2,932 research outputs found
A Review and Assessment of Enterprise Resource Planning for Make-To-Order Companies
Many vendors of Enterprise Resource Planning (ERP) systems claim that their products are widely applicable - configurable to meet the needs of any business, whatever the product or service offering. However, producers of high-variety and bespoke products, such as Make-To-Order (MTO) companies, present particular challenges to implementation; it remains unclear whether ERP systems can cater for their needs.. This paper provides a state-of-the-art review of ERP systems and an assessment of the applicability of ERP to the MTO sector. While several comprehensive reviews of the ERP literature have previously been presented, these either do not focus on the MTO sector, or seek to assess the applicability of ERP systems, or give sufficient attention to recent developments in the fast moving ERP industry. In assessing applicability, this paper considers factors such as the planning and control stages of relevance to MTO companies, the typical size and supply chain positioning of MTO companies, and market-related features. The assessment concludes that there is a significant gap between the requirements of MTO companies and the functionality of ERP systems. One such gap is between the customer enquiry management and design & engineering processes of MTO companies and those supported by ERP systems. Eight key areas in need of further research are described. These include: providing effective decision support tools for customer enquiry management activities in the MTO sector, linking ERP systems with production planning and control concepts of relevance to MTO companies, and conducting an in-depth empirical study into existing applications of ERP systems in MTO companies and their impact on performance
Extending the Current Theorization On Cyberbullying: Importance of Including Socio-Psychological Perspectives
Despite an abundance of research from multiple perspectives and disciplines, to date cyberbullying research has been fragmented and is often conducted atheoretically, using theories borrowed from general psychology and/or criminology, or considers only individual-level explanations such as demographics, personalities, and psychological conditions which may be insufficient to fully understand and explain the behaviour. Social psychological approaches that examine the everyday power relations in children\u2019s lives and the study of identity, relationships, and belonging systems may provide meaningful context and a more holistic perspective. The purpose of this paper is to demonstrate the positive impact of applying identity theories and a sociological perspective to the study of cyberbullying. This paper provides an overview of cyberbullying, followed by examples of how general psychological theories and theories borrowed from criminology and aggression have been applied to cyberbullying, including a cyberbullying-specific theory. Several key theories of identity that could be employed in the study of cyberbullying are then identified. Lastly, the utility of using a socio-psychological perspective using social identity theory and social network analysis to study of cyberbullying is explored. In order to manage cyber violence, we need to act on multiple levels, including individual, relational, organizational, and community levels
A test for within-lake niche differentiation in the nine-spined sticklebacks (Pungitius pungitius)
Specialization for the use of different resources can lead to ecological speciation. Accordingly, there are numerous examples of ecologically specialized pairs of fish species in postglacial lakes. Using a polymorphic panel of single nucleotide variants, we tested for genetic footprints of within-lake population stratification in nine-spined sticklebacks (Pungitius pungitius) collected from three habitats (viz. littoral, benthic, and pelagic) within a northern Swedish lake. Analyses of admixture, population structure, and relatedness all supported the conclusion that the fish from this lake form a single interbreeding unit.Peer reviewe
Evolution of Fields in a Second Order Phase Transition
We analyse the evolution of scalar and gauge fields during a second order
phase transition using a Langevin equation approach. We show that topological
defects formed during the phase transition are stable to thermal fluctuations.
Our method allows the field evolution to be followed throughout the phase
transition, for both expanding and non-expanding Universes. The results verify
the Kibble mechanism for defect formation during phase transitions.Comment: 12 pages of text plus 17 diagrams available on request, DAMTP 94-8
Zurek-Kibble domain structures: The Dynamics of Spontaneous Vortex formation in Annular Josephson Tunnel Junctions
Phase transitions executed in a finite time show a domain structure with
defects, that has been argued by Zurek and Kibble to depend in a characteristic
way on the quench rate. In this letter we present an experiment to measure the
Zurek-Kibble scaling exponent sigma. Using symmetric and long Josephson Tunnel
Junctions, for which the predicted index is sigma = 0.25, we find sigma = 0.27
+/- 0.05. Further, there is agreement with the ZK prediction for the overall
normalisation.Comment: To be published in Phys. Rev. Lett
Density of Bloch Waves after a Quench
Production of Bloch waves during a rapid quench is studied by analytical and
numerical methods. The density of Bloch waves decays exponentially with the
quench time. It also strongly depends on temperature. Very few textures are
produced for temperatures lower than a characteristic temperature proportional
to the square of the magnetic field.Comment: 4 pages in RevTex + 3 .ps files; improved presentation; version to
appear in PR
Defect Formation and Critical Dynamics in the Early Universe
We study the nonequilibrium dynamics leading to the formation of topological
defects in a symmetry-breaking phase transition of a quantum scalar field with
\lambda\Phi^4 self-interaction in a spatially flat, radiation-dominated
Friedmann-Robertson-Walker Universe. The quantum field is initially in a
finite-temperature symmetry-restored state and the phase transition develops as
the Universe expands and cools. We present a first-principles, microscopic
approach in which the nonperturbative, nonequilibrium dynamics of the quantum
field is derived from the two-loop, two-particle-irreducible closed-time-path
effective action. We numerically solve the dynamical equations for the
two-point function and we identify signatures of topological defects in the
infrared portion of the momentum-space power spectrum. We find that the density
of topological defects formed after the phase transition scales as a power law
with the expansion rate of the Universe. We calculate the equilibrium critical
exponents of the correlation length and relaxation time for this model and show
that the power law exponent of the defect density, for both overdamped and
underdamped evolution, is in good agreement with the "freeze-out" scenario of
Zurek. We introduce an analytic dynamical model, valid near the critical point,
that exhibits the same power law scaling of the defect density with the quench
rate. By incorporating the realistic quench of the expanding Universe, our
approach illuminates the dynamical mechanisms important for topological defect
formation. The observed power law scaling of the defect density with the quench
rate, observered here in a quantum field theory context, provides evidence for
the "freeze-out" scenario in three spatial dimensions.Comment: 31 pages, RevTex, 8 figures in EPS forma
The Hubble Diagram of Type Ia Supernovae in Non-Uniform Pressure Universes
We use the redshift-magnitude relation, as derived by D\c{a}browski (1995),
for the two exact non-uniform pressure spherically symmetric Stephani universes
with the observer positioned at the center of symmetry, to test the agreement
of these models with recent observations of high redshift type Ia supernovae
(SNIa), as reported in Perlmutter et al. (1997). By a particular choice of
model parameters, we show that these models give an excellent fit to the
observed redshifts and (corrected) B band apparent magnitudes of the SNIa data,
but for an age of the Universe which is typically about two Gyr greater than in
the corresponding Friedmann model.
Based on a value of and assuming , the P97 data
implies a Friedmann age of at most 13 Gyr and in fact a best-fit (for ) age of only 10 Gyr. Our Stephani models, on the other hand, can give a
good fit to the P97 data with an age of up to 15 Gyr and could, therefore,
significantly alleviate the conflict between recent cosmological and
astrophysical age predictions. The choice of model parameters is quite robust:
one requires only that the non-uniform pressure parameter, , in one of the
models is negative and satisfies |a| \lte 3 km s Mpc. By
allowing slightly larger, negative, values of one may `fine tune' the model
to give an even better fit to the P97 data.Comment: 36 pages, 2 tables, 6 figures, AAS Latex 4.0, vastly revised version,
new title and abstract, to appear in Ap
Enhanced chlorhexidine skin penetration with 1,8-cineole
BACKGROUND: Chlorhexidine (CHG) penetrates poorly into skin. The purpose of this study was to compare the depth of CHG skin permeation from solutions containing either 2% (w/v) CHG and 70% (v/v) isopropyl alcohol (IPA) or 2% (w/v) CHG, 70% (v/v) IPA and 2% (v/v) 1,8-cineole. METHODS: An ex-vivo study using Franz diffusion cells was carried out. Full thickness human skin was mounted onto the cells and a CHG solution, with or without 2% (v/v) 1,8-cineole was applied to the skin surface. After twenty-four hours the skin was sectioned horizontally in 100 μm slices to a depth of 2000 μm and the concentration of CHG in each section quantified using high performance liquid chromatography (HPLC). The data were analysed with repeated measures analysis of variance. RESULTS: The concentration of CHG in the skin on average was significantly higher (33.3% [95%, CI 1.5% - 74.9%]) when a CHG solution which contained 1,8-cineole was applied to the skin compared to a CHG solution which did not contain this terpene (P = 0.042). CONCLUSIONS: Enhanced delivery of CHG can be achieved in the presence of 1,8-cineole, which is the major component of eucalyptus oil. This may reduce the numbers of microorganisms located in the deeper layers of the skin which potentially could decrease the risk of surgical site infection
Quench Induced Vortices in the Symmetry Broken Phase of Liquid He
Motivated by the study of cosmological phase transitions, our understanding
of the formation of topological defects during spontaneous symmetry-breaking
and the associated non-equilibrium field theory has recently changed.
Experiments have been performed in superfluid He to test the new ideas
involved. In particular, it has been observed that a vortex density is seen
immediately after pressure quenches from just below the transition.
We discuss possible interpretations of these vortices, conclude they are
consistent with our ideas of vortex formation and propose a modification of the
original experiments.Comment: 29 pages, RevTeX with one EPS figur
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