429 research outputs found
A Note on the DQ Analysis of Anisotropic Plates
Recently, Bert, Wang and Striz [1, 2] applied the differential quadrature
(DQ) and harmonic differential quadrature (HDQ) methods to analyze static and
dynamic behaviors of anisotropic plates. Their studies showed that the methods
were conceptually simple and computationally efficient in comparison to other
numerical techniques. Based on some recent work by the present author [3, 4],
the purpose of this note is to further simplify the formulation effort and
improve computing efficiency in applying the DQ and HDQ methods for these
cases
Mineral Froth Image Classification and Segmentation
Accurate segmentation of froth images is always a problem in the research of floating modeling based on Machine Vision. Since a froth image is with the characteristic of complexity and diversity, it is a feasible research idea for the workflow of which the froth image is firstly classified and then segmented by the image segmentation algorithm designed for each type of froth images. This study proposes a new froth image classification algorithm. The texture feature is extracted to complete the classification. Meanwhile, an improved method based on the original valley‐edge detection algorithm is also proposed in the study. Firstly, the fractional differential is introduced to design the new valley‐edge detection templates which can extract more information on bubble edges after the enhancement of the weak edges, and finally the close bubble boundaries are obtained by carrying out the improved deburring and gap connection algorithms. Experimental results show that the new classification method can be used to distinguish the types of small, middle and large bubble images. The improved image segmentation algorithm can well reduce the problems of over‐segmentation and under‐segmentation, and it is in higher adaptability
On Semiabelian π-Regular Rings
A ring R is defined to be semiabelian if every idempotent of R is either right semicentral or left semicentral. It is proved that the set N(R) of nilpotent elements in a π-regular ring R is an ideal of R if and only if R/J(R) is abelian, where J(R) is the Jacobson radical of R. It follows that a semiabelian ring R is π-regular if and only if N(R) is an ideal of R and R/N(R) is regular, which extends the fundamental result of Badawi (1997). Moreover, several related results and examples are
given
ASPIE: A Framework for Active Sensing and Processing of Complex Events in the Internet of Manufacturing Things
Rapid perception and processing of critical monitoring events are essential to ensure healthy operation of Internet of Manufacturing Things (IoMT)-based manufacturing processes. In this paper, we proposed a framework (active sensing and processing architecture (ASPIE)) for active sensing and processing of critical events in IoMT-based manufacturing based on the characteristics of IoMT architecture as well as its perception model. A relation model of complex events in manufacturing processes, together with related operators and unified XML-based semantic definitions, are developed to effectively process the complex event big data. A template based processing method for complex events is further introduced to conduct complex event matching using the Apriori frequent item mining algorithm. To evaluate the proposed models and methods, we developed a software platform based on ASPIE for a local chili sauce manufacturing company, which demonstrated the feasibility and effectiveness of the proposed methods for active perception and processing of complex events in IoMT-based manufacturing
Construction of a polarization insensitive lens from a quasi-isotropic metamaterial slab
We propose to employ the quasiisotropic metamaterial (QIMM) slab to construct
a polarization insensitive lens, in which both E- and H-polarized waves exhibit
the same refocusing effect. For shallow incident angles, the QIMM slab will
provide some degree of refocusing in the same manner as an isotropic negative
index material. The refocusing effect allows us to introduce the ideas of
paraxial beam focusing and phase compensation by the QIMM slab. On the basis of
angular spectrum representation, a formalism describing paraxial beams
propagating through a QIMM slab is presented. Because of the negative phase
velocity in the QIMM slab, the inverse Gouy phase shift and the negative
Rayleigh length of paraxial Gaussian beam are proposed. We find that the phase
difference caused by the Gouy phase shift in vacuum can be compensated by that
caused by the inverse Gouy phase shift in the QIMM slab. If certain matching
conditions are satisfied, the intensity and phase distributions at object plane
can be completely reconstructed at image plane. Our simulation results show
that the superlensing effect with subwavelength image resolution could be
achieved in the form of a QIMM slab.Comment: 25 pages, 8 figure
Effects of Preparation Conditions on the Yield and Embedding Ratio of Vinyl Silicone Oil Microcapsules
Self-healing materials could repair themselves without external influences when they are damaged. In this paper, microcapsules are prepared by in-situ polymerization method, utilizing vinyl silicone oil as core material, polyurea formaldehyde as wall material and polyvinyl alcohol as dispersant. The morphology and structure of the microcapsules are tested with scanning electron microscopy, optical microscopy and laser particle analyzer. Effect of the reaction temperature, stirring speed and polyvinyl alcohol concentration on the yield, embedding ratio, particle size and its distribution are studied. Results show that the microcapsules can be successfully prepared by in-situ polymerization method. Under the reaction condition of temperature 60 °C, stirring speed 1000 r/min, dispersant concentration 0.1 wt.%, the yield and embedding ratio of the microcapsule are found to be 52.5 % and 50.1 %, respectively. The prepared microcapsules have smooth surface, good dispersibility, narrow particle size distribution and the average particle size is 13 μm
Zerumbone Attenuates the Severity of Acute Necrotizing Pancreatitis and Pancreatitis-Induced Hepatic Injury
This paper investigated the potential effects of zerumbone pretreatment on an acute necrotizing pancreatitis rat model induced by sodium taurocholate. The pancreatitis injury was evaluated by serum AMY, sPLA2, and pancreatic pathological score. Pancreatitis-induced hepatic injury was measured by ALT, AST, and hepatic histopathology. The expression of I-κBα and NF-κB protein was evaluated by western blot and immunohistochemistry assay while ICAM-1 and IL-1β mRNA were examined by RT-PCR. The results showed that AMY, sPLA2, ALT, and AST levels and histopathological assay of pancreatic and hepatic tissues were significantly reduced following administration of zerumbone. Applying zerumbone also has been shown to inhibit NF-κB protein and downregulation of ICAM-1 and IL-1β mRNA. The present paper suggests that treatment of zerumbone on rat attenuates the severity of acute necrotizing pancreatitis and pancreatitis-induced hepatic injury, via inhibiting NF-κB activation and downregulating the expression of ICAM-1 and IL-1β
Superluminal group velocity in an anisotropic metamaterial
Based on boundary condition and dispersion relation, the superluminal group
velocity in an anisotropic metamaterial (AMM) is investigated. The superluminal
propagation is induced by the hyperbolic dispersion relation associated with
the AMM. It is shown that a modulated Gaussian beam exhibits a superluminal
group velocity which depends on the choice of incident angles and optical axis
angles. The superluminal propagation does not violate the theory of special
relativity because the group velocity is the velocity of the peak of the
localized wave packet which does not carry information. It is proposed that a
triglycine sulfate (TGS) crystal can be designed and the superluminal group
velocity can be measured experimentally.Comment: 9 pages, 3 figure
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