Nonconventional concept for continuous reproduction of target movement

2020 ◽  
Vol 59 (24) ◽  
pp. 7279
Author(s):  
A. E. Martirosyan ◽  
R. B. Kostanyan ◽  
P. H. Muzhikyan ◽  
H. H. Azizbekyan
2015 ◽  
Vol 75 (3) ◽  
pp. 692-702 ◽  
Author(s):  
LS Andrade ◽  
M Antunes ◽  
PA Lima ◽  
M Furlan ◽  
IF Frameschi ◽  
...  

AbstractThe life cycle of the crab Callinectes danae is estuarine-dependent, and studies on aspects of their biology should also cover marine areas. The present study investigated the sexual maturity, as well as habitat preference by adults in different gonadal stages, and the crabs’ reproductive periodicity outside the estuary. Three bays on the subtropical southeastern coast of Brazil were sampled monthly for two years. For each bay, six transects were established, four of them parallel to the beach line (5, 10, 15 and 20 m depth), as well as one transect in an exposed area, and another sheltered from the action of waves. The results showed that the pattern of spatio-temporal distribution of adults C. danae was similar in three bays, although the highest abundance was found in Ubatumirim. Females with developed gonads/ovigerous females were found in greater abundance than females with rudimentary/developing gonads, mainly in deeper transects. Although the areas sampled have different environmental characteristics, the reproductive pattern of the species did not change, showing continuous reproduction throughout, with more abundance of reproductive females on spring and summer. Males reached maturity at larger sizes than females in all three bays.


Author(s):  
Shengyi Chen ◽  
Haibo Liu ◽  
Xiaochun Liu ◽  
Qifeng Yu

This paper presents a passive measuring method based on monocular trajectory intersection, aimed at realizing the position and velocity measurement of a non-cooperative maritime target for video satellite. Due to the fact that the target’s moving range is relatively small in comparison to that of the satellite during the observation time, a large measuring error results when directly using the monocular trajectory intersection method for 3D motion measurement. Therefore, the dynamic sea surface elevation model is employed to increase the maritime target movement constraints, which simplifies the 3D spatial motion of the target to 2D surface motion. By combining the surface constraint and monocular trajectory intersection method, measurement robustness for a non-cooperative maritime target can be greatly improved. Furthermore, a line-surface intersection method is proposed to obtain the initial solution for motion parameters, which increases the nonlinear optimization efficiency. Simulation experiments are conducted to analyze the effect of different error factors on position and velocity accuracy. The results indicate that the proposed method achieves high measurement accuracy and is feasible in practical applications for video satellite.


Nativa ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 33
Author(s):  
Patrícia Oliveira da Silva

Emmotum nitens é uma espécie bem conhecida em termos de florística e fitossociologia, entretanto, há poucos trabalhos que tratam-se de sua fenologia. Este estudo buscou avaliar a fenologia reprodutiva de uma população de E. nitens no Município de Rio Verde, Goiás. Observou-se mensalmente as fenofases reprodutivas (botão, antese, fruto imaturo e maduro) de 15 indivíduos. Para a coleta dos dados utilizou-se o método de Fournier e presença/ausência, e para analisar os mesmos utilizou-se a estatística circular e correlação com as variáveis meteorológicas (temperatura e precipitação). E. nitens produziu botões e flores de modo irregular ao longo do estudo, no entanto se correlacionaram positivamente com a temperatura. Durante todo estudo registrou-se frutos imaturos, embora as maiores concentrações ocorreram na transição do período seco-chuvoso e durante as chuvas, correlacionando-se positivamente com a precipitação. A maturação dos frutos iniciou-se no final da estação das chuvas, com maiores intensidades no período seco. Para E. nitens é mais vantajoso apresentar reprodução continua já que a mesma não é fortemente limitada pelas variáveis climáticas da área de estudo, do que seguir um padrão sazonal.Palavra-chave: fenologia, espécie de cerrado, eventos reprodutivos, correlação com metereologia. PHENOLOGICAL BEHAVIOR OF EMMOTUM NITENS (BENTH.) MIERS (METTENIUSACEAE) ON CERRADÃO FRAGMENT ABSTRACT:Emmotum nitens is a well-known species in terms of floristic and phytosociology, however, there are few studies that deal with its phenology. The objective of this study was to evaluate the reproductive phenology of a population of E. nitens in the municipality of Rio Verde, Goiás. The reproductive phenomena (flower bud, anthesis, immature fruit and ripe fruit) were observed monthly in 15 individuals. Fournier method and presence/absence were used to collect the data, and to analyze them, the circular statistic and correlation with the meteorological variables (temperature and precipitation) were used. E. nitens produced flower bud and flowers irregularly throughout the study, however they correlated positively with temperature. During the whole study immature fruits were recorded, although the highest concentrations occurred in the transition from the dry-rainy season and during the rains, correlating positively with the precipitation. Fruit maturation began at the end of the rainy season, with higher intensities in the dry season. For E. nitens it is more advantageous to present continuous reproduction since it is not strongly limited by the climatic variables of the study area, rather than following a seasonal pattern.Keywords: phenology, species of cerrado, reproductive events, correlation with meteorology. DOI:


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