From pre‐activation to pre‐updating: A threshold mechanism for commitment to strong predictions

2021 ◽  
Author(s):  
Tal Ness ◽  
Aya Meltzer‐Asscher
Keyword(s):  
Threshold Mechanism

scholarly journals Modelling and Optimization of Multi-Service Optical Switching Networks with Threshold Management Mechanisms

Electronics ◽  
2021 ◽  
Vol 10 (13) ◽  
pp. 1515
Author(s):  
Maciej Sobieraj ◽  
Piotr Zwierzykowski ◽  
Erich Leitgeb
Keyword(s):  
Optical Networks ◽  
Traffic Management ◽  
Optical Switching ◽  
Optical Network ◽  
Research Work ◽  
Simulation Environment ◽  
Switching Networks ◽  
Traffic Characteristics ◽  
Threshold Mechanism ◽  
Optical Switching Networks

DWDM networks make use of optical switching networks that allow light waves of multiple lengths to be serviced and provide the possibility of converting them appropriately. Research work on optical switching networks focuses on two main areas of interest: new non-blocking structures for optical switching networks and finding traffic characteristics of switching networks of the structures that are already well known. In practical design of switching nodes in optical networks, in many cases, the Clos switching networks are successfully used. Clos switching networks are also used in Elastic Optical Networks that can effectively manage allocation of resources to individual multi-service traffic streams. The research outcomes presented in this article deal with the problems of finding traffic characteristics in blocking optical switching networks with known structures. This article aims at presenting an analysis of the influence of traffic management threshold mechanisms on the traffic characteristics of multi-service blocking Clos switching networks that are used in the nodes of elastic optical networks as well as their influence on the traffic efficiency of network nodes. The analysis was carried out on the basis of research studies performed in a specially dedicated purpose-made simulation environment. The article presents a description of the simulation environment used in the experiments. The study was focused on the influence of the threshold mechanism, which is one of the most commonly used and elastic traffic management mechanisms, and on the traffic characteristics of switching networks that service different mixtures of multi-service Erlang, Engset and Pascal traffic streams. The conducted study validates the operational effectiveness and practicality of the application of the threshold mechanism to model traffic characteristics of nodes in an elastic optical network.

All-or-none craniorachischisis in Loop-tail mutant mouse chimeras

Development ◽  
1990 ◽  
Vol 110 (1) ◽  
pp. 229-237 ◽  
Author(s):  
T.S. Musci ◽  
R.J. Mullen
Keyword(s):  
Neural Tube ◽  
Mutant Gene ◽  
Mutant Phenotype ◽  
Progeny Testing ◽  
Wild Type ◽  
Glucose Phosphate ◽  
Threshold Mechanism ◽  
Mutant Cells ◽  
Intermediate Expression ◽  
Gross Examination

Mouse embryos homozygous for the mutant gene Loop-tail (Lp) are characterized by craniorachischisis, an open neural tube extending from the midbrain to the tail. In the present study, experimental chimeric mice containing mixtures of genetically mutant (from Lp/+ × Lp/+ matings) and genetically normal cells were produced. Our aim was to determine whether a ‘rescue,’ phenotypic gradient, or intermediate expression (i.e. alternating areas of open and closed neural tube) would be observed in these chimeras. We report our analyses of Loop-tail mutant chimeras (n = 82) by gross examination, progeny testing and quantitative analysis of glucose phosphate isomerase (GPI) isozyme levels. An all-or-none craniorachischisis in Loop-tail mutant chimeras was observed. Two multicolored adult chimeras, without any gross evidence of a neural tube defect, were shown to be homozygous Loop-tail chimeras (Lp/Lp in equilibrium +/+) by progeny testing. These results indicate that the normal phenotype can be expressed in the presence of mutant cells. Conversely, six neonates with craniorachischisis were shown to be chimeras by GPI analyses. These results show that the full mutant phenotype can be expressed even when one-third to one-half of the cells are genotypically wild-type. This study did not determine which tissue is primarily responsible for the defective neurulation in this mutant, but suggests that a ‘threshold’ mechanism underlies the Loop-tail mutant phenotype. In some chimeras that threshold is not reached and the neural tube remains open, whereas in other chimeras the threshold is reached and the neural tube closes completely.

The tabby syndrome in the mouse

1971 ◽  
Vol 179 (1055) ◽  
pp. 139-156 ◽  
Keyword(s):  
Critical Point ◽  
X Chromosome ◽  
Neural Tube ◽  
X Chromosome Inactivation ◽  
Cellular Level ◽  
Normal Allele ◽  
Linked Gene ◽  
Intercellular Interactions ◽  
Threshold Mechanism ◽  
Otic Vesicles

The tabby syndrome in the mouse (which is common to the sex-linked gene for tabby and autosomal genes for crinkled and downless) affects the coat, the sinus hairs, the teeth, many glands and some surface features like tail rings, plicae digitales and the papilla vallata of the tongue. All these structures develop by the downgrowth of solid epithelial buds into the underlying mesenchyme. Organs which arise by invagination (like the neural tube or the otic vesicles and certain glands) are not affected by the tabby syndrome. The rudiments of glands and sinus hairs are reduced in size, and if reduction goes beyond a critical point, stunted organs are formed or, more commonly, the rudiments regress altogether. The same is true for the teeth and apparently for the whole syndrome. Measurements show the same situation in Ta ♂♂(and Ta/Ta ♀♀) and in heterozygous Ta / + ♀♀. As in Ta ♂♂ and Ta/Ta ♀♀ there cannot be any doubt that a threshold mechanism is involved, there is no reason to assume that, in Ta / + ♀♀, the identical defects are derived clonally from ancestral cells in which the Xchromosome carrying the normal allele has been inactivated. Whereas the Ta / + phenotype does not give any evidence that the Ta locus is involved in X-chromosome inactivation, the possibility cannot be ruled out that, if inactivation should actually take place on the cellular level, the macroscopic phenotype could be the result of intercellular interactions along with the effects of threshold mechanisms.

Chloride Titration in the Dog: The Influence of Extracellular Fluid Expansion on the Pattern of Chloride Reabsorption

1973 ◽  
Vol 44 (4) ◽  
pp. 385-395 ◽  
Author(s):  
J. J. Cohen ◽  
Y. Bar-Khayim ◽  
S. Garella ◽  
J. A. Chazan
Keyword(s):  
Wide Spectrum ◽  
Extracellular Fluid ◽  
Chloride Concentration ◽  
Specific Pattern ◽  
Sodium Reabsorption ◽  
Elevated Plasma ◽  
Chloride Homeostasis ◽  
Threshold Mechanism ◽  
Two Factors ◽  
Plasma Chloride

1. The technique of chloride titration was employed in twenty dogs to determine the pattern of renal chloride handling in response to systematic increases in filtered chloride load. The influence of variations in sodium reabsorption on this pattern was also assessed by producing a wide spectrum of volume expansion during the titration protocols. 2. The results indicate that chloride reabsorption is proportional both to the rate of chloride filtration and to the rate of sodium reabsorption and, hence, that the specific pattern of each chloride titration curve is the fortuitous consequence of the interplay between these two factors. 3. The rate of chloride reabsorption relative to the simultaneous rate of sodium reabsorption was used as an index of the ability of the kidney to maintain chloride homeostasis and indicated that the kidney invariably tends to return depressed. plasma chloride concentration towards normal but, under the conditions of these acute experiments, consistently tends to reduce elevated plasma chloride concentration only when cation reabsorption is markedly depressed. 4. The present observations do not elucidate the mechanism responsible for these findings but suggest that plasma chloride concentration is not regulated through the operation of a threshold mechanism.

A novel topology identification method based on compressive sensing for multidimensional networks

2020 ◽  
Vol 34 (30) ◽  
pp. 2050294
Author(s):  
Shuheng Fang ◽  
Zhengmin Kong ◽  
Ping Hu ◽  
Li Ding
Keyword(s):  
Compressive Sensing ◽  
Matching Pursuit ◽  
Network Models ◽  
Reconstruction Algorithm ◽  
Identification Problem ◽  
Topology Identification ◽  
Network Recovery ◽  
Threshold Mechanism ◽  
Different Types ◽  
2D Network

In real-world scenarios, it is difficult to know about the complete topology of a huge network with different types of links. In this brief, we propose a method to identify the topology of multidimensional networks from information transmission data. We consider information propagating over edges of a two-dimensional (2D) network, where one type of links is known and the other type is unknown. Given the state of all nodes at each unit time, we can transform the topology identification problem into a compressive sensing framework. A modified reconstruction algorithm, called Sparsity Adaptive Matching Pursuit with Mixed Threshold Mechanism (SAMPMTM), is proposed to tackle the problem. Compared with the classical Sparsity Adaptive Matching Pursuit (SAMP) algorithm, the proposed SAMPMTM algorithm can reduce the conflict rate and improve the accuracy of network recovery. We further demonstrate the performance of this improved algorithm through Monte-Carlo simulations under different network models.

scholarly journals Sensor Fusion-Based Cooperative Trail Following for Autonomous Multi-Robot System

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 823 ◽  
Author(s):  
Mingyang Geng ◽  
Shuqi Liu ◽  
Zhaoxia Wu
Keyword(s):  
Sensor Fusion ◽  
Sensor Data ◽  
Great Success ◽  
Trail Following ◽  
Robust Performance ◽  
Robot System ◽  
Threshold Mechanism ◽  
Local View ◽  
In The Wild

Autonomously following a man-made trail in the wild is a challenging problem for robotic systems. Recently, deep learning-based approaches have cast the trail following problem as an image classification task and have achieved great success in the vision-based trail-following problem. However, the existing research only focuses on the trail-following task with a single-robot system. In contrast, many robotic tasks in reality, such as search and rescue, are conducted by a group of robots. While these robots are grouped to move in the wild, they can cooperate to lead to a more robust performance and perform the trail-following task in a better manner. Concretely, each robot can periodically exchange the vision data with other robots and make decisions based both on its local view and the information from others. This paper proposes a sensor fusion-based cooperative trail-following method, which enables a group of robots to implement the trail-following task by fusing the sensor data of each robot. Our method allows each robot to face the same direction from different altitudes to fuse the vision data feature on the collective level and then take action respectively. Besides, considering the quality of service requirement of the robotic software, our method limits the condition to implementing the sensor data fusion process by using the “threshold” mechanism. Qualitative and quantitative experiments on the real-world dataset have shown that our method can significantly promote the recognition accuracy and lead to a more robust performance compared with the single-robot system.

Hiding Images Using Dynamic Bit-Replacement and Human Visual System

2002 ◽  
pp. 190-205
Author(s):  
Chin-Chen Chang ◽  
Kuo-Feng Hwang
Keyword(s):  
Visual System ◽  
Human Visual System ◽  
Main Idea ◽  
Cover Image ◽  
Two Dimensional ◽  
Hiding Capacity ◽  
Partial Encryption ◽  
Secret Image ◽  
Threshold Mechanism ◽  
Human Eyes

A simple image hiding scheme in spatial domain is proposed in this chapter. The main idea is to utilize a threshold mechanism to embed as much information of the secret image into the cover image as possible. The changing of the cover image is hard to be discovered by the human eyes because the threshold mechanism is setup especially to fit the human visual system. The experimental results show that the human visual system has improved the quality in terms of perceptibility. On the hiding capacity issue, the proposed method has capability to embed two times the size of the secret image of previous work. A partial encryption strategy is used for the security of the secret image. In addition, a two-dimensional permutation function, torus automorphism, is also introduced in this chapter.

Initiation of each avian inspiration by a CO2 threshold mechanism

1979 ◽  
Vol 47 (1) ◽  
pp. 233-239 ◽  
Author(s):  
D. A. Miller ◽  
A. L. Kunz
Keyword(s):  
Threshold Model ◽  
Co2 Concentration ◽  
Threshold Level ◽  
Mean Value ◽  
Wave Form ◽  
Time Interval ◽  
Threshold Mechanism ◽  
The Mean ◽  
The Relationship ◽  
Respiratory Movements

The avian respiratory oscillator has been investigated in a unidirectionally ventilated chicken by changing the dynamic pattern of inflow CO2 concentration (FCO2). Stimulation with periodic FCO2 results in a one-to-one synchronization of the respiratory movements that we have called pacing (Respir. Physiol. 22: 167--177, 1974). A two-parameter CO2 threshold model is proposed to explain this behavior. The model states that when FCO2 reaches a threshold level (L), it initiates the beginning of inspiration a constant time interval (LB) later. According to this model, when a triangular FCO2 concentration is used to synchronize the breathing pattern, the time from the minimum of the wave form to the beginning of inspiration (C-B interval) is dependent on the mean value and the rate of rise of FCO2 as determined by period and amplitude of the triangle. Particularly interesting is the prediction that the direction of the relationship (increasing or decreasing) between FCO2 amplitude and the C-B interval is dependent on whether the mean value of FCO2 is above or below the threshold level. Experimental data obtained during amplitude changes support the above prediction.

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