170 research outputs found

    A practical image retrieval framework for tourism industry

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    Image Retrieval (IR) is one of the most exciting and fastest growing research domains in the field of multimedia technology. And in the industrial ecosystems, images of products, activities, marketing materials etc are needed to be managed and fetched in an efficient way to support and facilitate business processes. Current techniques for IR including keyword based, content based and ontology based image retrieval have several unsolved issues. We promote the ontology based IR approach and focus on two issues: firstly, the difficulty in constructing ontologies of images for those industries without ontology professionals, and, secondly, none of the existing approaches consider image content ranking in search results. In this paper, we propose a practical framework to tackle these issues by introducing an Abstract Image Ontology that serves as a blueprint of image ontologies and by incorporating a Concept Instance Ranking Scheme to allow ranking of each of the contents expressed in images, thus providing extra information for IR process. An application scenario in the tourism industry area is also presented

    Knowledge extraction from web based application source code: an approach to database reverse engineering for ontology development

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    This paper presents a novel approach for extracting knowledge from web-based application source code in supplementing and assisting ontology development from database schemas. The structure of web-based application source code is defined in order to distinguish different kinds of knowledge within the source code for ontology development. The connections between the relevant parts of web application source code and the backend database schema with their various forms are explicitly specified in detail. A knowledge processing and integration model for extracting and integrating the knowledge embedded in the source code for ontology development is then proposed

    Mapping relational data model to OWL ontology: knowledge conceptualization in OWL

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    In this paper, we introduce the issues and solutions of using OWL ontology to model extra restriction on 'Properties' of 'Classes' that are not provided by OWL specifications and to represent associations amongst 'Properties' other than 'Classes'. Two specific types of knowledge that cannot be modeled directly using OWL DL elements are identified and presented. Firstly the data value range constraint for a "DatatypeProperty"; secondly the calculation knowledge representation. Our approach to such issues is to conceptualize the knowledge in OWL and map the conceptualization in an implementation. Examples for each type of the knowledge and their OWL code are provided in detail to demonstrate our approach

    How online video platforms could support China’s independent microfilm (short film) makers and enhance the Chinese film industry

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    As with the US and EU media landscapes, the Chinese film industry is dominated by platforms similar to Netflix, Hulu and Amazon, most notably in the form of the BAT (Baidu, Alibaba, Tencent) companies that according to He (2015) are ‘taking over the film industry’. These have been described as ‘imperialistic’ in the monopolization of their respective markets and in the use of their financial muscle to squeeze content creators’ incomes (Jin, 2015). While in the western market this undermines the mainly middle-class professionals who drive creativity (Timberg,2015), in China it limits the opportunities for new talent to grow. This paper will, therefore, give an overview of the Chinese microfilm (online short movies) industry and investigate how Chinese BAT companies and other online video providers could enhance the Chinese film industry by developing infrastructure to direct revenue of microfilms to the creators

    International TV series distribution on Chinese digital platforms: marketing strategies and audience engagement

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    The relationship between online media platforms in China and fan groups is a dynamic one when it comes to the distribution of international TV series and other media content, as media platforms incorporate user-generated content to encourage or foster audience engagement. Through a series of case studies, this article investigates how international TV series are acquired, distributed, marketed and curated on Chinese online video platforms. This helps to identify specific strategies and themes used by these platforms to promote international content and engage users. These marketing techniques, however, are not always as successful as expected, suggesting the need for a closer examination of the types of engagement sought by media platforms, and the ways in which Chinese audiences have responded within their cultural context

    A monopolar symmetrical hybrid cascaded DC/DC converter for HVDC interconnections

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    With the rapid development of voltage source converter (VSC) based high voltage direct current (HVDC) transmission, it is an irresistible trend that HVDC grid will come into being. High-voltage and high-power DC/DC converters will serve as DC transformers in HVDC grid to interconnect DC lines with different voltage ratings. This paper proposes a monopolar symmetrical DC/DC converter which is composed of cascaded half-bridge sub-modules (SMs) and series-connected IGBTs. This hybrid topology features low capital costs, high efficiency, small footprint, and bidirectional power transfer capability. Operation principle, parameter design, and the control strategies of this topology are introduced. A 480MW, ±500kV/±160kV monopolar symmetrical DC/DC converter is simulated to verify its performance and evaluate the efficiency. In addition, a downscaled prototype rated at 2.4kW, ±300V/±100V has been built and tested. Experimental results further validate the effectiveness of the proposed DC/DC converter

    catena-Poly[[(5-phenyl-2,2′-bipyridine-κ2 N,N′)copper(I)]-μ-thio­cyanido-κ2 N:S]

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    The title compound, [Cu(NCS)(C16H12N2)]n, was synthesised under hydro­thermal conditions. The CuI ion shows distorted tetra­hedral geometry being coordinated by two N atoms from a 5-phenyl-2,2′-bipyridine ligand and by the N and S atoms from two different thio­cyanate anions. The CuI ions are bridged by thio­cyanide groups, forming a one-dimensional coordination polymer along the b axis. The crystal packing is through van der Waals contacts and C—H⋯π inter­actions

    Arabidopsis Transcriptome Analysis Reveals Key Roles of Melatonin in Plant Defense Systems

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    Melatonin is a ubiquitous molecule and exists across kingdoms including plant species. Studies on melatonin in plants have mainly focused on its physiological influence on growth and development, and on its biosynthesis. Much less attention has been drawn to its affect on genome-wide gene expression. To comprehensively investigate the role(s) of melatonin at the genomics level, we utilized mRNA-seq technology to analyze Arabidopsis plants subjected to a 16-hour 100 pM (low) and 1 mM (high) melatonin treatment. The expression profiles were analyzed to identify differentially expressed genes. 100 pM melatonin treatment significantly affected the expression of only 81 genes with 51 down-regulated and 30 up-regulated. However, 1 mM melatonin significantly altered 1308 genes with 566 up-regulated and 742 down-regulated. Not all genes altered by low melatonin were affected by high melatonin, indicating different roles of melatonin in regulation of plant growth and development under low and high concentrations. Furthermore, a large number of genes altered by melatonin were involved in plant stress defense. Transcript levels for many stress receptors, kinases, and stress-associated calcium signals were up-regulated. The majority of transcription factors identified were also involved in plant stress defense. Additionally, most identified genes in ABA, ET, SA and JA pathways were up-regulated, while genes pertaining to auxin responses and signaling, peroxidases, and those associated with cell wall synthesis and modifications were mostly down-regulated. Our results indicate critical roles of melatonin in plant defense against various environmental stresses, and provide a framework for functional analysis of genes in melatonin-mediated signaling pathways

    Feature extraction method based on VMD and MFDFA for fault diagnosis of reciprocating compressor valve

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    Aiming at the nonlinearity, nonstationarity and multi-component coupling characteristics of reciprocating compressor vibration signals, an integrated feature extraction method based on the variational mode decomposition (VMD) and multi-fractal detrended fluctuation analysis (MFDFA) is proposed for a fault diagnosis for a reciprocating compressor valve. Firstly, to eliminate the noise interference, a novel VMD method with superior anti-interference performance was utilized to obtain several components of the quasi-orthogonal band-limited intrinsic mode function (BLIMF) from a strong non-stationarity vibration signal, and a consistent number K of BLIMFs was selected based on a novel criterion for all fault states. Secondly, the MFDFA method, which can describe the multi-fractal structure feature of non-stationary time series, was applied to analyze each BLIMF component, and the parameters of MFDFA were employed as the eigenvectors to reflect the structure characteristics and local scale behavior of the vibration signal. Then, the principal component analysis (PCA) was introduced to refine the eigenvectors for a higher recognition efficiency and accuracy. Finally, the vibration signals of four types of reciprocating compressor valve faults were analyzed by this method, and the faults were identified correctly by pattern classifiers of BTSVM and CNN. Further results comparison with other feature extraction methods verifies the superiority of the proposed method

    Pathogenic Mutations Differentially Regulate Cell-to-Cell Transmission of α-Synuclein

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    Recent studies suggest that the cell-to-cell spread of pathological α-synuclein (α-syn) plays important roles in the development of Parkinson’s disease (PD). PD patients who carry α-syn gene mutations often have an earlier onset and more severe clinical symptoms and pathology than sporadic PD cases who carry the wild-type (WT) α-syn gene. However, the molecular mechanism by which α-syn gene mutations promote PD remains unclear. Here, we hypothesized that pathogenic mutations facilitate the intercellular transfer and cytotoxicity of α-syn, favoring an early disease onset and faster progression. We investigated the effects of eight known pathogenic mutations in human α-syn (A18T, A29S, A30P, E46K, H50Q, G51D, A53E, and A53T) on its pathological transmission in terms of secretion, aggregation, intracellular level, cytotoxicity, seeding, and induction of neuroinflammation in SH-SY5Y neuroblastoma cells, cultured rat neurons, and microglia, and the rat substantia nigra pars compacta. We found that 2 of the 8 mutations (H50Q and A53T) significantly increased α-syn secretion while 6 mutations (A18T, A29S, A30P, G51D, A53E, and E46K) tended to enhance it. In vitroα-syn aggregation experiments showed that H50Q promoted while G51D delayed aggregation most strongly. Interestingly, 3 mutations (E46K, H50Q, and G51D) greatly increased the intracellular α-syn level when cultured cells were treated with preformed α-syn fibrils (PFFs) compared with the WT, while the other 5 had no effect. We also demonstrated that H50Q, G51D, and A53T PFFs, but not E46K PFFs, efficiently seeded in vivo and acutely induced neuroinflammation in rat substantia nigra pars compacta. Our data indicate that pathogenic mutations augment the prion-like spread of α-syn at different steps and blockade of this pathogenic propagation may serve as a promising therapeutic intervention for PD
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