A Novel Classified Self-Organising Map Applied to Task Assignment

2020 ◽  
Vol 73 (5) ◽  
pp. 1129-1145
Author(s):  
Yun Qu ◽  
Daqi Zhu

With the development of sensor technology, sensor nodes are increasingly being used in underwater environments. The strategy presented in this paper is designed to solve the problem of using a limited number of autonomous underwater vehicles (AUVs) to complete tasks such as data collection from sensor nodes when the number of AUVs is less than the number of target sensors. A novel classified self-organising map algorithm is proposed to solve the problem. First, according to the K-means algorithm, targets are classified into groups that are determined by the number of AUVs. Second, according to the self-organising map algorithm, AUVs are matched with groups. Third, each AUV is provided with the accessible order of the targets in the group. The novel classified self-organising map algorithm can be used not only to reduce the total energy consumption in a multi-AUV system, but also to give the most efficient accessible order of targets for AUVs. Results of simulations conducted to prove the applicability of the algorithm are given.

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3414 ◽  
Author(s):  
Fahad Khan ◽  
Sehar Butt ◽  
Saad Khan ◽  
Ladislau Bölöni ◽  
Damla Turgut

Sensor nodes in underwater sensor networks may acquire data at a higher rate than their ability to communicate over underwater acoustic channels. Autonomous underwater vehicles may mitigate this mismatch by offloading high volumes of data from the sensor nodes and ferrying them to the sink. Such a mode of data transfer results in high latency. Occasionally, these networks need to report high priority events such as catastrophes or intrusions. In such a scenario the expectation is to have a minimal end-to-end delay for event reporting. Considering this, underwater vehicles should schedule their visits to the sensor nodes in a manner that aids efficient reporting of high-priority events. We propose the use of the Value of Information metric in order to improve the reporting of events in an underwater sensor network. The proposed approach classifies the recorded data in terms of its value and priority. The classified data is transmitted using a combination of acoustic and optical channels. We perform experiments with a binary event model, i.e., we classify the events into high-priority and low-priority events. We explore a couple of different path planning strategies for the autonomous underwater vehicle. Our results show that scheduling visits to sensor nodes, based on algorithms that address the value of information, improves the timely reporting of high priority data and enables the accumulation of larger value of information.


Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4110 ◽  
Author(s):  
Xingwang Wang ◽  
Debing Wei ◽  
Xiaohui Wei ◽  
Junhong Cui ◽  
Miao Pan

In this paper, we target solving the data gathering problem in underwater wireless sensor networks. In many underwater applications, it is not quick to retrieve sensed data, which gives us the opportunity to leverage mobile autonomous underwater vehicles (AUV) as data mules to periodically collect it. For each round of data gathering, the AUV visits part of the sensors, and the communication between AUV and sensor nodes is a novel high-speed magnetic-induction communication system. The rest of the sensors acoustically transmit their sensed data to the AUV-visit sensors. This paper deploys the HAS 4 (Heuristic Adaptive Sink Sensor Set Selection) algorithm to select the AUV-visited sensors for the purpose of energy saving, AUV cost reduction and network lifetime prolonging. By comparing HAS 4 with two benchmark selection methods, experiment results demonstrate that our algorithm can achieve a better performance.


Author(s):  
Yu Hsien Lin ◽  
Ming Chung Fang ◽  
Hui Hua Chang

This study develops a heuristic searching technique for obstacle-avoidance of autonomous underwater vehicles (AUVs) in varying ocean environments by using the self-tuning fuzzy controller. The corresponding hydrodynamic coefficients for the AUV are obtained by the test of Planar Motion Mechanism (PMM), which serves as the important data inputs for the control system. Subsequently, the self-tuning fuzzy controller would be adopted to command the propulsion of AUVs. The function of obstacle-avoidance is based on the underwater image detection method with the BK triangle sub-product of fuzzy relations which can evaluate the safety and remoteness of the candidate routes and the successive optimal strategic routing can then be selected. In the present simulations, the current effect is used to investigate the maneuvering performance of obstacle-avoidance. Eventually, the present study indicates that the self-tuning fuzzy controller, combined with the image detection technique based on BK triangle sub-product of fuzzy relations, is verified to be a useful searching technique for obstacle-avoidance of AUVs in depth variation.


Author(s):  
Pam Morris

Persuasion overtly foregrounds the self as embodied: physical accidents and sickness are recurrent. Sir Walter Eliot’s belief in the time-defying bodily grace of nobility is subject to Austen’s harshest irony. The transition from vertically ordered place to horizontal space in Persuasion is more extreme than in any other of the completed novels. Anne Elliot’s movement from social exclusiveness to socially inclusive possibility allows Austen to challenge gender and class hierarchies traditionally held to be inborn. Her writerly experimentation expands the possibilities of narrative perspective to encompass the porous boundaries of the physical, the emotional and the rational that constitute any moment of consciousness. Her focalisation techniques in the text look directly towards Woolf’s stylist innovations. A chain of references to guns and shooting gathers into the novel contentious contemporary discursive networks on class relations, notions of masculinity and the nature of creaturely life.


Think India ◽  
2019 ◽  
Vol 22 (2) ◽  
pp. 1-6
Author(s):  
A. Yacob ◽  
S. Veeramani

In the novel, Sweet Tooth, McEwan has employed an ethical code of conduct called, Dysfunction of Relationship. The analysis shows that he tries to convey something extraordinary to the readers. If it is not even the reader to understand such a typical thing, He himself represents a new ethical code of conduct. The character of the novel, Serena is almost a person who is tuned to such a distinct one. It is clear that the character of this type is purely representational. Understanding reality based on situation and ethics has been a new field of study in terms of Post- Theory. Intervening to such aspect of Interpretation, this research article establishes a new study in the writings of Ian McEwan. In the novel, Dysfunction is not on the ‘Self’ but it is on the ‘Other’. The author tries to integrate the function of the Character Serena, instead of fragmenting the self. Hence, Fragmentation makes sense only in the dysfunction of relationship.


Author(s):  
Larisa Botnari

Although very famous, some key moments of the novel In Search of Lost Time, such as those of the madeleine or the uneven pavement, often remain enigmatic for the reader. Our article attempts to formulate a possible philosophical interpretation of the narrator's experiences during these scenes, through a confrontation of the Proustian text with the ideas found in the System of Transcendental Idealism (1800) of the German philosopher F. W. J. Schelling. We thus try to highlight the essential role of the self in Marcel Proust's aesthetic thinking, by showing that the mysterious happiness felt by the narrator, and from which the project of creating a work of art is ultimately born, is similar to the experiences of pure self-consciousness evoked and analyzed by Schellingian philosophy of art.


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