In recent years, topics related to robotics have become one of the researching fields. In the meantime, intelligent mobile robots have great acceptance, but the control and navigation of these ...devices are very difficult, and the lack of dealing with fixed obstacles and avoiding them, due to safe and secure routing, is the basic requirement of these systems. In this paper, the modified artificial potential field (APF) method is proposed for that robot avoids collision with fixed obstacles and reaches the target in an optimal path; using this algorithm, the robot can run to the target in optimal environments without any problems by avoiding obstacles, and also using this algorithm, unlike the APF algorithm, the robot does not get stuck in the local minimum. We are looking for an appropriate cost function, with restrictions that we have, and the goal is to avoid obstacles, achieve the target, and do not stop the robot in local minimum. The previous method, APF algorithm, has advantages, such as the use of a simple math model, which is easy to understand and implement. However, this algorithm has many drawbacks; the major drawback of this problem is at the local minimum and the inaccessibility of the target when the obstacles are in the vicinity of the target. Therefore, in order to obtain a better result and to improve the shortcomings of the APF algorithm, this algorithm needs to be improved. Here, the obstacle avoidance planning algorithm is proposed based on the improvement of the artificial potential field algorithm to solve this local minimum problem. In the end, simulation results are evaluated using MATLAB software. The simulation results show that the proposed method is superior to the existing solution.
Kaartvedt et al. (2024; Mar Ecol Prog Ser 734:173-175) comment on the role internal waves played in the findings of Dewar-Fowler et al. (2023; Mar Ecol Prog Ser 715:27-39) that foray behaviour was ...present across a number of zooplankton species in the Polar Frontal Zone of the Southern Ocean. Kaartvedt et al. (2024) contend that foray behaviour may not be responsible for the capture of zooplankton by fixed-depth bi-directional net-traps because the influence of internal waves on transporting these organisms into the traps was not accounted for. In Figs. 4 & 5 of Dewar-Fowler et al. (2023), directional biases were apparent in the abundance and taxon-ratios captured by the upward and downward looking nets, which can only be explained by the active swimming and avoidance behaviours of zooplankton. This refutes the contention that physical processes such as internal waves dominated capture rates by the net-trap. Even within this physically dynamic oceanic frontal zone, biological indicators such as these biases support the assertion of Dewar-Fowler et al. (2023) that foray behaviour is detectable and prevalent within zooplankton communities.
Approach and avoidance are typical behavioral tendencies of consumers when exposed to a new environment. Drawing on the stimulus-organism-response (S-O-R) framework, this study investigates the ...effects of atmospheric cues on consumers' approach and avoidance intentions in social commerce environments. We elucidate the interaction mechanisms between atmospheric cues (task, aesthetic and social cues) and consumers' evaluations through the lens of perceived affordances. Then we investigate how three types of perceived affordances (utilitarian, hedonic and connective) influence consumers’ approach and avoidance behavioral intentions. A three-way factorial experiment provides strong evidence that task cues, aesthetic cues and social cues elicit perceived utilitarian, hedonic and connective affordances, respectively. Approach behavioral intentions were affected by all three types of perceived affordances, yet avoidance intentions were only affected by perceived utilitarian and hedonic affordances. This paper discusses both theoretical and practical implications for social commerce research.
•Different types of atmospheric cues stimulate perceived affordances differently.•More task cues induces a higher level of perceived utilitarian affordances.•The presence of aesthetic cues induces perceive hedonic affordances.•The presence of social cues induces perceive connective affordances.•Approach and avoidance intentions are influenced by different perceived affordances.
This paper addresses formation control with obstacle avoidance problem for a class of second-order stochastic nonlinear multiagent systems under directed topology. Different with deterministic ...multiagent systems, stochastic cases are more practical and challenging because the exogenous disturbances depicted by the Wiener process are considered. In order to achieve control objective, both the leader-follower formation approach and the artificial potential field (APF) method are combined together, where the artificial potential is utilized to solve obstacle avoidance problem. For obtaining good system robustness to the undesired side effects of the artificial potential, H ∞ analysis is implemented. Based on the Lyapunov stability theory, it is proven that control objective can be achieved, of which obstacle avoidance is proven by finding an energy function satisfying that its time derivative is positive. Finally, a numerical simulation is carried out to further demonstrate the effectiveness of the proposed formation schemes.
•Psychological reactions to COVID-19 include over-response and under-response.•Over-response is characterized by strong beliefs about dangerousness of COVID-19.•Over-response is associated with ...disproportionate distress and excessive avoidance.•Under-response occurs when people downplay the significance of the pandemic.•Under-response is associated with disregard for social distancing.
: Recent psychological research into the effects of COVID-19 has focused largely on understanding excessive fear reactions (“over-responses”). Equally important, but neglected phenomena concern “under-responses”, in which people downplay the significance of COVID-19. People who do not take the pandemic seriously may be less likely to adhere to social distancing policies. The present study is, to our knowledge, the first to investigate the differential predictors of over- and under-responses to COVID-19.
: A large community sample from the United States and Canada (N = 6,854) completed measures of beliefs associated with over- and under-responses, along with measures of distress, excessive avoidance, and nonadherence to social distancing. Over-response beliefs were assessed by scales measuring beliefs about the dangerousness of COVID-19 (personal health and socio-economic threats) and COVID-19-related xenophobia (beliefs that foreigners are spreading the virus). Under-response beliefs were assessed by scales measuring beliefs that the threat of COVID-19 has been exaggerated, and beliefs that one is sufficiently healthy to be robust against the effects of COVID-19.
: In regression analyses, medium or large effects were obtained whereby over-response beliefs predicted distress (including distress associated with self-isolation) and excessive avoidance during the pandemic, whereas under-response beliefs predicted the disregard for social distancing.
: This study relied on self-reported cross-sectional data and focused on extreme forms of disregard for social distancing guidelines,
: It is important to understand under-responses to COVID-19 and how these relate to distress, excessive avoidance, and nonadherence to social distancing. Implications for addressing the problems of over- and under-response are discussed.
Investigating approach-avoidance behavior regarding affective stimuli is important in broadening the understanding of one of the most common psychiatric disorders, social anxiety disorder. Many ...studies in this field rely on approach-avoidance tasks, which mainly assess hand movements, or interpersonal distance measures, which return inconsistent results and lack ecological validity. Therefore, the present study introduces a virtual reality task, looking at avoidance parameters (movement time and speed, distance to social stimulus, gaze behavior) during whole-body movements. These complex movements represent the most ecologically valid form of approach and avoidance behavior. These are at the core of complex and natural social behavior. With this newly developed task, the present study examined whether high socially anxious individuals differ in avoidance behavior when bypassing another person, here virtual humans with neutral and angry facial expressions. Results showed that virtual bystanders displaying angry facial expressions were generally avoided by all participants. In addition, high socially anxious participants generally displayed enhanced avoidance behavior towards virtual people, but no specifically exaggerated avoidance behavior towards virtual people with a negative facial expression. The newly developed virtual reality task proved to be an ecological valid tool for research on complex approach-avoidance behavior in social situations. The first results revealed that whole body approach-avoidance behavior relative to passive bystanders is modulated by their emotional facial expressions and that social anxiety generally amplifies such avoidance.
The dorsal striatum has been linked to decision-making under conflict, but the mechanism by which striatal neurons contribute to approach-avoidance conflicts remains unclear. We hypothesized that ...striatopallidal dopamine D2 receptor (D2R)-expressing neurons promote avoidance, and tested this hypothesis in two exploratory approach-avoidance conflict paradigms in mice: the elevated zero maze and open field. Genetic elimination of D2Rs on striatopallidal neurons (iMSNs), but not other neural populations, increased avoidance of the open areas in both tasks, in a manner that was dissociable from global changes in movement. Population calcium activity of dorsomedial iMSNs was disrupted in mice lacking D2Rs on iMSNs, suggesting that disrupted output of iMSNs contributes to heightened avoidance behavior. Consistently, artificial disruption of iMSN output with optogenetic stimulation heightened avoidance of open areas of these tasks, while inhibition of iMSN output reduced avoidance. We conclude that dorsomedial striatal iMSNs control approach-avoidance conflicts in exploratory tasks, and highlight this neural population as a potential target for reducing avoidance in anxiety disorders.
In this article, we propose a reciprocal collision avoidance system for autonomous drones, based on computer vision and using relative positioning in an indoor environment. This dynamic environment ...represents a demanding challenge, but it is crucial for any future existence of multiple drones operating in urban areas. We use commercial AR Drone 2.0 robots, which represent that our proposal is suitable for low-cost equipment. In our case, we attempt to achieve the collision avoidance of two drones that fly one towards the other and react online autonomously to signals received by their computer vision systems with a decentralized control strategy. We test this in four different experiments with demanding conditions. For this purpose, we get the camera signal of the onboard drones and tune their behavior to react smoothly and precisely. We report encouraging positive results and provide the code we use in the experiments for replication.
Body checking and avoidance among dancers Drury, Catherine R.; Armeli, Stephen; Loeb, Katharine L.
Eating behaviors : an international journal,
August 2024, Volume:
54
Journal Article
Peer reviewed
Open access
Dancers are at heightened risk for eating disorders (EDs) and have job and training demands that obscure ED assessment and likely impede treatment. Two behavioral manifestations of ED psychopathology ...that may present uniquely in a dance environment are body checking and body avoidance. The current study sought to provide a foundational understanding of the phenomenology of body checking and avoidance among dancers by assessing the reliability (i.e., internal consistency) of existing body checking and avoidance measures and the relationships, or convergent validity, between measures of body checking and avoidance and measures of related constructs. Eighty professional and pre-professional (i.e., conservatory level) dancers (78.8 % female) from seven dance genres completed self-report measures of body checking and avoidance, ED pathology, clinical perfectionism, depression, and anxiety. Across the dancer sample, body checking and avoidance measures demonstrated adequate internal consistency. More frequent body checking and body avoidance was strongly related to higher levels of ED pathology. There were moderate to strong correlations between body checking and body avoidance and clinical perfectionism, depression, and anxiety such that higher body checking and body avoidance was related to higher clinical perfectionism, depression, and anxiety. Exploratory analyses found no significant differences between ballet dancers and dancers of other dance genres; professional dancers scored in the normative range on measures of body checking and body avoidance. Dancers' qualitative descriptions of body checking and avoidance revealed behaviors not included in existing questionnaires, such as unique mirror use behaviors, technology-assisted body checking, and the checking and avoidance of body parts relevant to the dance-specific body ideal. Results support the inclusion of body checking and avoidance interventions in ED treatments for dancers (particularly pre-professional dancers) and emphasize the need for dancer-specific ED assessment methods.
•Body checking/avoidance measures have adequate internal consistency in dancers.•Higher body checking/avoidance relates to higher eating disorder pathology in dancers.•Higher body checking/avoidance relates to higher mood symptoms among dancers.•Existing measures do not assess dancer-specific body checking/avoidance behaviors.
In this article, we present an active simultaneous localization and mapping (SLAM) framework for a mobile robot to obtain a collision-free trajectory with good performance in SLAM uncertainty ...reduction and in an area coverage task. Based on a model predictive control framework, these two tasks are solved by the introduction of a control switching mechanism. For SLAM uncertainty reduction, graph topology is used to approximate the original problem as a constrained nonlinear least squares problem. A convex half-space representation is applied to relax nonconvex spatial constraints that represent obstacle avoidance. Using convex relaxation, the problem is solved by a convex optimization method and a rounding procedure based on singular value decomposition. The area coverage task is addressed with a sequential quadratic programming method. A submap joining approach, called linear SLAM, is used to address the associated challenges of avoiding local minima, minimizing control switching, and potentially high computational cost. Finally, various simulations and experiments using an aerial robot are presented that verify the effectiveness of the proposed method, showing that our method produces a more accurate SLAM result and is more computationally efficient compared with multiple existing methods.
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