32 research outputs found
Signs of Language: Embodied Sign Language Fingerspelling Acquisition from Demonstrations for Human-Robot Interaction
Learning fine-grained movements is a challenging topic in robotics,
particularly in the context of robotic hands. One specific instance of this
challenge is the acquisition of fingerspelling sign language in robots. In this
paper, we propose an approach for learning dexterous motor imitation from video
examples without additional information. To achieve this, we first build a URDF
model of a robotic hand with a single actuator for each joint. We then leverage
pre-trained deep vision models to extract the 3D pose of the hand from RGB
videos. Next, using state-of-the-art reinforcement learning algorithms for
motion imitation (namely, proximal policy optimization and soft actor-critic),
we train a policy to reproduce the movement extracted from the demonstrations.
We identify the optimal set of hyperparameters for imitation based on a
reference motion. Finally, we demonstrate the generalizability of our approach
by testing it on six different tasks, corresponding to fingerspelled letters.
Our results show that our approach is able to successfully imitate these
fine-grained movements without additional information, highlighting its
potential for real-world applications in robotics
DNA Molecular Storage System: Transferring Digitally Encoded Information through Bacterial Nanonetworks
Since the birth of computer and networks, fuelled by pervasive computing and
ubiquitous connectivity, the amount of data stored and transmitted has
exponentially grown through the years. Due to this demand, new solutions for
storing data are needed, and one promising media is the DNA. This storage
solution provides numerous advantages, which includes the ability to store
dense information while achieving long-term stability. However, the question as
how the data can be retrieved from a DNA-based archive, still remains. In this
paper, we aim to address this question by proposing a new storage solution that
relies upon molecular communication, and in particular bacterial nanonetworks.
Our solution allows digitally encoded information to be stored into non-motile
bacteria, which compose an archival architecture of clusters, and to be later
retrieved by engineered motile bacteria, whenever reading operations are
needed. We conducted extensive simulations, in order to determine the
reliability of data retrieval from non-motile storage clusters, placed at
different locations. Aiming to assess the feasibility of our solution, we have
also conducted wet lab experiments that show how bacteria nanonetworks can
effectively retrieve a simple message, such as "Hello World", by conjugation
with non-motile bacteria, and finally mobilize towards a final point.Comment: 22 pages, 13 figures; removed wrong venue references, reordered
bibliography accordingly to ACM guideline
Diseño y construcción de una plataforma experimental de evaluación de sistemas híbridos basados en pilas de combustible
Este trabajo consiste en el estudio, diseño, construcción y validación experimental de una plataforma para la evaluación de Sistemas Híbridos de Generación de Energía (SHGE) a partir de pilas de combustible de hidrógeno. La herramienta desarrollada permitirá el diseño y propuesta de nuevas estrategias de control que optimicen la extracción de energía de los sistemas híbridos.
En este contexto, el sistema propuesto se encuentra conformado principalmente por un convertidor electrónico de potencia de CC-CC conmutado y aislado, con topología tipo Puente Completo con modulación por Desplazamiento de Fase (PS-FBC por sus siglas en inglés); monitoreado mediante la medición de sus estados de tensión y corriente eléctrica, y controlado por una excitación de tipo PWM provista por un DSC (Digital Signal Controller) de alto rendimiento. La topología de convertidor bajo estudio permite adaptar la tensión variable que entrega cada pila de combustible, típicamente de bajo valor, a la tensión de salida fija de un bus común de 75V conectado al SHGE.
De esta manera, a lo largo del trabajo se realiza el análisis de la plataforma desarrollada a partir de la descripción de los bloques fundamentales que la conforman. Una vez realizado el estudio y diseño de la plataforma propuesta, el sistema es desarrollado mediante la herramienta EDA KiCad de generación de circuitos eléctricos y enviada para su fabricación. Finalizado el proceso de construcción del módulo propuesto, se llevaron a cabo diferentes ensayos experimentales para la validación de su correcto funcionamiento.Facultad de Ingenierí
Effect of Daily Consumption of Lactobacillus reuteri CRL 1098 on Cholesterol Reduction in Hypercholesterolemic Subjects
The effect of daily consumption of a yogurt containing Lactobacillus reuteri CRL 1098 on the lipid profile of hypercholesterolemic subjects was evaluated by performing a prospective, randomized, double-blind, cross-over placebo controlled clinical study. Participants consumed daily a yogurt containing L. reuteri CRL 1098 or a placebo for four weeks, separated by a wash-out period. Total cholesterol, triacylglycerol, high-density (HDL) and low-density (LDL) lipoprotein levels were assessed at the beginning and at the end of each period. We found a statistically significant reduction of total (−7.86 g/dl) and LDL (−7.02 g/dl) cholesterol in absolute changes (before-after) as well as a decreasing trend in the group receiving the yogurt containing L. reuteri with respect to the placebo group, without detecting changes in HDL-cholesterol and triacylglycerol levels. Our results suggest that low amounts of yogurt (125 g/day) and low doses of the CRL 1098 strain (106 CFU) are sufficient to reduce total and LDL-cholesterol levels in hypercholesterolemic subjects.Facultad de Ciencias Médica
Biological control of invasive stink bugs: review of global state and future prospects
Invasive stink bugs (Hemiptera: Pentatomidae) are responsible for high economic losses to agriculture on a global scale. The most important species, dating from recent to old invasions, include Bagrada hilaris (Burmeister), Halyomorpha halys (St\ue5l), Piezodorus guildinii (Westwood), Nezara viridula (L.), and Murgantia histrionica (Hahn). Bagrada hilaris, H. halys, and N. viridula are now almost globally distributed. Biological control of these pests faces a complex set of challenges that must be addressed to maintain pest populations below the economic injury level. Several case studies of classical and conservation biological control of invasive stink bugs are reported here. The most common parasitoids in their geographical area of origin are egg parasitoids (Hymenoptera: Scelionidae, Encyrtidae, and Eupelmidae). Additionally, native parasitoids of adult stink bugs (Diptera: Tachinidae) have in some cases adapted to the novel hosts in the invaded area and native predators are known to prey on the various instars. Improving the efficacy of biocontrol agents is possible through conservation biological control techniques and exploitation of their chemical ecology. Moreover, integration of biological control with other techniques, such as behavioural manipulation of adult stink bugs and plant resistance, may be a sustainable pest control method within organic farming and integrated pest management programs. However, additional field studies are needed to verify the efficacy of these novel methods and transfer them from research to application
Bridging the Communication Gap: Artificial Agents Learning Sign Language through Imitation
This paper explores acquiring non-verbal communication skills through learning from demonstrations, with potential applications in sign language comprehension and expression. In particular, we focus on imitation learning for artificial agents, exemplified by teaching a simulated humanoid American Sign Language. We use computer vision and deep learning to extract information from videos, and reinforcement learning to enable the agent to replicate observed actions. Compared to other methods, our approach eliminates the need for additional hardware to acquire information. We demonstrate how the combination of these different techniques offers a viable way to learn sign language. Our methodology successfully teaches 5 different signs involving the upper body (i.e., arms and hands). This research paves the way for advanced communication skills in artificial agents