6,683 research outputs found
Supersymmetry in the Standard Model
We prove that the bosons and massless fermions of one generation of the
standard model are supersymmetric partners of each other. Except for one
additional auxilliary vector boson, there are no other SUSY particles.Comment: RevTex, 6 pages, uuencoded tar compressed fil
Infrared analysis of propagators and vertices of Yang--Mills theory in Landau and Coulomb gauge
The infrared behaviour of gluon and ghost propagators, ghost-gluon vertex and
three-gluon vertex is investigated for both the covariant Landau and the
non-covariant Coulomb gauge. Assuming infrared ghost dominance, we find a
unique infrared exponent in the d=4 Landau gauge, while in the d=3+1 Coulomb
gauge we find two different infrared exponents. We also show that a finite
dressing of the ghost-gluon vertex has no influence on the infrared exponents.
Finally, we determine the infrared behaviour of the three-gluon vertex
analytically and calculate it numerically at the symmetric point in the Coulomb
gauge.Comment: 25 pages, 6 figures, accepted by Phys. Rev. D, references added,
typos correcte
Online Bin Covering: Expectations vs. Guarantees
Bin covering is a dual version of classic bin packing. Thus, the goal is to
cover as many bins as possible, where covering a bin means packing items of
total size at least one in the bin.
For online bin covering, competitive analysis fails to distinguish between
most algorithms of interest; all "reasonable" algorithms have a competitive
ratio of 1/2. Thus, in order to get a better understanding of the combinatorial
difficulties in solving this problem, we turn to other performance measures,
namely relative worst order, random order, and max/max analysis, as well as
analyzing input with restricted or uniformly distributed item sizes. In this
way, our study also supplements the ongoing systematic studies of the relative
strengths of various performance measures.
Two classic algorithms for online bin packing that have natural dual versions
are Harmonic and Next-Fit. Even though the algorithms are quite different in
nature, the dual versions are not separated by competitive analysis. We make
the case that when guarantees are needed, even under restricted input
sequences, dual Harmonic is preferable. In addition, we establish quite robust
theoretical results showing that if items come from a uniform distribution or
even if just the ordering of items is uniformly random, then dual Next-Fit is
the right choice.Comment: IMADA-preprint-c
Proof of concept of a workflow methodology for the creation of basic canine head anatomy veterinary education tool using augmented reality
Neuroanatomy can be challenging to both teach and learn within the undergraduate veterinary medicine and surgery curriculum. Traditional techniques have been used for many years, but there has now been a progression to move towards alternative digital models and interactive 3D models to engage the learner. However, digital innovations in the curriculum have typically involved the medical curriculum rather than the veterinary curriculum. Therefore, we aimed to create a simple workflow methodology to highlight the simplicity there is in creating a mobile augmented reality application of basic canine head anatomy. Using canine CT and MRI scans and widely available software programs, we demonstrate how to create an interactive model of head anatomy. This was applied to augmented reality for a popular Android mobile device to demonstrate the user-friendly interface. Here we present the processes, challenges and resolutions for the creation of a highly accurate, data based anatomical model that could potentially be used in the veterinary curriculum. This proof of concept study provides an excellent framework for the creation of augmented reality training products for veterinary education. The lack of similar resources within this field provides the ideal platform to extend this into other areas of veterinary education and beyond
Light Quark Mass Reweighting
We present a systematic study of the effectiveness of light quark mass
reweighting. This method allows a single lattice QCD ensemble, generated with a
specific value of the dynamical light quark mass, to be used to determine
results for other, nearby light dynamical quark masses. We study two gauge
field ensembles generated with 2+1 flavors of dynamical domain wall fermions
with light quark masses m_l=0.02 (m_\pi=620 MeV) and m_l=0.01 (m_\pi=420 MeV).
We reweight each ensemble to determine results which could be computed directly
from the other and check the consistency of the reweighted results with the
direct results. The large difference between the 0.02 and 0.01 light quark
masses suggests that this is an aggressive application of reweighting as can be
seen from fluctuations in the magnitude of the reweighting factor by four
orders of magnitude. Never-the-less, a comparison of the reweighed topological
charge, average plaquette, residual mass, pion mass, pion decay constant, and
scalar correlator between these two ensembles shows agreement well described by
the statistical errors. The issues of the effective number of configurations
and finite sample size bias are discussed. An examination of the topological
charge distribution implies that it is more favorable to reweight from heavier
mass to lighter quark mass.Comment: 24 pages and 10 figure
Food security and the commons in ASEAN: the role of Singapore
Conference Theme: Beyond Borders: Building a Regional Commons in Southeast AsiaSince the conception of the ASEAN Integrated Food Security (AIFS) Framework in 2008, ASEAN member states have taken steps to implement the components and strategic thrusts laid out in the AIFS Framework. These actions can be seen as contributing to the development of a regional “commons” which is based on prioritizing the right of “all people, at all times, [to] have physical and economic access to sufficient, safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life” (FAO 1996). Although a wide range of conditions exist with regard to this right across the ASEAN member states, as a net-food importing country which imports 90% of its food from a limited number of sources, in this paper Singapore is presented as a case study for the increasing importance of taking a commons perspective on food supply and security. The paper is particularly concerned with actions to diversify food sources, increase local food production and promote food and agro-based industry, research, and development. In the context of a highly urbanized population with limited land and natural resources, the paper argues that those seeming disadvantages can serve to benefit both the local and wider community.
Initially part of a design research project to discover, document, and test potential strategies to address Hong Kong’s situation as a net-food importing territory which relies on a limited number of sources -95% of its food is imported and 60% of that comes from Mainland China - this paper traces the recent history of food security policies and actions in Singapore with respect to increasing local production. The paper examines several case studies that demonstrate the application of the AIFS framework, in particular the development of research, technology and community resources for urban agricultural production. The paper concludes with a reflection on Singapore’s role in providing for a food secure future for itself, and by extension, the entire region.published_or_final_versio
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