Kamesh Namuduri | University of North Texas (original) (raw)

Papers by Kamesh Namuduri

On behalf of the organizers, we extend a warm welcome to the first ACM MobiHoc workshop on "... more On behalf of the organizers, we extend a warm welcome to the first ACM MobiHoc workshop on "Airborne Networks and Communications" to all participants. An airborne network is a mobile network consisting of manned and unmanned air vehicles as well as ground vehicles. The ability of ground and air vehicles to communicate voice, video, and data offers enhanced safety and efficiency for the next generation (NextGen) air transportation systems. Airborne networks can benefit many civilian applications such as air-traffic control, border patrol, and search and rescue missions. This workshop is a result of the ideas that emerged from the meetings held over the past few years on topics that focused on cyber-physical systems (CPS) for air transportation as well as NextGen aviation systems. We believe that the time is right for airborne networking and communications to be part of main stream conferences. We believe that this workshop is an opportunity for researchers engaged in airborne networking and communications to discuss state-of-the-art, share their research results with their peers, and develop directions for future research in this emerging field. Airborne networking is a cyber-physical system. While computation, communication and networking elements form the cyber components of the system, flight-paths, maneuver geometries, and multi-mode resources including ground-based nodes and control stations form the physical components of the CPS. The synergy between the cyber and physical components, if explored and exploited, will significantly enhance the safety and security capabilities of Next Generation air transportation systems. However, fundamental design principles which are needed to explore this synergy do not exist and experimental datasets which are needed to develop such design principles are beyond the reach of academic community. During this workshop, we will hear from experienced speakers coming from the industry, universities, and federal laboratories on topics covering theoretical foundations and models for mobility, connectivity, and coverage, cyber-physical system perspective of airborne networks, airborne/satellite communication and networking platforms and strategies, protocols for secure information sharing, swarming, collaboration, and self-organization, network trials, test-beds, experiments, and measurements and applications of airborne networking to real world domains such as border patrol, air-traffic control, search and rescue missions, and unmanned cargo. We look forward to your active participation in this workshop.

The redundancy in digital image representation can be classified into two categories: local and g... more The redundancy in digital image representation can be classified into two categories: local and global. In this paper, we present an analysis of two image characteristics that give rise to local and global redundancy in image representation. Based on this study, we propose a lossless image compression scheme that exploits redundancy both at local and global levels in order to obtain maximum compression efficiency. The proposed algorithm segments the image into variable size blocks and encodes them depending on the characteristics exhibited by the pixels within the block. The proposed algorithm is implemented in software and its performance is better than other lossless compression schemes such as the Huffman, the arithmetic, the Lempel-Ziv and the JPEG.

Mobile Ad Hoc Networking and Computing, Aug 11, 2014

On behalf of the organizers, we extend a warm welcome to the third ACM MobiHoc workshop on "... more On behalf of the organizers, we extend a warm welcome to the third ACM MobiHoc workshop on "Airborne Networks and Communications" to all participants. Airborne networking has emerged as an important research discipline over the past few years. This workshop series is created to encouragefundamental as well as applied research in this important domain. It is a result of the ideas that emerged from the meetings held over the past several years on topics that focused on cyber-physical systems (CPS) for transportation. We believe that this workshop gives us an opportunity to discuss state-of-the-art, share our research results with our peers, and develop directions for future research in this emerging field. Research and development work in airborne networking and communications has been limited to military domain until a few years ago. However, over the past few years, the industry, federal organizations, and universities have started exploring the civilian applications of aerial networks, especially networks involving unmanned aerial vehicles (UAVs) or unmanned aircraft systems (UAS). UAVs have already proven to be efficient and economical in many applications including border and port surveillance, earth and atmospheric studies, monitoring events such as forest fires, protecting critical infrastructure, and environmental monitoring, among others. With the proposed integration of UAS into National Airspace System (NAS) by FAA, numerous other civilian applications including pipeline patrol, law enforcement, cargo delivery, border patrol, and critical infrastructure protection are being envisioned. The use of UAS leads to significant cost benefits in such applications. Before UAS can be deployed in the civilian airspace, there are significant challenges that we as a research community need to tackle. Enhancing situational awareness, sense and avoid, safety and security capabilities, and improving vehicle autonomy are the most important among these challenges as discussed in the recent workshop on Transportation CPS that was held in January 2014. In addition, as emphasized in the same workshop, there is also a need for experimental flight tests to demonstrate the safety and security of people in heavily populated areas. During this workshop, we will hear from researchers around the world who are currently engaged in research activities related to airborne networking and communications. The topics include experimental test-beds, routing protocols in tactical airborne networking, and exploring data mule concepts in UAV swarms. The papers showcase the state of the art in UAV networking and communications, demonstrate the challenges in designing real-world applications involving airborne networking and communications. We encourage the readers to take a look at the special issue of IEEE Communications Magazine on enabling next-generation airborne communications that was published in May 2014.

Journal of Emergency Management, Nov 1, 2021

The motivation for developing, administering, and participating in full-scale disaster drills is ... more The motivation for developing, administering, and participating in full-scale disaster drills is multifold. Emergency drills not only test the capacity of emergency systems but also allow organizations to learn as well as improve processes and communication structures before disasters strike. They have been used as a platform to develop and maintain collaborative networks. This article examines the extent to which organizations collaborate with others during emergency/disaster drills. A social network analysis is employed to determine the patterns of communication and interorganizational networks during the planning and implementation of a full-scale emergency exercise. Specifically, we seek to understand the communication lines that stakeholders used to receive updated information, who they reached out to when standard communication channels were down, and what backup systems were in place. The research was conducted in a municipality located in north central Texas. This study was based on field observations and involved 14 face-to-face interviews with experienced public officials and first responders involved in a municipal government emergency drill/exercise. The interviews were administered after the 2017 full-scale emergency drill. Three major findings can be emphasized from this study. First, two types of organizations, namely, city fire departments and a university partaking in the exercise, played central role as a “bridge” between various organizations during the emergency drill. Second, the types of information considered important during the exercise can be categorized as strategic, procedural, and technical information. Finally, several back-up systems including ham radio, cellphones, internet back-up, and satellite were used to maintain communication channels.

IEEE Vehicular Technology Magazine, Dec 1, 2022

IEEE Sensors Journal, Jun 1, 2012

Eurasip Journal on Wireless Communications and Networking, Dec 1, 2005

ABSTRACT Security has been a major concern for computer networks, and required levels of security... more ABSTRACT Security has been a major concern for computer networks, and required levels of security continue to increase and become more complicated to provide. Wireless devices face new challenges in securely exchanging information due to their limitations such as power and bandwidth. Powerful algorithms have also been developed to provide authentication, confidentially, and integrity to information exchanged over computer networks. We evaluate security protocols, designed to overcome these limitations and quantitatively determine the performance differences between them. All the protocols were developed based on the assumption that a certificate authority (CA) exists and maintains the certificates of each device.

This paper provides an analytical framework for estimating the routing overhead due to mobility a... more This paper provides an analytical framework for estimating the routing overhead due to mobility and link break- age. Detailed analysis is presented for estimating the number of control packets (RREQ, RREP and RERR) as a function of time, number of nodes, node degree, transmission range, mobility of nodes, average hop count and link density. In order to validate the proposed model, two on-demand routing protocols namely ad hoc on demand distance vector (AODV) routing and dynamic source routing (DSR) are analyzed and compared in terms of normalized load. The quantitative and simulation results presented in this paper are useful for selecting a suitable on-demand routing protocol and for designing novel and efficient routing protocols for ad-hoc wireless networks.

Safety and security are the most discussed topics in the aviation field. Latest security initiati... more Safety and security are the most discussed topics in the aviation field. Latest security initiatives in the field of aviation propose the aircraft carriers to implement video surveillance within the aircraft at strategic locations. The current proposals allow the video surveillance data to be stored within the aircraft and monitored by one of the flight crew. The monitoring crew will

IEEE Aerospace and Electronic Systems Magazine, Oct 1, 2009

IEEE Sensors Letters, 2020

The primary goal of this letter is to study the impact of mobility in wireless sensor networks mo... more The primary goal of this letter is to study the impact of mobility in wireless sensor networks modeled as a leader-follower structure. Although it is intuitively known that mobility enhances the convergence rate of consensus-building in a sensor network, analytical reasoning for this intuition is not available in the literature. For filling the gap, this letter provides concrete proofs to demonstrate the benefits of introducing mobility in a sensor network with two leaders in terms of improved convergence rate in consensus building.

Proceedings of SPIE, Sep 8, 2011

ABSTRACT This paper focuses on the 2D-3D camera pose estimation using one LiDAR view and one cali... more ABSTRACT This paper focuses on the 2D-3D camera pose estimation using one LiDAR view and one calibrated camera view. The pose estimation employs an intelligent search over the extrinsic camera parameters and uses an error metric based on line-segment matching. The goal of this search process is to estimate the pose parameters without any apriori knowledge and in less processing time. We demonstrated the validity of the proposed approach by experimenting on two sets of perspective views using lines as feature.

Proceedings of SPIE, Sep 8, 2011

This papers explores the use of an error metric based on intensity gradients in an automatic came... more This papers explores the use of an error metric based on intensity gradients in an automatic camera pose recovery method for 2D-3D image registration. The method involves extraction of lines from the 3D image and then uses intensity gradients to register these onto the 2D image. This approach have overcome the limitations of matching the features to register the 2D-3D images. The goal of our algorithm is to estimate pose parameters without any apriori knowledge (GPS) and in less processing time. We demonstrated the validity of our approach by experimenting on perspective view using lines as feature.

On behalf of the organizers, we extend a warm welcome to the first ACM MobiHoc workshop on "... more On behalf of the organizers, we extend a warm welcome to the first ACM MobiHoc workshop on "Airborne Networks and Communications" to all participants. An airborne network is a mobile network consisting of manned and unmanned air vehicles as well as ground vehicles. The ability of ground and air vehicles to communicate voice, video, and data offers enhanced safety and efficiency for the next generation (NextGen) air transportation systems. Airborne networks can benefit many civilian applications such as air-traffic control, border patrol, and search and rescue missions. This workshop is a result of the ideas that emerged from the meetings held over the past few years on topics that focused on cyber-physical systems (CPS) for air transportation as well as NextGen aviation systems. We believe that the time is right for airborne networking and communications to be part of main stream conferences. We believe that this workshop is an opportunity for researchers engaged in airborne networking and communications to discuss state-of-the-art, share their research results with their peers, and develop directions for future research in this emerging field. Airborne networking is a cyber-physical system. While computation, communication and networking elements form the cyber components of the system, flight-paths, maneuver geometries, and multi-mode resources including ground-based nodes and control stations form the physical components of the CPS. The synergy between the cyber and physical components, if explored and exploited, will significantly enhance the safety and security capabilities of Next Generation air transportation systems. However, fundamental design principles which are needed to explore this synergy do not exist and experimental datasets which are needed to develop such design principles are beyond the reach of academic community. During this workshop, we will hear from experienced speakers coming from the industry, universities, and federal laboratories on topics covering theoretical foundations and models for mobility, connectivity, and coverage, cyber-physical system perspective of airborne networks, airborne/satellite communication and networking platforms and strategies, protocols for secure information sharing, swarming, collaboration, and self-organization, network trials, test-beds, experiments, and measurements and applications of airborne networking to real world domains such as border patrol, air-traffic control, search and rescue missions, and unmanned cargo. We look forward to your active participation in this workshop.

The redundancy in digital image representation can be classified into two categories: local and g... more The redundancy in digital image representation can be classified into two categories: local and global. In this paper, we present an analysis of two image characteristics that give rise to local and global redundancy in image representation. Based on this study, we propose a lossless image compression scheme that exploits redundancy both at local and global levels in order to obtain maximum compression efficiency. The proposed algorithm segments the image into variable size blocks and encodes them depending on the characteristics exhibited by the pixels within the block. The proposed algorithm is implemented in software and its performance is better than other lossless compression schemes such as the Huffman, the arithmetic, the Lempel-Ziv and the JPEG.

Mobile Ad Hoc Networking and Computing, Aug 11, 2014

On behalf of the organizers, we extend a warm welcome to the third ACM MobiHoc workshop on "... more On behalf of the organizers, we extend a warm welcome to the third ACM MobiHoc workshop on "Airborne Networks and Communications" to all participants. Airborne networking has emerged as an important research discipline over the past few years. This workshop series is created to encouragefundamental as well as applied research in this important domain. It is a result of the ideas that emerged from the meetings held over the past several years on topics that focused on cyber-physical systems (CPS) for transportation. We believe that this workshop gives us an opportunity to discuss state-of-the-art, share our research results with our peers, and develop directions for future research in this emerging field. Research and development work in airborne networking and communications has been limited to military domain until a few years ago. However, over the past few years, the industry, federal organizations, and universities have started exploring the civilian applications of aerial networks, especially networks involving unmanned aerial vehicles (UAVs) or unmanned aircraft systems (UAS). UAVs have already proven to be efficient and economical in many applications including border and port surveillance, earth and atmospheric studies, monitoring events such as forest fires, protecting critical infrastructure, and environmental monitoring, among others. With the proposed integration of UAS into National Airspace System (NAS) by FAA, numerous other civilian applications including pipeline patrol, law enforcement, cargo delivery, border patrol, and critical infrastructure protection are being envisioned. The use of UAS leads to significant cost benefits in such applications. Before UAS can be deployed in the civilian airspace, there are significant challenges that we as a research community need to tackle. Enhancing situational awareness, sense and avoid, safety and security capabilities, and improving vehicle autonomy are the most important among these challenges as discussed in the recent workshop on Transportation CPS that was held in January 2014. In addition, as emphasized in the same workshop, there is also a need for experimental flight tests to demonstrate the safety and security of people in heavily populated areas. During this workshop, we will hear from researchers around the world who are currently engaged in research activities related to airborne networking and communications. The topics include experimental test-beds, routing protocols in tactical airborne networking, and exploring data mule concepts in UAV swarms. The papers showcase the state of the art in UAV networking and communications, demonstrate the challenges in designing real-world applications involving airborne networking and communications. We encourage the readers to take a look at the special issue of IEEE Communications Magazine on enabling next-generation airborne communications that was published in May 2014.

Journal of Emergency Management, Nov 1, 2021

The motivation for developing, administering, and participating in full-scale disaster drills is ... more The motivation for developing, administering, and participating in full-scale disaster drills is multifold. Emergency drills not only test the capacity of emergency systems but also allow organizations to learn as well as improve processes and communication structures before disasters strike. They have been used as a platform to develop and maintain collaborative networks. This article examines the extent to which organizations collaborate with others during emergency/disaster drills. A social network analysis is employed to determine the patterns of communication and interorganizational networks during the planning and implementation of a full-scale emergency exercise. Specifically, we seek to understand the communication lines that stakeholders used to receive updated information, who they reached out to when standard communication channels were down, and what backup systems were in place. The research was conducted in a municipality located in north central Texas. This study was based on field observations and involved 14 face-to-face interviews with experienced public officials and first responders involved in a municipal government emergency drill/exercise. The interviews were administered after the 2017 full-scale emergency drill. Three major findings can be emphasized from this study. First, two types of organizations, namely, city fire departments and a university partaking in the exercise, played central role as a “bridge” between various organizations during the emergency drill. Second, the types of information considered important during the exercise can be categorized as strategic, procedural, and technical information. Finally, several back-up systems including ham radio, cellphones, internet back-up, and satellite were used to maintain communication channels.

IEEE Vehicular Technology Magazine, Dec 1, 2022

IEEE Sensors Journal, Jun 1, 2012

Eurasip Journal on Wireless Communications and Networking, Dec 1, 2005

ABSTRACT Security has been a major concern for computer networks, and required levels of security... more ABSTRACT Security has been a major concern for computer networks, and required levels of security continue to increase and become more complicated to provide. Wireless devices face new challenges in securely exchanging information due to their limitations such as power and bandwidth. Powerful algorithms have also been developed to provide authentication, confidentially, and integrity to information exchanged over computer networks. We evaluate security protocols, designed to overcome these limitations and quantitatively determine the performance differences between them. All the protocols were developed based on the assumption that a certificate authority (CA) exists and maintains the certificates of each device.

This paper provides an analytical framework for estimating the routing overhead due to mobility a... more This paper provides an analytical framework for estimating the routing overhead due to mobility and link break- age. Detailed analysis is presented for estimating the number of control packets (RREQ, RREP and RERR) as a function of time, number of nodes, node degree, transmission range, mobility of nodes, average hop count and link density. In order to validate the proposed model, two on-demand routing protocols namely ad hoc on demand distance vector (AODV) routing and dynamic source routing (DSR) are analyzed and compared in terms of normalized load. The quantitative and simulation results presented in this paper are useful for selecting a suitable on-demand routing protocol and for designing novel and efficient routing protocols for ad-hoc wireless networks.

Safety and security are the most discussed topics in the aviation field. Latest security initiati... more Safety and security are the most discussed topics in the aviation field. Latest security initiatives in the field of aviation propose the aircraft carriers to implement video surveillance within the aircraft at strategic locations. The current proposals allow the video surveillance data to be stored within the aircraft and monitored by one of the flight crew. The monitoring crew will

IEEE Aerospace and Electronic Systems Magazine, Oct 1, 2009

IEEE Sensors Letters, 2020

The primary goal of this letter is to study the impact of mobility in wireless sensor networks mo... more The primary goal of this letter is to study the impact of mobility in wireless sensor networks modeled as a leader-follower structure. Although it is intuitively known that mobility enhances the convergence rate of consensus-building in a sensor network, analytical reasoning for this intuition is not available in the literature. For filling the gap, this letter provides concrete proofs to demonstrate the benefits of introducing mobility in a sensor network with two leaders in terms of improved convergence rate in consensus building.

Proceedings of SPIE, Sep 8, 2011

ABSTRACT This paper focuses on the 2D-3D camera pose estimation using one LiDAR view and one cali... more ABSTRACT This paper focuses on the 2D-3D camera pose estimation using one LiDAR view and one calibrated camera view. The pose estimation employs an intelligent search over the extrinsic camera parameters and uses an error metric based on line-segment matching. The goal of this search process is to estimate the pose parameters without any apriori knowledge and in less processing time. We demonstrated the validity of the proposed approach by experimenting on two sets of perspective views using lines as feature.

Proceedings of SPIE, Sep 8, 2011

This papers explores the use of an error metric based on intensity gradients in an automatic came... more This papers explores the use of an error metric based on intensity gradients in an automatic camera pose recovery method for 2D-3D image registration. The method involves extraction of lines from the 3D image and then uses intensity gradients to register these onto the 2D image. This approach have overcome the limitations of matching the features to register the 2D-3D images. The goal of our algorithm is to estimate pose parameters without any apriori knowledge (GPS) and in less processing time. We demonstrated the validity of our approach by experimenting on perspective view using lines as feature.