3,570 research outputs found
Deep Semantic Clustering by Partition Confidence Maximisation
By simultaneously learning visual features and data grouping, deep clustering has shown impressive ability to deal with unsupervised learning for structure analysis of high-dimensional visual data. Existing deep clustering methods typically rely on local learning constraints based on inter-sample relations and/or self-estimated pseudo labels. This is susceptible to the inevitable errors distributed in the neighbourhoods and suffers from error-propagation during training. In this work, we propose to solve this problem by learning the most confident clustering solution from all the possible separations, based on the observation that assigning samples from the same semantic categories into different clusters will reduce both the intra-cluster compactness and inter-cluster diversity, i.e. lower partition confidence. Specifically, we introduce a novel deep clustering method named PartItion Confidence mAximisation (PICA). It is established on the idea of learning the most semantically plausible data separation, in which all clusters can be mapped to the ground-truth classes one-to-one, by maximising the 'global' partition confidence of clustering solution. This is realised by introducing a differentiable partition uncertainty index and its stochastic approximation as well as a principled objective loss function that minimises such index, all of which together enables a direct adoption of the conventional deep networks and mini-batch based model training. Extensive experiments on six widely-adopted clustering benchmarks demonstrate our model's performance superiority over a wide range of the state-of-the-art approaches. The code is available online
Translocal imagination of Hong Kong connections: the shifting of Chow Yun-Fat's star image since 1997
Anyone who is interested in Hong Kong cinema must be familiar with one name: Chow Yun-fat (b. 1955). He rose to film stardom in the 1980s when Hong Kong cinema started to attract global attention beyond East Asia. During his early screen career, Chow established a star image as an urban citizen of modern Hong Kong through films such as A Better Tomorrow/Yingxiong bense (John Woo, 1986), City on Fire/Longhu fengyun (Ringo Lam, 1987), All About Ah-Long/A Lang de gushi (Johnnie To, 1989), God of Gamblers/Du shen (Wong Jing, 1989), and Hard Boiled/Lashou shentan (John Woo, 1992)
Energy-aware integrated process planning and scheduling for job shops
Process planning that is based on environmental consciousness and energy-efficient scheduling currently plays a critical role in sustainable manufacturing processes. Despite their interrelationship, these two topics have often been considered to be independent of each other. It therefore would be beneficial to integrate process planning and scheduling for an integrated energy-efficient optimisation of product design and manufacturing in a sustainable manufacturing system. This article proposes an energy-aware mathematical model for job shops that integrates process planning and scheduling. First, a mixed integrated programming model with performance indicators such as energy consumption and scheduling makespan is established to describe a multi-objective optimisation problem. Because the problem is strongly non-deterministic polynomial-time hard (NP-hard), a modified genetic algorithm is adopted to explore the optimal solution (Pareto solution) between energy consumption and makespan. Finally, case studies of energy-aware integrated process planning and scheduling are performed, and the proposed algorithm is compared with other methods. The approach is shown to generate interesting results and can be used to improve the energy efficiency of sustainable manufacturing processes at the process planning and scheduling levels
Phase transition in spin systems with various types of fluctuations
Various types ordering processes in systems with large fluctuation are overviewed. Generally, the so-called order–disorder phase transition takes place in competition between the interaction causing the system be ordered and the entropy causing a random disturbance. Nature of the phase transition strongly depends on the type of fluctuation which is determined by the structure of the order parameter of the system. As to the critical property of phase transitions, the concept “universality of the critical phenomena” is well established. However, we still find variety of features of ordering processes. In this article, we study effects of various mechanisms which bring large fluctuation in the system, e.g., continuous symmetry of the spin in low dimensions, contradictions among interactions (frustration), randomness of the lattice, quantum fluctuations, and a long range interaction in off-lattice systems
International human resource management strategies of Chinese multinationals operating abroad
Strategic international human resource management (SIHRM) is crucial for the effective leveraging of human resources in organizations to achieve the desired business strategies. There is a rich collection of studies on western multinational corporations (MNCs) in China, but few studies that explore the SIHRM of Chinese MNCs operating overseas. This study utilizes cross-level, in-depth interviews to analyse SIHRM of three large Chinese multinationals. The paper contributes to literature by addressing two contextual SIHRM issues, namely the characteristics of the SIHRM for Chinese multinationals and how their SIHRM orientation facilitates their international investment and operation. The findings indicate that organizational transformation is the starting point for latecomers matching their international HRM strategies. Their SIHRM approaches, such as forming learning organizations, reliance on host-country nationals, reconciling both home and host-country effects and promoting ‘best practices’, facilitate their international operations
Center-of-Mass Properties of the Exciton in Quantum Wells
We present high-quality numerical calculations of the exciton center-of-mass
dispersion for GaAs/AlGaAs quantum wells of widths in the range 2-20 nm. The
k.p-coupling of the heavy- and light-hole bands is fully taken into account. An
optimized center-of-mass transformation enhances numerical convergence. We
derive an easy-to-use semi-analytical expression for the exciton groundstate
mass from an ansatz for the exciton wavefunction at finite momentum. It is
checked against the numerical results and found to give very good results. We
also show multiband calculations of the exciton groundstate dispersion using a
finite-differences scheme in real space, which can be applied to rather general
heterostructures.Comment: 19 pages, 12 figures included, to be published in Phys. Rev.
A Highly Redundant BAC Library of Atlantic salmon (Salmo salar): An Important Tool for Salmon Projects
Background: As farming of Atlantic salmon is growing as an aquaculture enterprise, the need to identify thegenomic mechanisms for specific traits is becoming more important in breeding and management of the animal.Traits of importance might be related to growth, disease resistance, food conversion efficiency, color or taste.To identify genomic regions responsible for specific traits, genomic large insert libraries have previously provento be of crucial importance. These large insert libraries can be screened using gene or genetic markers in orderto identify and map regions of interest. Furthermore, large-scale mapping can utilize highly redundant libraries ingenome projects, and hence provide valuable data on the genome structure.Results: Here we report the construction and characterization of a highly redundant bacterial artificialchromosome (BAC) library constructed from a Norwegian aquaculture strain male of Atlantic salmon (Salmosalar). The library consists of a total number of 305 557 clones, in which approximately 299 000 are recombinants.The average insert size of the library is 188 kbp, representing 18-fold genome coverage. High-density filters eachconsisting of 18 432 clones spotted in duplicates have been produced for hybridization screening, and are publiclyavailable [1]. To characterize the library, 15 expressed sequence tags (ESTs) derived overgos and 12 oligosequences derived from microsatellite markers were used in hybridization screening of the complete BAC library.Secondary hybridizations with individual probes were performed for the clones detected. The BACs positive forthe EST probes were fingerprinted and mapped into contigs, yielding an average of 3 contigs for each probe.Clones identified using genomic probes were PCR verified using microsatellite specific primers.Conclusion: Identification of genes and genomic regions of interest is greatly aided by the availability of theCHORI-214 Atlantic salmon BAC library. We have demonstrated the library\u27s ability to identify specific genes andgenetic markers using hybridization, PCR and fingerprinting experiments. In addition, multiple fingerprintingcontigs indicated a pseudo-tetraploidity of the Atlantic salmon genome. The highly redundant CHORI-214 BAClibrary is expected to be an important resource for mapping and sequencing of the Atlantic salmon genome
Recoil Polarization for Delta Excitation in Pion Electroproduction
We measured angular distributions of recoil-polarization response functions
for neutral pion electroproduction for W=1.23 GeV at Q^2=1.0 (GeV/c)^2,
obtaining 14 separated response functions plus 2 Rosenbluth combinations; of
these, 12 have been observed for the first time. Dynamical models do not
describe quantities governed by imaginary parts of interference products well,
indicating the need for adjusting magnitudes and phases for nonresonant
amplitudes. We performed a nearly model-independent multipole analysis and
obtained values for Re(S1+/M1+)=-(6.84+/-0.15)% and Re(E1+/M1+)=-(2.91+/-0.19)%
that are distinctly different from those from the traditional Legendre analysis
based upon M1+ dominance and sp truncation.Comment: 5 pages, 2 figures, for PR
blaKPC and rmtB on a single plasmid in Enterobacter amnigenus and Klebsiella pneumoniae isolates from the same patient
Enterobacter amnigenus (EA76) and Klebsiella pneumoniae (KP76) isolates with multidrug-resistant (MDR) patterns were identified from the same patient in the neurosurgery department of our hospital. An outbreak of MDR K. pneumoniae had also occurred in this department. To characterize the resistance mechanism and molecular epidemiology of these isolates, sequential experiments including antimicrobial susceptibility testing, polymerase chain reaction (PCR), plasmid analysis, pulsed field gel electrophoresis (PFGE), and multilocus sequence typing (MLST) were performed. EA76 and KP76 were resistant to all of the antibiotics tested, except colistin and tigecycline. blaKPC-2, blaTEM-1, blaSHV-12, blaCTX-M-3, blaCTX-M-14, and rmtB genes were identified in both isolates, with blaKPC-2, blaTEM-1, blaCTX-M-14, and rmtB being co-carried on one plasmid in each isolate. Further analysis showed different restriction patterns between the two KPC-carrying plasmids. Of the 11 carbapenem-resistant isolates found in the outbreak, all were resistant to all of the β-lactams tested, with 63.64% (7/11) also exhibiting resistance to aminoglycosides and 72.73% (8/11) exhibiting resistance to quinolones. PCR analysis and molecular typing of the 11 K. pneumoniae strains revealed that the seven aminoglycoside-resistant isolates shared the same antibiotic-resistant gene pattern and identical or one-band-difference PFGE profiles relative to KP76. In addition, all of the eight aminoglycoside-resistant isolates, including KP76, belonged to the national epidemic clone ST11. The overall results indicate the emergence of E. amnigenus and outbreak of ST11 K. pneumoniae, with both co-harboring blaKPC and rmtB genes on a single plasmid in our neurosurgery wards
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