scholarly journals Roost-Tier Preference in Roost-Trees: A Case Study in the Bats Pteropus giganteus

2021 ◽  
Author(s):  
Susanta Mallick ◽  
Asif Hossain ◽  
Srimanta Kumar Raut
Keyword(s):  
West Bengal ◽  
Arid Zone ◽  
Statistical Tests ◽  
Tamarindus Indica ◽  
Albizia Lebbeck ◽  
Flying Foxes ◽  
Highly Correlated ◽  
Roost Trees ◽  
One Way Anova

The Indian flying foxes Pteropus giganteus are habituated to spend the day hours roosting in suitable roost trees. They are seen hanging here and there in a roost tree. It is not known whether they have preferred roost sites rather hanging spots in the concerned roost tree. To testify the said hypothesis we selected two roost trees, Albizia lebbeck and Tamarindus indica locating at distant places (75 km apart) in the arid zone of West Bengal, India during the period of last ten years. It is revealed that P. giganteus preferred branches of the roost tree which are locating in the mid-tier of tree. But depending upon the situations the less preferred sites are not spared as these sites are used by the late comers. Statistical tests following application of one-way ANOVA justified significant effect of the roost branch on the abundance of bat population (P<0.05), abundance of bats in the roost branches is highly correlated in respect to the study years (r=0.96) is also justified from the study of normality distribution plot, and the results of GLMM strongly support the hypothesis irrespective of the variables, that is branches of the roost tree and the year of observations (P = 0.0).

Deprivation of Women Migrants: A Case Study of Titagarh,Municipality, North 24 Pargana,West Bengal

2011 ◽  
Vol 3 (10) ◽  
pp. 1-6
Author(s):  
Shatarupa Dey Neogi Shatarupa Dey Neogi ◽  
◽  
Rumela Dutta
Keyword(s):  
West Bengal ◽  
Women Migrants

Automatic identification system data-driven model for analysis of ship domain near bridge-waters

2021 ◽  
pp. 1-22
Author(s):  
Lei Jinyu ◽  
Liu Lei ◽  
Chu Xiumin ◽  
He Wei ◽  
Liu Xinglong ◽  
...  
Keyword(s):  
Least Squares Method ◽  
Automatic Identification ◽  
Identification System ◽  
Collision Risk ◽  
Automatic Identification System ◽  
Domain Models ◽  
System Data ◽  
Quantification Model ◽  
Highly Correlated

Abstract The ship safety domain plays a significant role in collision risk assessment. However, few studies take the practical considerations of implementing this method in the vicinity of bridge-waters into account. Therefore, historical automatic identification system data is utilised to construct and analyse ship domains considering ship–ship and ship–bridge collisions. A method for determining the closest boundary is proposed, and the boundary of the ship domain is fitted by the least squares method. The ship domains near bridge-waters are constructed as ellipse models, the characteristics of which are discussed. Novel fuzzy quaternion ship domain models are established respectively for inland ships and bridge piers, which would assist in the construction of a risk quantification model and the calculation of a grid ship collision index. A case study is carried out on the multi-bridge waterway of the Yangtze River in Wuhan, China. The results show that the size of the ship domain is highly correlated with the ship's speed and length, and analysis of collision risk can reflect the real situation near bridge-waters, which is helpful to demonstrate the application of the ship domain in quantifying the collision risk and to characterise the collision risk distribution near bridge-waters.

scholarly journals Scalable information-theoretic path planning for a rover-helicopter team in uncertain environments

2021 ◽  
Vol 18 (2) ◽  
pp. 172988142199958
Author(s):  
Larkin Folsom ◽  
Masahiro Ono ◽  
Kyohei Otsu ◽  
Hyoshin Park
Keyword(s):  
Path Planning ◽  
Lower Risk ◽  
Information Gain ◽  
Probability Distributions ◽  
Single Agent ◽  
Uncertain Environments ◽  
Information Theoretic ◽  
Highly Correlated ◽  
Naive Approach

Mission-critical exploration of uncertain environments requires reliable and robust mechanisms for achieving information gain. Typical measures of information gain such as Shannon entropy and KL divergence are unable to distinguish between different bimodal probability distributions or introduce bias toward one mode of a bimodal probability distribution. The use of a standard deviation (SD) metric reduces bias while retaining the ability to distinguish between higher and lower risk distributions. Areas of high SD can be safely explored through observation with an autonomous Mars Helicopter allowing safer and faster path plans for ground-based rovers. First, this study presents a single-agent information-theoretic utility-based path planning method for a highly correlated uncertain environment. Then, an information-theoretic two-stage multiagent rapidly exploring random tree framework is presented, which guides Mars helicopter through regions of high SD to reduce uncertainty for the rover. In a Monte Carlo simulation, we compare our information-theoretic framework with a rover-only approach and a naive approach, in which the helicopter scouts ahead of the rover along its planned path. Finally, the model is demonstrated in a case study on the Jezero region of Mars. Results show that the information-theoretic helicopter improves the travel time for the rover on average when compared with the rover alone or with the helicopter scouting ahead along the rover’s initially planned route.

Gender Bias in Education Expenditure among Religious and Social Groups: A Case Study for Below Class 10 Level in West Bengal

2021 ◽  
pp. 097674792110464
Author(s):  
Chayanika Mitra
Keyword(s):  
Gender Bias ◽  
West Bengal ◽  
Social Groups ◽  
National Sample ◽  
Sample Survey ◽  
Education Expenditure ◽  
Individual Level ◽  
Expenditure Data ◽  
The Social

This article attempts to capture gender bias in education expenditure among the religious (Hindu, Muslim and others) and the social groups (SC, ST and General) in West Bengal. Oaxaca–Blinder decomposition technique is used to obtain gender bias for a specific demographic group. Further, an attempt has been made to identify the religious or social groups with the acute problem of gender bias. In this work, 71st round (January–June 2014) education expenditure data (individual level) provided by NSSO (National Sample Survey Office) is used. JEL: I24, R1, C55

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