A citation-based review of study on image retrieval

Driven by the development of the information retrieval technologies, image retrieval has been studied for more than several decades. This study centers on revealing the current status and future directions of image retrieval based on reviewing previous related studies. The citation-based analysis was applied to 2243 articles retrieved from Web of Science database. The time series plots of the citation relationships between the retrieved articles reveal a fundamental research article that lay the foundation for the image retrieval field. Co-citation analysis identifies that the existing studies formed two clusters. Each cluster represents one of the two major areas in the field of image retrieval: the text-based image retrieval and the content-based image retrieval. The visualization map shows that the research of content-based image retrieval has received more attention than the area of text-based image retrieval. Relevance feedback was identified as a promising research direction for the future study

AN INVESTIGATION ON THE ERROR OF CALIBRATING EXTERIOR POINTS WITH INTERIOR POINTS

This study was to investigate the accuracy of calibrating exterior points with interior points using a frame with the same structure as Peak frame. Two cameras were used. Some points of the frame were used as control points to calibrate others using the DLT method. When we calibrated exterior points with interior points, the minimal and maximal errors were 0.171 cm and 1.797 cm respectively in the horizontal direction (X), 0.213 cm and 4.856 cm in the horizontal direction (Y), 0.103 cm and 1.608 cm in the vertical direction (Z). When we calibrated the interior points with exterior points, almost all errors were less than 1cm. It was concluded that to get the most accurate 3D reconstruction of human movement, it is necessary to make sure that the space formed by control points contains the objects to be calibrated

An experimental study of non-coaxial soil behaviour using hollow cylinder testing

Non-coaxiality of the principal stress direction and principal strain increment direction has been observed in both numerical modelling and experimental studies. The importance of non-coaxiality has been widely recognised in the geomechnical engineering. Without considering the non-coaxiality in the design may lead to an unsafe soil structure. Therefore, it is essential to understand the non-coaxial soil behaviour better and take it into account in the numerical modelling. A new Hollow Cylinder Apparatus in Nottingham Centre of Geomechanics (NCG) has been employed in this study. A series of preliminary tests have been carried out to validate the reliability and repeatability of the testing results. Three series of tests, including 24 tests on Portaway sand and 2 tests on Leighton Buzzard sand, were conducted to study the non-coaxial soil behaviour of granular materials. The three stress paths followed were monotonic loading along fixed principal stress direction, pure rotation of the principal stress axes with constant deviator stress and combined rotation of principal stress axes with increasing deviator stress. Portaway sand was chosen because it has been used in NCG to investigate granular soil behaviour. Therefore, stress-strain behaviour including non-coaxial behaviour can be observed and used by the other researchers in NCG to develop or verify numerical models. The evidence of non-coaxiality has been obtained from the tests. In general, the non-coaxiality is relatively small in monotonic loading tests, but is more significant in the pure rotation tests and combined loading tests. The degree of non-coaxiality is affected by the density of the specimen, the stress path followed, the stress level and the material particle properties

COX-2 Inhibitor Nimesulide Analogs are Aromatase Suppressors in Breast Cancer Cells

Cyclooxygenase-2 (COX-2) inhibitor nimesulide derivatives compounds A and B decreased aromatase activity in breast cancer cells via a novel mechanism different to aromatase inhibitors (AIs), and were defined as “aromatase suppressors”. Breast carcinoma cells (MCF-7aro and T47Daro) transfected with aromatase full gene were used to explore the mechanisms of the two compounds. They dose and time-dependently suppressed aromatase activity in MCF-7aro and T47Daro cells in the nanomole range. However, they neither directly inhibited aromatase, nor improved aromatase degradation even at much higher concentrations. They could also suppress androgen stimulated cell growth, but did not affect estrogen enhanced cell proliferation. These results suggest that compounds A and B selectively interfere with aromatase in breast cancer cells, but not estrogen receptor (ER) downstream to disrupt androgen mediated cell growth. Interestingly, compound B effectively inhibited LTED (long-term estrogen deprived MCF-7aro cell) cell growth, which is a model for AIs resistance, with an IC50 of 4.68 ± 0.54 μM. The results indicate that compound B could potentially overcome AI resistance in breast cancer cell and could be used as a lead to design more potent derivatives

A Fast Learning Method for Multilayer Perceptrons in Automatic Speech Recognition Systems

We propose a fast learning method for multilayer perceptrons (MLPs) on large vocabulary continuous speech recognition (LVCSR) tasks. A preadjusting strategy based on separation of training data and dynamic learning-rate with a cosine function is used to increase the accuracy of a stochastic initial MLP. Weight matrices of the preadjusted MLP are restructured by a method based on singular value decomposition (SVD), reducing the dimensionality of the MLP. A back propagation (BP) algorithm that fits the unfolded weight matrices is used to train the restructured MLP, reducing the time complexity of the learning process. Experimental results indicate that on LVCSR tasks, in comparison with the conventional learning method, this fast learning method can achieve a speedup of around 2.0 times with improvement on both the cross entropy loss and the frame accuracy. Moreover, it can achieve a speedup of approximately 3.5 times with only a little loss of the cross entropy loss and the frame accuracy. Since this method consumes less time and space than the conventional method, it is more suitable for robots which have limitations on hardware

Building crack monitoring based on digital image processing

Building crack monitoring is of great value to the judgment of building safety. In this study, the digital image processing technology was studied and applied to the monitoring of building cracks. Crack images were collected by CCD camera, and then operations such as graying, correction, denoising and segmentation were carried out to obtain clear crack images. The obtained images are processed morphologically to further improve the quality. Finally, the width and length of cracks are calculated. In the case analysis, the results of 15 cracks measured by microscope were taken as the standards and compared with the calculated results. The results showed that the results calculated in this study and the manual measurement results differed little, and the average error of the width and length is 0.021 mm and 0.024 mm respectively, which suggested that the method proposed had high reliability. The findings of this study provides a new idea for the further development of building crack monitoring field, which is conducive to the accurate assessment of building safety

Role of C9orf72 hexanucleotide repeat expansions in ALS/FTD pathogenesis

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are progressive neurological disorders that share neurodegenerative pathways and features. The most prevalent genetic causes of ALS/FTD is the GGGGCC hexanucleotide repeat expansions in the first intron region of the chromosome 9 open reading frame 72 (C9orf72) gene. In this review, we comprehensively summarize the accumulating evidences elucidating the pathogenic mechanism associated with hexanucleotide repeat expansions in ALS/FTD. These mechanisms encompass the structural polymorphism of DNA and transcribed RNA, the formation of RNA foci via phase separation, and the cytoplasmic accumulation and toxicities of dipeptide-repeat proteins. Additionally, the formation of G-quadruplex structures significantly impairs the expression and normal function of the C9orf72 protein. We also discuss the sequestration of specific RNA binding proteins by GGGGCC RNA, which further contributes to the toxicity of C9orf72 hexanucleotide repeat expansions. The deeper understanding of the pathogenic mechanism of hexanucleotide repeat expansions in ALS/FTD provides multiple potential drug targets for these devastating diseases

Holographic Charged Fluid with Chiral Electric Separation Effect

Hydrodynamics with both vector and axial currents is under study within a holographic model, consisting of canonical $U(1)_V\times U(1)_A$ gauge fields in an asymptotically AdS$_5$ black brane. When gravitational back-reaction is taken into account, the chiral electric separation effect (CESE), namely the generation of an axial current as the response to an external electric field, is realized naturally. Via fluid/gravity correspondence, all the first order transport coefficients in the hydrodynamic constitutive relations are evaluated analytically: they are functions of vector chemical potential $\mu$, axial chemical potential $\mu_5$ and the fluid's temperature $T$. Apart from the proportionality factor $\mu\mu_5$, the CESE conductivity is found to be dependent on the dimensionless quantities $\mu/T$ and $\mu_5/T$ nontrivially. As a complementary study, frequency-dependent transport phenomena are revealed through linear response analysis, demonstrating perfect agreement with the results obtained from fluid/gravity correspondence.Comment: 39 pages, 6 figures, 1 table; Matches published version, the main results are summarized in sec 1.1 and we thank the referee for valuable suggestion