Levels of modeling of mechanisms of visually guided behavior

1987 ◽  
Vol 10 (3) ◽  
pp. 407-436 ◽  
Author(s):  
Michael A. Arbib
Keyword(s):  
Neural Circuits ◽  
Neural Circuitry ◽  
Learning Approach ◽  
Visually Guided ◽  
Visuomotor Coordination ◽  
Prey Recognition ◽  
High Level ◽  
Organizational Principles ◽  
Different Levels ◽  
Dextrous Hands

AbstractIntermediate constructs are required as bridges between complex behaviors and realistic models of neural circuitry. For cognitive scientists in general, schemas are the appropriate functional units; brain theorists can work with neural layers as units intermediate between structures subserving schemas and small neural circuits.After an account of different levels of analysis, we describe visuomotor coordination in terms of perceptual schemas and motor schemas. The interest of schemas to cognitive science in general is illustrated with the example of perceptual schemas in high-level vision and motor schemas in the control of dextrous hands.Rana computatrix, the computational frog, is introduced to show how one constructs an evolving set of model families to mediate flexible cooperation between theory and experiment. Rana computatrix may be able to do for the study of the organizational principles of neural circuitry what Aplysia has done for the study of subcellular mechanisms of learning. Approach, avoidance, and detour behavior in frogs and toads are analyzed in terms of interacting schemas. Facilitation and prey recognition are implemented as tectal-pretectal interactions, with the tectum modeled by an array of tectal columns. We show how layered neural computation enters into models of stereopsis and how depth schemas may involve the interaction of accommodation and binocular cues in anurans.

scholarly journals Aircraft Requirements for Sustainable Regional Aviation

Aerospace ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 61
Author(s):  
Dominik Eisenhut ◽  
Nicolas Moebs ◽  
Evert Windels ◽  
Dominique Bergmann ◽  
Ingmar Geiß ◽  
...  
Keyword(s):  
Systems Engineering ◽  
System Level ◽  
Policy Initiative ◽  
The European Union ◽  
Calculation Methods ◽  
Figures Of Merit ◽  
Performance Requirements ◽  
High Level ◽  
Different Levels ◽  
The Eu

Recently, the new Green Deal policy initiative was presented by the European Union. The EU aims to achieve a sustainable future and be the first climate-neutral continent by 2050. It targets all of the continent’s industries, meaning aviation must contribute to these changes as well. By employing a systems engineering approach, this high-level task can be split into different levels to get from the vision to the relevant system or product itself. Part of this iterative process involves the aircraft requirements, which make the goals more achievable on the system level and allow validation of whether the designed systems fulfill these requirements. Within this work, the top-level aircraft requirements (TLARs) for a hybrid-electric regional aircraft for up to 50 passengers are presented. Apart from performance requirements, other requirements, like environmental ones, are also included. To check whether these requirements are fulfilled, different reference missions were defined which challenge various extremes within the requirements. Furthermore, figures of merit are established, providing a way of validating and comparing different aircraft designs. The modular structure of these aircraft designs ensures the possibility of evaluating different architectures and adapting these figures if necessary. Moreover, different criteria can be accounted for, or their calculation methods or weighting can be changed.

scholarly journals Mutual Impact between Clock Gating and High Level Synthesis in Reconfigurable Hardware Accelerators

Electronics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 73
Author(s):  
Francesco Ratto ◽  
Tiziana Fanni ◽  
Luigi Raffo ◽  
Carlo Sau
Keyword(s):  
Low Power ◽  
Integrated Circuit ◽  
Systems Design ◽  
Hardware Acceleration ◽  
High Level Synthesis ◽  
Clock Gating ◽  
Technology Application ◽  
Positive Effects ◽  
High Level ◽  
Different Levels

With the diffusion of cyber-physical systems and internet of things, adaptivity and low power consumption became of primary importance in digital systems design. Reconfigurable heterogeneous platforms seem to be one of the most suitable choices to cope with such challenging context. However, their development and power optimization are not trivial, especially considering hardware acceleration components. On the one hand high level synthesis could simplify the design of such kind of systems, but on the other hand it can limit the positive effects of the adopted power saving techniques. In this work, the mutual impact of different high level synthesis tools and the application of the well known clock gating strategy in the development of reconfigurable accelerators is studied. The aim is to optimize a clock gating application according to the chosen high level synthesis engine and target technology (Application Specific Integrated Circuit (ASIC) or Field Programmable Gate Array (FPGA)). Different levels of application of clock gating are evaluated, including a novel multi level solution. Besides assessing the benefits and drawbacks of the clock gating application at different levels, hints for future design automation of low power reconfigurable accelerators through high level synthesis are also derived.

scholarly journals Application of an Artificial Neural Network to Automate the Measurement of Kinematic Characteristics of Punches in Boxing

2021 ◽  
Vol 11 (3) ◽  
pp. 1223
Author(s):  
Ilshat Khasanshin
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Kinematic Parameters ◽  
Constant Control ◽  
Measurement Units ◽  
Artificial Neural ◽  
Artificial Neural Network Ann ◽  
Effective Development ◽  
High Level ◽  
Different Levels

This work aimed to study the automation of measuring the speed of punches of boxers during shadow boxing using inertial measurement units (IMUs) based on an artificial neural network (ANN). In boxing, for the effective development of an athlete, constant control of the punch speed is required. However, even when using modern means of measuring kinematic parameters, it is necessary to record the circumstances under which the punch was performed: The type of punch (jab, cross, hook, or uppercut) and the type of activity (shadow boxing, single punch, or series of punches). Therefore, to eliminate errors and accelerate the process, that is, automate measurements, the use of an ANN in the form of a multilayer perceptron (MLP) is proposed. During the experiments, IMUs were installed on the boxers’ wrists. The input parameters of the ANN were the absolute acceleration and angular velocity. The experiment was conducted for three groups of boxers with different levels of training. The developed model showed a high level of punch recognition for all groups, and it can be concluded that the use of the ANN significantly accelerates the collection of data on the kinetic characteristics of boxers’ punches and allows this process to be automated.

scholarly journals Model-Driven Architectural Framework towards Safe and Secure Nuclear Power Reactors

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5136
Author(s):  
Bassem Ouni ◽  
Christophe Aussagues ◽  
Saadia Dhouib ◽  
Chokri Mraidha
Keyword(s):  
Nuclear Power ◽  
Nuclear Reactors ◽  
System Development ◽  
Levels Of Abstraction ◽  
Model Driven ◽  
Case System ◽  
Architectural Framework ◽  
Performance Check ◽  
High Level ◽  
Different Levels

Sensor-based digital systems for Instrumentation and Control (I&C) of nuclear reactors are quite complex in terms of architecture and functionalities. A high-level framework is highly required to pre-evaluate the system’s performance, check the consistency between different levels of abstraction and address the concerns of various stakeholders. In this work, we integrate the development process of I&C systems and the involvement of stakeholders within a model-driven methodology. The proposed approach introduces a new architectural framework that defines various concepts, allowing system implementations and encompassing different development phases, all actors, and system concerns. In addition, we define a new I&C Modeling Language (ICML) and a set of methodological rules needed to build different architectural framework views. To illustrate this methodology, we extend the specific use of an open-source system engineering tool, named Eclipse Papyrus, to carry out many automation and verification steps at different levels of abstraction. The architectural framework modeling capabilities will be validated using a realistic use case system for the protection of nuclear reactors. The proposed framework is able to reduce the overall system development cost by improving links between different specification tasks and providing a high abstraction level of system components.

scholarly journals Saliency Detection by Multilevel Deep Pyramid Model

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Hai Wang ◽  
Lei Dai ◽  
Yingfeng Cai ◽  
Long Chen ◽  
Yong Zhang
Keyword(s):  
Background Noise ◽  
State Of The Art ◽  
Saliency Detection ◽  
Saliency Map ◽  
Multiple Features ◽  
Low Level ◽  
Pyramid Model ◽  
High Level ◽  
Different Levels ◽  
Better Than

Traditional salient object detection models are divided into several classes based on low-level features and contrast between pixels. In this paper, we propose a model based on a multilevel deep pyramid (MLDP), which involves fusing multiple features on different levels. Firstly, the MLDP uses the original image as the input for a VGG16 model to extract high-level features and form an initial saliency map. Next, the MLDP further extracts high-level features to form a saliency map based on a deep pyramid. Then, the MLDP obtains the salient map fused with superpixels by extracting low-level features. After that, the MLDP applies background noise filtering to the saliency map fused with superpixels in order to filter out the interference of background noise and form a saliency map based on the foreground. Lastly, the MLDP combines the saliency map fused with the superpixels with the saliency map based on the foreground, which results in the final saliency map. The MLDP is not limited to low-level features while it fuses multiple features and achieves good results when extracting salient targets. As can be seen in our experiment section, the MLDP is better than the other 7 state-of-the-art models across three different public saliency datasets. Therefore, the MLDP has superiority and wide applicability in extraction of salient targets.

scholarly journals Working memory gates visual input to primate prefrontal neurons

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Behrad Noudoost ◽  
Kelsey Lynne Clark ◽  
Tirin Moore
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Sensory Input ◽  
Neural Circuits ◽  
Visual Input ◽  
Visually Guided ◽  
Visual Neurons ◽  
Cortical Inputs ◽  
Behaving Monkeys ◽  
Visual Cortical

Visually guided behavior relies on the integration of sensory input and information held in working memory (WM). Yet it remains unclear how this is accomplished at the level of neural circuits. We studied the direct visual cortical inputs to neurons within a visuomotor area of prefrontal cortex in behaving monkeys. We show that the efficacy of visual input to prefrontal cortex is gated by information held in WM. Surprisingly, visual input to prefrontal neurons was found to target those with both visual and motor properties, rather than preferentially targeting other visual neurons. Furthermore, activity evoked from visual cortex was larger in magnitude, more synchronous, and more rapid, when monkeys remembered locations that matched the location of visual input. These results indicate that WM directly influences the circuitry that transforms visual input into visually guided behavior.

scholarly journals Spatiotemporal Evaluation of The Human Footprint in Colombia: Four Decades of Anthropic Impact in Highly Biodiverse Ecosystems

2020 ◽  
Author(s):  
Camilo Andrés Correa Ayram ◽  
Andres Etter ◽  
Jhonatan Julián Díaz-Timoté ◽  
Susana Rodríguez Buriticá ◽  
Wilson Ramírez ◽  
...  
Keyword(s):  
Land Use Planning ◽  
Anthropic Impact ◽  
Natural Systems ◽  
Goods And Services ◽  
Human Footprint ◽  
Ecosystem Risk ◽  
Valle Del Cauca ◽  
High Level ◽  
Different Levels ◽  
Risk Categories

ABSTRACTThe maintenance of biodiversity and the capacity of natural systems to provide goods and services for people is affected on different levels by the intensity of human activities on ecosystems. In this study, we apply a Legacy-adjusted Human Footprint Index (LHFI) to evaluate the spatiotemporal variation of anthropic impact in Colombia in 1970, 1990, 2000 and 2015. We identified hotspots of change in LHFI and we evaluated the intensity of anthropic pressures in natural regions and ecosystems. We found that LHFI in Colombia increased between 1970 and 2015. The Andean and Caribbean regions presented the highest levels of anthropic impact, remaining stable over time. Hotspots of change were mainly located in the following regions: Andean (Antioquia, Cauca and Valle del Cauca states), Amazon (Amazonas, parts of Meta, Guaviare and Putumayo states) and Orinoco (Casanare and parts of Meta and Vichada states). In addition, ecosystems that under the IUCN ecosystem risk categories are Critically Endangered (CR) and Vulnerable (VU) were the most affected by a high level of human impact. Spatiotemporal evaluation of the human footprint in Colombia provides new insights about trends in human pressures on ecosystems and constitutes an analytical tool with high potential for harmonizing land use planning and biodiversity conservation.

scholarly journals Neural Changes Underlying Rapid Fly Song Evolution

2017 ◽  
Author(s):  
Yun Ding ◽  
Joshua L. Lillvis ◽  
Jessica Cande ◽  
Gordon J. Berman ◽  
Benjamin J. Arthur ◽  
...  
Keyword(s):  
Nervous System ◽  
Drosophila Melanogaster ◽  
Experimental Approach ◽  
Neural Circuits ◽  
Neural Circuitry ◽  
Courtship Song ◽  
Neural Basis ◽  
Electrophysiological Properties ◽  
Song Types ◽  
Behavioural Diversity

AbstractThe neural basis for behavioural evolution is poorly understood. Functional comparisons of homologous neurons may reveal how neural circuitry contributes to behavioural evolution, but homologous neurons cannot be identified and manipulated in most taxa. Here, we compare the function of homologous courtship song neurons by exporting neurogenetic reagents that label identified neurons in Drosophila melanogaster to D. yakuba. We found a conserved role for a cluster of brain neurons that establish a persistent courtship state. In contrast, a descending neuron with conserved electrophysiological properties drives different song types in each species. Our results suggest that song evolved, in part, due to changes in the neural circuitry downstream of this descending neuron. This experimental approach can be generalized to other neural circuits and therefore provides an experimental framework for studying how the nervous system has evolved to generate behavioural diversity.

The state of the adrenal cortex in cows with different levels of productivity and their breed affiliation

2021 ◽  
pp. 59-65
Author(s):  
V. Eremenko ◽  
О. Sein ◽  
К. Leshchukov ◽  
G. Gorozhankina ◽  
A. Sidorov
Keyword(s):  
Adrenal Cortex ◽  
Functional Activity ◽  
Cortisol Concentration ◽  
Milk Productivity ◽  
Subsequent Increase ◽  
Functional Load ◽  
Lactating Cows ◽  
Functional Reserves ◽  
High Level ◽  
Different Levels

Purpose: the goal is to study the condition and functional reserves of adrenal cortex in cows with different levels of dairy productivity and their breed accessories.Materials and methods. In the first experience, the object of the study was cows of a holstered black-motley breed with a high and relatively low level of milk productivity (n = 10 in each group). The second experience was carried out on four breeds of lactating cows: Holsteinated black-made, red-made, Montbeliard and Jersey (n = 10 in each group). The blood of animals were taken from the tail vein 1 time per month during lactation to morning feeding. In both experiments, in the third month of lactation, all animals were performed by a two-time functional load of ACTH (dose – 0,5 units / kg of alive mass intramuscularly). After one hour, blood selection was performed and re-injected by adrenocorticotropic hormone in the same dose. After the second introduction, the ACTH was selected through 1.2 and 3 hours. The calculation of the index of the functional activity of the adrenal cortex was carried out according to the JACN = K2 / K1 formula where K1 is the level of cortisol 1 hour after the first load, K2 is the level of cortisol after the second load of the ACTH.Results. In the 1st experience of the highest values, the level of cortisol reached a 3 month lactation. In a highly productive group, the level of cortisol was 86,1 ± 5,3 nmol / l, and in the low product group 74,5 ± 5,7 nmol / l. At 8 months, the lowest cortisol concentration levels are fixed, followed by an increase of 10 months. Differences between groups on 2, 3 and 4 months of lactation are noted as statistically significant (p<0,05). After the load of the ACTH, an index of the functional activity of the adrenal cortex (JACN) was established - in the first high productive group, it was 1.42, and in the second less productive group it was lower and amounted to 1,04.In the 2nd experience at the peak of lactation, which also corresponded to 3 months, the level of cortisol concentration increased from a holstered black-motley breed, Mont Belärd, Red-motley and Jersey to 79,3 ± 5,5; 70,2 ± 3,7; 80,3 ± 3,2; 80,5 ± 3,6 nmol / l, respectively. For 8 months of lactation, this figure decreased with the subsequent increase of the 10th month. After establishing Jacnes in a holstered black-motley breed, Montbeliard, red-motley and jersey recorded the following indicators: 1,21; 1,24; 1,18 and 0,89, respectively.Conclusion. The studies have indicated that in all periods of lactation relative to the high level of cortisol recorded in cows with a higher level of milk productivity. When comparing different rocks, it was established that the limit of the functioning of the adrenal glands in the cows of the Jersey breed was implemented after the first functional load of the ACTH, which gives reason to consider it less stress-resistant with respect to rocks a holstered black and motley, red-motley and monobeldam.

Sign in / Sign up

Export Citation Format

Share Document