scholarly journals Scalable and Anonymous Group Communication with MTor

2016 ◽  
Vol 2016 (2) ◽  
pp. 22-39 ◽  
Author(s):  
Dong Lin ◽  
Micah Sherr ◽  
Boon Thau Loo
Keyword(s):  
Group Composition ◽  
Group Communication ◽  
File Transfer ◽  
Collaborative Editing ◽  
Network Bandwidth ◽  
Multicast Trees ◽  
Group Members ◽  
Overall Performance ◽  
Bandwidth Savings ◽  
Baseline Approach

AbstractThis paper presents MTor, a low-latency anonymous group communication system. We construct MTor as an extension to Tor, allowing the construction of multi-source multicast trees on top of the existing Tor infrastructure. MTor does not depend on an external service to broker the group communication, and avoids central points of failure and trust. MTor’s substantial bandwidth savings and graceful scalability enable new classes of anonymous applications that are currently too bandwidth-intensive to be viable through traditional unicast Tor communication-e.g., group file transfer, collaborative editing, streaming video, and real-time audio conferencing.We detail the design of MTor and then analyze its performance and anonymity. By simulating MTor in Shadow and TorPS using realistic models of the live Tor network’s topology and recent consensus records from the live Tor network, we show that MTor achieves a 29% savings in network bandwidth and a 73% reduction in transmission time as compared to the baseline approach for anonymous group communication among 20 group members. We also demonstrate that MTor scales gracefully with the number of group participants, and allows dynamic group composition over time. Importantly, as more Tor users switch to group communication, we show that the overall performance and utilization for group communication improves. Finally, we discuss the anonymity implications of MTor and measure its resistance to traffic correlation.

scholarly journals Evaluating the Performance of Three Popular Web Mapping Libraries: A Case Study Using Argentina’s Life Quality Index

2020 ◽  
Vol 9 (10) ◽  
pp. 563
Author(s):  
Alejandro Zunino ◽  
Guillermo Velázquez ◽  
Juan Pablo Celemín ◽  
Cristian Mateos ◽  
Matías Hirsch ◽  
...  
Keyword(s):  
Life Quality ◽  
Web Technologies ◽  
Web Mapping ◽  
Network Bandwidth ◽  
Web Map ◽  
Raster Maps ◽  
Dynamic Web ◽  
Network Usage ◽  
Overall Performance

Recent Web technologies such as HTML5, JavaScript, and WebGL have enabled powerful and highly dynamic Web mapping applications executing on standard Web browsers. Despite the complexity for developing such applications has been greatly reduced by Web mapping libraries, developers face many choices to achieve optimal performance and network usage. This scenario is even more complex when considering different representations of geographical data (raster, raw data or vector) and variety of devices (tablets, smartphones, and personal computers). This paper compares the performance and network usage of three popular JavaScript Web mapping libraries for implementing a Web map using different representations for geodata, and executing on different devices. In the experiments, Mapbox GL JS achieved the best overall performance on mid and high end devices for displaying raster or vector maps, while OpenLayers was the best for raster maps on all devices. Vector-based maps are a safe bet for new Web maps, since performance is on par with raster maps on mid-end smartphones, with significant less network bandwidth requirements.

Turning Points in Group Life: Using High-Tension Moments to Promote Group Purpose and Mutual Aid

2003 ◽  
Vol 84 (3) ◽  
pp. 433-440 ◽  
Author(s):  
Alex Gitterman ◽  
Julianne Wayne
Keyword(s):  
Environmental Factors ◽  
Interpersonal Relationships ◽  
Social Worker ◽  
Group Composition ◽  
Turning Points ◽  
Mutual Aid ◽  
Group Life ◽  
High Tension ◽  
Group Members ◽  
Professional Interventions

The interactions among and between group members and a social worker often generate natural interpersonal tensions in group life. If handled with skill, these difficult moments have the potential to become significant turning points in members' ability to feel safe in the group and in their motivation to achieve the group's purpose through a mutual aid process. In this article the authors examine five areas of group life that are often sources of tension-filled situations. These areas are group composition, group purpose and the working agreement, the worker's authority, members' interpersonal relationships, painful material, and environmental factors. The authors recommend professional interventions aimed at converting high-tension moments into incidents that promote trust, caring, and mutual aid.

scholarly journals A Method of Optimizing Network Topology Structure Combining Viterbi Algorithm and Bayesian Algorithm

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xiaoxiao Shi
Keyword(s):  
Performance Optimization ◽  
Viterbi Algorithm ◽  
Flow Distribution ◽  
Bottom Layer ◽  
Bayesian Algorithm ◽  
Recommendation Algorithm ◽  
Average Value ◽  
Network Bandwidth ◽  
5G Network ◽  
Overall Performance

With Internet entering all walks of life, development of internet and usage expansion demand better performance, especially the application of 5G network that adopts NAS networking mode. Some of the network bandwidth cannot fully support the current network demand, which causes network fluctuations and other concerns. In this paper, a method for optimizing the topological structure of the bottom layer of the communication network is proposed that has outage performance close to optimal routing scheme. In specific, path in areas with poor network conditions is first optimized using Viterbi algorithm. Then, network element nodes on the path are optimized using Bayes recommendation algorithm for reasonable flow distribution. Dual planning of improved Viterbi algorithm is used to realize the main and standby path planning, and then, Bayesian recommendation algorithm based on the average value is used to optimize the network elements. Therefore, it is very efficient to realize overall performance optimization.

scholarly journals A Blockchain-Based Authentication and Dynamic Group Key Agreement Protocol

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4835
Author(s):  
Zisang Xu ◽  
Feng Li ◽  
Han Deng ◽  
Minfu Tan ◽  
Jixin Zhang ◽  
...  
Keyword(s):  
Key Agreement ◽  
Group Communication ◽  
Single Node ◽  
Node Failure ◽  
Group Key ◽  
Group Key Agreement ◽  
Key Agreement Protocol ◽  
Dynamic Group ◽  
Group Members ◽  
Group Key Agreement Protocol

With the rapid development of mobile networks, there are more and more application scenarios that require group communication. For example, in mobile edge computing, group communication can be used to transmit messages to all group members with minimal resources. The group key directly affects the security of the group communication. Most existing group key agreement protocols are often flawed in performance, scalability, forward or backward secrecy, or single node failure. Therefore, this paper proposes a blockchain-based authentication and dynamic group key agreement protocol. With our protocol, each group member only needs to authenticate its left neighbor once to complete the authentication, which improved authentication efficiency. In addition, our protocol guarantees the forward secrecy of group members after joining the group and the backward secrecy of group members after leaving the group. Based on blockchain technology, we solve the problem of single node failure. Furthermore, we use mathematics to prove the correctness and security of our protocol, and the comparison to related protocols shows that our protocol reduces computation and communication costs.

Collaborative Problem-Solving with Logo: Effects of Group Size and Group Composition

1987 ◽  
Vol 3 (3) ◽  
pp. 313-334 ◽  
Author(s):  
Edgar Guntermann ◽  
Mariela Tovar
Keyword(s):  
Group Composition ◽  
Process Analysis ◽  
Collaborative Problem Solving ◽  
Experimental Session ◽  
Female Group ◽  
Practice Session ◽  
Collaborative Problem ◽  
Interaction Processes ◽  
Group Members ◽  
Mixed Groups

This study investigated productivity in individuals versus groups of two or three as well as the interaction processes underlying differences between dyads and triads and differences between male, female or mixed groups learning LOGO on microcomputers. Thirty-six students aged ten learned LOGO individually or in groups of two or three for one session, had a practice session, then were required to produce a graphic in LOGO for the experimental session. No differences were found between individuals and groups, in terms of productivity. Group interaction (as measured by the Bales Interaction Process Analysis [1], was found to be similar in two and three person groups. However, significant ( p < .05) differences were observed among male, female, and mixed groups. The direction of these differences were as follows: males displayed more solidarity than females or mixed groups, the female group members were much more likely to express agreement with their peers than were members of the males group. There was also more asking of information in the male groups than the female groups. Finally, males expressed much more antagonism than females or mixed groups. These results are discussed in light of previous studies in this area.

scholarly journals Factors Contributing to the Performance of Farmer Producer Organizations (FPOs) – a Study in Medak District of Telangana State

2021 ◽  
Vol 12 (3) ◽  
pp. 192-198
Author(s):  
Amitha, C. D. ◽  
◽  
Savitha. B. ◽  
Sudha Rani. V. ◽  
Laxminarayana, P. ◽  
...  
Keyword(s):  
Group Communication ◽  
Independent Research ◽  
Education Group ◽  
Ex Post ◽  
Ex Post Facto ◽  
Leadership Group ◽  
Overall Performance ◽  
Team Spirit ◽  
Telangana State ◽  
Organization Centre

A study was conducted on the performance of FPOs and the factors contributing to performance of FPOs in Medak district of Telangana State, India. Three FPOs were selected randomly from 3 different promoting institutes viz., Suraksha Farmers Producer Company Ltd (SFPCL) promoted by independent research organization Centre for Sustainable Agriculture (CSA), Marpalli Kisan Kranthi Producer Company Ltd (MKKPCL) promoted by Vrutti NGO and Siddipet Kisan Agro Farmers Producer Company Ltd (SKAFPCL) promoted by International Crops Research Institute for the Semi-arid Tropics (ICRISAT). The Ex-post facto research design was adopted for the study with a sample of 90 producer members, covering three FPOs in erstwhile Medak district of Telangana State. From the analysis, it was found that overall performance of FPOs in Medak district was average to poor. The factors viz., education, group leadership, group communication, adherence to rules, group participation, and team spirit had showed positive and significant relationship with performance. The results of regression analysis inferred that all the selected twelve factors put together explained the variation to the extent of 72.47% in the performance of the FPO with leadership of officials and participation of members contributing significantly to the performance of FPOs.

PENGARUH MOTIF PENGGUNAAN MEDIA TERHADAP KEPUASAN ANGGOTA WHATSAPP GROUP NEW WAVE INTERNATIONAL MINISTRY

2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Tang Natasha Chrisanti Saputra ◽  
Siti Meisyaroh
Keyword(s):  
Group Communication ◽  
Personal Relationships ◽  
Online Media ◽  
Sampling Techniques ◽  
New Wave ◽  
Considerable Influence ◽  
Global Era ◽  
Group Members ◽  
International Ministry ◽  
Method Approach

Humans as social beings communicate for various purposes, in this global era, online media is the choice for audiences when compared to other media. One of the most important communication media in Indonesia is WhatsApp with the WhatsApp group feature for group communication. The theory used is the Theory of Uses and Gratifications which examines the effect of media use. The method approach used in this study is quantitative by explanatory survey and using saturated sampling or census sampling techniques by distributing questionnaires to 113 respondents who are members of the WhatsApp group New Wave International Ministry. The influence of the motives of personal relationships has a considerable influence on the satisfaction of WhatsApp group members New Wave International Ministry, while the motives of surveillance, motives of personal identity and motives of diversity have sufficient influence on the satisfaction of WhatsApp members in the New Wave International Ministry. Keywords: Motive, Satisfaction, WhatsApp group

A NEW APPROACH FOR CENTRALIZED END-SYSTEM MULTICAST PROTOCOL

2006 ◽  
Vol 03 (01) ◽  
pp. 77-84 ◽  
Author(s):  
AYMAN EL-SAYED
Keyword(s):  
Load Balance ◽  
Multicast Routing ◽  
Group Communication ◽  
Communication Service ◽  
New Approach ◽  
Multicast Protocol ◽  
Group Control ◽  
Application Level Multicast ◽  
Single Host ◽  
Group Members

In this paper we propose a new approach of application-level multicast protocol providing a group communication service. This protocol, called End-System Multicast (ESM), and can be used when native multicast routing is not available. ESM is a centralized protocol where everything is being controlled by a single host called Rendez-vous point (RPL1), connected indirectly to the group members via some hosts called secondary Rendez-vous Point (RPL2). Each RPL2 has some group members that constitute a cluster, and each cluster is controlled by its RPL2. Since the group control is divided among some RPL2 and a main controller (RPL1) manages the relation among RPL2 s and between itself and RPL2 s , we found that the scalability is improved and it also avoids the bottleneck problem near the RPL1, or there is a load balance.

Deadband feedback-based scheduling approach for networked control system with variable sampling period

2021 ◽  
pp. 014233122098142
Author(s):  
Zhongda Tian
Keyword(s):  
Control System ◽  
Sampling Period ◽  
Networked Control System ◽  
Networked Control ◽  
Control Performance ◽  
Control Loops ◽  
Network Bandwidth ◽  
Network Utilization ◽  
Variable Sampling ◽  
Overall Performance

Reasonable information scheduling strategies in the networked control system (NCS) can improve the quality of service of the network, reduce the conflict of information transmission in the network, and improve the overall performance of the NCS. In order to improve the performance of the NCS, a deadband feedback-based scheduling approach for the NCS with a variable sampling period is proposed. For the NCS with multi control loops, considering the limitation of network bandwidth resources, the dynamic real-time adjustment of a multi-loop sampling period is achieved through network utilization prediction, network bandwidth configuration and sampling period calculation. Furthermore, deadband feedback scheduling is combined with a variable sampling period algorithm. Deadband is set in the sensor and controller nodes to effectively adjust the information flow of the forward channel and the feedback channel. The proposed scheduling approach can reduce the impact of network conflict and network delay on system stability, make the network resources allocated reasonably, save network data traffic, and improve the overall performance of the NCS. A NCS with five control loops is used as the simulation object and carried out by True Time toolbox. The simulation results show that the proposed scheduling approach can improve output control performance of the system, reduce integral absolute error value of the control loops, and improve network utilization. The overall control performance of the system is improved.

scholarly journals Repeated Interaction and Its Impact on Cooperation and Surplus Allocation—An Experimental Analysis

Games ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 25
Author(s):  
Sibilla Di Guida ◽  
The Anh Han ◽  
Georg Kirchsteiger ◽  
Tom Lenaerts ◽  
Ioannis Zisis
Keyword(s):  
Group Composition ◽  
Behavioral Model ◽  
Repeated Interaction ◽  
Aggregate Behavior ◽  
Group Members ◽  
Computer Based ◽  
Fear Of Rejection ◽  
Experimental Treatments ◽  
The Impact ◽  
Selection Of

This paper investigates how the possibility of affecting group composition combined with the possibility of repeated interaction impacts cooperation within groups and surplus distribution. We developed and tested experimentally a Surplus Allocation Game where cooperation of four agents is needed to produce surplus, but only two have the power to allocate it among the group members. Three matching procedures (corresponding to three separate experimental treatments) were used to test the impact of the variables of interest. A total of 400 subjects participated in our research, which was computer-based and conducted in a laboratory. Our results show that allowing for repeated interaction with the same partners leads to a self-selection of agents into groups with different life spans, whose duration is correlated with the behavior of both distributors and receivers. While behavior at the group level is diverse for surplus allocation and amount of cooperation, aggregate behavior is instead similar when repeated interaction is allowed or not allowed. We developed a behavioral model that captures the dynamics observed in the experimental data and sheds light into the rationales that drive the agents’ individual behavior, suggesting that the most generous distributors are those acting for fear of rejection, not for true generosity, while the groups lasting the longest are those composed by this type of distributors and “undemanding” receivers.

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