scholarly journals Wind and route choice affect performance of bees flying above versus within a cluttered obstacle field

2021 ◽  
Author(s):  
Nicholas Burnett ◽  
Marc Badger ◽  
Stacey Combes
Keyword(s):  
The Other ◽  
Foraging Efficiency ◽  
Flight Performance ◽  
Complex Environments ◽  
Wild Bees ◽  
Ground Speed ◽  
Tunnel Floor ◽  
Natural Landscapes ◽  
Narrow Space ◽  
Physical Challenges

Bees flying through natural landscapes encounter physical challenges, such as wind and cluttered vegetation. The influence of these factors on the flight performance of bees remains unknown. We analyzed 548 videos of wild-caught honeybees (Apis mellifera) flying through an enclosure containing a field of vertical obstacles that bees could fly within (through open corridors, without maneuvering) or above. We examined how obstacle field height, wind presence and direction (headwinds or tailwinds) affected altitude, ground speed, and side-to-side casting (lateral excursions) of bees. When obstacle fields were short, bees flew at altitudes near the midpoint between the tunnel floor and ceiling. When obstacle fields approached or exceeded this midpoint, bees typically, but not always, increased their altitudes to fly over the obstacles. Bees that flew above the obstacle fields exhibited 40% faster ground speeds and 36% larger lateral excursions than bees that flew within the obstacle fields, likely due to the visual feedback from obstacles and narrow space available within the obstacle field. Wind had a strong effect on ground speed and lateral excursions, but not altitude. Bees flew 12-19% faster in tailwinds than in the other wind conditions, but their lateral excursions were 19% larger in any wind, regardless of its direction, than in still air. Our results show that bees flying through complex environments display flexible flight behaviors (e.g., flying above versus within obstacles), which affect flight performance. Similar choices in natural landscapes could have broad implications for foraging efficiency, pollination, and mortality in wild bees.

Assessing the Utilization of Automata in Representing Players' Behaviors in Game Theory

Game Theory ◽  
2017 ◽  
pp. 106-119
Author(s):  
Khaled Suwais
Keyword(s):  
Game Theory ◽  
Cellular Automata ◽  
Finite Automata ◽  
The State ◽  
The Other ◽  
Direct Impact ◽  
Complex Environments ◽  
Other Hand ◽  
Different Types ◽  
State Of Art

Representing players' strategies in game theory has a direct impact on the players' performance. The state of art shows that automata are one of the primary techniques used for representing players' strategies and behaviors. In this paper, the author will identify different types of automata and assess their utilization in the field of game theory. Is has been found that finite automata, adaptive automata, and cellular automata are widely adopted in game theory. The utilization of finite automata is found to be limited to represent simpler players' behavior. On the other hand, adaptive automata and cellular automata are intensively applied in complex environments, where the number of interacted players is large and therefore, representing complex behaviors are needed.

scholarly journals HKSiamFC: Visual-Tracking Framework Using Prior Information Provided by Staple and Kalman Filter

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2137 ◽  
Author(s):  
Chenpu Li ◽  
Qianjian Xing ◽  
Zhenguo Ma
Keyword(s):  
Kalman Filter ◽  
Visual Tracking ◽  
Prior Information ◽  
State Of The Art ◽  
The Other ◽  
Robust Tracking ◽  
Similarity Learning ◽  
Complex Environments ◽  
Color Information ◽  
Learning Problem

In the field of visual tracking, trackers based on a convolutional neural network (CNN) have had significant achievements. The fully-convolutional Siamese (SiamFC) tracker is a typical representation of these CNN trackers and has attracted much attention. It models visual tracking as a similarity-learning problem. However, experiments showed that SiamFC was not so robust in some complex environments. This may be because the tracker lacked enough prior information about the target. Inspired by the key idea of a Staple tracker and Kalman filter, we constructed two more models to help compensate for SiamFC’s disadvantages. One model contained the target’s prior color information, and the other the target’s prior trajectory information. With these two models, we design a novel and robust tracking framework on the basis of SiamFC. We call it Histogram–Kalman SiamFC (HKSiamFC). We also evaluated HKSiamFC tracker’s performance on dataset of the online object tracking benchmark (OTB) and Temple Color (TC128), and it showed quite competitive performance when compared with the baseline tracker and several other state-of-the-art trackers.

scholarly journals Modeling and Control of a Dragonfly-Like Robot

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Micael S. Couceiro ◽  
N. M. Fonseca Ferreira ◽  
J. A. Tenreiro Machado
Keyword(s):  
System Performance ◽  
Computational Simulation ◽  
The Other ◽  
Control Algorithms ◽  
Kinematics And Dynamics ◽  
Flight Performance ◽  
Modeling And Control ◽  
Wing Motion ◽  
Simulation Based ◽  
And Control

Dragonflies demonstrate unique and superior flight performances than most of the other insect species and birds. They are equipped with two pairs of independently controlled wings granting an unmatchable flying performance and robustness. In this paper, the dynamics of a dragonfly-inspired robot is studied. The system performance is analyzed in terms of time response and robustness. The development of computational simulation based on the dynamics of the robotic dragonfly allows the test of different control algorithms. We study different movements, the dynamics, and the level of dexterity in wing motion of the dragonfly. The results are positive for the construction of flying platforms that effectively mimic the kinematics and dynamics of dragonflies and potentially exhibit superior flight performance than existing flying platforms.

Age, Expertise, Structural Similarity, and Time-Sharing Efficiency

1995 ◽  
Vol 39 (2) ◽  
pp. 124-128
Author(s):  
Pamela S. Tsang ◽  
Tonya L. Shaner
Keyword(s):  
Structural Similarity ◽  
Age Effects ◽  
The Other ◽  
Interactive Effects ◽  
Flight Performance ◽  
Time Sharing ◽  
Resource Model ◽  
Dual Tasks ◽  
Multiple Resource ◽  
Practical Implications

Interactive effects of age, expertise, and structural similarity on time-sharing efficiency were examined. Half of 90 subjects who ranged from age 20 to 80 years were nonpilots. The other half were pilots who were considered to have expertise in time-sharing. Five dual tasks were selected to represent various cognitive aspects of flight performance and to represent various degrees of structural similarity defined by Wickens' multiple resource model. Several main findings were of note. One, time-sharing efficiency increased as structural similarity decreased. Two, time-sharing efficiency decreased with increased age. Three, pilots had higher level of time-sharing efficiency than nonpilots. Four, expertise in time-sharing appeared to be able to moderate some of the deleterious age effects. Theoretical and practical implications of these findings were considered.

Latitudinal and altitudinal variation in ecologically important traits in a widespread butterfly

2019 ◽  
Vol 128 (3) ◽  
pp. 742-755 ◽  
Author(s):  
Franziska Günter ◽  
Michaël Beaulieu ◽  
Massimo Brunetti ◽  
Lena Lange ◽  
Angela Schmitz Ornés ◽  
...  
Keyword(s):  
Evolutionary Biology ◽  
Environmental Gradients ◽  
Individual Development ◽  
Strong Wind ◽  
Flight Performance ◽  
Adaptive Responses ◽  
Complex Environments ◽  
Altitudinal Variation ◽  
Pieris Napi ◽  
Anthropogenic Global Change

Abstract Understanding how organisms adapt to complex environments lies at the very heart of evolutionary biology and ecology, and is of particular concern in the current era of anthropogenic global change. Variation in ecologically important traits associated with environmental gradients is considered to be strong evidence for adaptive responses. Here, we study phenotypic variation along a latitudinal and an altitudinal cline in 968 field-collected males of the widespread European butterfly Pieris napi. In contrast to our expectations, body size decreased with increasing latitude and altitude, suggesting that warmer rather than cooler conditions may be more beneficial for individual development in this species. Higher altitudes but not latitudes seemed to be associated with increased flight performance, suggesting stronger challenges for flight activity in high-altitude environments (e.g. due to strong wind). Moreover, wing melanization increased while yellow reflectance decreased towards colder environments in both clines. Thus, increased melanization under thermally challenging conditions seems to compromise investment into a sexually selected trait, resulting in a trade-off. Our study, although exclusively based on field-collected males, revealed indications of adaptive patterns along geographical clines. It documents the usefulness of field-collected specimens, and the strength of comparing latitudinal and altitudinal clines to identify traits being potentially under thermal selection.

scholarly journals NUCLEAR ENVELOPE-CHLOROPLAST RELATIONSHIPS IN ALGAE

1962 ◽  
Vol 14 (3) ◽  
pp. 433-444 ◽  
Author(s):  
Sarah P. Gibbs
Keyword(s):  
Nuclear Envelope ◽  
Outer Membrane ◽  
Related Species ◽  
The Other ◽  
Chloroplast Envelope ◽  
Outer Envelope ◽  
Starch Grains ◽  
Ochromonas Danica ◽  
Narrow Space

In Ochromonas danica and two related species (Chrysophyceae) and in Rhodomonas lens and Cryptomonas sp. (Cryptophyceae), the chloroplast is surrounded by an outer double-membraned envelope which lies outside the usual double-membraned chloroplast envelope. At the borders of the area where the chloroplast lies adjacent to the nucleus, this outer envelope is continuous with the outer membrane of the nuclear envelope as a double-membraned outfolding, so that the entire chloroplast in these species lies within a double-membraned sac, one wall of which is the nuclear envelope. In Olisthodiscus sp. (Chrysophyceae ?), each of the small peripheral chloroplasts is surrounded by a similar double-membraned outer envelope, but in this species no connections with the nuclear envelope were observed. In the Ochromonadaceae, a characteristic array of tubules is present within the sac in the narrow space which separates the chloroplast from the nucleus. In the other species studied, tubules are present at places between the chloroplast envelope and the outer envelope. In the Cryptophyceae, the starch grains lie outside the chloroplast envelope, but within the outer double-membraned sac. A double-membraned outer envelope appears to be present outside the chloroplasts of the Phaeophyta and Euglenophyta, but seems to be absent in the other groups of algae.

scholarly journals Let's Learn Their Language? A Case for Planning with Automata-Network Languages from Model Checking

2020 ◽  
Vol 34 (09) ◽  
pp. 13569-13575
Author(s):  
Jorg Hoffmann ◽  
Holger Hermanns ◽  
Michaela Klauck ◽  
Marcel Steinmetz ◽  
Erez Karpas ◽  
...  
Keyword(s):  
Model Checking ◽  
Formal Methods ◽  
Side Effect ◽  
The Other ◽  
Modeling Language ◽  
Ai Planning ◽  
Complex Environments ◽  
Exogenous Agents ◽  
Automata Network

It is widely known that AI planning and model checking are closely related. Compilations have been devised between various pairs of language fragments. What has barely been voiced yet, though, is the idea to let go of one's own modeling language, and use one from the other area instead. We advocate that idea here – to use automata-network languages from model checking instead of PDDL – motivated by modeling difficulties relating to planning agents surrounded by exogenous agents in complex environments. One could, of course, address this by designing additional extended planning languages. But one can also leverage decades of work on modeling in the formal methods community, creating potential for deep synergy and integration with their techniques as a side effect. We believe there's a case to be made for the latter, as one modeling alternative in planning among others.

scholarly journals Wind and obstacle motion affect honeybee flight strategies in cluttered environments

2020 ◽  
Vol 223 (14) ◽  
pp. jeb222471
Author(s):  
Nicholas P. Burnett ◽  
Marc A. Badger ◽  
Stacey A. Combes
Keyword(s):  
Apis Mellifera ◽  
Flight Tunnel ◽  
Flight Performance ◽  
Natural Habitats ◽  
Cluttered Environments ◽  
Ground Speed ◽  
Moving Obstacles ◽  
Speed Up ◽  
Stationary Obstacles

ABSTRACTBees often forage in habitats with cluttered vegetation and unpredictable winds. Navigating obstacles in wind presents a challenge that may be exacerbated by wind-induced motions of vegetation. Although wind-blown vegetation is common in natural habitats, we know little about how the strategies of bees for flying through clutter are affected by obstacle motion and wind. We filmed honeybees Apis mellifera flying through obstacles in a flight tunnel with still air, headwinds or tailwinds. We tested how their ground speeds and centering behavior (trajectory relative to the midline between obstacles) changed when obstacles were moving versus stationary, and how their approach strategies affected flight outcome (successful transit versus collision). We found that obstacle motion affects ground speed: bees flew slower when approaching moving versus stationary obstacles in still air but tended to fly faster when approaching moving obstacles in headwinds or tailwinds. Bees in still air reduced their chances of colliding with obstacles (whether moving or stationary) by reducing ground speed, whereas flight outcomes in wind were not associated with ground speed, but rather with improvement in centering behavior during the approach. We hypothesize that in challenging flight situations (e.g. navigating moving obstacles in wind), bees may speed up to reduce the number of wing collisions that occur if they pass too close to an obstacle. Our results show that wind and obstacle motion can interact to affect flight strategies in unexpected ways, suggesting that wind-blown vegetation may have important effects on foraging behaviors and flight performance of bees in natural habitats.

Foraging ecology and organisation of a desert bat fauna

2002 ◽  
Vol 50 (5) ◽  
pp. 529 ◽  
Author(s):  
N. L. McKenzie ◽  
A. N. Start ◽  
R. D. Bullen
Keyword(s):  
Foraging Ecology ◽  
Foraging Strategy ◽  
The Other ◽  
Design Parameters ◽  
Microhabitat Use ◽  
Flight Performance ◽  
Sandy Desert ◽  
Stability And Control ◽  
Family Level ◽  
And Control

Airframe design parameters related to flight performance, stability and control had tight, functionally appropriate relationships with the foraging niches and echolocation parameters of nine species comprising the bat fauna of the Little Sandy Desert, Australia. The airframe parameters segregated into two near-independent groups, one related to microhabitat use, the other to foraging strategy. The structure of the desert's bat fauna is displayed in these terms, and its organisation is compared with the faunas of surrounding regions. A diversity–productivity model of faunal structure is revealed, with an organisation that conforms with the 'specialisation' hypothesis. Clear family-level relationships between phylogeny and foraging ecology imply that ecological specialisations occurred early in the evolution of bats.

scholarly journals A model of resource partitioning between foraging bees

2020 ◽  
Author(s):  
Thibault Dubois ◽  
Cristian Pasquaretta ◽  
Andrew B. Barron ◽  
Jacques Gautrais ◽  
Mathieu Liho-reau
Keyword(s):  
Resource Partitioning ◽  
Positive Reinforcement ◽  
Negative Reinforcement ◽  
Central Place ◽  
Foraging Efficiency ◽  
Complex Environments ◽  
Plant Resources ◽  
Agent Based ◽  
Open Question ◽  
Artificial Flowers

AbstractCentral place foraging pollinators tend to develop multi-destination routes (traplines) to exploit several patchily distributed plant resources. While the formation of traplines by individual pollinators has been studied in details, how populations of individuals exploit resources in a common area is an open question difficult to address experimentally. Here we explored conditions for the emergence of resource partitioning among traplining bees using agent-based models built from experimental data of bumblebees foraging on artificial flowers. In the models, bees learn to develop routes as a consequence of feedback loops that change their probabilities of moving between flowers. While a positive reinforcement of route segments leading to rewarding flowers is sufficient for the emergence of resource partitioning when flowers are evenly distributed, a negative reinforcement of route segments leading to unrewarding flowers is necessary when flowers are patchily distributed. In these more complex environments, the negative experiences of individual bees favour the spatial segregation of foragers and high levels of collective foraging efficiency.

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