The failure to detect any cohort should never be allowed to occur, and with regular and persistent updating of available stringent records, we are at least adopting the correct and useful approach as a reawakening strategy to securing food safety. In this perspective, traceability based on a National Identification System is required
Clusters and Fluctuations at Mean-Field Critical Points and Spinodals
We show that the structure of the fluctuations close to spinodals and
mean-field critical points is qualitatively different than the structure close
to non-mean-field critical points. This difference has important implications
for many areas including the formation of glasses in supercooled liquids. In
particular, the divergence of the measured static structure function in
near-mean-field systems close to the glass transition is suppressed relative to
the mean-field prediction in systems for which a spatial symmetry is broken.Comment: 5 pages, 1 figur
Theory of Systematic Computational Error in Free Energy Differences
Systematic inaccuracy is inherent in any computational estimate of a
non-linear average, due to the availability of only a finite number of data
values, N. Free energy differences (DF) between two states or systems are
critically important examples of such averages in physical, chemical and
biological settings. Previous work has demonstrated, empirically, that the
``finite-sampling error'' can be very large -- many times kT -- in DF estimates
for simple molecular systems. Here, we present a theoretical description of the
inaccuracy, including the exact solution of a sample problem, the precise
asymptotic behavior in terms of 1/N for large N, the identification of
universal law, and numerical illustrations. The theory relies on corrections to
the central and other limit theorems, and thus a role is played by stable
(Levy) probability distributions.Comment: 5 pages, 4 figure
Why do ultrasoft repulsive particles cluster and crystallize? Analytical results from density functional theory
We demonstrate the accuracy of the hypernetted chain closure and of the
mean-field approximation for the calculation of the fluid-state properties of
systems interacting by means of bounded and positive-definite pair potentials
with oscillating Fourier transforms. Subsequently, we prove the validity of a
bilinear, random-phase density functional for arbitrary inhomogeneous phases of
the same systems. On the basis of this functional, we calculate analytically
the freezing parameters of the latter. We demonstrate explicitly that the
stable crystals feature a lattice constant that is independent of density and
whose value is dictated by the position of the negative minimum of the Fourier
transform of the pair potential. This property is equivalent with the existence
of clusters, whose population scales proportionally to the density. We
establish that regardless of the form of the interaction potential and of the
location on the freezing line, all cluster crystals have a universal Lindemann
ratio L = 0.189 at freezing. We further make an explicit link between the
aforementioned density functional and the harmonic theory of crystals. This
allows us to establish an equivalence between the emergence of clusters and the
existence of negative Fourier components of the interaction potential. Finally,
we make a connection between the class of models at hand and the system of
infinite-dimensional hard spheres, when the limits of interaction steepness and
space dimension are both taken to infinity in a particularly described fashion.Comment: 19 pages, 5 figures, submitted to J. Chem. Phys; new version: minor
changes in structure of pape
Aging and ultra-slow equilibration in concentrated colloidal hard spheres
We study the dynamic behaviour of concentrated colloidal hard spheres using
Time Resolved Correlation, a light scattering technique that can detect the
slow evolution of the dynamics in out-of-equilibrium systems. Surprisingly,
equilibrium is reached a very long time after sample initialization, the
non-stationary regime lasting up to three orders of magnitude more than the
relaxation time of the system. Before reaching equilibrium, the system displays
unusual aging behaviour. The intermediate scattering function decays faster
than exponentially and its relaxation time evolves non-monotonically with
sample age.Comment: Submitted to the proceedings of the 6th EPS Liquid Matter Conference,
Utrecht 2-6 July 200
Beware of density dependent pair potentials
Density (or state) dependent pair potentials arise naturally from
coarse-graining procedures in many areas of condensed matter science. However,
correctly using them to calculate physical properties of interest is subtle and
cannot be uncoupled from the route by which they were derived. Furthermore,
there is usually no unique way to coarse-grain to an effective pair potential.
Even for simple systems like liquid Argon, the pair potential that correctly
reproduces the pair structure will not generate the right virial pressure.
Ignoring these issues in naive applications of density dependent pair
potentials can lead to an apparent dependence of thermodynamic properties on
the ensemble within which they are calculated, as well as other
inconsistencies. These concepts are illustrated by several pedagogical
examples, including: effective pair potentials for systems with many-body
interactions, and the mapping of charged (Debye-H\"{u}ckel) and uncharged
(Asakura-Oosawa) two-component systems onto effective one-component ones.Comment: 22 pages, uses iopart.cls and iopart10.clo; submitted to Journal of
Physics Condensed Matter, special issue in honour of professor Jean-Pierre
Hanse
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