Ad Hoc Communication Topology Switching during Disasters from Altruistic to Individualistic and Back

2020 ◽  
Author(s):  
Indushree Banerjee ◽  
Martijn Warnier ◽  
Frances Brazier
Keyword(s):  
Ad Hoc ◽  
Communication Topology

A Graph-Intersection-Based Algorithm to Determine Maximum Lifetime Communication Topologies for Cognitive Radio Ad Hoc Networks

2019 ◽  
pp. 1215-1225
Author(s):  
Natarajan Meghanathan
Keyword(s):  
Cognitive Radio ◽  
Ad Hoc ◽  
Time Instant ◽  
Upper Bounds ◽  
Secondary User ◽  
Maximum Lifetime ◽  
Communication Topology ◽  
Shortest Path Trees ◽  
Hoc Networks ◽  
Entire Network

The authors propose a generic graph intersection-based benchmarking algorithm to arrive at upper bounds for the lifetimes of any communication topology that spans the entire network of secondary user (SU) nodes in a cognitive radio ad hoc network wherein the SUs attempt to access the licensed channels that are not in use. At any time, instant t when we need a stable communication topology spanning the entire network, the authors look for the largest value of k such that the intersection of the static SU graphs from time instants t to t+k, defined as the mobile graph Gt...t+k(SU) = Gt(SU) ∩ Gt+1(SU) ∩ .... ∩ Gt+k(SU), is connected and Gt...t+k+1(SU) is not connected. The authors repeat the above procedure for the entire network session to determine the sequence of longest-living instances of the mobile graphs and the corresponding instances of the topology of interest such that the number of topology transitions is the global minimum. They prove the theoretical correctness of the algorithm and study its effectiveness by implementing it to determine a sequence of maximum lifetime shortest path trees.

A Graph-Intersection-Based Algorithm to Determine Maximum Lifetime Communication Topologies for Cognitive Radio Ad Hoc Networks

2018 ◽  
pp. 6536-6545
Author(s):  
Natarajan Meghanathan
Keyword(s):  
Cognitive Radio ◽  
Ad Hoc ◽  
Time Instant ◽  
Upper Bounds ◽  
Secondary User ◽  
Maximum Lifetime ◽  
Communication Topology ◽  
Shortest Path Trees ◽  
Hoc Networks ◽  
Entire Network

We propose a generic graph intersection-based benchmarking algorithm to arrive at upper bounds for the lifetimes of any communication topology that spans the entire network of secondary user (SU) nodes in a cognitive radio ad hoc network wherein the SUs attempt to access the licensed channels that are not in use. At any time instant t when we need a stable communication topology spanning the entire network, we look for the largest value of k such that the intersection of the static SU graphs from time instants t to t+k, defined as the mobile graph Gt...t+k(SU) = Gt(SU) n Gt+1(SU) n .... n Gt+k(SU), is connected and Gt...t+k+1(SU) is not connected. We repeat the above procedure for the entire network session to determine the sequence of longest-living instances of the mobile graphs and the corresponding instances of the topology of interest such that the number of topology transitions is the global minimum. We prove the theoretical correctness of the algorithm and study its effectiveness by implementing it to determine a sequence of maximum lifetime shortest path trees.

scholarly journals Relay Based Performance Metrics of Bluetooth Scatternet Scheduling

2018 ◽  
Vol 11 (2) ◽  
pp. 469
Author(s):  
Ramachandran Kanagavalli ◽  
B. Sankaragomathi
Keyword(s):  
Ad Hoc ◽  
Mobile Ad Hoc Network ◽  
Performance Metrics ◽  
Relay Node ◽  
Poor Performance ◽  
Active Devices ◽  
Communication Topology ◽  
Efficient Data ◽  
Mobile Ad Hoc ◽  
Primary Focus

<p>Bluetooth is an emerging mobile ad-hoc network that accredits wireless communication to connect various short range devices.  A single hop network called piconet is the basic communication topology of bluetooth which allows only eight active devices for communication among them seven are active slaves controlled by one master. Multiple piconets are interconnected through a common node, known as Relay, to form a massive network called as Scatternet. It is obvious that the performance of Scatternet scheduling is highly dependent and directly proportionate with the performance of the Relay node.  In contrary, by reducing the number of Relays, it may lead to poor performance, since every Relay has to perform and support several piconet connections.  The primary focus of this study is to observe the performance metrics that affects the inter-piconet scheduling since the Relay node’s role is like switch between multiple piconets. In this paper, we address and analyze the performance issues to be taken into consideration for efficient data flow in Scatternet based on Relay node.</p>

Die COVID-19-Pandemie im akutstationären Setting aus Sicht von Führungspersonen und Hygienefachkräften in der Pflege

Pflege ◽  
2020 ◽  
Vol 33 (5) ◽  
pp. 289-298
Author(s):  
Katharina Silies ◽  
Angelika Schley ◽  
Janna Sill ◽  
Steffen Fleischer ◽  
Martin Müller ◽  
...  
Keyword(s):  
Ad Hoc ◽  
Qualitative Studie ◽  
Skill Mix ◽  
Task Forces

Zusammenfassung. Hintergrund: Die COVID-19-Pandemie ist eine Ausnahmesituation ohne Präzedenz und erforderte zahlreiche Ad-hoc-Anpassungen in den Strukturen und Prozessen der akutstationären Versorgung. Ziel: Ziel war es zu untersuchen, wie aus Sicht von Führungspersonen und Hygienefachkräften in der Pflege die stationäre Akutversorgung durch die Pandemiesituation beeinflusst wurde und welche Implikationen sich daraus für die Zukunft ergeben. Methoden: Qualitative Studie bestehend aus semistrukturierten Interviews mit fünf Verantwortlichen des leitenden Pflegemanagements und drei Hygienefachkräften in vier Krankenhäusern in Deutschland. Die Interviews wurden mittels qualitativer Inhaltsanalyse ausgewertet. Ergebnisse: Die Befragten beschrieben den auf die prioritäre Versorgung von COVID-19-Fällen hin umstrukturierten Klinikalltag. Herausforderungen waren Unsicherheit und Angst bei den Mitarbeiter_innen, relative Ressourcenknappheit von Material und Personal und die schnelle Umsetzung neuer Anforderungen an die Versorgungleistung. Dem wurde durch gezielte Kommunikation und Information, massive Anstrengungen zur Sicherung der Ressourcen und koordinierte Steuerung aller Prozesse durch bereichsübergreifende, interprofessionelle Task Forces begegnet. Schlussfolgerungen: Die in der COVID-19-Pandemie vorgenommenen Anpassungen zeigen Entwicklungspotenziale für die zukünftige Routineversorgung auf, z. B. könnten neue Arbeits- und Skill Mix-Modelle aufgegriffen werden. Für die Konkretisierung praktischer Implikationen sind vertiefende Analysen der Daten mit zeitlichem Abstand erforderlich.

Tests und Tools

2006 ◽  
Vol 5 (2) ◽  
pp. 68-71 ◽  
Author(s):  
Simone Kauffeld
Keyword(s):  
Ad Hoc ◽  
Non Profit

Zusammenfassung. Der FEO, der in Kooperation mit betrieblichen Praktikern entwickelt wurde, dient der Erfassung des Organisationsklimas. Er umfasst 82 Items und bildet 12 Skalen ab. Eine Stärke des FEO im Gegensatz zu ad hoc entwickelten Befragungsinstrumenten sind die Vergleichsdaten, die für Profit- und Non-Profit-Organisationen bereit gestellt werden. Kritisch diskutiert wird die theoretische Verortung, die Anwenderfreundlichkeit sowie der Nutzen der individuellen Auswertung. Die konsensuale, konvergente, diskriminante und kriterienbezogene Validierung steht aus.

Test Use in Spain, Portugal and Latin American Countries

1999 ◽  
Vol 15 (2) ◽  
pp. 151-157 ◽  
Author(s):  
José Muñiz ◽  
Gerardo Prieto ◽  
Leandro Almeida ◽  
Dave Bartram
Keyword(s):  
Latin American ◽  
Ad Hoc ◽  
Task Force ◽  
Test Construction ◽  
European Federation ◽  
Psychometric Characteristics ◽  
Testing Practices ◽  
Professional Psychologists ◽  
Test Use ◽  
Latin American Countries

Summary: The two main sources of errors in educational and psychological evaluation are the lack of adequate technical and psychometric characteristics of the tests, and especially the failure to properly implement the testing process. The main goal of the present research is to study the situation of test construction and test use in the Spanish-speaking (Spain and Latin American countries) and Portuguese-speaking (Portugal and Brazil) countries. The data were collected using a questionnaire constructed by the European Federation of Professional Psychologists Association (EFPPA) Task Force on Tests and Testing, under the direction of D. Bartram . In addition to the questionnaire, other ad hoc data were also gathered. Four main areas of psychological testing were investigated: Educational, Clinical, Forensic and Work. Key persons were identified in each country in order to provide reliable information. The main results are presented, and some measures that could be taken in order to improve the current testing practices in the countries surveyed are discussed. As most of the tests used in these countries were originally developed in other cultures, a problem that appears to be especially relevant is the translation and adaptation of tests.

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