2,593 research outputs found
Enhanced Dielectric Constant for Efficient Electromagnetic Shielding Based on Carbon-Nanotube-Added Styrene Acrylic Emulsion Based Composite
An efficient electromagnetic shielding composite based on multiwalled carbon nanotubes (MWCNTs)-filled styrene acrylic emulsion-based polymer has been prepared in a water-based system. The MWCNTs were demonstrated to have an effect on the dielectric constants, which effectively enhance electromagnetic shielding efficiency (SE) of the composites. A low conductivity threshold of 0.23 wt% can be obtained. An EMI SE of ~28 dB was achieved for 20 wt% MWCNTs. The AC conductivity (σac) of the composites, deduced from imaginary permittivity, was used to estimate the SE of the composites in X band (8.2–12.4 GHz), showing a good agreement with the measured results
A compact threshold-voltage model of MOSFETs with stack high-k gate dielectric
In this paper, a compact threshold-voltage model is developed for stack high-k gate-dielectric MOSFET with a thin interiayer. The simulated results are in good agreement with 2-D simulations. The influences of k value of the interlayer on threshold behaviors are investigated in detail. A low-k interlayer can effectively improve the threshold-voltage behaviors. Furthermore, the ratio of low-k interiayer EOT (equivalent oxide thickness) to high-k layer EOT is optimized by considering both threshold-voltage roll-off and gate leakage current. ©2009 IEEE.published_or_final_versionThe IEEE International Conference of Electron Devices and Solid-State Circuits (EDSSC 2009), Xian, China, 25-27 December 2009. In Proceedings of EDSSC, 2009, p. 236-23
PPI-IRO: A two-stage method for protein-protein interaction extraction based on interaction relation ontology
Mining Protein-Protein Interactions (PPIs) from the fast-growing biomedical literature resources has been proven as an effective approach for the identifi cation of biological regulatory networks. This paper presents a novel method based on the idea of Interaction Relation Ontology (IRO), which specifi es and organises words of various proteins interaction relationships. Our method is a two-stage PPI extraction method. At fi rst, IRO is applied in a binary classifi er to determine whether sentences contain a relation or not. Then, IRO is taken to guide PPI extraction by building sentence dependency parse tree. Comprehensive and quantitative evaluations and detailed analyses are used to demonstrate the signifi cant performance of IRO on relation sentences classifi cation and PPI extraction. Our PPI extraction method yielded a recall of around 80% and 90% and an F1 of around 54% and 66% on corpora of AIMed and Bioinfer, respectively, which are superior to most existing extraction methods. Copyright © 2014 Inderscience Enterprises Ltd
Molecular cloning and characterization of a novel expressed sequence tag (EST) associated with fecundity in goats
To screen the genes controlling the fecundity traits in goats, a DDRT-PCR technique was applied. We found a new EST which highly expressed in Chinese native prolific goat breed, Haimen goats. There exists a difference of EST expression level between the prolific and non-prolific goat breed, indicating EST might associate to fecundity in goats. A full-length cDNA with 2253 base pairs was obtained by the 3’- and 5’-RACE method based on the EST sequence encoding a protein segment of 201 amino acid residues. Tissue specific distribution and sequence analysis implicated the likely involvement of EST in the regulation of the hormones related to fecundity
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Luxury shopping tourism: views from Chinese post-1990s female tourists
Purpose
This study aims to explore how the concept of extended self-influences luxury shopping tourism consumption among Chinese tourists. It explores why luxury shopping is important for Chinese tourists. Specifically, this study focuses on a strategically important emerging market segment: post-1990s female Chinese tourists.
Design/methodology/approach
To explore the link between the extended self and luxury shopping tourism consumption among post-1990s Chinese female tourists, this study adopted a qualitative and interpretive approach. A total of 22 semi-structured in-depth interviews were carried out to collect the data.
Findings
This qualitative inquiry found that luxury shopping during overseas holidays has some subtle differences from luxury shopping in China, as the conceptualisation of luxury is highly context-based. Through a focus on gender and generational differences, the current study reveals that the idea of individuality has started to influence their luxury purchases.
Practical implications
The study shows how different selves are associated with luxury shopping. It thus provides empirical evidence regarding the reasons behind their motivation, especially for shopping overseas to get a good price and an exclusive and enjoyable luxury shopping experience abroad. Also, it was found that curiosity about buying luxury products is viewed as less favoured and logical shopping will be a future trend. Individuality is becoming a trend for younger consumers.
Originality/value
Theoretically, by linking the “extended self” with luxury shopping tourism, this study provides the social-psychological aspects of luxury shopping tourism. Instead of focusing on particular destinations, this study provides compressed but also focused inquiries to explore how the concept of the self-influences post-1990s female Chinese tourists’ shopping consumption while on holiday, and how this luxury shopping experience influences their concept of the self.目标
本文运用“延伸自我”概念对中国泳客在境外购买奢侈品的行为和意义进行探讨, 从而进一步了解中国游客对奢侈品的消费形态。 研究主要专注在中国90后女性市场, 女性市场已被许多学者以即市场营销人员认定为新兴市场领域。
设计
通过22个深度访谈的所得数据表明境外奢侈品高买行为与自我概念有着紧密的联系, 并为消费者购买动机背后的原因提供了实证
主要结论
在境外旅游过程中购买奢侈品有非常大的价格优势, 同时又能为消费者提供独特的购物体验, 中国90后女性的奢侈品购买行为日趋理性并在出行之前做好详细的购物计划, 个性的展示将成为中国年轻女性奢侈品消费的主导因素。
理论贡献
该研究的理论贡献是探索自我概念如何影响90年代后中国女性游客在境外旅行度假时的奢侈品购物行为, 以及这种奢侈品购物体验如何影响其自我概念。
关键词 购物,中国游客,女性, 延伸自我,自我概念
文章类型 研究论文Propósito
El estudio se dedica a explorar cómo influir el conceptöauto-extensión¨ al comportamiento de comprar los artículos de lujo en el extranjero entre los chinos turísticos, también a explorar la importancia de tal caso para ellos.
Metodología
Este estudio ha adaptado un enfoque cualitativo entre 22 entrevistas en profundidad semiestructuradas para la recopilación de datos y muestra cómo se asocian diferentes seres con las compras de lujo.
Resultados
Por lo tanto, se proporciona las pruebas evidentemente sobre las razones detrás de su motivación. Comprar artículos de lujo durante los viajes al extranjero tiene una gran ventaja de precio, al tiempo que las ofrece una experiencia especial. Estos actos se están volviendo más racionales y tienen planes de compras detallados antes de viajar. La exhibición de la personalidad se convertirá en el factor dominante en cuanto al consumo de artículos de lujo por parte de tales chinas.
Originalidad
Principalmente se enfoca a un nuevo campo del mercado en lo cual los consumidores son las chicas quienes nacieron después del año 1990
A computational cognition model of perception, memory, and judgment
The mechanism of human cognition and its computability provide an important theoretical foundation to intelligent computation of visual media. This paper focuses on the intelligent processing of massive data of visual media and its corresponding processes of perception, memory, and judgment in cognition. In particular, both the human cognitive mechanism and cognitive computability of visual media are investigated in this paper at the following three levels: neurophysiology, cognitive psychology, and computational modeling. A computational cognition model of Perception, Memory, and Judgment (PMJ model for short) is proposed, which consists of three stages and three pathways by integrating the cognitive mechanism and computability aspects in a unified framework. Finally, this paper illustrates the applications of the proposed PMJ model in five visual media research areas. As demonstrated by these applications, the PMJ model sheds some light on the intelligent processing of visual media, and it would be innovative for researchers to apply human cognitive mechanism to computer science.</p
Synthesis and characterization of folate-poly(ethylene glycol) chitosan graft-polyethylenimine as a non-viral carrier for tumor-targeted gene delivery
The use of chitosan and chitosan derivatives for gene delivery is limited due to the low transfection efficiency and difficulty in transfecting into a variety of cell types, including some cancer cells overexpressing folate receptor (FRs). In order to solve this problem, folate (FA) and poly(ethylene glycol) (PEG) was conjugated to chitosan-graft-polyethylenimine (CHI-g-PEI) to enhance water-solubility and the transfection efficiency. In the present study, a cell specific targeting molecule FA was linked on PEG and then grafted the FA-PEG onto CHI-g-PEI. The FA-PEG-grafted CHI-g-PEI (FA-PEG-CHI-g-PEI) effectively condensed the plasmid DNA (pDNA) into nanoparticles with positive surface charge under the suitable nitrogen/phosphorus (N/P) ratio. In vitro, transfection efficiency of the FA-PEG-CHI-g-PEI /pDNA complex in 293T cells and LoVo cells (FRs over-expressing cell lines) increased with increasing N/P ratio under N/P = 15 and was more than 50%, but no significant difference in human lung carcinoma cells (A549) cells (FRs deficient cell lines). Importantly, in vivo luciferase expression showed that the efficiency of FA-PEG-CHI-g-PEI -mediated transfection (50 μg luciferase plasmid (pLuc), N/P ratio = 15) was comparable to that of adenovirus-mediated luciferase transduction (1 × 109 pfu) in melanomabearing mice. It was concluded that FA-PEG-CHI-g-PEI, which has improved transfection efficiency and FRs specificity in vitro and in vivo, may be useful in gene therapy.Key words: Folate poly(ethylene glycol)-chitosan-grafted-polyethylenimine (FA-PEG-CHI-g-PEI), gene transfection, non-virus vector, in vitro, in viv
Decadal link between longitudinal morphological changes in branching channels of Yangtze Estuary and movement of the offshore depo-center
In estuaries, the morphology of inland and offshore areas usually evolves synergistically. This study examines the decadal link between longitudinal changes in morphology of branching channels and movement of the offshore depo-center (where sediment deposition rate is maximum) of the Yangtze River estuary, under intense human interference. Integrated data analysis is provided on morphology, runoff discharge, and ebb partition ratio from 1950 to 2017. Channel-volume reductions and change rates between isobaths in branching channels reflect the impact of estuarine engineering projects. Ebb partition ratio and duration of discharge ≥ 60 000 m3 s-1 act as proxies for the water excavating force in branching channels and runoff intensity. It is found that deposition occurs in the lower/upper sub-reaches (or further downstream/upstream channels) of the inland north/south branching channels, and the offshore depo-center moves southward or southeastward, as runoff intensity grows; the reverse occurs as runoff intensity declines. This is because the horizontal circumfluence in the Yangtze estuary rotates clockwise as ebb partition ratios of the north/south branching channels increase/decrease for increasing runoff, and conversely rotates anticlockwise for decreasing runoff. Land reclamation activities, the Deepwater Channel Project, and the Qingcaosha Reservoir have impacted greatly on longitudinal changes of morphology in the North Branch and the South Passage and on ebb partition ratio variations in the North/South Channel and the North/South Passage. Dam-induced runoff flattening has enhanced deposition in the upper/lower sub-reaches of the north/south branching channels and caused northward movement of the offshore depo-center, except in areas affected by estuarine engineering projects. Dam-induced longitudinal evolution of branching channel morphology and offshore depo-center movement will likely persist in the future, given the ongoing construction of large cascade dams in the upper Yangtze and the completion of major projects in the Yangtze estuary
Optimizing the Dice Score and Jaccard Index for Medical Image Segmentation: Theory & Practice
The Dice score and Jaccard index are commonly used metrics for the evaluation
of segmentation tasks in medical imaging. Convolutional neural networks trained
for image segmentation tasks are usually optimized for (weighted)
cross-entropy. This introduces an adverse discrepancy between the learning
optimization objective (the loss) and the end target metric. Recent works in
computer vision have proposed soft surrogates to alleviate this discrepancy and
directly optimize the desired metric, either through relaxations (soft-Dice,
soft-Jaccard) or submodular optimization (Lov\'asz-softmax). The aim of this
study is two-fold. First, we investigate the theoretical differences in a risk
minimization framework and question the existence of a weighted cross-entropy
loss with weights theoretically optimized to surrogate Dice or Jaccard. Second,
we empirically investigate the behavior of the aforementioned loss functions
w.r.t. evaluation with Dice score and Jaccard index on five medical
segmentation tasks. Through the application of relative approximation bounds,
we show that all surrogates are equivalent up to a multiplicative factor, and
that no optimal weighting of cross-entropy exists to approximate Dice or
Jaccard measures. We validate these findings empirically and show that, while
it is important to opt for one of the target metric surrogates rather than a
cross-entropy-based loss, the choice of the surrogate does not make a
statistical difference on a wide range of medical segmentation tasks.Comment: MICCAI 201
DeepTIO: a deep thermal-inertial odometry with visual hallucination
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordVisual odometry shows excellent performance in a wide range of environments. However, in visually-denied scenarios (e.g. heavy smoke or darkness), pose estimates degrade or even fail. Thermal cameras are commonly used for perception and inspection when the environment has low visibility. However, their use in odometry estimation is hampered by the lack of robust visual features. In part, this is as a result of the sensor measuring the ambient temperature profile rather than scene appearance and geometry. To overcome this issue, we propose a Deep Neural Network model for thermal-inertial odometry (DeepTIO) by incorporating a visual hallucination network to provide the thermal network with complementary information. The hallucination network is taught to predict fake visual features from thermal images by using Huber loss. We also employ selective fusion to attentively fuse the features from three different modalities, i.e thermal, hallucination, and inertial features. Extensive experiments are performed in hand-held and mobile robot data in benign and smoke-filled environments, showing the efficacy of the proposed model
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