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1.
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An experimental machine vision apparatus was used to identify and extract recyclable plastic bottles out of a conveyor belt. Color images were taken with a commercially available Webcam, and the recognition was performed by our homemade software, based on the shape and dimensions of object images. The software was able to manage multiple bottles in a single image and was additionally extended to cases involving touching bottles. The identification was fulfilled by comparing the set of measured features with an existing database and meanwhile integrating various recognition techniques such as minimum distance in the feature space, self-organized maps, and neural networks. The recognition system was tested on a set of 50 different bottles and provided so far an accuracy of about 97% on bottle identification. The extraction of the bottles was performed by means of a pneumatic arm, which was activated according to the plastic type; polyethylene-terephthalate (PET) bottles were left on the conveyor belt, while non-PET bottles were extracted. The software was designed to provide the best compromise between reliability and speed for real-time applications in view of the commercialization of the system at existing recycling plants.  相似文献   

3.
The construction of the cables is a key step for erecting suspen-dome structures. In practical engineering, it is difficult to ensure that the designed pre-stresses of cables have been exactly introduced into the structures in the site; so it is necessary to evaluate the influence of the variation of the pre-stresses on the structural behavior. In the present work, an orthogonal design method was employed to investigate the pre-stressed cables' sensitivity to the suspen-dome system. The investigation was concentrated on a Kiewitt suspen-dome. Parametric studies were carried out to study the sensitivity of the structure's static behavior, dynamic behavior, and buckling loads when the pre-stresses in the cables varied. The investigation indicated that suspen-dome structures are sensitive to the pre-stresses in all cables; and that the sensitivity depended on the location of the cables and the kind of structural behavior. Useful suggestions are given at the end of the paper.  相似文献   

4.
We carried out a wind tunnel test to measure cladding loads for a high-rise building of 295 m in height, which would be located in the business center of Chongqing Municipality, P. R. China. The rigid model was used to determine fluctuating local pressures on the exterior surfaces of the building. The wind tunnel test results show the cr/tical zone of wind pressures on building surfaces in both standalone and interference conditions. The computational fluid dynamics (CFD) was conducted by using the FLUENT Code to compare with the wind tunnel test results, and the steady three-dimensional turbulent flow with Realizable k-ε as a turbulence model was used. The CFD results are agree with the wind tunnel test results in regards to distributions of wind pressures over a high-rise building's surfaces.  相似文献   

5.
The recently developed elastic-viscoplastic self-consistent model with various self-consistent schemes was applied to study the effect of basal texture on the mechanical behavior of magnesium alloy AZ31B sheet. The influence of the basal texture was investigated using various initial textures generated by artificially tilting the measured texture of the reference AZ31B sheet around in a transverse direction. The material parameters for the various models were fitted to experimental uniaxial tension and compression along the rolling direction and were then used to study the effects of the basal texture on the yield stress, R value, ultimate stress and uniform strain under uniaxial tension. The effect of the basal texture on sheet metal forming was further assessed by calculating the limit strain under in-plane plane strain tension. An assessment of the predictive capability of polycrystal plasticity models was made based on comparisons of predictions and experimental observations. Among the available self-consistent approaches, the Affine self-consistent scheme resulted in the best overall performance.  相似文献   

6.
Objective To investigate the effects of nivalenol(NIV) and selenium(Se) on the metabolism of aggrecan in the cultured chondrocytes,and to explore the mechanism involved in cartilage aggrecan catabolism in the process of Kashin-Beck Disease(KBD).Method Aggrecan mRNA expression was studied by RT-PCR.The concentration of GlcUA in culture medium was determined by diphenylenimine-sulfuric acid method.Result NIV significantly decrease aggrecan mRNA expression.That Se can partially antagonize the effect of NIV on aggrecan mRNA expression.The content of GlcUA in medium with NIV was high er than that in other groups.Conclusion NIV could inhibit chondrocyte synthesis aggrecan,promote the loss of aggrecan from cartilage.All the effects result in the metabolic disorder of the cartilage aggrecan,which eventually leads to irreversible mechani cal destruction of the cartilage.It suggested that Se can partially alleviate the effects of NIV on chondrocytes cultured in vitro.  相似文献   

7.
A measurement model based on torsion pendulum was established,in which nonlinear damping and nonlinear restoring force were considered.The calculation method of the moment of inertia was based on Hilbert transform.The motion of torsion pendulum showed the time-frequency characteristics due to the nonlinear factors,which were validated by the experimental data.The analytical signal was formed by Hilbert transform of the angular displacement signal of the test object.The moment of inertia can be computed by the instantaneous undamped natural frequency with Hilbert transform.Prior to the implementation of Hilbert transform,the empirical mode decomposition was used to filter the experimental signal.The moment of inertia of the test object was measured by the torsion pendulum system.The experimental results show that the relative measurement error of the moment of inertia was within 0.7%,which indicated the validity of the measurement method.  相似文献   

8.
The effect of axial shallow groove on the nonlinear dynamic response and buckling of laminated cylindrical shells subjected to radial compression loading was investigated. Based on the first-order shear deformation theory (FSDT), the nonlinear dynamic equations involving the transverse shear deformation and initial geometric imperfections were derived with the Hamilton philosophy. The axial shallow groove of the laminated composite cylindrical shell was treated as the initial geometric imperfections in the dynamic equations. A semi-analytical method of expanding displacements and loads along the circumferential direction and employing the finite difference method along the axial direction and in the time domain is used to solve the governing equations and obtain the dynamic response of the laminated shell. The B-R criterion was employed to determine the critical loads of dynamic buckling of the shell. The effects of the parameters of the shallow groove on the dynamic response and buckling were discussed in this paper and the results show that the axial shallow grooves greatly affect the dynamic response and buckling.  相似文献   

9.
A cluster analyzing algorithm based on grids is introduced in this paper,which is applied to data mining in the city emergency system. In the previous applications, data mining was based on the method of analyzing points and lines, which was not efficient enough in dealing with the geographic information in units of police areas. The proposed algorithm maps an event set stored as a point set to a grid unit set, utilizes the cluster algorithm based on grids to find out all the clusters, and shows the results in the method of visualization. The algorithm performs well when dealing with high dimensional data sets and immense data. It is suitable for the data mining based on geographic information system and is supportive to decision-makings in the city emergency system.  相似文献   

10.
The United Nations Human Development Program has released its yearly study on the quality of life for people around the world. The U-N report was started in 1990 to measure the progress of nations based on the lives of their citizens.This year's report lists 173 countries. It is based on the length of time citizens are expected to live, their education level and the amount of money they earn. Norway was listed as the country providing the best  相似文献   

11.
胡燕 《海外英语》2011,(7):234-235
Nathaniel Hawthorne was one of the well-known romantic novelists of the 19th century in American literature.Most of his works emphasized on the morality.Symbolism is one of the most important writing skills of literature,which endows the concrete images with abstract meanings to enlighten the reader’s imagination and to express a deeper meaning.He was once claimed as the pioneer of symbolism in American literature.He usually used symbolism in his works to analyze the "sin" of the humankind that is an eternal topic for us humankind.This paper mainly focuses on the analysis of the symbolism used in The Scarlet Letter,Hawthorne’s masterpiece.The Scarlet Letter is a novel with numerous symbolisms,which leaves deep imaginable and mysterious impression on people.The scene in the novel,the "A" is full of symbolism meanings.This paper mainly uses comprising and contrast,analogy to support the writer’s ideas.  相似文献   

12.
Combined with the printing application, an image registration method based on the multi-resolution morphology contour detection was proposed. First, a direction based multi-resolution gray morphology in the scheme was proposed to realize the contour extraction. Then, based on the contour features, the subspace image registration was proposed to deal with issues of the computing complexity appeared in the traditional image registration methods. The proposed image registration was efficiently applied in the defect inspection of printing images.  相似文献   

13.
There were three traditions of subjective well-being (SWB) measures research: measures related to quality of life, measures related to mental health, and measures related to psychological development. Although the western researchers had made great progress in this field, there still had been some problems, including the integration of various indicators, the innovation to research methodology, and the cultural difference. Based on the past literature on measures of SWB and related literature on happiness from metaphysics, the author proposed the standpoint and train of thought through experience view. it was considered that happiness was the subjective reflection to the real-life, it was not only related to the people's objective life condition, but also related to their needs and value. SWB is the positive psychological experience to one's status of existence and development. The respect of measures research through experience view was the content of the experience, namely the object that brought the experience. The measures research through experience view would study in the conformity train of thought; and it would focus on the relatively steady psychological phenomenon. The measurement instrument developed through this view would be suitable generally.  相似文献   

14.
The aim of this work was to construct a novel food-grade industrial arming yeast displaying β-1,3-1,4-glucanase and to evaluate the thermal stability of the glucanase for practical application. For this purpose, a bi-directional vector containing galactokinase (GAL1) and phosphoglycerate kinase 1 (PGK1) promoters in different orientations was constructed. The β-1,3-1,4-glucanase gene from Bacillus subtilis was fused to α-agglutinin and expressed under the control of the GAL1 promoter. α-galactosidase induced by the constitutive PGK1 promoter was used as a food-grade selection marker. The feasibility of the α-galactosidase marker was confirmed by the growth of transformants harboring the constructed vector on a medium containing melibiose as a sole carbon source, and by the clear halo around the transformants in Congo-red plates owing to the expression of β-1,3-1,4-glucanase. The analysis of β-1,3-1,4-glucanase activity in cell pellets and in the supernatant of the recombinant yeast strain revealed that β-1,3-1,4-glucanase was successfully displayed on the cell surface of the yeast. The displayed β-1,3-1,4-glucanase activity in the recombinant yeast cells increased immediately after the addition of galactose and reached 45.1 U/ml after 32-h induction. The thermal stability of β-1,3-1,4-glucanase displayed in the recombinant yeast cells was enhanced compared with the free enzyme. These results suggest that the constructed food-grade yeast has the potential to improve the brewing properties of beer.  相似文献   

15.
A laser collimating system based on 2-D position sensitive detector (PSD) is presented in this paper. The working principle of PSD is depicted in detail. A calibration device was developed to check the nonlinearity errors of PSD and a multilayer feedforward neural network based on error back-propagation algorithm was used to compensate errors. With the aid of computer-based data acquisition system, an automatic dynamic measuring process was realized. A series of experiments, including comparison tests with laser interferometer, were done to evaluate the performance of the measuring system. The experimental results show that the spatial straightness errors of guide rails can be measured with high accuracy. The maximum differences between the device and laser interferometer are 0. 027 mm in Y direction, and 0. 053 mm in X direction in the measuring distance of 6 m.  相似文献   

16.
The purpose of this study was to explore what salient characteristics can be found in some university teachers' approaches to teaching in Finland, Japan and India, and in what ways university teachers in Finland, India and Japan use ICTs (information and communication technologies) in their own teaching. Furthermore, this study aimed to investigate what ICT applications these same teachers use in their teaching. The data were collected via an electronic survey and interviews. The participants (N=21) were university teachers from Finland (N=8), Japan (N=I0) and India (N=3). Their approaches to teaching were explored by applying the ATI (approaches to teaching inventory) and its modified version focusing on the use of ICTs in teaching. The study reported in this paper was a pilot study, thus the results are based on the limited number of respondents. The ATI and ATI ICT subscales and ICT inventory applied in this study have been confirmed to be valid. The university teachers in Japan and Finland differed in their approaches to teaching: The Finnish teachers scored higher on the CCSF (conceptual change orientated, student-focused) approach to teaching than the Japanese teachers, while the Japanese teachers scored higher on the ITTF (information transmitting, teacher-focused) approach to teaching. Two Indian teachers were classified as having a teacher-focused approach to teaching, while the third was classified as having a student-focused approach to teaching. The teachers' differences in their use of ICTs related more to their disciplinary status than to their cultural background.  相似文献   

17.
Based on the strength reduction method and strain-softening model,a method for progressive failure analysis of strain-softening slopes was presented in this paper.The mutation is more pronounced in strain-softening analysis,and the mutation of displacement at slope crest was taken as critical failure criterion.An engineering example was provided to demonstrate the validity of the present method.This method was applied to a cut slope in an industry site.The results are as follows:(1) The factor of safety and the critical slip surface obtained by the present method are between those by peak and residual strength.The analysis with peak strength would lead to non-conservative results,but that with residual strength tends to be overly conservative.(2) The thickness of the shear zone considering strain-softening behaviour is narrower than that with non-softening analysis.(3) The failure of slope is the process of the initiation,propagation and connection of potential failure surface.The strength parameters are mobilized to a non-uniform degree while progressive failure occurs in the slope.(4) The factor of safety increases with the increase of residual shear strain threshold and elastic modulus.The failure mode of slope changes from shallow slip to deep slip.Poisson’s ratio and dilation angle have little effect on the results.  相似文献   

18.
Pan  Chengcheng  Song  Yang  Jin  Weixian  Qin  Zhenbo  Song  Shizhe  Hu  Wenbin  Xia  Da-Hai 《天津大学学报(英文版)》2020,26(2):135-141
The purpose of this work was to enhance the corrosion resistance of the passive film on 304 stainless steel(SS) by chemical modification in alkaline phosphate–molybdate solutions. The 304 SS was passivated in both phosphate and phosphate–molybdate mixed solutions to investigate the effect of molybdate on its corrosion resistance. The experimental results indicated that the passive film showed better corrosion resistance in Cl--containing solutions after modification in phosphate–molybdate solutions than in phosphate-only solutions. Energy-dispersive spectroscopy analyses revealed that the passive film formed in phosphate–molybdate solutions contained Mo and P after modification, which is the reason for the enhanced corrosion resistance.  相似文献   

19.
李筱叶 《海外英语》2016,(4):136-138
The Call of the Wild is one of the representative works of the American writer Jack London.It was published in 1903.Once appearance,it quickly achieved great success for its beautiful language and multiple levels of the theme.Based on the industrialised and capitalistic society in American history,this novel vividly reproduces the Gold Rush in Klondike.The main plot describes a process of how a domesticated dog degenerated into a wild one and went back to nature.The hero Buck is endowed with human senses and characteristics,for London tried to use animal characters to illustrate moral precepts and exhibit human behaviours.The thesis intends to demonstrate the fascination of this great novel on one hand and on the other hand, to disclose the cruelty of the social reality at that time,in hope of providing a profound comprehension for the readers.  相似文献   

20.
A computational model of water migration flux of fine porous soil in frost heave was investigated in a closed system. The model was established with the heat-mass conservation law and from some previous experimental results. Through defining an auxiliary function an empirical function in the water migration flux, which is difficult to get, was replaced. The data needed are about the water content along the soft colunm after test with enough long time. We adopt the test data of sample soil colunms in [1] to verify the model. The result shows it can reflect the real situation on the whole.  相似文献   

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