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排序方式: 共有6436条查询结果,搜索用时 15 毫秒
31.
Quansheng ChenAuthor Vitae Jiewen ZhaoAuthor VitaeZhe ChenAuthor Vitae Hao LinAuthor VitaeDe-An ZhaoAuthor Vitae 《Sensors and actuators. B, Chemical》2011,159(1):294-300
Electronic nose (E-nose) technique was attempted to discriminate green tea quality instead of human panel test in this work. Four grades of green tea, which were classified by the human panel test, were attempted in the experiment. First, the E-nose system with eight metal oxide semiconductors gas sensors array was developed for data acquisition; then, the characteristic variables were extracted from the responses of the sensors; next, the principal components (PCs), as the input of the discrimination model, were extracted by principal component analysis (PCA); finally, three different linear or nonlinear classification tools, which were K-nearest neighbors (KNN), artificial neural network (ANN) and support vector machine (SVM), were compared in developing the discrimination model. The number of PCs and other model parameters were optimized by cross-validation. Experimental results showed that the performance of SVM model was superior to other models. The optimum SVM model was achieved when 4 PCs were included. The back discrimination rate was equal to 100% in the training set, and predictive discrimination rate was equal to 95% in the prediction set, respectively. The overall results demonstrated that E-nose technique with SVM classification tool could be successfully used in discrimination of green tea's quality, and SVM algorithm shows its superiority in solution to classification of green tea's quality using E-nose data. 相似文献
32.
In the forming process of picture tube panel, the accumulated residual stresses cause the formed part to shrink, and the thermal
and mechanical loads cause the mold blocks to deform. These two factors result in large deviations on the dimensions of the
formed panel, which are both modeled and simulated in this paper. For residual stresses analysis, a thermo-rheologically simple
viscoelastic material model is introduced to consider the stresses relaxation effect and to describe the mechanical behavior
according to the temperature change. The shrinkage of formed parts induced by the residual stresses is calculated based on
the theory of shells, represented as an assembly of flat elements formed by combining the constant strain and the discrete
Kirchhoff triangular elements. A thermoelastic model is presented to predict the deformation of the mold blocks during pressing,
which is based on the steady mold temperature field and thermoelastic boundary element method. The integrated simulation results
suggest the amounts that the mold cavity should be machined by, and have been verified by comparing the dimensional precision
of the panels produced by the mold considering a uniform part shrinkage and mold expansion or the mold considering the predicted
ununiform part shrinkage and mold deformation. 相似文献
33.
对于面板数据, 首先给出面板数据的空间投射方法, 将面板数据投射为空间的向量序列. 然后, 基于空间向量的夹角和距离分别构建相似性和接近性关联度模型. 具体方法为: 利用向量夹角构建面板数据的相似性关联度模型; 同时, 基于向量差的模构建面板数据的接近性关联度模型. 分别讨论两种关联度模型的规范性和对称性等性质. 最后, 通过实例验证了相似性和接近性关联度模型的合理性. 分析结果表明, 所提出的关联度模型能较好地反映面板数据的相似性和接近性的关联程度.
相似文献34.
A robust projector–camera interactive display system based on finger touch control by fusing finger and its shadow 下载免费PDF全文
A robust projector–camera interactive display system consisting of one camera and one projector is proposed, which enables users to interact with computer by touching on arbitrary surfaces with bare hand. The system utilizes the camera to recover 3D information of fingertip for touch detection. Firstly, predicted image generated from geometric and photometric calibration matrix is used to segment hand and its shadow. Secondly, fusion degree of the hand and its shadow is detected using linear‐scanning method. Finally, a square tracking mask is used to determine the touch action on the projection surface. Experimental results show that the proposed system is robust to different lighting conditions. The touch detection accuracy is 93.0% and the average processing time of each frame is 36 ms. 相似文献
35.
Kwang Hee Ko Taezoon Park Kyong-Hwan Kim Yonghwan Kim Dong Ho Yoon 《Computer aided design》2011,(8):848-862
In this paper, a panel generation system for analyzing seakeeping performance of a ship is developed. Given a set of offset data representing the ship hull, the system first creates a surface model of the ship. From the surface model, the wetted part of the ship is obtained by computing the intersection between the water surface and the hull, which is then processed to generate quadrilateral panels for the hull and the water surface. The system is designed to handle various kinds of ships such as ships with a mono-skeg, a twin-skeg and/or a bulbous bow in either an automatic or an interactive manner. Moreover, it can generate input panels for three different seakeeping analysis methods. Examples are provided to demonstrate the capabilities of the system. 相似文献
36.
Matthew Bone 《Journal of the Society for Information Display》2001,9(3):227-232
Abstract— Optical designs for three‐panel LCoS projection systems are reviewed. The impact of polarization aberrations in prism‐based systems is discussed and a simple model to analyze the sensitivity of contrast to thermal gradients in prisms is presented. To eliminate stress birefringence in LCoS projection systems, we have developed a projection optical system that does not require the use of polarizing prisms. An improved off‐axis design has been designed that simplifies manufacture and reduces cost. The performance of systems based on this architecture will be discussed. 相似文献
37.
The current status of colloidal tube
production in China and the technique process of the tube prod uction are described in
brief. The funct ions and the implementation of the control system, the mathematical
model of the PID operation and the block diagram of program are introduced in detail. 相似文献
38.
基于组件的虚拟仪器控制面板的设计与实现 总被引:3,自引:0,他引:3
介绍了组件技术及虚拟仪器软件系统,讨论了虚拟仪器控制面板的一般要求,并结合实例分析了虚拟仪器控制的组件化设计及实现的方法。 相似文献
39.
介绍了控制面板组件的工作原理,给出了用Visual C++开发 控制面板组件的方法,实现自己正确操作系统控制面板之目的,且给出了应用实例。 相似文献
40.
Abstract— Bit‐partitioned and conventional shifts, as well as type transformations of multimedia data, are frequently used for display image‐processing systems. A data manipulation unit with fault‐recovery capability based on redundancies is proposed for system‐on‐panel with low processing technology yield. Utilizing data manipulations that are similar to normal shift operation, a proposed data‐manipulation unit is designed with a few additional paths added to the existing barrel shifter. The design methodologies are verified with FPGA and the performance is evaluated in terms of the advantages. 相似文献