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1.
This paper presents an online feature selection algorithm using genetic programming (GP). The proposed GP methodology simultaneously selects a good subset of features and constructs a classifier using the selected features. For a c-class problem, it provides a classifier having c trees. In this context, we introduce two new crossover operations to suit the feature selection process. As a byproduct, our algorithm produces a feature ranking scheme. We tested our method on several data sets having dimensions varying from 4 to 7129. We compared the performance of our method with results available in the literature and found that the proposed method produces consistently good results. To demonstrate the robustness of the scheme, we studied its effectiveness on data sets with known (synthetically added) redundant/bad features.  相似文献   
2.
In a given size of symmetric involute gear designed through conventional approach, as the load carrying capacity is restricted at the higher pressure angle due to tipping formation, the use of the asymmetric toothed gear to improve the fillet capacity in bending is examined in this study. Non-standard asymmetric rack cutters with required pressure angles and module are developed to generate the required pinion and gear of a drive with asymmetric involute surfaces and trochoidal fillet profiles. The respective profiles thus generated are optimized for balanced fillet stresses that are equal and possibly the lowest also. For this study of optimization, several non-standard asymmetric rack cutters are designed to accommodate different combinations in the values of pressure angle, top land thickness ratio, profile shift, speed ratio and the asymmetric factors. However for any drive with a given center distance and a speed ratio, only two non-standard asymmetric rack cutters, one for the pinion and other for the gear are used to generate a required numbers of pinion and gear with different cutter shift values for the purpose of optimization. The influence of these parameters on the maximum fillet stress has been analyzed to suggest the optimum values of these parameters that improve the fillet capacity in bending. The optimization of the asymmetric spur gear drive is carried out using an iterative procedure on the calculated maximum fillet stresses through FEM for different rack cutter shifts and finally the optimum values of rack cutter shifts are suggested for the given center distance and the speed ratio of an asymmetric gear drive. Comparisons have also been made successfully with the results of the AGMA and the ISO codes for symmetric gears to justify the results of the finite element method pertaining to this study.  相似文献   
3.
Personal experience on the use of 111In-DTPA-octreotide scintigraphy (Octreoscan) in the staging of neuroendocrine and non-neuroendocrine tumors of the lung is reported. From July 1995 to May 1996 26 scintigraphic studies were performed in patients affected by lung cancer at the Department of Thoracic Surgery and at the Service of Nuclear Medicine of the University of Turin. The scintigraphy allowed to detect the lesion in all the neuroendocrine tumors and in 63.2% of the non neuroendocrine ones. Their preliminary results are discussed and stress is laid on the importance of this scintigraphic procedure in the staging and the follow-up of neoplastic patients.  相似文献   
4.
Vector-controlled induction motor drives are quite popular in the industry in applications that demand high dynamic performance. This paper describes the implementation of a complete industrial vector-controlled drive for a 30 kW induction motor. The control algorithms for the drive are implemented using a TMS320F28335 Digital Signal Controller (DSC). Various monitoring and protection functions for the drive are implemented using a Cyclone IV FPGA that communicates with the DSC, and acts as the master controller for the drive. The FPGA also communicates with a Human–Machine Interface to provide a simple graphical control interface to the operator.  相似文献   
5.
In a field study, the influence of organic mulches viz. paddy straw and citronella (Cymbopogon winterianus Jowitt) distillation waste on herb and essential oil yield and fertilizer N use efficiency in Japanese mint (Mentha arvensis L.) were examined for two years. Herb yield (dry weight) increased by 17 and 31% with paddy straw and citronella distillation waste, respectively over the use of no mulch. Essential oil yield also significantly increased due to mulching. A significant response to N was observed with 200 kg N ha–1 in unmulched plots as against 150 kg N ha–1 in mulched plots. Mulched soils have been observed to contain 2 to 4% higher moisture as compared to unmulched soils. Nitrogen uptake by plants increased by 18 and 25% over no mulch with using paddy straw and citronella distillation waste, respectively.  相似文献   
6.
Strong near‐surface electromagnetic field formed by collective oscillation of electrons on Cu nanostructure a shows a strong dependence on geometry, offering a promising approach to boost the light absorption of ZnO photoactive layers with enhanced plasmon scattering. Here, a facile way to fabricate UV photodetectors with tunable configuration of the self‐assembled Cu nanostructures on ZnO thin films is reported. The incident lights are effectively confined in ZnO photoactive layers with the existence of the uplayer Cu nanostructures, and the interdiffusion of Cu atoms during fabrication of the Cu nanostructures can improve the carrier transfer in ZnO thin films. The optical properties of the hybrid architectures are successfully tailored over a control of the geometric evolution of the Cu nanostructures, resulting in significantly enhanced photocurrent and responsivity of 2.26 mA and 234 A W?1 under a UV light illumination of 0.62 mW cm?2 at 10 V, respectively. The photodetectors also exhibit excellent reproducibility, stability, and UV–visible rejection ratio (R370 nm/R500 nm) of ≈370, offering an approach of high‐performance UV photodetectors for practical applications.  相似文献   
7.
The spectral analysis of the signals generated by a physical system is a powerful way to analyse that system's behaviour. In the past the inability to achieve realtime analysis of signals and the high cost of spectrum analysers limited the use of this method of study in the area of physical system control. Today the availability of cheap and powerful devices — digital signal processors, overcomes the earlier problems. The paper presents a system for realtime spectral analysis based on a TMS32010 DSP chip. This system consists of two main components: a DSP board where data are processed, and a PC which acts as a terminal for the operator, as a display for the analysis results and as a temporary database. The system's hardware and software architectures and an application in seismic signal monitoring are described.  相似文献   
8.
9.
Since the last decade, electrospinning is garnering more attention in the scientific research community, industries, applications like sensing (glucose, H2O2, dopamine, ascorbic acid, uric acid, neurotransmitter, etc.), biomedical applications (wound dressing, wound healing, skin, nerve, bone tissue engineering, and drug delivery systems), water treatment, energy harvesting, and storage applications. This review paper provides a brief overview of the electrospinning method, history of the electrospinning, factors affecting the electrospun nanofibers, and their morphology with different materials and composites (metals, metal oxides, 2D material, polymers and copolymers, carbon-based materials, etc.) used in the electrospinning technique with optical spinning parameters. Moreover, this paper deliberates the application of electrospun nanofibers and fibrous mats for sensing (electrochemical, optical, fluorescence, colorimetric, mechanical, photoelectric, mass sensitive change, resistive, ultrasensitive, etc.) in most illustrative representations. In the end, the challenges, opportunities of the electrospun nanofibers, and new direction for future progress are also discussed.  相似文献   
10.
Journal of Materials Science: Materials in Electronics - In this work, we report the enhanced photocatalytic behaviour of copper tin hydroxide (CuSn(OH)6)-based catalyst materials for the...  相似文献   
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