scholarly journals A Multi-Dimension Spatial Method for Topology Awareness and Multipath Generating

Symmetry ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 870 ◽  
Author(s):  
Yunchong Guan ◽  
Weimin Lei ◽  
Wei Zhang ◽  
Yuzhuo Zhan ◽  
Hao Li ◽  
...  
Keyword(s):  
Autonomous System ◽  
Overlay Networks ◽  
Autonomous Systems ◽  
Negative Influence ◽  
Spatial Mechanisms ◽  
Multiple Dimensions ◽  
Transmission Quality ◽  
Spatial Method ◽  
Multipath Diversity ◽  
Topology Awareness

Multipath diversity significantly impacts multipath transmission quality. Enough multipath diversity would minimize the negative influence brought by an individual path, thus improving tolerance capability of network congestion and failure. However, multipath diversity is hard to guarantee on overlay networks because of inaccurate awareness of underlay network and multipath generating methods considering little about underlay diversity. In this paper, we design a multi-dimension spatial method for topology awareness and multipath generating. Analyzing that the complicated underlay networks with multiple autonomous systems reduce the accuracy of network positioning for topology awareness, we decompose the underlay networks into multiple dimensions, namely intra and inter autonomous system dimensions. We generate independent views for each autonomous system and merge views by embedding exchange points. Then, we design some spatial mechanisms to evaluate link diversity and to constrain multipath generating. Based on the multi-dimensional view, multipath generating is conducted in inter and intra autonomous system phases. Experiments demonstrate that the proposed method improves topology awareness accuracy and guarantees multipath diversity better and the transmission quality is improved.

scholarly journals On (h0,h)-stability of autonomous systems

1992 ◽  
Vol 5 (4) ◽  
pp. 331-337 ◽  
Author(s):  
Xinzhi Liu
Keyword(s):  
Asymptotic Stability ◽  
Autonomous System ◽  
Autonomous Systems ◽  
Qualitative Behavior ◽  
Initial Values

In this paper, we discuss the qualitative behavior of a map h along solutions of an autonomous system whose initial values are measured by a second map h0. By doing this, we may deal with, in a unified way, several concepts and associated problems, which are usually considered separately. Five theorems on asymptotic stability are given and two examples are worked out.

scholarly journals Refugees Hosting Other Refugees: Endurance and Maintenance of Care in Ouzaii (Lebanon)

2019 ◽  
Author(s):  
Batoul Yassine ◽  
Howayda Al-Harithy ◽  
Camillo Boano
Keyword(s):  
Humanitarian Aid ◽  
Urban Setting ◽  
Right To The City ◽  
Social Infrastructure ◽  
The Gaze ◽  
Spatial Mechanisms ◽  
Multiple Dimensions ◽  
The Social ◽  
The Everyday ◽  
The City

Abstract This article examines the socio-spatial mechanisms that emerge when refugees host other refugees. It argues that there is an underlying social infrastructure of care that impacts the refugees’ choice of destinations and modes of survival. When refugees host other refugees from close networks of relatives and neighbours, they create their own spatial clusters. In the process, the social infrastructure of care offers one mode of security to vulnerable refugees. Care as a concept and an approach is related to ideas of endurance and maintenance. It facilitates multiple dimensions, from space, to affection and to the everyday. It is able to reconfigure a life possible, life-enduring and a life meaningful in an urban setting. We focus on Ouzaii in Beirut, Lebanon. Ouzaii has been a destination for multiple displaced groups over different periods of time. Ouzaii currently hosts an approximate 10,000 Syrian refugees. They chose Ouzaii as their destination after they were helped by existing refugees who offered shelter and access to jobs. The resultant socio-spatial practices, flourishing businesses and leisurely facilities are evidence of successful social networks that form an infrastructure of care. They also play a role in the reconstitution of Ouzaii itself. We conclude with reflections on how urban informality may offer refugees an alternative right to the city while allowing them to escape the gaze of the humanitarian-aid apparatus that can signify their vulnerability by reducing them to only being aid recipients. Instead, they form protective socio-spatial networks that have proved to be powerful in sustaining their livelihoods, guarding them from possible social discrimination or political threats.

scholarly journals Mathematics of Web science: structure, dynamics and incentives

2013 ◽  
Vol 371 (1987) ◽  
pp. 20120377 ◽  
Author(s):  
Jennifer Chayes
Keyword(s):  
Autonomous System ◽  
World Wide ◽  
Autonomous Systems ◽  
Large Graphs ◽  
Finite Graphs ◽  
Online Networks ◽  
The People ◽  
Web Science ◽  
The World ◽  
Online Experience

Dr Chayes’ talk described how, to a discrete mathematician, ‘all the world’s a graph, and all the people and domains merely vertices’. A graph is represented as a set of vertices V and a set of edges E, so that, for instance, in the World Wide Web, V is the set of pages and E the directed hyperlinks; in a social network, V is the people and E the set of relationships; and in the autonomous system Internet, V is the set of autonomous systems (such as AOL, Yahoo! and MSN) and E the set of connections. This means that mathematics can be used to study the Web (and other large graphs in the online world) in the following way: first, we can model online networks as large finite graphs; second, we can sample pieces of these graphs; third, we can understand and then control processes on these graphs; and fourth, we can develop algorithms for these graphs and apply them to improve the online experience.

scholarly journals OCEANIDS: Building Next Generation Maritime Autonomous Systems

2018 ◽  
Author(s):  
M Furlong ◽  
R Marlow ◽  
S McPhail ◽  
A Munafo ◽  
M Pebody ◽  
...  
Keyword(s):  
Long Range ◽  
Autonomous System ◽  
Technological Development ◽  
Autonomous Systems ◽  
Deep Ocean ◽  
Next Generation ◽  
Hazardous Environments ◽  
Long Duration ◽  
Navigational System ◽  
Long Endurance

Oceanids is a 4-year programme for the technological development of innovative Maritime Autonomous System (MAS) platforms and associated sensors that will include next generation robotic AUVs, sensors and networks to undertake ambitious, long-range, long-endurance deployments in extreme and hazardous environments, such as the deep ocean or under-ice environments. This paper describes the design of two new types of robotic AUVs, the Autosub 2000 Under-Ice and the Autosub Long Range 1500 vehicles that are being developed under the programme. Two key components of the AUVs are described, the autonomy framework and the navigational system, which relies on a newly developed terrain-aided navigation (TAN) system. At-sea results of the TAN are also reported as obtained during long duration operational deployments done in 2017. 

scholarly journals Algorithmic Bias in Autonomous Systems

2017 ◽  
Author(s):  
David Danks ◽  
Alex John London
Keyword(s):  
Autonomous System ◽  
Autonomous Systems ◽  
Descriptive Term ◽  
Proper Functioning ◽  
Different Types ◽  
Algorithmic Bias

Algorithms play a key role in the functioning of autonomous systems, and so concerns have periodically been raised about the possibility of algorithmic bias. However, debates in this area have been hampered by different meanings and uses of the term, "bias." It is sometimes used as a purely descriptive term, sometimes as a pejorative term, and such variations can promote confusion and hamper discussions about when and how to respond to algorithmic bias. In this paper, we first provide a taxonomy of different types and sources of algorithmic bias, with a focus on their different impacts on the proper functioning of autonomous systems. We then use this taxonomy to distinguish between algorithmic biases that are neutral or unobjectionable, and those that are problematic in some way and require a response. In some cases, there are technological or algorithmic adjustments that developers can use to compensate for problematic bias. In other cases, however, responses require adjustments by the agent, whether human or autonomous system, who uses the results of the algorithm. There is no "one size fits all" solution to algorithmic bias.

A Hierarchical Approach to Reduce Power Consumption in Core and Edge Networks

2014 ◽  
pp. 164-194
Author(s):  
Shankar Raman ◽  
Balaji Venkat ◽  
Gaurav Raina
Keyword(s):  
Fault Tolerance ◽  
Low Power ◽  
Traffic Engineering ◽  
Autonomous System ◽  
Autonomous Systems ◽  
Hierarchical Approach ◽  
Unique Challenge ◽  
Reduce Power Consumption ◽  
Data Packets ◽  
Edge Networks

With unicast, the metric is used to determine a low-power path between sources and destinations. The source and destination entities could be attached to Autonomous Systems (ASes) or to routing areas within the Autonomous System. Determining a low-power path within an Autonomous System provides a unique challenge as the topology of the constituent areas may not be known. To that end, we propose the use of a selective leak technique for disclosing low-power paths. Additionally, the proposed method can also be used to determine disjoint or redundant paths for load-balancing or fault tolerance. With multicast, the metric serves the twin purpose of finding low-power multicast paths as well as multicast replication points. Once low-power paths in either the unicast or the multicast cases are identified, then currently available traffic engineering techniques could be used to route the data packets.

Advanced Alert and Warning Systems

2012 ◽  
Vol 594-597 ◽  
pp. 2232-2236 ◽  
Author(s):  
Ivana Turekova ◽  
Zuzana Turňová ◽  
Martin Pastier
Keyword(s):  
Autonomous System ◽  
Systematic Approach ◽  
Autonomous Systems ◽  
Warning Systems ◽  
Industrial Accidents ◽  
Technical Standards

Modern autonomous systems (AUS) correspond to the current global technical standards and European principles of prevention of industrial accidents. Their construction requires a purposeful and systematic approach of investors. The paper presents an elaborated standard project of an autonomous system with ammonia as a kind of refrigerant for an ice rink. The implementation of the proposed project can make the process of warning and alerting the population in danger more effective.

scholarly journals Reliability and Safety of Autonomous Systems Based on Semantic Modelling for Self-Certification

Robotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 10
Author(s):  
Osama Zaki ◽  
Matthew Dunnigan ◽  
Valentin Robu ◽  
David Flynn
Keyword(s):  
Autonomous System ◽  
Autonomous Systems ◽  
Dynamic Environment ◽  
Computational Time ◽  
Finite State Automaton ◽  
Confined Space ◽  
Semantic Relationships ◽  
Autonomous Operation ◽  
Finite State ◽  
Run Time

A novel modelling paradigm for online diagnostics and prognostics for autonomous systems is presented. A model for the autonomous system being diagnosed is designed using a logic-based formalism. The model supports the run-time ability to verify that the autonomous system is safe and reliable for operation within a dynamic environment. The paradigm is based on the philosophy that there are different types of semantic relationships between the states of different parts of the system. A finite state automaton is devised for each sensed component and some of the non-sensed components. To capture the interdependencies of components within such a complex robotic platform, automatons were related to each other by semantic relationships. Modality was utilised by the formalism to abstract the relationships and to add measures for the possibility and uncertainty of the relationships. The complexity of the model was analysed to evaluate its scalability and applicability to other systems. The results demonstrate that the complexity is not linear and a computational time of 10 ms was required to achieve run-time diagnostics for 2200 KB of knowledge for complex system interdependences. The ability to detect and mitigate hardware related failures was demonstrated within a confined space autonomous operation. Our findings provide evidence of the applicability of our approach for the significant challenge of run-time safety compliance and reliability in autonomous systems.

scholarly journals Induced dynamics in hyperspaces of non-autonomous discrete systems

Filomat ◽  
2019 ◽  
Vol 33 (7) ◽  
pp. 1911-1920
Author(s):  
Radhika Vasisht ◽  
Ruchi Das
Keyword(s):  
Dynamical System ◽  
Autonomous System ◽  
Autonomous Systems ◽  
Discrete Systems ◽  
Vietoris Topology ◽  
Shadowing Property ◽  
Dynamical Properties ◽  
Autonomous Dynamical System ◽  
Compact Subsets

In this paper, the interrelations of some dynamical properties of a non-autonomous dynamical system (X, f1, ?) and its induced non-autonomous dynamical system (K(X), f1, ?) are studied, where K(X) is the hyperspace of all non-empty compact subsets of X, endowed with Vietoris topology. Various stronger forms of sensitivity and transitivity are considered. Some examples of non-autonomous systems are provided to support the results. A relation between shadowing property of the non-autonomous system (X, f1, ?) and its induced system (K(X), f1, ?) is studied.

scholarly journals On constructing single-input non-autonomous systems of full rank

2018 ◽  
Keyword(s):  
Vector Field ◽  
Nonlinear System ◽  
Differential Equations ◽  
Autonomous System ◽  
Vector Fields ◽  
Autonomous Systems ◽  
Full Rank ◽  
System Of Differential Equations ◽  
Single Input ◽  
Class C

For a nonlinear system of differential equations $\dot x=f(x)$, a method of constructing a system of full rank $\dot x=f(x)+g(x)u$ is studied for vector fields of the class $C^k$, $1\le k<\infty$, in the case when $f(x)\not=0$. A method for constructing a non-autonomous system of full rank is proposed in the case when the vector field $f(x)$ can vanish.

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