3,126 research outputs found
Quantum density anomaly in optically trapped ultracold gases
We show that the Bose-Hubbard Model exhibits an increase in density with
temperature at fixed pressure in the regular fluid regime and in the superfluid
phase. The anomaly at the Bose-Einstein condensate is the first density anomaly
observed in a quantum state. We propose that the mechanism underlying both the
normal phase and the superfluid phase anomalies is related to zero point
entropies and ground state phase transitions. A connection with the typical
experimental scales and setups is also addressed. This key finding opens a new
pathway for theoretical and experimental studies of water-like anomalies in the
area of ultracold quantum gases
Molecular correlations and solvation in simple fluids
We study the molecular correlations in a lattice model of a solution of a
low-solubility solute, with emphasis on how the thermodynamics is reflected in
the correlation functions. The model is treated in Bethe-Guggenheim
approximation, which is exact on a Bethe lattice (Cayley tree). The solution
properties are obtained in the limit of infinite dilution of the solute. With
, , and the three pair correlation functions
as functions of the separation (subscripts 1 and 2 referring to solvent and
solute, respectively), we find for lattice steps that
. This illustrates a general
theorem that holds in the asymptotic limit of infinite . The three
correlation functions share a common exponential decay length (correlation
length), but when the solubility of the solute is low the amplitude of the
decay of is much greater than that of , which in turn is
much greater than that of . As a consequence the amplitude of the
decay of is enormously greater than that of . The
effective solute-solute attraction then remains discernible at distances at
which the solvent molecules are essentially no longer correlated, as found in
similar circumstances in an earlier model. The second osmotic virial
coefficient is large and negative, as expected. We find that the
solvent-mediated part of the potential of mean force between solutes,
evaluated at contact, , is related in this model to the Gibbs free energy
of solvation at fixed pressure, , by , where is the coordination number of the lattice, the
pressure, and the volume of the cell associated with each lattice site. A
large, positive associated with the low solubility is thus
reflected in a strong attraction (large negative at contact), which is the
major contributor to the second osmotic virial coefficient. In this model, the
low solubility (large positive ) is due partly to an unfavorable
enthalpy of solvation and partly to an unfavorable solvation entropy, unlike in
the hydrophobic effect, where the enthalpy of solvation itself favors high
solubility, but is overweighed by the unfavorable solvation entropy.Comment: 9 pages, 2 figure
Towards a relational model for component interconnection
The basic motivation of component based development is to replace conventional programming by the composition of reusable off-the-shelf units, externally coordinated through a network of connecting devices, to achieve a common goal. This paper introduces a new relational model for software connectors and discusses some preliminary work on its implementation in HASKELL. The proposed model adopts a coordination point of view in order to deal with components’ temporal and spatial decoupling and, therefore, to provide support for looser levels of inter-component dependency and effective external control
An orchestrator for dynamic interconnection of software components
Composing and orchestrating software components is a fundamental concern in modern software engineering. This paper addresses the possibility of such orchestration being dynamic, in the sense that the structure of component's interconnection patterns can change at run-time. The envisaged approach extends previous work by the authors on the use of coalgebraic models for the specification of software connectors.POSI/ICHS/44304/200
Looking Beyond Appearances: Synthetic Training Data for Deep CNNs in Re-identification
Re-identification is generally carried out by encoding the appearance of a
subject in terms of outfit, suggesting scenarios where people do not change
their attire. In this paper we overcome this restriction, by proposing a
framework based on a deep convolutional neural network, SOMAnet, that
additionally models other discriminative aspects, namely, structural attributes
of the human figure (e.g. height, obesity, gender). Our method is unique in
many respects. First, SOMAnet is based on the Inception architecture, departing
from the usual siamese framework. This spares expensive data preparation
(pairing images across cameras) and allows the understanding of what the
network learned. Second, and most notably, the training data consists of a
synthetic 100K instance dataset, SOMAset, created by photorealistic human body
generation software. Synthetic data represents a good compromise between
realistic imagery, usually not required in re-identification since surveillance
cameras capture low-resolution silhouettes, and complete control of the
samples, which is useful in order to customize the data w.r.t. the surveillance
scenario at-hand, e.g. ethnicity. SOMAnet, trained on SOMAset and fine-tuned on
recent re-identification benchmarks, outperforms all competitors, matching
subjects even with different apparel. The combination of synthetic data with
Inception architectures opens up new research avenues in re-identification.Comment: 14 page
A hybrid genetic approach to solve real make-to-order job shop scheduling problems
Tese (doutorado) - Universidade Federal de Santa Catarina, Centro TecnologicoProcedimentos de busca local (ex. busca tabu) e algoritmos genéticos têm apresentado excelentes resultados em problemas clássicos de programação da produção em ambientes job shop. No entanto, estas abordagens apresentam pobres habilidades de modelamento e poucas aplicações com restrições de ambientes reais de produção têm sido publicadas. Além disto, os espaços de busca considerados nestas aplicações são nomlalmente incompletos e as restrições reais são poucas e dependentes do problema em questão. Este trabalho apresenta uma abordagem genética híbrida para resolver problemas de programação em ambientes job shop com grande número de restrições reais, tais como produtos com vários níveis de submontagem, planos de processamento altemativos para componentes e recursos alternativos para operações, exigência de vários recursos para executar uma operação (ex., máquina, ferramentas, operadores), calendários para todos os recursos, sobreposição de operações, restrições de disponibilidade de matéria-prima e componentes comprados de terceiros, e tempo de setup dependente da sequência de operações. A abordagem também considera funções de avaliação multiobjetivas. O sistema usa algoritmos modificados de geração de programação, que incorporam várias heurísticas de apoio à decisão, para obter um conjunto de soluções iniciais. Cada solução inicial é melhorada por um algoritmo de subida de encosta. Então, um algoritmo genético híbrido com procedimentos de busca local é aplicado ao conjunto inicial de soluções localmente ótimas. Ao utilizar técnicas de programação de alta perfomlance (heurísticas construtivas, procedimentos de busca local e algoritmos genéticos) em problemas reais de programação da produção, este trabalho reduziu o abismo existente entre a teoria e a prática da programação da produção
Burberry, tisci and streetwear
The main purpose of the following report is to try to reach the expected quantitative value Riccardo Tisci with his streetwear collections may bring to Burberry in the next five financial years. Due to a lack of resources, many assumptions were made in order to reach a quantitative final result. Notwithstanding these assumptions were based on consulting reliable sources. I do believe that with more data and more complete empirical and behavioral research could bring more concrete results.The report starts with a brief introduction to the streetwear trend and why Riccardo Tisci to be chosen based on new Burberry’s strategy
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