Violet Mwaffo

New York University, Tandon School of Engineering · Mechanical and Aerospace Engineering

The next generation of United States Navy uncrewed aerial systems (UASs) is expected to operate in global positioning system and radio frequency-denied maritime environments. In these challenging conditions, these UASs must accurately identify specific surface vessels among multiple similar vessels using passive onboard sensors. This study explores...

The response of heterogeneous groups of fish including a few leaders, several followers, and a few fish initiating escape reaction is investigated. This alarm response is often observed in animal groups where exposure to strong stimuli such as a predator can force a few individuals to initiate sudden and abrupt turns to move to safer locations. In...

The United States Navy aims to enhance its fleet by expanding the deployment of unmanned aircraft in carrier air wings. However, certifying the autonomous refueling of unmanned aerial platforms currently lacks a publicly available method. Ongoing research at the United States Naval Academy focuses on investigating certification evidence that would...

In animal groups, startle reaction is classified among alarm reactions observed during anti-predatory or chemical reactions in the context of fear-inducing stimulation. For fish groups, this behavior often initiated by a few individuals in response to a strong stimulus is characterized by sudden and abrupt turns coupled to increasing speed that can...

A bio-inspired state estimation and control algorithm is experimentally tested to autonomously balance a team of robots on a circle. In this control scheme inspired from the social behavior of some insects species, a leader is elected randomly and periodically moves at a constant angular speed. The followers triggered by the leader motion, implemen...

In this work, we analyze the decentralized formation control problem for a class of multi-robotic systems evolving on slippery surfaces. Grounded on experimental data of robots moving on a gravel surface inducing slippery, we show that a deterministic model cannot capture the uncertainties resulting from the kinematics of the robots while, instead,...

Startle reaction is an alarm behavior observed in animal groups during anti-predatory response or fear-inducing stimulation. This behavior is characterized by spontaneous change in heading direction and increasing speed that can drastically affect group coordination. In this work, we leverage a mathematical model of fish social behavior to recreate...

Leader-follower relationships are commonly hypothesized as a fundamental mechanism underlying collective behaviour in many biological and physical systems. Understanding the emergence of such behaviour is relevant in science and engineering to control the dynamics of complex systems toward a desired state. In prior works, due in part to the limitat...

Zebrafish has recently become a species of choice in a number of preclinical studies to examine whether and how psychoactive compounds modulate individual and social behaviors. Here, we sought to contribute an improved understanding of the effects of caffeine, a well-known anxiogenic compound, on the swimming activity and the collective response of...

Zebrafish is emerging as a species of choice for the study of a number of biomechanics problems, including balance development, schooling, and neuromuscular transmission. The precise quantification of the flow physics around swimming zebrafish is critical toward a mechanistic understanding of the complex swimming style of this fresh-water species....

Data of zebrafish locomotory patterns and fluid velocity and pressure field

Collective motion in animal groups manifests itself in the form of highly coordinated maneuvers determined by local interactions among individuals. A particularly critical question in understanding the mechanisms behind such interactions is to detect and classify leader–follower relationships within the group. In the technical literature of coupled...

Research in animal behavior is increasingly benefiting from the field of robotics, whereby robots are being continuously integrated in a number of hypothesis-driven studies. A variety of robotic fish have been designed after the morphophysiology of live fish to study social behavior. Of the current design factors limiting the mimicry of live fish,...

As the zebrafish is rapidly becoming a species of choice in preclinical research, several efforts are being placed toward creating educational programs for K-12 students based on this promising model organism. However, as any other model organisms, the use of zebrafish in classroom settings requires additional experimental resources and poses ethic...

The study of zebrafish behavior represents a cornerstone upon which basic researchers promise to advance knowledge in life sciences. Although zebrafish swim in a three-dimensional (3D) space, their behavior in the lab is almost exclusively scored in two dimensions, whereby zebrafish are recorded using a single camera providing 2D videos. Whether th...

Zebrafish is fast becoming a species of choice in biomedical research for the investigation of functional and dysfunctional processes coupled with their genetic and pharmacological modulation. As with mammals, experimentation with zebrafish constitutes a complicated ethical issue that calls for the exploration of alternative testing methods to redu...

Most of the mathematical models of collective behavior describe uncertainty in individual decision making through additive uniform noise. However, recent data driven studies on animal locomotion indicate that a number of animal species may be better represented by more complex forms of noise. For example, the popular zebrafish model organism has be...

As zebrafish emerge as a species of choice for the investigation of biological processes, a number of experimental protocols are being developed to study their social behaviour. While live stimuli may elicit varying response in focal subjects owing to idiosyncrasies, tiredness and circadian rhythms, video stimuli suffer from the absence of physical...

Supplementary material: Zebrafish response to a robotic replica in three dimensions

Zebrafish is becoming an important animal model in pre-clinical studies for its genetic similarity to humans and ease of use in the laboratory. In recent years, animal experimentation has faced several ethical issues, calling for alternative methods that capitalize on dynamical systems theory. Here, we propose a computational modeling framework to...

Collective behavior affords several advantages to fish in avoiding predators, foraging, mating, and swimming. Although fish schools have been traditionally considered egalitarian superorganisms, a number of empirical observations suggest the emergence of leadership in gregarious groups. Detecting and classifying leader-follower relationships is cen...

Recent progress in three-dimensional (3D) printing technology has enabled rapid prototyping of complex models at a limited cost. Virtually every research laboratory has access to a 3D printer, which can assist in the design and implementation of hypothesis-driven studies on animal behavior. In this study, we explore the possibility of using 3D prin...

As zebrafish emerge as a species of choice for the investigation of biological processes, a number of experimental protocols are being developed to study their social behaviour. While live stimuli may elicit varying response in focal subjects owing to idiosyncrasies, tiredness and circadian rhythms, video stimuli suffer from the absence of physical...

As zebrafish emerge as a species of choice for the investigation of biological processes, a number of experimental protocols are being developed to study their social behaviour. While live stimuli may elicit varying response in focal subjects owing to idiosyncrasies, tiredness and circadian rhythms, video stimuli suffer from the absence of physical...

In this work, we analyze the coordination of interacting individuals in two nonlinear dynamical models that are subject to a new form of noise. Specifically, we propose extensions both to the classical Vicsek model, whereby each individual averages the orientation of its geographically proximal neighbors, and to the vectorial network model, in whic...

In this work, we study the collective behavior of a multi-agent system of stochastically interacting leaders and followers. In this time-varying network, the nodes update their states through a noisy interaction with a randomly selected subset of neighbors, including leaders whose average orientation is not updated in time. By linearizing the syste...

Zebrafish is becoming a species of choice in neurobiological and behavioral studies of alcohol-related disorders. In these efforts, the activity of adult zebrafish is typically quantified using indirect activity measures that are either scored manually or identified automatically from the fish trajectory. The analysis of such activity measures has...

Zebrafish is emerging as a species of choice in alcohol-related pharmacological studies. In these studies, zebrafish are often exposed to acute ethanol treatments and their activity scored during behavioral assays. Computational modeling of zebrafish behavior is expected to positively impact these efforts by offering a predictive toolbox to plan hy...

Zebrafish has been recently proposed as a valid animal model to investigate the fundamental mechanisms regulating emotional behavior and evaluate the modulatory effects exerted by psychoactive compounds. In this study, we propose a novel methodological framework based on robotics and information theory to investigate the behavioral response of zebr...

Zebrafish is becoming a popular animal model in preclinical research, and zebrafish turning rate has been proposed for the analysis of activity in several domains. The turning rate is often estimated from the trajectory of the fish centroid that is output by commercial or custom-made target tracking software run on overhead videos of fish swimming....

Zebrafish are gaining momentum as a laboratory animal species for the investigation of several functional and dysfunctional biological processes. Mathematical models of zebrafish behaviour are expected to considerably aid in the design of hypothesis-driven studies by enabling preliminary in silico tests that can be used to infer possible experiment...

This paper investigates the controllability of discrete-time networks of coupled chaotic maps through stochastic pinning. In this control scheme, the network dynamics are steered towards a desired trajectory through a feedback control input that is applied stochastically to the network nodes. The network controllability is studied by analyzing the...