Group Communication Mechanism Research Articles

Memes Contest: The Group Communication Mechanism of Internet Memes in Group Emoji Competition

Memes Contest: The Group Communication Mechanism of Internet Memes in Group Emoji Competition

Online Support Group Participation and Social Support: Incorporating Identification and Interpersonal Bonds

An increasing number of people with chronic diseases exchange social support using online support groups (OSGs). However, there is little understanding of group communication mechanisms that underpin the relationship between OSG participation and social support. Drawing on Prentice, Miller, and Lightdale’s common-identity and common-bond framework, we propose and test a theoretical model that explains group communication mechanisms through which members’ participation influences their perceived social support. In the process, we identified and empirically validated a three-factor solution for an OSG participation scale. Based on 356 users across 12 popular OSGs, we find that two group communication mechanisms—identification with the community and interpersonal bonds with other members—mediate the relationship between OSG participation and perceived social support. Specifically, identification has a stronger mediating effect than interpersonal bonds in the relationship between OSG participation and perceived social support. We also discuss theoretical and practical implications.

ONTOLOGY-BASED EMERGENCY MANAGEMENT SYSTEM IN A SOCIAL CLOUD

The need for Emergency Management continually grows as the population and exposure to catastrophic failures increase. The ability to offer appropriate services at these emergency situations can be tackled through group communication mechanisms. The entities involved in the group communication include people, organizations, events, locations and essential services. Cloud computing is a "as a service" style of computing that enables on-demand network access to a shared pool of resources. So this work focuses on proposing a social cloud constituting group communication entities using an open source platform, Eucalyptus. The services are exposed as semantic web services, since the availability of machine-readable metadata (Ontology) will enable the access of these services more intelligently. The objective of this paper is to propose an Ontology-based Emergency Management System in a social cloud and demonstrate the same using emergency healthcare domain.

Secure Multicast Routing Protocol in Manets Using Efficient ECGDH Algorithm

An Ad-hoc Network covers a set of autonomous mobile nodes that communicates through wireless communication in an infrastructure-less environment. Mostly MANETs are used in group communication mechanisms like military applications, emergency search, rescue operations, vehicular ad-hoc communications and mining operations etc. In such type of networks, group communication is takes place by multicasting technique. Communication and collaboration is necessary among the nodes in the groups in multicast protocols. PUMA has the best multicast routing protocol compared to tree and mesh based multicast protocols although it suffers from security issues. PUMA mainly suffers from Man In The middle attack. MITM attack generates traffic flow, drop the packets and miscommunicate the neighbor nodes with false hop count. So defending from MITM attack we designed a new mechanism called Elliptic Curve Group Diffie-Hellman (ECGDH). This paper compares results of PUMA [1] routing protocol with legitimate, under attack and after providing security against attack. Finally we observed ECGDH [2] gives efficient results even attack has happened.

Secure Multicast Routing Protocol in Manets Using Efficient ECGDH Algorithm

An Ad-hoc Network covers a set of autonomous mobile nodes that communicates through wireless communication in an infrastructure-less environment. Mostly MANETs are used in group communication mechanisms like military applications, emergency search, rescue operations, vehicular ad-hoc communications and mining operations etc. In such type of networks, group communication is takes place by multicasting technique. Communication and collaboration is necessary among the nodes in the groups in multicast protocols. PUMA has the best multicast routing protocol compared to tree and mesh based multicast protocols although it suffers from security issues. PUMA mainly suffers from Man In The middle attack. MITM attack generates traffic flow, drop the packets and miscommunicate the neighbor nodes with false hop count. So defending from MITM attack we designed a new mechanism called Elliptic Curve Group Diffie-Hellman (ECGDH). This paper compares results of PUMA [1] routing protocol with legitimate, under attack and after providing security against attack. Finally we observed ECGDH [2] gives efficient results even attack has happened.

Ontology-Based Emergency Management System in a Social Cloud

The need for Emergency Management continually grows as the population and exposure to catastrophic failures increase. The ability to offer appropriate services at these emergency situations can be tackled through group communication mechanisms. The entities involved in the group communication include people, organizations, events, locations and essential services. Cloud computing is a “as a service” style of computing that enables on-demand network access to a shared pool of resources. So this work focuses on proposing a social cloud constituting group communication entities using an open source platform, Eucalyptus. The services are exposed as semantic web services, since the availability of machine-readable metadata (Ontology) will enable the access of these services more intelligently. The objective of this paper is to propose an Ontology-based Emergency Management System in a social cloud and demonstrate the same using emergency healthcare domain.

A distributed algorithm for ordered, atomic and simultaneous group communication

The group communication algorithms are employed in fault-tolerant distributed computing systems, where the members of a group coordinate by using multicast messages. The messages need to be totally ordered at the nodes in order to maintain global consistency among the nodes. In the large scale distributed systems having replicated servers, the asynchronous as well as simultaneous group communication mechanism is required. This paper proposes a distributed algorithm intended to unidirectional virtual ring for asynchronous and simultaneous group communication in a close group maintaining totally ordered as well as atomic communication. The algorithm is easy to implement and computationally inexpensive having reduced overall message complexity. The algorithm is implemented in distributed system setup in large scale and the experimental results illustrate that algorithm is scalable, where the message complexity per node is comparatively lower. This paper describes the design, analysis and experimental validation of the algorithm.

SMACK

Network protocol designers, both at the physical and network level, have long considered interference and simultaneous transmission in wireless protocols as a problem to be avoided. This, coupled with a tendency to emulate wired network protocols in the wireless domain, has led to artificial limitations in wireless networks. In this paper, we argue that wireless protocols can exploit simultaneous transmission to reduce the cost of reliable multicast by orders of magnitude. With an appropriate application interface, simultaneous transmission can also greatly speed up common group communication primitives, such as anycast, broadcast, leader election and others. The proposed method precisely fits into the domain of directly reachable nodes where many group communication mechanisms are commonly used in routing protocols and other physical-layer mechanisms. We demonstrate how simultaneous transmission can be used to implement a reliable broadcast for an infrastructure and peer-to-peer network using a prototype reconfigurable hardware. We also validate the notion of using simple spectrum sensing techniques to distinguish multiple transmissions. We then describe how the mechanism can be extended to solve group communication problems and the challenges inherent to build innovative protocols which are faster and reliable at the same time.

Study on group communication mechanism of migrating instances in migrating workflow management system

Migrating Instance(MI) is a task executor in the migrating workflow management system,and can be cloned or derived from authorized work palaces in order to support decomposing and paralleling in business process.Migrating instance together with its clone and derivation composes a cooperative group.In this paper,a migrating instances group communication model based on service domain was proposed.Moreover the model definition and architecture were given,the reason for communication scheme choice was proved,and the key communication algorithms were depicted.The experimental results show that the model not only can ensure the message be transferred fast and reliably,but also can save the network bandwidth and computing resources of nodes dramatically,therefore the model can meet the requirements of high-efficient quality and scalability in migrating workflow system.

Mobility-aware ad hoc routing protocols for networking mobile robot teams

Mobile multi-robot teams are useful in many critical applications such as search and rescue. Explicit communication among robots in such mobile multi-robot teams is useful for the coordination of such teams as well as exchanging data. Since many applications for mobile robots involve scenarios in which communication infrastructure may be damaged or unavailable, mobile robot teams frequently need to communicate with each other via ad hoc networking. In such scenarios, low-overhead and energy-efficient routing protocols for delivering messages among robots are a key requirement. Two important primitives for communication are essential for enabling a wide variety of mobile robot applications. First, unicast communication (between two robots) needs to be provided to enable coordination and data exchange. Second, in many applications, group communication is required for flexible control, organization, and management of the mobile robots. Multicast provides a bandwidth-efficient communication method between a source and a group of robots. In this paper, we first propose and evaluate two unicast routing protocols tailored for use in ad hoc networks formed by mobile multi-robot teams: Mobile robot distance vector (MRDV) and mobile robot source routing (MRSR). Both protocols exploit the unique mobility characteristics of mobile robot networks to perform efficient routing. Our simulation study show that both MRDV and MRSR incur lower overhead while operating in mobile robot networks when compared to traditional mobile ad hoc network routing protocols such as DSR and AODV. We then propose and evaluate an efficient multicast protocol mobile robot mesh multicast (MRMM) for deployment in mobile robot networks. MRMM exploits the fact that mobile robots know what velocity they are instructed to move at and for what distance in building a long lifetime sparse mesh for group communication that is more efficient. Our results show that MRMM provides an efficient group communication mechanism that can potentially be used in many mobile robot application scenarios.

On optimal batch rekeying for secure group communications in wireless networks

Advances in wireless communications and mobile computing have led to the emergence of group communications and applications over wireless. In many of these group interactions, new members can join and current members can leave at any time, and existing members must communicate securely to achieve application-specific missions or network-specific functionality. Since wireless networks are resource-constrained, a key challenge is to provide secure and efficient group communication mechanisms that satisfy application requirements while minimizing the communication cost. Instead of individual rekeying, i.e., performing a rekey operation right after each join or leave request, periodic batch rekeying has been proposed to alleviate rekeying overhead in resource-constrained wireless networks. In this paper, we propose an analytical model to address the issue of how often batch rekeying should be performed. We propose threshold-based batch rekeying schemes and demonstrate that an optimal rekey interval exists for each scheme. We further compare these schemes to identify the best scheme that can minimize the communication cost of rekeying while satisfying application requirements when given a set of parameter values characterizing the operational and environmental conditions of the system. In a highly dynamic wireless environment in which the system parameter values change at runtime, our work may be used to adapt the rekeying interval accordingly.

Source Filtering in IP Multicast Routing

IP multicasting is an efficient group communication mechanism. It avoids transmitting packets from a sender to each of the receivers separately. Under the current IP multicast model, once having joined a group, the host will receive all data destined to the group from any source, irrespective of whether it wishes to receive them. This paper studies source filtering (SF) in IP multicasting. Source filtering allows individual hosts to specify the reception of packets sent to a multicast group only from a list of source addresses or to explicitly identify a list of the sources whose data the hosts do not want to receive. We investigate the issue of source filtering in the context of multicast routing protocols, and provide support of source filtering for shared-tree based IP multicast routing. We also discuss how source filtering improves the performance of existing work on IP multicast. Finally, we provide analysis and conduct simulations to evaluate the performance of the proposed SF mechanism. The results show that our mechanism allows better bandwidth utilization and scalability than those without the capability of source filtering, thus achieving a truly efficient use of resources for IP multicasting

A scalable group communication mechanism for mobile agents

Many multi-agent applications based on mobile agents require message propagation among group of agents. A fast and scalable group communication mechanism can considerably improve performance of these applications. Unfortunately, most of the existing approaches do not scale well and disseminate messages slowly when the number of agents grows. In this paper, we propose Sama, a new group communication mechanism, to speed up message delivery for a group of mobile agents on a heterogeneous internetwork. The main contribution of Sama is distribution and parallelization of message propagation in an efficient way to achieve scalability and high-speed of message delivery to group members. Sama uses message dispatcher objects (MDOs), which are stationary agents on each host, to propagate messages concurrently. The proposed mechanism is independent of agent locations and transparently delivers messages to the group using constant number of remote messages. It also transparently recovers from host failures. We also present a Hop-Ring protocol that considerably improves the performance of message dissemination in Sama. Our experimental results show that message propagation in Sama is significantly fast compared to the previously proposed methods.

CAMPOUT: a control architecture for tightly coupled coordination of multirobot systems for planetary surface exploration

Exploration of high risk terrain areas such as cliff faces and site construction operations by autonomous robotic systems on Mars requires a control architecture that is able to autonomously adapt to uncertainties in knowledge of the environment. We report on the development of a software/hardware framework for cooperating multiple robots performing such tightly coordinated tasks. This work builds on our earlier research into autonomous planetary rovers and robot arms. Here, we seek to closely coordinate the mobility and manipulation of multiple robots to perform examples of a cliff traverse for science data acquisition, and site construction operations including grasping, hoisting, and transport of extended objects such as large array sensors over natural, unpredictable terrain. In support of this work we have developed an enabling distributed control architecture called control architecture for multirobot planetary outposts (CAMPOUT) wherein integrated multirobot mobility and control mechanisms are derived as group compositions and coordination of more basic behaviors under a task-level multiagent planner. CAMPOUT includes the necessary group behaviors and communication mechanisms for coordinated/cooperative control of heterogeneous robotic platforms. In this paper, we describe CAMPOUT, and its application to ongoing physical experiments with multirobot systems at the Jet Propulsion Laboratory in Pasadena, CA, for exploration of cliff faces and deployment of extended payloads.

Group communication security on regional PC communication networks

Security management is an important issue on computer networks with a large number of subscribers. The authors have proposed a regional information network system, which establishes a virtual local area network (LAN) environment for the home users based on the optical subscriber system. A group communication mechanism was proposed, where the subscriber terminals are connected in a loop, so that the access from other subscriber terminals can be prevented without burdening the user by procedures such as address registration. This article shows two implementations for such a group communication, from the side of the subscriber and from the center. The security of each implementation is evaluated, being reduced to physical safety, and the conditions for guaranteeing safety in group communication are derived. It is shown that the safety of group communication is secured by terminal authentication in the regional PC communication network system, basic on the physical composition of the port in the center, containing the multiplexing router, an automatic registration function for the MAC address of the terminal, and the star topology of the optical subscriber system. ? 1999 Scripta Technica, Electron Comm Jpn Pt 1, 83(2): 10–19, 2000