Set-Membership Proportionate Affine Projection Algorithms

Proportionate adaptive filters can improve the convergence speed for the identification of sparse systems as compared to their conventional counterparts. In this paper, the idea of proportionate adaptation is combined with the framework of set-membership filtering (SMF) in an attempt to derive novel computationally efficient algorithms. The resulting algorithms attain an attractive faster converge for both situations of sparse and dispersive channels while decreasing the average computational complexity due to the data discerning feature of the SMF approach. In addition, we propose a rule that allows us to automatically adjust the number of past data pairs employed in the update. This leads to a set-membership proportionate affine projection algorithm (SM-PAPA) having a variable data-reuse factor allowing a significant reduction in the overall complexity when compared with a fixed data-reuse factor. Reduced-complexity implementations of the proposed algorithms are also considered that reduce the dimensions of the matrix inversions involved in the update. Simulations show good results in terms of reduced number of updates, speed of convergence, and final mean-squared error

Modeling of Electric Disturbance Signals Using Damped Sinusoids via Atomic Decompositions and Its Applications

<p/> <p>The number of waveforms monitored in power systems is increasing rapidly. This creates a demand for computational tools that aid in the analysis of the phenomena and also that allow efficient transmission and storage of the information acquired. In this context, signal processing techniques play a fundamental role. This work is a tutorial reviewing the principles and applications of atomic signal modeling of electric disturbance signals. The disturbance signal is modeled using a linear combination of damped sinusoidal components which are closely related to the phenomena typically observed in power systems. The signal model obtained is then employed for disturbance signal denoising, filtering of "DC components," and compression.</p

Seedling formation and field production of beetroot and lettuce in Aquidauana, Mato Grosso do Sul, Brazil Formação de mudas e produção a campo de beterraba e alface em Aquidauana-MS

In horticulture, the proper use of containers and substrates for the production of seedlings are important factors that affect crop productivity in the field. This study aimed to evaluate the effect of different containers and substrates in the production of lettuce (Lactuca sativa, cv Veneranda) and beetroot (Beta vulgaris, cv Top Tall Early Wonder) seedlings in nursery with monofilament screen, 50% of shading, and the productivity of these species when transplanted to field plots. In protected cultivation, a completely randomized experimental design, in a 3 x 3 factorial scheme (three polystyrene trays, R1= 72, R2= 128 and R3= 200 cells and three substrates, S1= 93% of soil + 7% of organic compost, S2= 86% of soil + 14% of organic compost and S3= 79% of soil + 21% of organic compost) was used, with 15 replications, where one plantlet was a replication. In the field, the nine treatments were evaluated in a completely randomized experimental design. The 72 cells tray with 7% commercial organic compost substrate promoted the best beetroot and lettuce seedlings. In the field, the plants from the 72 cell tray produced greater plants, independent of substrates type.<br>Na olericultura o uso adequado de recipientes e substratos para a produção de mudas são fatores importantes e que afetam a produtividade das culturas a campo. No presente trabalho objetivou-se avaliar, em viveiro de tela de monofilamento com 50% de sombreamento, o efeito de diferentes recipientes e substratos na produção de mudas de alface (Lactuca sativa, cv Veneranda) e beterraba (Beta vulgaris, cv Top Tall Early Wonder), bem como a produtividade dessas espécies quando transplantadas em canteiros a campo. No ambiente protegido utilizou-se o delineamento experimental inteiramente casualizado, em esquema fatorial 3 x 3, sendo os fatores 3 recipientes (R1= 72, R2= 128 e R3= 200 células de poliestireno) e 3 substratos (S1= 93% de solo + 7% de composto orgânico, S2= 86% de solo + 14% de composto orgânico e S3= 79% de solo + 21% de composto orgânico), totalizando nove tratamentos com quinze repetições, onde a plântula constituiu a repetição. A campo os nove tratamentos foram dispostos nos canteiros sob delineamento inteiramente casualizado. A bandeja de 72 células em conjunto com o substrato contendo 7% de composto orgânico propiciaram as melhores mudas de beterraba e alface. No campo as plantas provenientes dessa bandeja apresentaram os melhores resultados, independente do tipo de substrato