scholarly journals AUTOREGRESSIVE ANALYSIS OF VARIANCE FOR EXPERIMENTS WITH SPATIAL DEPENDENCE BETWEEN PLOTS: A SIMULATION STUDY

2019 ◽  
Vol 37 (2) ◽  
pp. 244 ◽  
Author(s):  
Diogo Francisco ROSSONI ◽  
Renato Ribeiro de LIMA

The analysis of variance remains one of the most appreciated techniques of field experiment, even despite almost a hundred years of its first proposal. However, in many cases, its application can be several impaired due the fact of lack – or even forgotten - of assumptions. In several experiments, the researchers make use of blocks to control the local heterogeneity, nevertheless, in some cases, only this it cannot be enough, especially in experiments where the data have some kind of spatial dependence. Therefore, to increase the accuracy of comparisons between treatments, an alternative is to consider the study of the spatial dependence of the variables in the analysis. With the knowledge of the relative positions of the plots (referenced data), the spatial variability can be used as a positive factor, collaborating with the experimental results. To develop this study we used data generated by simulation. The data was generated according a Randomized Complete Block Design (RCBD), with eighteen and five treatments per block; and several scenarios of spatial dependence in the error. We compared the non-spatial analysis (which considers the errors independent) with spatial analysis (analysis of variance considering the autoregressive model - ANOVA-AR). The use of spatial statistical tools in the analysis of data increased the precision of the analysis, through the reduction of the Mean Squared Error. We also noticed a reduction of Mean Squared Block and Mean Squared Treatment. The greater reduction was notice in ANOVA-AR3 for great part of the simulated scenarios, mainly in those with strong spatial dependence. The experiments with a small number of treatments per block did not present a reduction of Mean Squared Error, however, the reduction of Mean Squared Block and Mean Squared Treatment, ally to the fact that data are spatial dependent justify the use of ANOVA-AR.

2011 ◽  
Vol 60 (2) ◽  
pp. 248-255 ◽  
Author(s):  
Sangmun Shin ◽  
Funda Samanlioglu ◽  
Byung Rae Cho ◽  
Margaret M. Wiecek

2018 ◽  
Vol 10 (12) ◽  
pp. 4863 ◽  
Author(s):  
Chao Huang ◽  
Longpeng Cao ◽  
Nanxin Peng ◽  
Sijia Li ◽  
Jing Zhang ◽  
...  

Photovoltaic (PV) modules convert renewable and sustainable solar energy into electricity. However, the uncertainty of PV power production brings challenges for the grid operation. To facilitate the management and scheduling of PV power plants, forecasting is an essential technique. In this paper, a robust multilayer perception (MLP) neural network was developed for day-ahead forecasting of hourly PV power. A generic MLP is usually trained by minimizing the mean squared loss. The mean squared error is sensitive to a few particularly large errors that can lead to a poor estimator. To tackle the problem, the pseudo-Huber loss function, which combines the best properties of squared loss and absolute loss, was adopted in this paper. The effectiveness and efficiency of the proposed method was verified by benchmarking against a generic MLP network with real PV data. Numerical experiments illustrated that the proposed method performed better than the generic MLP network in terms of root mean squared error (RMSE) and mean absolute error (MAE).


2016 ◽  
Vol 5 (1) ◽  
pp. 39 ◽  
Author(s):  
Abbas Najim Salman ◽  
Maymona Ameen

<p>This paper is concerned with minimax shrinkage estimator using double stage shrinkage technique for lowering the mean squared error, intended for estimate the shape parameter (a) of Generalized Rayleigh distribution in a region (R) around available prior knowledge (a<sub>0</sub>) about the actual value (a) as initial estimate in case when the scale parameter (l) is known .</p><p>In situation where the experimentations are time consuming or very costly, a double stage procedure can be used to reduce the expected sample size needed to obtain the estimator.</p><p>The proposed estimator is shown to have smaller mean squared error for certain choice of the shrinkage weight factor y(<strong>×</strong>) and suitable region R.</p><p>Expressions for Bias, Mean squared error (MSE), Expected sample size [E (n/a, R)], Expected sample size proportion [E(n/a,R)/n], probability for avoiding the second sample and percentage of overall sample saved  for the proposed estimator are derived.</p><p>Numerical results and conclusions for the expressions mentioned above were displayed when the consider estimator are testimator of level of significanceD.</p><p>Comparisons with the minimax estimator and with the most recent studies were made to shown the effectiveness of the proposed estimator.</p>


CERNE ◽  
2015 ◽  
Vol 21 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Manoel Cléber de Sampaio Alves ◽  
Luiz Fernando Frezzatti Santiago ◽  
Marcos Tadeu Tiburcio Gonçalves ◽  
Ivaldo De Domênico Valarelli ◽  
Francisco Mateus Faria de Almeida Varasquim

The present paper aims to evaluate the influence of the factors (belt speed, pressure and grit size) on the output parameters (temperature and surface roughness) for Pinus elliottii wood sanding, processed parallel to the fibers. Three levels of belt speed, three levels of pressure and four levels of grit size were employed, with six replicates for each process, totaling 216 observations. The experiment conducted under a randomized complete block design (RCBD). The results were analyzed employing the analysis of variance (ANOVA) with 5% of significance level. Only grit sizes were significant to different temperature levels. The same outcome was observed for roughness, where only grits sizes were significant. No interaction between the pressure and belt speed factors were observed for all the results analyzed.


2020 ◽  
Vol 2020 ◽  
pp. 1-22
Author(s):  
Byung-Kwon Son ◽  
Do-Jin An ◽  
Joon-Ho Lee

In this paper, a passive localization of the emitter using noisy angle-of-arrival (AOA) measurements, called Brown DWLS (Distance Weighted Least Squares) algorithm, is considered. The accuracy of AOA-based localization is quantified by the mean-squared error. Various estimates of the AOA-localization algorithm have been derived (Doğançay and Hmam, 2008). Explicit expression of the location estimate of the previous study is used to get an analytic expression of the mean-squared error (MSE) of one of the various estimates. To validate the derived expression, we compare the MSE from the Monte Carlo simulation with the analytically derived MSE.


2013 ◽  
Vol 5 (2) ◽  
pp. 232-237
Author(s):  
Sali ALIU ◽  
Imer RUSINOVCI ◽  
Shukri FETAHU ◽  
Kemajl BISILIMI

Twelve local maize populations were evaluated at the experimental farm, University of Prishtina, Kosovo. The study was conducted to assess the magnitude of genetic variation in local maize populations for different morphological-physiological and chemical composition under field and laboratory conditions. Randomized complete block design (RCBD) with three replications was used for laying out the experiment. The results showed that there were significant differences for most morphological and physiological traits under study. The mean grain yield of all populations was 102.96 g plant-1. The protein and oil contents ranged between 11.53 to 9.43% and 4.23 to 4.87% respectively. The cellulose content varied from 6.03 to 6.37%. There were also big differences regarding phenotypic correlations. The present study revealed considerable amount of diversity among the local maize populations which could be manipulated for further improvement in maize breeding.


Author(s):  
Yohanna J, A. ◽  
Muhammad A, M.

Field experiment was carried out during 2010 rainy season to find the effect of seeding rate on the growth and yield of okra (Abelmuschus esculentus) in Zuru Northern Guinea Savannah. Zuru is located in Zuru Local government area of Kebbi State (Latitude 11o 251 to 11o 551 North and Longitude 4o 51 to 5o 251 East of the equator). The experiment consisted of three treatments that is planting okra at one plant per stand (S1), two plants per stand (S2) and three plants per stand (S3). The experiment was laid out in randomized complete block design (RCBD) and the treatments replicated three time. The result of the experiment has shown that plant height and number of leaves/plant at 3, 6 and 9 weeks after planting (    WAP) were significantly influenced by seeding rate (P<0.05). At 3, 6 and 9 WAP tallest plants were obtained from okra plants planted at three plants/stand (27.83, 54.0 and 77.0cm) respectively followed by okra planted at two plant/stand (24.77, 50.67 and 74.33 leave/plant respectively ). However, more number of leaves/plant were obtained from okra plant at one plant/stand (9.67, 24.67 and 48.0 leaves/plant respectively) followed by okra planted at two plants/stand (8.33, 18.33 and 36.33 leaves/plant respectively). Seeding rate had significant influence on time of 50 percent flowering with one plant/stand first attaining 50 percent flowering stage just within 36.33 days followed by okra planted at two plants/stand (38 days). The mean fresh fruit yield of okra was also significantly influenced by seeding rate with the highest yield of fresh fruits obtained from three plants/stand (83.34/ha) followed by okra planted at two plants/stand (55.56/ha). However, the result of the findings recommends that, okra should be planted at two plants/stand for medium sized and marketable okra fresh fruits since at three plants/stand leads to the production of undersized fresh fruits which do not often attract customers. At one plant/stand, there seemed to be early fruiting and bigger sized fresh fruits but low total yield due to underutilization of land resource/space. Planting at one plant/stand should therefore be avoided


Author(s):  
Kareen Lynn E. Negado

This study evaluates the growth performance of lettuce (Lactuca sativa L.) utilizing various fermented products as organic fertilizers. Growth performance is determined through the plant’s weight and leaves and significant differences in growth among various treatments: (a) fish trash, (b) scrap seaweeds, (c) kangkong, and control groups urea (positive) and water (negative) was also determined. Kangkong leaves are fermented for 10 days, fish trash for 14 days and 1 month for seaweeds. Lettuce seeds are sown before transplanting (15 days after germination) into pots and placed in raised beds. Randomized complete block design is utilized in the experiment. Growth performance is measured through the number of leaves 10, 20, and 30 days after transplant and mass of plant upon harvest. After 30 days, the lettuce was harvested. Based on the findings, the soil and fermented products are acidic and the needed organic matter for optimum growth of lettuce are not sufficient as well as some nutrients of the fermented products. Among the organic fertilizers, kangkong at 30 ml performs best in terms of the growth performance of lettuce. Urea performs best in terms of the mass upon harvest. Significant differences exist in the mean number of leaves of lettuce treated with various amounts of organic fertilizers with the plants that receive urea. Lettuce produce more number of leaves and with the highest mass upon harvest when treated with urea compared with organic fertilizers applied after 30 days from transplant. Keywords: fermented kangkong; fish trash; growth performance; lettuce; scrap seaweeds


2019 ◽  
Vol 9 (2) ◽  
pp. 66-71
Author(s):  
Arfan ◽  
Ratnawati ◽  
Hasmari Noer ◽  
Lisa Indriani ◽  
Asli ◽  
...  

The purposes of this research the examine the effectiveness various concentrations neem leaf ekstract on the intensity of attack Liriomyza spp on shallot Lembah Palu variety . Field research was carried out in Guntarano Village, Tanantovea Subdistrict, Donggala Regency, Central Sulawesi.  This research conducted from February to April 2016 .The experiment was done using Randomized Complete Block  Design with three replications, consists of six  treatments, i.e. P0 : control (without aplication neem leaf ekstract); P1: neem leaf ekstract 10 gr /litre;  P2 : neem leaf ekstract 20 gr / litre; P3 : neem leaf ekstract 30 gr / litre; P4 : neem leaf ekstract 40 gr / litre; P5 : neem leaf ekstract 50 gr / litre. To find out the effect of threatment, the analysis of variance, and the real influence is continued with the standard  ά = 0.05 BNT test.  The results showed that use of seed and leaf extracts of neem plant can control Liriomyza spp attack, only 3,04 percent of attack rate and shallot Lembah Palu variety productivity is 3,02/area.


Sign in / Sign up

Export Citation Format

Share Document