A Novel Approach to Design Low-Cost Two-Stage Frequency-Response Masking Filters

2015 ◽  
Vol 62 (10) ◽  
pp. 982-986 ◽  
Author(s):  
Ying Wei ◽  
Shaoguang Huang ◽  
Xiaojie Ma
2003 ◽  
Vol 12 (05) ◽  
pp. 631-642 ◽  
Author(s):  
SERGIO L. NETTO ◽  
LUIZ C. R. de BARCELLOS ◽  
PAULO S. R. DINIZ

A new cosine-modulated filter bank (CMFB) structure is proposed based on the frequency-response masking (FRM) approach using masking filter decomposition. The resulting structure, the so-called FRM2-CMFB, presents reasonable computational complexity (number of arithmetic operations per output sample) and allows one to design filter banks with extremely large number of bands. The examples include the use of M=1024 bands, where the standard minimax method cannot be employed. These examples indicate that the reduction in computational complexity can be as high as 60% of the original FRM-CMFB structure, which does not use masking filter decomposition.


2018 ◽  
pp. 53-57 ◽  
Author(s):  
G. G. Savenkov ◽  
V. P. Razinkin ◽  
A. D. Mekhtiev

Applications of modern terminal loads and its relevant disadvantages are described in this paper. The decomposing method of wideband microwave high power microstrip loads design is proposed in this paper with purpose of matching quality improving. Multiple extension of multistage load bandwidth is provided by using of external matching circuit and internal matching inductive elements. The maximum reachable bandwidth of multistage load is estimated and optimal values of mathing circuit elements are founded on basis of equivalent lumped scheme. The topology of microstrip two-stage high power microwave load is developed and its frequency response, calculated via numeric electrodynamic modelling method is outlined in the paper. Modelling results show good matching quality of considered load at the frequency band below 3,5 GHz.


Author(s):  
Paloma Hohmann Poier ◽  
Francisco Godke ◽  
José Aguiomar Foggiatto ◽  
Leandra Ulbricht

Abstract OBJECTIVE Develop and evaluate a low-cost walker with trunk support for senior citizens. METHOD Two-stage descriptive study: development of a walker with trunk support and evaluation with fourth age senior citizens. RESULTS Twenty-three fourth age senior citizens were selected. The evaluated criteria were the immediate influence of the walker on the static stabilometry with baropodometer and the evaluation of gait with accelerometers monitoring time and amplitude of the hip movement. There was a significant decrease in the body oscillation of senior citizens with the use of the developed walker, and there were changes in the joint amplitudes of the hip, but they were not significant. CONCLUSION Using low-cost materials, it was possible to develop and equipment that met resistance and effectiveness requirements. The walker interfered in the balance of the senior citizens, reducing significantly the static body oscillation.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Hsi-Chien Liu ◽  
Gou-Jen Wang

The object of this paper is to develop a high antireflection silicon solar cell. A novel two-stage metal-assisted etching (MAE) method is proposed for the fabrication of an antireflective layer of a micronanohybrid structure array. The processing time for the etching on an N-type high-resistance (NH) silicon wafer can be controlled to around 5 min. The resulting micronanohybrid structure array can achieve an average reflectivity of 1.21% for a light spectrum of 200–1000 nm. A P-N junction on the fabricated micronanohybrid structure array is formed using a low-cost liquid diffusion source. A high antireflection silicon solar cell with an average efficiency of 13.1% can be achieved. Compared with a conventional pyramid structure solar cell, the shorted circuit current of the proposed solar cell is increased by 73%. The major advantage of the two-stage MAE process is that a high antireflective silicon substrate can be fabricated cost-effectively in a relatively short time. The proposed method is feasible for the mass production of low-cost solar cells.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
João Gama Monteiro ◽  
Jesús L. Jiménez ◽  
Francesca Gizzi ◽  
Petr Přikryl ◽  
Jonathan S. Lefcheck ◽  
...  

AbstractUnderstanding the complex factors and mechanisms driving the functioning of coastal ecosystems is vital towards assessing how organisms, ecosystems, and ultimately human populations will cope with the ecological consequences of natural and anthropogenic impacts. Towards this goal, coastal monitoring programs and studies must deliver information on a range of variables and factors, from taxonomic/functional diversity and spatial distribution of habitats, to anthropogenic stress indicators such as land use, fisheries use, and pollution. Effective monitoring programs must therefore integrate observations from different sources and spatial scales to provide a comprehensive view to managers. Here we explore integrating aerial surveys from a low-cost Remotely Piloted Aircraft System (RPAS) with concurrent underwater surveys to deliver a novel approach to coastal monitoring. We: (i) map depth and substrate of shallow rocky habitats, and; (ii) classify the major biotopes associated with these environmental axes; and (iii) combine data from i and ii to assess the likely distribution of common sessile organismal assemblages over the survey area. Finally, we propose a general workflow that can be adapted to different needs and aerial platforms, which can be used as blueprints for further integration of remote-sensing with in situ surveys to produce spatially-explicit biotope maps.


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