Kathiravelu Ganeshan

Topology aware feedback transmission for real-time control protocol

Real-time Transport Protocol (RTP) is a protocol for delivering time sensitive data such as audio and video over the Internet. RTP is usually used in conjunction with Real-time Control Protocol (RTCP), which provides statistics about flow of data using RTP. Certain problems related to RTCP scalability have arisen, mostly due to growth in the IPTV market and higher demands on bigger broadcasting sessions. Several solutions based on tree structures such as S-RTCP, MS-RTCP, TTP and others have been introduced. This paper proposes a method for constructing an optimal and well organized hierarchical tree structure with respect to standard RTCP. The proposed method can be integrated with most of the current solutions, including S-RTCP, MS-RTCP and TTP. Experience gained by us deploying our method on a global research network called PlanetLab is also discussed at the end of this paper.

The role of Social Networking Sites in e-learning

This paper explores the role of Social Networking Sites (SNS) in e-learning by investigating the attitudes, behaviors, knowledge and views of computing students towards the use of SNS in e-learning. Data was collected from an online survey and interviews, and analyzed to discover the practices, tendencies and the current status of the use of SNS in e-learning as well as how these can be improved. Major factors that facilitate the usage of SNS in e-learning were identified as collaboration, communication, resource sharing, social influence, usefulness and ease of use. Facebook was identified as the most popular SNS. The role of SNS in e-learning is supportive and important. Although the participants were computing students with a high level of IT literacy, and were interested in using SNS for e-learning, only a few were frequently using SNS for e-learning. Reasons for this minimal utilization of SNS for e-learning were identified as security and privacy concerns, reliability and currency of content and network issues such as speed of access, real time synchronization and efficiency. We believe that SNS can play a major supporting role in e-learning and that the potential for using SNS in e-learning is not fully reached. The situation may be improved by providing increased guidance and training to students. Learning activities using SNS should be planned and organized. Brief guidelines on using SNS in e-learning are also included in this paper. These guidelines may be further refined and adapted for use in other institutions.

Feedback transmission in large-scale IPTV sessions

In this paper, we introduce the Tree Transmission Protocol (TTP), which we use for the organization of a tree structure consisting of IPTV nodes for hierarchical feedback aggregation in large-scale IPTV (Internet Protocol Television) systems. The feedback transmission is based on the hierarchical feedback aggregation algorithm, which gives a lower feedback reporting interval compared with the standard feedback transmission in the RTP/RTCP protocol stack. We use the TTP protocol to establish a tree structure by grouping IPTV nodes into groups using a defined set of parameters. One of the parameters we use is the logical position of the IPTV nodes. The motivation for utilizing this parameter in the TTP protocol is to optimize communication in the created overlay network for feedback transmission. We use the Vivaldi algorithm for the localization of the IPTV nodes. In this paper, we also describe the implementation of the TTP protocol on the PlanetLab experimental network as well as the application, we used for the visualization of the established tree.

Performance Comparison of Video Protocols Using Dual-Stack and Tunnelling Mechanisms

This paper investigates the performance of Video Protocols over IPv6 and IP transition mechanisms. It mainly focuses on the impact caused by IP transition mechanisms on video packets and compares this with pure IPv6 based networks. The video protocols selected in this experiment were MPEG-1, MPEG-2, MPEGP-4, MKV and FLV. In this experiment a Dual-Stack and two tunnelling mechanisms were established and the impact of these mechanisms on five video protocols was measured. The parameters measured were actual-throughput over a pure IPv6 network, impacted-throughput (due IP transition mechanisms) and CPU utilization. The results indicate that video packet with large size had been impacted more than packets with small size using these IP transition mechanisms. Dual-Stack mechanism performed much better than two tunnelling mechanisms (IPv6to4 & IPv6in4) tested. IPv6in4 tunnelling mechanism had more impact than IPv6to4 tunnelling mechanism over all the video protocols tested with IPv6to4 marginally close for all protocols tested. Performance comparison between video protocols shows that FLV protocol was least impacted while MPEG-2 was highly impacted by the tunnelling mechanisms. Further detail is covered in this paper including specification for actual-throughput, impacted-throughput and CPU utilization.

An intelligent student advising system using collaborative filtering

We propose a web based intelligent student advising system using collaborative filtering, a technique commonly used in recommendation systems assuming that users with similar characteristics and behaviors will have similar preferences. With our advising system, students are sorted into groups and given advice based on their similarities to the groups. If a student is determined to be similar to a group students, a course preferred by that group might be recommended to the student. K-means algorithm has been used to determine the similarity of the students. This is an extremely efficient and simple algorithm for clustering analysis and widely used in data mining. Given a value of K, the algorithm partitions a data set into K clusters. Seven experiments on the whole data set and ten experiments on the training data set and testing data set were conducted. A descriptive analysis was performed on the experiment results. Based on these results, K=7 was identified as the most informative and effective value for the K-means algorithm used in this system. The high performance, merit performance and low performance student groups were identified with the help of the clusters generated by the K-means algorithm. Future work will make use of a two-phase approach using Cobweb to produce a balanced tree with sub-clusters at the leaves as in [11], and then applying K-means to the resulting sub-clusters. Possible improvements for the student model were identified. Limitation of this research is discussed.

Designing a socially assistive companion robotic wheel chair: RoboChair

Developing socially assistive robots is an emerging interdisciplinary research area, which requires collaboration between a wide range of disciplines. Among recent research projects, there have been attempts to develop assistive robotic solutions to solve various health and social issues. In most current research attempts to design socially assistive robots, the focus is on designing new robotic agents that can interact with people by various means. Since people do not have much experience with robots, usually extensive field trials are conducted in order to assess the usability of these robots. However, determining the usability of these robotic agents is a difficult task, since the results of field trials are not always conclusive. In this paper, an attempt to overcome the difficulty of evaluating usability of assistive robots is presented. This paper presents the design of the first version of a companion robot called RoboChair. RoboChair is in the form of a wheel chair. But, functionally it is a socially assistive companion robot. The proposed robotic chair is a mobile robot that can carry a person. It is equipped with several measuring devices for taking clinical measurements mentioned above. In addition to that, it is equipped with several sensors for obstacle avoidance, map building, localization, detecting humans etc. It is also equipped with motor controllers and other actuators for motion control. The robot chair is capable of engaging users with interactive dialogs through a touch screen and by using human-robot interaction techniques. It has a scalable modular architecture so that adding new hardware and software modules is straightforward. The software framework is based on Robot Operating System (ROS) open source robotic middleware. RoboChair is controlled by a distributed controller that spans multiple hardware devices and multiple operating systems.