3,192 research outputs found
Cork Re-Wall: computational methods of automatic generation and digital fabrication of partition walls for building renovation
Developments in computational design methods and their integration with digital fabrication processes enable us to envisage a mass customized fabrication paradigm. Such is particularly suited to building renovation, a diversified corpus in which interventions are surgical and unique, and where partition walls are the most frequently replaced
components. The main objective is to develop a disassemble-able and customizable solution of partition walls, with natural and renewable materials, insulation cork board and wood, for the context of building renovation.
To meet this end is necessary to develop the construction system, the generative process for digital design and fabrication and a graphical user interface for building owners to interact. This design-to-production system will generate drawings for fabrication, instructions for assembly, and cost estimation. We foresee that the adoption of a file-to-factory process will present several advantages in this context: maximizing efficiency and speed of the construction process without reducing scope or increasing cost, contributing to a more sustainable construction process.info:eu-repo/semantics/acceptedVersio
Detection of Multiparticle Entanglement: Quantifying the Search for Symmetric Extensions
We provide quantitative bounds on the characterisation of multiparticle
separable states by states that have locally symmetric extensions. The bounds
are derived from two-particle bounds and relate to recent studies on quantum
versions of de Finetti's theorem. We discuss algorithmic applications of our
results, in particular a quasipolynomial-time algorithm to decide whether a
multiparticle quantum state is separable or entangled (for constant number of
particles and constant error in the LOCC or Frobenius norm). Our results
provide a theoretical justification for the use of the Search for Symmetric
Extensions as a practical test for multiparticle entanglement.Comment: 5 pages, 1 figur
Inertial-Hall effect: the influence of rotation on the Hall conductivity
Inertial effects play an important role in classical mechanics but have been
largely overlooked in quantum mechanics. Nevertheless, the analogy between
inertial forces on mass particles and electromagnetic forces on charged
particles is not new. In this paper, we consider a rotating non-interacting
planar two-dimensional electron gas with a perpendicular uniform magnetic field
and investigate the effects of the rotation in the Hall conductiv
Macroscopic Entanglement and Phase Transitions
This paper summarises the results of our research on macroscopic entanglement
in spin systems and free Bosonic gases. We explain how entanglement can be
observed using entanglement witnesses which are themselves constructed within
the framework of thermodynamics and thus macroscopic observables. These
thermodynamical entanglement witnesses result in bounds on macroscopic
parameters of the system, such as the temperature, the energy or the
susceptibility, below which entanglement must be present. The derived bounds
indicate a relationship between the occurrence of entanglement and the
establishment of order, possibly resulting in phase transition phenomena. We
give a short overview over the concepts developed in condensed matter physics
to capture the characteristics of phase transitions in particular in terms of
order and correlation functions. Finally we want to ask and speculate whether
entanglement could be a generalised order concept by itself, relevant in
(quantum induced) phase transitions such as BEC, and that taking this view may
help us to understand the underlying process of high-T superconductivity.Comment: 9 pages, 7 figures (color), Submitted to special OSID issue,
Proceedings of the 38th Symposium on Mathematical Physics - Quantum
Entanglement & Geometry, Torun (Poland), June 200
Schmidt balls around the identity
Robustness measures as introduced by Vidal and Tarrach [PRA, 59, 141-155]
quantify the extent to which entangled states remain entangled under mixing.
Analogously, we introduce here the Schmidt robustness and the random Schmidt
robustness. The latter notion is closely related to the construction of Schmidt
balls around the identity. We analyse the situation for pure states and provide
non-trivial upper and lower bounds. Upper bounds to the random Schmidt-2
robustness allow us to construct a particularly simple distillability
criterion. We present two conjectures, the first one is related to the radius
of inner balls around the identity in the convex set of Schmidt number
n-states. We also conjecture a class of optimal Schmidt witnesses for pure
states.Comment: 7 pages, 1 figur
Cavilha cefalomedular antirrotativa versus placa e parafuso dinâmico no tratamento de fraturas trocantéricas instáveis da anca.
As fraturas da extremidade superior do fémur, nomeadamente as fraturas trocantéricas, continuam a representar um sério problema de saúde pública em idosos com osteoporose, presentando um elevado índice de morbilidade e mortalidade, apesar dos avanços registados tanto na sua
prevenção como no seu tratamento. Apenas o tratamento cirúrgico pode permitir uma marcha e uma recuperação funcional precoces, por forma que o doente consiga uma autonomia próxima da anterior à lesão. Para isso, o
ortopedista dispõe atualmente de um leque alargado de implantes cirúrgicos que não tem, todavia, o mesmo valor e indicações, estando na dependência da “personalidade da fratura”.
O objetivo central deste trabalho foi determinar, através de um estudo
comparativo, os resultados radiológicos, clínicos e ortopédicos de uma série de 116 fraturas trocantéricas instáveis do fémur (AO 31 A2), em que se
utilizaram dois tipos diferentes de implantes, a cavilha cefaloendomedular antirrotativa (PFNA®) e placa e parafuso dinâmico (DHS®).
Foram analisados os registos clínicos de 116 doentes com fraturas trocantéricas instáveis, com um tempo de recuo igual ou superior a 12 meses. 66 casos foram tratados com DHS® e os restantes 50 com PFNA®.
Procedeu-se ao registo do tempo operatório, do tempo de internamento, do tipo e qualidade da redução da fratura, do tempo de consolidação da fratura, da necessidade de transfusão sanguínea e das complicações clínicas
e ortopédicas. Os dados obtidos foram sujeitos a um estudo estatístico usando o programa SPSS - Statistical Package for Social Sciences, versão 22.0 para Windows. Considerando a totalidade das fraturas 31 A2, o DHS® apresentou taxas
superiores de reduções das fraturas consideradas insatisfatórias (23,4% e 18,0% para DHS® e PFNA®, respetivamente) e de complicações clínicas (34,8% e 32,0% para DHS® e PFNA®, respetivamente) e ortopédicas
(15,2% e 14,0% para DHS® e PFNA®, respetivamente). O tempo de cirurgia, a necessidade de transfusão sanguínea (53,0% e 68,0% para DHS® e PFNA®, respectivamente) e a proporção de reduções das fraturas
consideradas anatómicas (21,9% e 36,0% para DHS® e PFNA®, respectivamente) foi superior no grupo do PFNA®. O tempo de internamento e as taxas de consolidação foram semelhantes nos dois tipos
de implante. Restringindo a análise apenas para o tipo específico de fraturas 31 A2.2., alguns resultados estatísticos sofreram alterações. As taxas de complicações clínicas (20,7% e 14,3% para DHS® e PFNA®,
respectivamente) e ortopédicas (37,9% e 31,0% para DHS® e PFNA®, respetivamente) acentuaram-se no grupo do DHS®, com taxas de
transfusão (69,0% e 64,3% para DHS® e PFNA®,respetivamente) semelhantes em ambos os grupos.
No tratamento das fraturas trocantéricas instáveis da anca (31 A2.2) o PFNA® mostrou ser superior ao DHS®, em termos da qualidade de redução da fratura e nas taxas de complicações clínicas e ortopédicas. Nas estantes variáveis, o PFNA® não mostrou resultados inferiores
Entangled inputs cannot make imperfect quantum channels perfect
Entangled inputs can enhance the capacity of quantum channels, this being one
of the consequences of the celebrated result showing the non-additivity of
several quantities relevant for quantum information science. In this work, we
answer the converse question (whether entangled inputs can ever render noisy
quantum channels have maximum capacity) to the negative: No sophisticated
entangled input of any quantum channel can ever enhance the capacity to the
maximum possible value; a result that holds true for all channels both for the
classical as well as the quantum capacity. This result can hence be seen as a
bound as to how "non-additive quantum information can be". As a main result, we
find first practical and remarkably simple computable single-shot bounds to
capacities, related to entanglement measures. As examples, we discuss the qubit
amplitude damping and identify the first meaningful bound for its classical
capacity.Comment: 5 pages, 2 figures, an error in the argument on the quantum capacity
corrected, version to be published in the Physical Review Letter
Interactive algorithm for generating accurate as-built plans by building owners
Mass Customization systems in architecture have yet to adequately address the problem of capturing physical context, a fundamental aspect of dealing with building renovation, which has limited their scope of application. Previous research has demonstrated that existing methods of capturing as-built plans of rooms by non-expert users do not produce sufficiently accurate results for digital fabrication. The present paper reports on research into the development of an algorithm for semi-automated survey of convex or non-convex rooms by building owners. The improved workflow is tested by expert and non-expert users in a to-be renovated building and the results are compared with existing methods of survey.info:eu-repo/semantics/publishedVersio
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