2,492 research outputs found
EFFICACY OF ELECTRON BEAM IRRADIATION OF PROCESSED PORK PRODUCTS
The research reported on in this paper was conducted as part of a larger project. That project is on-going and is focused on ascertaining if irradiation of processed meats would be effective and economical. It involved the examination, through modeling, of the irradiation of one of many currently produced ready-to-eat (RTE) convenience-oriented, value-added pork products, sliced boneless ham. The results and findings reported in this paper represent the initial estimates of the cost and potential profitability or economic viability of irradiation of processed meats. The results and findings in this paper should be considered preliminary with extension and verification to be reported in a later paper by the authors. The objective of the portion of that project reported on in this paper was to conduct cost analysis of alternative irradiation methods and to ascertain the cost of each of those methods. Three scenarios were considered for cost analysis. The first scenario was the installation of an X-ray irradiator at an existing meat processing plant. The second scenario was the installation of a Cobalt-60 irradiator at an existing meat processing plant. The third scenario assumed that the meat processor contracted for irradiation services from an off-site company providing such service to a number of clients. For purposes of this study it was assumed that irradiation of sliced boneless ham would result in either a .06/pound increase in willingness to pay [price] or an equivalent combination of reduced costs and increased price. Total cost per pound for the irradiation process applied to sliced boneless ham ranged from 0.069 at the 50 million pound annual throughput rate when contracting with an off-site company.Food Consumption/Nutrition/Food Safety,
PushPush and Push-1 are NP-hard in 2D
We prove that two pushing-blocks puzzles are intractable in 2D. One of our
constructions improves an earlier result that established intractability in 3D
[OS99] for a puzzle inspired by the game PushPush. The second construction
answers a question we raised in [DDO00] for a variant we call Push-1. Both
puzzles consist of unit square blocks on an integer lattice; all blocks are
movable. An agent may push blocks (but never pull them) in attempting to move
between given start and goal positions. In the PushPush version, the agent can
only push one block at a time, and moreover when a block is pushed it slides
the maximal extent of its free range. In the Push-1 version, the agent can only
push one block one square at a time, the minimal extent---one square. Both
NP-hardness proofs are by reduction from SAT, and rely on a common
construction.Comment: 10 pages, 11 figures. Corrects an error in the conference version:
Proc. of the 12th Canadian Conference on Computational Geometry, August 2000,
pp. 211-21
PushPush is NP-hard in 2D
We prove that a particular pushing-blocks puzzle is intractable in 2D,
improving an earlier result that established intractability in 3D [OS99]. The
puzzle, inspired by the game *PushPush*, consists of unit square blocks on an
integer lattice. An agent may push blocks (but never pull them) in attempting
to move between given start and goal positions. In the PushPush version, the
agent can only push one block at a time, and moreover, each block, when pushed,
slides the maximal extent of its free range. We prove this version is NP-hard
in 2D by reduction from SAT.Comment: 18 pages, 13 figures, 1 table. Improves cs.CG/991101
A ripple effect from leadership coaching: Understanding the reach of coaching in organisations
Companies today need to draw on the whole organisational team for the energy, ideas and collaborative approaches that bring sustainable organisational success in an interconnected world. Leadership and organisational studies increasingly support this endeavour by considering relational and interconnected approaches. However the leadership coaching literature tends to adopt a hierarchical approach focused on individuals and teams at the helm of organisations. A ripple effect is the metaphorical focus of the study drawing attention to an interplay of influences in an organisation following a leadership coaching initiative. This initiative is the starting point for this in depth organisational case study which is interested in drawing out the human dimension of organisational life. Multiple methods - interviews,
anecdote circles and a company questionnaire - are used to explore patterns of influence flowing from leadership coaching in a small-medium sized enterprise (SME). Thematic network analysis of the experiences of participants in this study produced three categories of findings: personal needs, perceptions of leadership and cultural concerns. Each category is made up of competing influences that signify spectrums of opportunity for learning and development. From this investigation an holistic model of a ripple effect is developed showing the flow from specific coaching outcomes that blend business and human aspects. The concept of reciprocal learning space captures the scope for learning and change by uncovering competing influences that represent the variety of responses to coaching outcomes. An holistic framework for organisation focused coaching offers a practical contribution to coaching by setting out a route to identifying reciprocal learning space and helping to address wider organisational needs. It is argued that remaining in a hierarchical, leader centred mode limits the potential reach of coaching in organisations. This study offers a new integrated approach to coaching that signifies the potential to reach much more widely into organisations
Examples, Counterexamples, and Enumeration Results for Foldings and Unfoldings between Polygons and Polytopes
We investigate how to make the surface of a convex polyhedron (a polytope) by
folding up a polygon and gluing its perimeter shut, and the reverse process of
cutting open a polytope and unfolding it to a polygon. We explore basic
enumeration questions in both directions: Given a polygon, how many foldings
are there? Given a polytope, how many unfoldings are there to simple polygons?
Throughout we give special attention to convex polygons, and to regular
polygons. We show that every convex polygon folds to an infinite number of
distinct polytopes, but that their number of combinatorially distinct gluings
is polynomial. There are, however, simple polygons with an exponential number
of distinct gluings.
In the reverse direction, we show that there are polytopes with an
exponential number of distinct cuttings that lead to simple unfoldings. We
establish necessary conditions for a polytope to have convex unfoldings,
implying, for example, that among the Platonic solids, only the tetrahedron has
a convex unfolding. We provide an inventory of the polytopes that may unfold to
regular polygons, showing that, for n>6, there is essentially only one class of
such polytopes.Comment: 54 pages, 33 figure
Enumerating Foldings and Unfoldings between Polygons and Polytopes
We pose and answer several questions concerning the number of ways to fold a
polygon to a polytope, and how many polytopes can be obtained from one polygon;
and the analogous questions for unfolding polytopes to polygons. Our answers
are, roughly: exponentially many, or nondenumerably infinite.Comment: 12 pages; 10 figures; 10 references. Revision of version in
Proceedings of the Japan Conference on Discrete and Computational Geometry,
Tokyo, Nov. 2000, pp. 9-12. See also cs.CG/000701
Diagnostic accuracy of a brief screening tool forAttention Deficit/Hyperactivity Disorder in UK prison inmates
BackgroundAttention deficit hyperactivity disorder (ADHD) is overrepresented in prison, making it imperative to identify a screening tool that can be quickly applied to efficiently detect the disorder. We explored the discrimination ability of a widely used ADHD screen, the Barkley Adult ADHD Rating Scale (BAARS-IV), against a clinical diagnostic interview. A brief version of the screen was then developed in order to simplify its use in the prison context, and maximize its diagnostic properties.MethodA cross-sectional study of 390 male prison inmates was performed in the UK, all participants were screened and interviewed via the Diagnostic Interview for ADHD in Adults 2.0 (DIVA-2).ResultsA total of 47 (12.1%) inmates screened positive for ADHD using the full BAARS-IV, and 96 (24.6%) were clinically diagnosed, for a sensitivity of 37.9 and a specificity of 96.3. Our models identified the six items that most predicted ADHD diagnosis, with adjusted odds ratios ranging from 2.66 to 4.58. Sensitivity, specificity and accuracy were 0.82, 0.84 and 0.84, respectively, for the developed brief scale, and 0.71, 0.85 and 0.81 for its validation. Weighted probability scores produced an area under the curve of 0.89 for development, and 0.82 for validation of the brief scale.ConclusionsThe original BAARS-IV performed poorly at identifying prison inmates with ADHD. Our developed brief scale substantially improved diagnostic accuracy. The brief screening instrument has great potential to be used as an accurate and resource-effective tool to screen young people and adults for likely ADHD in the criminal justice system.</jats:sec
Continuous Blooming of Convex Polyhedra
We construct the first two continuous bloomings of all convex polyhedra.
First, the source unfolding can be continuously bloomed. Second, any unfolding
of a convex polyhedron can be refined (further cut, by a linear number of cuts)
to have a continuous blooming.Comment: 13 pages, 6 figure
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