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Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 112
Author(s):  
Larisa Corcoz ◽  
Florin Păcurar ◽  
Victoria Pop-Moldovan ◽  
Ioana Vaida ◽  
Vlad Stoian ◽  
...  

Grassland ecosystems occupy significant areas worldwide and represent a reservoir for biodiversity. These areas are characterized by oligotrophic conditions that stimulate mycorrhizal symbiotic partnerships to meet nutritional requirements. In this study, we selected Festuca rubra for its dominance in the studied mountain grassland, based on the fact that grasses more easily accept a symbiotic partner. Quantification of the entire symbiosis process, both the degree of colonization and the presence of a fungal structure, was performed using the root mycorrhizal pattern method. Analysis of data normality indicated colonization frequency as the best parameter for assessing the entire mycorrhizal mechanism, with five equal levels, each of 20%. Most of the root samples showed an intensity of colonization between 0 and 20% and a maximum of arbuscules of about 5%. The colonization degree had an average value of 35%, which indicated a medium permissiveness of roots for mycorrhizal partners. Based on frequency regression models, the intensity of colonization presented high fluctuations at 50% frequency, while the arbuscule development potential was set to a maximum of 5% in mycorrhized areas. Arbuscules were limited due to the unbalanced and unequal root development and their colonizing hyphal networks. The general regression model indicated that only 20% of intra-radicular hyphae have the potential to form arbuscules. The colonization patterns of dominant species in mountain grasslands represent a necessary step for improved understanding of the symbiont strategies that sustain the stability and persistence of these species.


2021 ◽  
Vol 116 ◽  
pp. 123-130
Author(s):  
Mateusz Niedbała

The effect of the use of a soil improver based on waste brown coal on the enzymatic activity of soil in the cultivation of Paulownia hybrids (Paulownia Siebold & Zuccarini, 1835). An important element in controlling the condition of the soil and the plants grown on it are tests of the enzymatic activity of the soil matrix. One of the greatest advantages of using enzyme tests is the ability to make an assessment that also includes other non-measurable factors that affect soil health and condition. The diagnosed changes in soil enzymatic activity are the best parameter for determining the biochemical processes taking place there. This article describes the enzymatic activity of lessive soils on which the Paulownia hybrid variety is cultivated and a soil improver based on waste brown coal is used


Author(s):  
Shaheen Solwa ◽  
Ayodeji James Bamisaye

Evolutionary algorithms (EAs) have recently been applied to Uncoded Space-Time Labeling Diversity (USTLD) systems to produce labeling diversity mappers. However, the most challenging task is choosing the best parameter setting for the EA to create a more ‘optimal’ mapper design. This paper proposes a ‘meta-Genetic Algorithm (GA)’ used to tune hyperparameters for the Labeling Diversity EA. The algorithm is examined on 16, 32 and 64QAM; 32 and 64PSK; 16, 32 and 64APSK and 16APSK constellations that do not show diagonal symmetry. Furthermore, the meta-GA settings and original GA settings are compared in terms of the number of generations taken to converge to a solution. For QAM constellations, the output using the meta-GA settings matched but did not improve with the original settings. However, the number of generations needed to converge to a solution took 120 times less than the number of generations using the original settings. In the 64PSK constellation, a diversity gain of [Formula: see text][Formula: see text]dB was observed while improving on the actual fitness value from 0.0575 to 0.0661. Similarly, with 32APSK constellation, an improvement in fitness value from 0.1457 to 0.1748 was made while showing diversity gains of [Formula: see text][Formula: see text]dB. 64APSK constellation fitness value improved from 0.0708 to 0.0957, and a [Formula: see text][Formula: see text]dB gain was observed. The most significant improvement was made by the asymmetric 16APSK constellation, with gains of [Formula: see text][Formula: see text]dB and increasing its fitness value three times (0.0981 to 0.3000). A study of the effects of optimizing the GA parameters shows that the number of swaps during crossover [Formula: see text] and the radius [Formula: see text] were the two most important variables to optimize when executing this GA.


SIMULATION ◽  
2021 ◽  
pp. 003754972110633
Author(s):  
Andre N Costa ◽  
Felipe LL Medeiros ◽  
Joao PA Dantas ◽  
Diego Geraldo ◽  
Nei Y Soma

As simulation becomes more present in the military context for variate purposes, the need for accurate behaviors is of paramount importance. In the air domain, a noteworthy behavior relates to how a group of aircraft moves in a coordinated way. This can be defined as formation flying, which, combined with a move-to-goal behavior, is the focus of this work. The objective of the formation control problem considered is to ensure that simulated aircraft fly autonomously, seeking a formation, while moving toward a goal waypoint. For that, we propose the use of artificial potential fields, which reduce the complexities that implementing a complete cognition model could pose. These fields define forces that control the movement of the entities into formation and to the prescribed waypoint. Our formation control approach is parameterizable, allowing modifications that translate how the aircraft prioritize its sub-behaviors. Instead of defining this prioritization on an empirical basis, we elaborate metrics to evaluate the chosen parameters. From these metrics, we use an optimization methodology to find the best parameter values for a set of scenarios. Thus, our main contribution is bringing together artificial potential fields and simulation optimization to achieve more robust results for simulated military aircraft to fly in formation. We use a large set of scenarios for the optimization process, which evaluates its objective function through the simulations. The results show that the use of the proposed approach may generate gains of up to 27% if compared to arbitrarily selected parameters, with respect to one of the metrics adopted. In addition, we were able to observe that, for the scenarios considered, the presence of a formation leader was an obstacle to achieving the best results, demonstrating that our approach may lead to conclusions with direct operational impacts.


2021 ◽  
Vol 11 (22) ◽  
pp. 10941
Author(s):  
Chun-Ling Ho ◽  
Yung-Chih Tang ◽  
Wen-Chih Chiu

A growing number of manufacturers are realizing cost and environmental benefits through the sustainability of innovation and optimization processes. Based on polluting less and creating less, the study is pursuing sustainability on increasing operational efficiency by reducing costs and waste. Pulse dust collection systems are commonly used filtration equipment in industries and have lots of energy consumption due to running all day. This study is focused on the optimal parameters for energy saving and cost reduction, and the model is represented by the pressure drop of the filter and the residual powder. The characteristic values of the cleaning efficiency and the air permeability reduction are used for MATLAB to analyze the optimization state. This study found that the material of filter elements, the type of dust, the conditions of pulse-jet, and the filtering speed are the factors that affect the operational efficiency. In terms of cost, the pulse interval time in 10 s is the best parameter, and the pulse time does not affect the overall cost of the filter. Considering energy saving, 0.1 s of the pulse time is the best parameter. In addition, a lower dust concentration is a way to improve efficiency for increasing the filter life and reducing cost.


2021 ◽  
Vol 6 (2) ◽  
pp. 1492-1495
Author(s):  
Sanjib Kumar Sah ◽  
Suman Pokhrel ◽  
Umesh Kumar Mehata ◽  
Raju Kumar Chaudhary ◽  
Rajesh Kumar Shah

Introduction: Sexual dimorphism refers to differences in size, stature and appearance between male and female. It is a known fact that tooth crown is formed to full size in childhood even before eruption into oral cavity. The shape and size of the teeth permits an interesting dimension of study for sexual dimorphism, we aimed to delineate the sexual dimorphism by measuring the mesiodistal (MD) and buccolingual (BL) diameters of permanent maxillary first molar in Nepalese population of Eastern Nepal. Objectives: The aim of this study was to evaluate the sexual dimorphism in maxillary first molar among Nepalese population of eastern Nepal Methodology: 100 participants of either sex (50 males & 50 females) aged between 17 to 25 years were enrolled in the study. After thorough dental examination, impression of the maxillary arch was made and MD diameter and BL diameters were measured with the help of vernier caliper. A P value of <0.05 was considered as statistically significant. Results: Sexual dimorphism was found in MD and BL diameters of maxillary first molar in males measuring higher than females. Right mesiodistal showed the highest sexual dimorphism, whereas right buccolingual showed the least. Conclusions: This study confirms that permanent maxillary first molar shows significant sexual dimorphism, out of which mesiodistal measurement stands out to be the best parameter in Nepalese population of Eastern region.


2021 ◽  
Vol 2110 (1) ◽  
pp. 012011
Author(s):  
D N Hikmah ◽  
D K Sandi ◽  
F Nurosyid ◽  
Y Iriani

Abstract Strontium Titanate (SrTiO3) is one attractive material studied. In this study, SrTiO3 has been fabricated via the co-precipitation technique. The samples were sintered at 800°C and 900°C with holding times of 2 h and 4 h for each temperature. The purposes of this study were to synthesize SrTiO3 material using co-precipitation technique and to observe the microstructure and chemical bonds of the SrTiO3 as the variations of the sintering temperatures and holding times. According to the X-Ray Diffraction (XRD) results, the sintering temperatures and holding times influenced the intensity values and peak broadening. The alteration in both parameters consequently changed the crystallite size and lattice strain of the SrTiO3 material. Furthermore, the Fourier Transform Infrared (FTIR) results validated the SrTiO3 material by existence of Sr-Ti-O chemical bonds. Also, the absorption peaks of O-H, C-H, and C=O chemical bonds in the SrTiO3 declined due to the higher temperature and longer holding time demonstrating impurities declined. Therefore, according to this study, the sintering temperature of 900°C and the holding time of 4 h was the best parameter for fabricating SrTiO3 powder.


2021 ◽  
Vol 926 (1) ◽  
pp. 012106
Author(s):  
M R Virgiawan ◽  
J Pitulima

Abstract PT Timah Tbk has been processing residual ore (SHP) with a low tin grade of ± 10-30% wt. To increase tins grade and associated mineral products to be a high grade (> 70% wt), an evaluation and optimization process is needed on Induced Roll Magnetic Separator processing equipment. The evaluation and optimization process was carried out on magnetic products, especially ilmenite minerals. Sampling is done on the feed and the product based on the tool parameter settings. The feed rate is set at 380, 320, 250, 420, and 470 gr/10s. The splitter opening is set at 10, 15, 20 mm of magnetic rollers. While the electric current is set at 2, 4, 6, 8, 10, 12, 14 amperes. Mass and grade data are then analyzed by regression and variance statistical methods and optimized by the response surface method. The evaluation results show that only the splitter opening parameters and electric current strength are significant in explaining the product results obtained with a level of hypothesis error of 5%. The results of IRMS optimization show that the best parameter conditions are in the 2-4 ampere of electric current and 10-15 mm of splitter openings with illmenite grade capable of> 80% wt in the second order of central composite design.


2021 ◽  
pp. 1-10
Author(s):  
Luyi Bai ◽  
Zengmei Cui ◽  
Xinyi Duan ◽  
Hao Fu

With the increasing popularity of XML for data representations, there is a lot of interest in keyword query on XML. Many algorithms have been proposed for XML keyword queries. But the existing approaches fall short in their abilities to analyze the logical relationship between keywords of spatiotemporal data. To overcome this limitation, in this paper, we firstly propose the concept of query time series (QTS) according to the data revision degree. For the logical relationship of keywords in QTS, we study the intra-coupling logic relationship and the inter-coupling logic relationship separately. Then a calculation method of keyword similarity is proposed and the best parameter in the method is found through experiment. Finally, we compare this method with others. Experimental results show that our method is superior to previous approaches.


Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5645
Author(s):  
Chiara Ursini ◽  
Luca Collini

Nowadays, fused deposition modeling additive technology is becoming more and more popular in parts manufacturing due to its ability to reproduce complex geometries with many different thermoplastic materials, such as the TPU. On the other hand, objects obtained through this technology are mainly used for prototyping activities. For this reason, analyzing the functional behavior of FDM parts is still a topic of great interest. Many studies are conducted to broaden the spectrum of materials used to ensure an ever-increasing use of FDM in various production scenarios. In this study, the effects of several phenomena that influence the mechanical properties of printed lattice structures additively obtained by FDM are evaluated. Three different configurations of lattice structures with designs developed from unit cells were analyzed both experimentally and numerically. As the main result of the study, several parameters of the FDM process and their correlation were identified as possible detrimental factors of the mechanical properties by about 50% of the same parts used as isotropic cell solids. The best parameter configurations in terms of mechanical response were then highlighted by numerical analysis.


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