Vishal Singh - Academia.edu (original) (raw)
Papers by Vishal Singh
Synthetic Communications, 1988
Presence technology based on Session Initiation Protocol can be used as an enabling platform for ... more Presence technology based on Session Initiation Protocol can be used as an enabling platform for delivering communication and providing event-based services. We present a mobile workforce management solution which integrates fleet management with presence-based communication to show how presence technology can be used to realize location-based communication services. In particular, our solution integrates a user's presence information with their vehicle's status and location information to enable safe communications with a mobile user. Our solution can provide services for both consumer (residential) and an enterprise scenario, for example, E911, rental car management, delivery companies (e.g., Fedex), for purposes like scheduling and automatic dispatching of mobile crews. We discuss our solution in the context of Verizon's mobile workforce (mobile employee) management scenario. The solution incorporates integration of the mobile employee's location obtained from a GPS device in a vehicle; the mobile employee's presence information obtained from his/her cell-phone and laptop as well as the status and diagnostic information of the vehicle. A prototype system and its realization is presented to show the main concepts, feasibility and usefulness of such a solution.
As the complexity of networked systems increases, we need mechanisms to automatically detect fail... more As the complexity of networked systems increases, we need mechanisms to automatically detect failures in the network and diagnose the cause of such failures. To realize true self-healing networks, we also need mechanisms to fix these failures and ensure service availability by providing alternatives when a failure is detected. In this paper, we address the detection and diagnosis of network failures. We introduce DYSWIS ("Do you see what I see") which observes the system from multiple points in the network. Our system consists of detection nodes and diagnosis nodes. Detection nodes detect failures by passive traffic monitoring and active probing. Diagnosis nodes determine the cause of failures using historical information about similar failures and by performing active tests. They are based on a rule engine and represent network dependency relationship encoded as rules. We present our prototype system which considers network components present in a VoIP network and show the feasibility of our solution.
With the growth of presence based services, it is important to securely manage and distribute sen... more With the growth of presence based services, it is important to securely manage and distribute sensitive presence information such as user location. We survey techniques that are used for security and privacy of presence information. In particular, we describe the SIMPLE based presence specific authentication, integrity and confidentiality. We also discuss the IETF's common policy for geo-privacy, presence authorization for presence information privacy and distribution of different levels of presence information to different watchers. Additionally, we describe an open problem of getting the aggregated presence from the trusted server without the server knowing the presence information, and propose a solution. Finally, we discuss denial of service attacks on the presence system and ways to mitigate them.
With the growth of presence-based services, it is important to provision the network to support h... more With the growth of presence-based services, it is important to provision the network to support high traffic and load generated by presence services. Presence event distribution systems amplify a single incoming PUBLISH message into possibly numerous outgoing NOTIFY messages from the server. This can increase the network load on inter-domain links and can potentially disrupt other QoS-sensitive applications. In this document, we present existing as well as new techniques that can be used to reduce presence traffic both in inter-domain and intra-domain scenarios. Specifically, we propose two new techniques: sending common NOTIFY for multiple watchers and batched notifications. We also propose some generic heuristics that can be used to reduce network traffic due to presence.
Journal of Applied Polymer Science, 2003
Dielectric properties of Al-epoxy composites were characterized as a function of composition, fre... more Dielectric properties of Al-epoxy composites were characterized as a function of composition, frequency, and temperature. The dielectric constant increased smoothly with an increase in the concentration of aluminum. An increase in dielectric constant was also observed with an increase in temperature as well as with a decrease in frequency. In general, dissipation factor values for composites with higher concentrations of aluminum were greater than those with lower volume content of aluminum. Also, the dissipation factor showed an increase both with a decrease in frequency and an increase in temperature. The increase in values of dielectric constant and dissipation fac-tor with an increase in concentration of aluminum was attributed to interfacial polarization. The absence of any discontinuity in the plot of dielectric constant versus composition was ascribed to the absence of continuous aluminum chains in the composition range investigated. The increase in dielectric constant with a rise in temperature was attributed to the segmental mobility of the polymer molecules.
Materials Science and Engineering B-advanced Functional Solid-state Materials, 1996
Synthetic Communications, 1988
Presence technology based on Session Initiation Protocol can be used as an enabling platform for ... more Presence technology based on Session Initiation Protocol can be used as an enabling platform for delivering communication and providing event-based services. We present a mobile workforce management solution which integrates fleet management with presence-based communication to show how presence technology can be used to realize location-based communication services. In particular, our solution integrates a user's presence information with their vehicle's status and location information to enable safe communications with a mobile user. Our solution can provide services for both consumer (residential) and an enterprise scenario, for example, E911, rental car management, delivery companies (e.g., Fedex), for purposes like scheduling and automatic dispatching of mobile crews. We discuss our solution in the context of Verizon's mobile workforce (mobile employee) management scenario. The solution incorporates integration of the mobile employee's location obtained from a GPS device in a vehicle; the mobile employee's presence information obtained from his/her cell-phone and laptop as well as the status and diagnostic information of the vehicle. A prototype system and its realization is presented to show the main concepts, feasibility and usefulness of such a solution.
As the complexity of networked systems increases, we need mechanisms to automatically detect fail... more As the complexity of networked systems increases, we need mechanisms to automatically detect failures in the network and diagnose the cause of such failures. To realize true self-healing networks, we also need mechanisms to fix these failures and ensure service availability by providing alternatives when a failure is detected. In this paper, we address the detection and diagnosis of network failures. We introduce DYSWIS ("Do you see what I see") which observes the system from multiple points in the network. Our system consists of detection nodes and diagnosis nodes. Detection nodes detect failures by passive traffic monitoring and active probing. Diagnosis nodes determine the cause of failures using historical information about similar failures and by performing active tests. They are based on a rule engine and represent network dependency relationship encoded as rules. We present our prototype system which considers network components present in a VoIP network and show the feasibility of our solution.
With the growth of presence based services, it is important to securely manage and distribute sen... more With the growth of presence based services, it is important to securely manage and distribute sensitive presence information such as user location. We survey techniques that are used for security and privacy of presence information. In particular, we describe the SIMPLE based presence specific authentication, integrity and confidentiality. We also discuss the IETF's common policy for geo-privacy, presence authorization for presence information privacy and distribution of different levels of presence information to different watchers. Additionally, we describe an open problem of getting the aggregated presence from the trusted server without the server knowing the presence information, and propose a solution. Finally, we discuss denial of service attacks on the presence system and ways to mitigate them.
With the growth of presence-based services, it is important to provision the network to support h... more With the growth of presence-based services, it is important to provision the network to support high traffic and load generated by presence services. Presence event distribution systems amplify a single incoming PUBLISH message into possibly numerous outgoing NOTIFY messages from the server. This can increase the network load on inter-domain links and can potentially disrupt other QoS-sensitive applications. In this document, we present existing as well as new techniques that can be used to reduce presence traffic both in inter-domain and intra-domain scenarios. Specifically, we propose two new techniques: sending common NOTIFY for multiple watchers and batched notifications. We also propose some generic heuristics that can be used to reduce network traffic due to presence.
Journal of Applied Polymer Science, 2003
Dielectric properties of Al-epoxy composites were characterized as a function of composition, fre... more Dielectric properties of Al-epoxy composites were characterized as a function of composition, frequency, and temperature. The dielectric constant increased smoothly with an increase in the concentration of aluminum. An increase in dielectric constant was also observed with an increase in temperature as well as with a decrease in frequency. In general, dissipation factor values for composites with higher concentrations of aluminum were greater than those with lower volume content of aluminum. Also, the dissipation factor showed an increase both with a decrease in frequency and an increase in temperature. The increase in values of dielectric constant and dissipation fac-tor with an increase in concentration of aluminum was attributed to interfacial polarization. The absence of any discontinuity in the plot of dielectric constant versus composition was ascribed to the absence of continuous aluminum chains in the composition range investigated. The increase in dielectric constant with a rise in temperature was attributed to the segmental mobility of the polymer molecules.
Materials Science and Engineering B-advanced Functional Solid-state Materials, 1996