scholarly journals Improved technique for design of perfect reconstruction FIR QMF banks with lossless polyphase matrices

1989 ◽  
Vol 37 (7) ◽  
pp. 1042-1056 ◽  
Author(s):  
P.P. Vaidyanathan ◽  
T.Q. Nguyen ◽  
Z. Doganata ◽  
T. Saramaki
1970 ◽  
Vol 23 (03) ◽  
pp. 601-620 ◽  
Author(s):  
Th. B Tschopp

SummaryAggregation of cat platelets in the citrated plasma is examined by means of Born’s absorptiometer. A marked tendency of the platelets of this species to spontaneous aggregation necessitated first of all the development of an improved technique of blood collection.A hypothesis according to which 5-HT is released from the platelets, explains the absence of oscillations on the base line of the absorptiometer, the absence of platelet swelling, when ADP is added, and the effect of stirring on the aggregation curves in cat PRP. The average volume of cat platelets amounts to 10.46 μ3 when directly fixed in the blood, when fixed from PRP to 12.17 μ3, when fixed from stirred PRP to 13.51 μ3.In low concentrations (0.3-2 μM) ADP produce reversible aggregation; in narrowly restricted, individually dissimilar mean concentrations irreversible aggregation in two phases and in high concentrations, irreversible aggregation in one phase. Like ADP serotonin produces 2 phase irreversible aggregation in concentrations of 3-10 μM, but unlike ADP, the aggregation velocity decreases again with high 5-HT concentrations (>100 μM). Adrenaline does not produce aggregation and it is likely that adenosine and adenosine monophosphate inhibit the aggregation by serotonin but not by ADP. Species differences in the aggregation of human, rabbit and cat platelets are discussed.


2001 ◽  
Vol 56 (12) ◽  
pp. 8 ◽  
Author(s):  
Oscar G. Ibarra-Manzano ◽  
Yuriy V. Shkvarko ◽  
Rene Jaime-Rivas ◽  
Jose A. Andrade-Lucio ◽  
Gordana Jovanovic-Dolecek

2012 ◽  
Vol 58 (2) ◽  
pp. 177-192 ◽  
Author(s):  
Marek Parfieniuk ◽  
Alexander Petrovsky

Near-Perfect Reconstruction Oversampled Nonuniform Cosine-Modulated Filter Banks Based on Frequency Warping and Subband MergingA novel method for designing near-perfect reconstruction oversampled nonuniform cosine-modulated filter banks is proposed, which combines frequency warping and subband merging, and thus offers more flexibility than known techniques. On the one hand, desirable frequency partitionings can be better approximated. On the other hand, at the price of only a small loss in partitioning accuracy, both warping strength and number of channels before merging can be adjusted so as to minimize the computational complexity of a system. In particular, the coefficient of the function behind warping can be constrained to be a negative integer power of two, so that multiplications related to allpass filtering can be replaced with more efficient binary shifts. The main idea is accompanied by some contributions to the theory of warped filter banks. Namely, group delay equalization is thoroughly investigated, and it is shown how to avoid significant aliasing by channel oversampling. Our research revolves around filter banks for perceptual processing of sound, which are required to approximate the psychoacoustic scales well and need not guarantee perfect reconstruction.


2012 ◽  
Vol 21 (03) ◽  
pp. 176-180 ◽  
Author(s):  
Sameh Aknoukh Labib ◽  
Albert Martin Pendleton
Keyword(s):  

2012 ◽  
Vol 15 (2-3) ◽  
pp. 127-139
Author(s):  
Tung Tran Anh ◽  
Laurent Berquez ◽  
Laurent Boudou ◽  
Juan Martinez-Vega ◽  
Alain Lacarnoy

2021 ◽  
pp. 1-10
Author(s):  
Yu-Heng Xu ◽  
Si-Yi Cheng ◽  
Hu-Biao Zhang

To solve the problem of the missing data of radiator during the aerial war, and to address the problem that traditional algorithms rely on prior knowledge and specialized systems too much, an algorithm for radiator threat evaluation with missing data based on improved Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) has been proposed. The null estimation algorithm based on Induced Ordered Weighted Averaging (IOWA) is adopted to calculate the aggregate value for predicting missing data. The attribute reduction is realized by using the Rough Sets (RS) theory, and the attribute weights are reasonably allocated with the theory of Shapley. Threat degrees can be achieved through quantization and ranking of radiators by constructing a TOPSIS decision space. Experiment results show that this algorithm can solve the incompleteness of radiator threat evaluation, and the ranking result is in line with the actual situation. Moreover, the proposed algorithm is highly automated and does not rely on prior knowledge and expert systems.


2021 ◽  
Author(s):  
Vincenzo Barrile ◽  
Antonino Fotia

AbstractThere are several studies related to the cultural heritage digitization through HBIM (Heritage Building Information Modelling) techniques. Today, BIM (Building Information Modelling) software cannot represent old buildings with complex prominent and particularly detailed architecture perfectly, and multiple software are combined to obtain the buildings’ representation. In this paper, in order to find an alternative way of replicating the complex details present in antique buildings, a new methodology is presented. The methodology is based on a process of direct insertion of various 3D model parts (.obj), into a BIM environment. These 3D model elements, coming from the points cloud segmentation (from UAV and Laser Scanner), are transformed in intelligent objects and interconnected to form the smart model. The methodology allows to represent detail of the objects that make up an element of cultural heritage, although not standardizable in shape. Although this methodology allows to ensure a perfect reconstruction and digital preservation and to represent the different “defects” that represent and make unique a particular object of cultural heritage, it is not however fast compared with the traditional phases of point cloud tracing and more software are necessary for data processing. The proposed methodology was tested on two specific structures’ reconstruction in Reggio Calabria (South Italy): the Sant’Antonio Abate church and the Vitrioli’s portal.


Ion cyclotron resonance (i. c. r.) is a technique for the study of ion-molecule reactions in the collisional range from thermal to several electron volts. The study of these reactions at low energy has been given impetus by the discovery of their importance in the ionosphere and in interstellar space. This communication identifies some possible weaknesses inherent in current i. c. r. work and suggests an improved technique with which it is possible to determine absolute rate constants more reliably. As an illustration of the technique a measurement of the rate constant for the reaction CH 4 + + CH 4 → k CH 5 + + CH 3 is presented. This value is k = 1.21 ± 0.09 × 10 -15 m 3 s -1 . A new i. c. r. cell design is discussed with which it is hoped to provide further improvement in reliability by the production of a homogeneous radiofrequency field within a true quadrupole trap.


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