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排序方式: 共有1362条查询结果,搜索用时 15 毫秒
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This reported paper presents the design and analysis of wideband nature inspired planar antenna of 46 × 18 × 1.6 mm3 size, designed using FR4 (Flame Retardant) substrate. The antenna patch is delineated from the growth pattern of sneezewort plant with supplementary notion of golden ratio in branching and branch width. The total number of branches in each stage follows the Fibonacci series and the branch width is calculated from the golden ratio concept. Starting from one feed line and two branches, the maximum numbers of branches are increased to 20. There has been significant enhancement in the radiation performance of proposed geometry by increasing the number of branches to 21 and by modifying ground with T‐shaped slot. The antenna covers wide impedance bandwidth of 8.2 to 16.5 GHz by possessing stable radiation characteristics. 相似文献
3.
Some picture fuzzy Bonferroni mean operators with their application to multicriteria decision making
In this paper, we extend the Bonferroni mean (BM) operator with the picture fuzzy numbers (PFNs) to propose novel picture fuzzy aggregation operators and demonstrate their application to multicriteria decision making (MCDM). On the basis of the algebraic operational rules of PFNs and BM, we introduce some aggregation operators: the picture fuzzy Bonferroni mean, the picture fuzzy normalized weighted Bonferroni mean, and the picture fuzzy ordered weighted Bonferroni mean. Then, a new picture fuzzy MCDM method is proposed with the help of the proposed operators. Lastly, a practical application of proposed model is given to verify the developed model and related results of the proposed model is compared with the results of the existing models to indicate its applicability. 相似文献
4.
针对层次分析法(AHP)处理可靠性分配问题时存在的局限性,将直觉梯形模糊数与层次分析法相结合,提出了一种新的数控机床可靠性分配方法。在确定影响机床可靠性分配的重要因素种类及分配原则后,利用层次分析法确定数控机床可靠性分配问题的层次模型和可靠性分配中影响因素的重要性权重。运用直觉梯形模糊数准确表达出模糊信息和专家意见,最终确定子系统在可靠性分配中的分配比例。以一数控机床为例,通过和层次分析法进行对比,证明了该方法的有效性。 相似文献
5.
杨春巍 《土木建筑与环境工程》1991,13(1)
组合数是基础数的概念,被普遍的使用.由组合数构成的行列式具有特色.本文研究了组合数行列式的独特、奇妙的性质,并给出了严密的证明。 相似文献
6.
Xingwei Liu Shengkun Jia Yiqing Luo Xigang Yuan 《American Institute of Chemical Engineers》2022,68(3):e17541
Integer decisions on stage numbers and feed locations, and global optimality are still challenging for rigorous optimization of distillation processes. In the present article, we propose a smooth penalty function method to address both these problems. The proposed method is based on the relaxation of the integer decision problem into continuous nonlinear programming (NLP) problem by adopting the bypass efficiency model developed by Dowling and Biegler. A smooth penalty term (SPT) is proposed and added to the total annual cost (TAC) function to form a new objective function, namely, the smooth penalty function. Using the new objective function, the problem is initially solved with negative weight coefficients for the SPTs regarding each column section to get an optimum near the global optimum of the SPT. Then, starting from this solution, the problem is solved again iteratively by increasing the values of the weight coefficients until all the stage numbers become integers. The performance of the method is validated by an illustrating problem and in three case studies, including a reactive distillation optimization problem. 相似文献
7.
观测矩阵在信号压缩感知中十分重要,直接决定信号的重构质量。为保证信号的重构精度,要求观测矩阵具有很强的随机性,但随机矩阵硬件实现非常困难;确定性观测矩阵易于实现,但其重构精度不足。针对观测矩阵对随机性与确定性的双重要求,提出利用超素数产生超长周期的伪随机序列,解决确定性观测矩阵对随机性的要求;结合托普利兹观测矩阵的确定性结构特征,得到一种改进的托普利兹观测矩阵。实验仿真表明:改进的托普利兹观测矩阵与高斯随机观测矩阵和常用托普利兹观测矩阵相比,其信号重构精度得到了很好的改善,且易于硬件实现。 相似文献
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Rapid Quantification of Live Cell Receptors Using Bioluminescence in a Flow‐Based Microfluidic Device 下载免费PDF全文
Cheong Fook Cheong Hiroaki Hirata Abdur Rub Abdur Rahman Chwee Teck Lim 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(8):943-951
The number of receptors expressed by cells plays an important role in controlling cell signaling events, thus determining its behaviour, state and fate. Current methods of quantifying receptors on cells are either laborious or do not maintain the cells in their native form. Here, a method integrating highly sensitive bioluminescence, high precision microfluidics and small footprint of lensfree optics is developed to quantify cell surface receptors. This method is safe to use, less laborious, and faster than the conventional radiolabelling and near field scanning methods. It is also more sensitive than fluorescence based assays and is ideal for high throughput screening. In quantifying β1 adrenergic receptors expressed on the surface of H9c2 cardiomyocytes, this method yields receptor numbers from 3.12 × 105 to 9.36 × 105 receptors/cell which are comparable with current methods. This can serve as a very good platform for rapid quantification of receptor numbers in ligand/drug binding and receptor characterization studies, which is an important part of pharmaceutical and biological research. 相似文献
10.
Akhil Arora Jianping Li Manali S. Zantye M. M. Faruque Hasan 《American Institute of Chemical Engineers》2020,66(2):e16802
A methodology is proposed to reduce the cost and capital intensity of small-scale chemical processes by creating new opportunities for economies of numbers through standardizing the equipment designs across multiple processes. We depart from asynchronous design of single-processes and adopt a common-functionality based simultaneous design of multiple processes that use similar unit operations. A generalized cost function is used to appropriately balance the trade-offs between economies of scale and economies of numbers. An optimization-based framework for design standardization is developed and illustrated using two case studies. The first involves the simultaneous synthesis of methanol and ammonia processes, and the second addresses the optimal synthesis of multi-column natural gas liquid (NGL) fractionation processes for different natural gas sources. We observe that considerable reduction in capital intensity of small-scale processes is possible through equipment standardization. 相似文献