Relative efficiency of replicated and non-replicated statistical designs in quantifying the variations in maize grain yield

Received: June 9th, 2021 ; Accepted: July 11th, 2021 ; Published: August 2nd, 2021 ; Correspondence: [email protected] field experiment was conducted at the Agricultural Research Station, Faculty of Agriculture, Alexandria University, Egypt, during the two successive summer seasons of 2018 and 2019. The main aim was to evaluate the relative efficiency of two groups of experimental designs in quantifying the variations in maize grain yield as influenced by sowing date (SD), plant density (PD) and phosphorous (P) fertilization, and their interactions. The single hybrid Giza 168 maize (Zea mays, L.) cultivar was used during both seasons. The experimental designs under evaluation included replicated (RCBD, SPD, SSPD and 3-DLD), in three replications, and nonreplicated (one-rep without and with center points, RCCD and PRCCD) designs. The 3-DLD design was more efficient, within the replicated group, than the RCBD (reference design) with relative efficiency of 3.68. The SPD and SSPD had higher relative efficiencies at the sub-plot and sub sub-plot levels compared to RCBD. Within the non-replicated designs, the one-rep with center points, RCCD and PRCCD were more efficient than one-rep without center points (reference design) in discriminating the more important factors affecting grain yield in maize cultivar Giza 168

Dynamic graphics for experimental design

When designing an experiment, it is often assumed that the response to be measured can be modelled as a linear function of a vector of parameters plus an error term, y = X[beta] + [epsilon]. Using this model several properties of the design can be defined in terms of the matrix X[superscript]\u27 X, including A-, D-, E- and G-optimality. In this dissertation we review some common design properties and develop new graphical methods for displaying them using dynamic graphics techniques, including interactive updating, linking, animation and rotation. The effects of perturbations to the design on these properties are also displayed, and a new graphical search technique for improving designs is introduced. Our results indicate that these graphs can help to verify the stability of standard experimental designs, highlight weaknesses present in non-standard designs, and suggest possible remedies;In addition, an adaptation of Cook\u27s method for assessing local influence is developed to examine the effects of local perturbations to the model and to the design on selected design properties. Perturbations are made to case weights, design variables, and added variables not included in the assumed model. The design properties examined are D-optimality and the mean squared error of estimating the response at selected points in the design region. Graphical displays are used to interpret the results

NASA SBIR abstracts of 1990 phase 1 projects

The research objectives of the 280 projects placed under contract in the National Aeronautics and Space Administration (NASA) 1990 Small Business Innovation Research (SBIR) Phase 1 program are described. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses in response to NASA's 1990 SBIR Phase 1 Program Solicitation. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 280, in order of its appearance in the body of the report. The document also includes Appendixes to provide additional information about the SBIR program and permit cross-reference in the 1990 Phase 1 projects by company name, location by state, principal investigator, NASA field center responsible for management of each project, and NASA contract number

Marshall Space Flight Center Research and Technology Report 2019

Today, our calling to explore is greater than ever before, and here at Marshall Space Flight Centerwe make human deep space exploration possible. A key goal for Artemis is demonstrating and perfecting capabilities on the Moon for technologies needed for humans to get to Mars. This years report features 10 of the Agencys 16 Technology Areas, and I am proud of Marshalls role in creating solutions for so many of these daunting technical challenges. Many of these projects will lead to sustainable in-space architecture for human space exploration that will allow us to travel to the Moon, on to Mars, and beyond. Others are developing new scientific instruments capable of providing an unprecedented glimpse into our universe. NASA has led the charge in space exploration for more than six decades, and through the Artemis program we will help build on our work in low Earth orbit and pave the way to the Moon and Mars. At Marshall, we leverage the skills and interest of the international community to conduct scientific research, develop and demonstrate technology, and train international crews to operate further from Earth for longer periods of time than ever before first at the lunar surface, then on to our next giant leap, human exploration of Mars. While each project in this report seeks to advance new technology and challenge conventions, it is important to recognize the diversity of activities and people supporting our mission. This report not only showcases the Centers capabilities and our partnerships, it also highlights the progress our people have achieved in the past year. These scientists, researchers and innovators are why Marshall and NASA will continue to be a leader in innovation, exploration, and discovery for years to come

A Comparison Study of Second-Order Screening Designs and Their Extension

Recent literature has proposed employing a single experimental design capable of preforming both factor screening and response surface estimation when conducting sequential experiments is unrealistic due to time, budget, or other constraints. Military systems, particularly aerodynamic systems, are complex. It is not unusual for these systems to exhibit nonlinear response behavior. Developmental testing may be tasked to characterize the nonlinear behavior of such systems while being restricted in how much testing can be accomplished. Second-order screening designs provide a means in a single design experiment to effectively focus test resources onto those factors driving system performance. Sponsored by the Office of the Secretary of Defense (ODS) in support of the Science of Test initiative, this research characterizes and adds to the area of second-order screening designs, particularly as applied to defense testing. Existing design methods are empirically tested and examined for robustness. The leading design method, a method that is very run efficient, is extended to overcome limitations when screening for non-linear effects. A case study and screening design guidance for defense testers is also provided

Concurrent geometrico-topological tuning of nanoengineered auxetic lattices fabricated by material extrusion for enhancing multifunctionality: multiscale experiments, finite element modeling and data-driven prediction

This study demonstrates the multifunctional performance of innovative 2D auxetic lattices through a combination of multiscale experiments, finite element modeling and data-driven prediction. A geometric modeling approach utilizing Voronoi partitioning and a unique branch-stem-branch (BSB) structure, patterned according to 2D wallpaper symmetries, enables precise concurrent geometric and topological tuning of lattices across a continuous parameter space. Selected architectures are physically realized via material extrusion of polylactic acid (PLA) infused with carbon black (CB). Experimental characterizations, supported by Finite Element modeling, reveal the significant influence of BSB structure's design parameters on mechanical and piezoresistive performance under tensile loading, with a remarkable Poisson’s ratio of -0.74, accompanied by a 15-fold increase in elastic stiffness and a 34-fold increase in strain sensitivity. Additionally, architecturally, and topologically tailored lattice structures exhibit tunable damage sensitivity, reflecting the rate of conductive network destruction within the lattice. This offers insights into the rapidity of cell wall failure, with a steeper slope of the piezoresistance curve in the inelastic regime indicating a faster breakdown and quicker onset of mechanical failure. Integration of Gaussian Process Regression enables accurate exploration of the design space beyond realized structures, highlighting the potential of these intelligent lattice structures for applications such as sensors and in situ health monitoring, marking a significant advancement in multifunctional materials

A response surface approach to noise optimization of engine structures

The work presented within this thesis concerns the optimization of finite element models of engine structures to reduce radiated noise. For many engineering problems, current methods of structural optimization provide an efficient means by which to identify an optimum design, subject to a set of imposed bounds and constraints. They do not, however, have the flexibility to carry out efficient investigation of a range of different constraint criteria, and this is often a requirement of a noise optimization study. In order to address this restriction, an alternative method of noise optimization is developed, which is based on the techniques of experimental design theory and response, surface methodology. The main feature of this approach is that values of the response functions of interest are calculated at a number of selected points Within the design variable space, from which an approximating mathematical model is generated. It is this analytical model of the original responses which is used as the basis of the optimization procedure. Experimental design theory is employed in order to ensure that a sufficiently accurate model can be generated With the minimum number of function evaluations. A number of competing experimental designs and mathematical models are considered, and numerical trials are carried out to evaluate their performance in representing the noise function. A quadratic model is found to perform well throughout the design region, and can be estimated efficiently using a particular class of economic second-order designs. A number of detailed noise optimization studies are presented, involving up to seven design variables, which illustrate the ways in which the requirements of the noise optimization problem can be met using the response surface approach

Neutron and Photon Imaging Capabilities of Bismuth-loaded Plastic

Plastic scintillators utilizing iridium complex fluorophores offer substantial improvements in light yield, and their light yield is not significantly quenched in compositions with bismuth metalorganic loading at 21% weight. These advances may resolve significant capability gaps for low-cost, portable, and durable dual-particle imaging (DPI) systems for nuclear safety, security, and safeguard purposes. However, all candidate materials should first undergo investigation utilizing industry standards to quantify and evaluate their capabilities. As such, a 21% bismuth-loaded polyvinyl toluene (BiPVT) scintillator fabricated by Lawrence Livermore National Laboratory (LLNL) is computationally and experimentally evaluated as a small, pixelated radiographic array, with individual pixel dimensions of 2×2×19 mm. To facilitate direct comparisons, the same evaluations are conducted for two same-sized arrays made from EJ-200 and EJ-256 scintillator, respectively. ASTM standard test methods and practices are utilized to calculate the modulation transfer function and basic spatial resolution for each array, both from measured and simulated data. Measurements are recorded by pressure coupling all three arrays to a commercial a-Si digital radiographic panel, and the computational model replicates the experimental design. Computational and experimental results are compared for all three arrays in the x-ray and fast neutron environments. The x-ray results demonstrate equivalent performance between the evaluated BiPVT array and the more ideally manufactured EJ-200 array, while the BiPVT array outperforms a similar array made from EJ-256. The agreement between simulated and experimental x-ray results validates the applied computational methodology and suggests more ideally manufactured BiPVT arrays may significantly outperform similar arrays made from EJ-200. Experimental results in a fast neutron environment demonstrate superior performance of the BiPVT array compared to the EJ-256 array, while the EJ-200 array is found to outperform both. Additionally, the performance of a second array made from a separate 21% bismuth-loaded plastic (Ir-Bi-Plastic) is evaluated experimentally in both x-ray and neutron environments using the same radiographic panel and methodology. The Ir-Bi-Plastic array consists of 64 pixels with individual dimensions of 5×5×20 mm, and the results suggest it will outperform similar arrays made from EJ-200 in both x-ray and neutron environments. These findings suggest plastic scintillators with iridium complex fluorophores and 21% weight bismuth-loading hold promise over more traditional material alternatives for DPI applications supporting nuclear safety, security, and safeguard missions

A Process for Assessing NASA's Capability in Aircraft Noise Prediction Technology

An acoustic assessment is being conducted by NASA that has been designed to assess the current state of the art in NASA s capability to predict aircraft related noise and to establish baselines for gauging future progress in the field. The process for determining NASA s current capabilities includes quantifying the differences between noise predictions and measurements of noise from experimental tests. The computed noise predictions are being obtained from semi-empirical, analytical, statistical, and numerical codes. In addition, errors and uncertainties are being identified and quantified both in the predictions and in the measured data to further enhance the credibility of the assessment. The content of this paper contains preliminary results, since the assessment project has not been fully completed, based on the contributions of many researchers and shows a select sample of the types of results obtained regarding the prediction of aircraft noise at both the system and component levels. The system level results are for engines and aircraft. The component level results are for fan broadband noise, for jet noise from a variety of nozzles, and for airframe noise from flaps and landing gear parts. There are also sample results for sound attenuation in lined ducts with flow and the behavior of acoustic lining in ducts