International Journal of Pattern Recognition and Artificial Intelligence
Microsoft Kinect, a low-cost motion sensing device, enables users to interact with computers or g... more Microsoft Kinect, a low-cost motion sensing device, enables users to interact with computers or game consoles naturally through gestures and spoken commands without any other peripheral equipment. As such, it has commanded intense interests in research and development on the Kinect technology. In this article, we present a comprehensive survey on Kinect applications, and the latest research and development on motion recognition using data captured by the Kinect sensor. On the applications front, we review the applications of the Kinect technology in a variety of areas, including healthcare, education and performing arts, robotics, sign language recognition, retail services, workplace safety training, as well as 3D reconstructions. On the technology front, we provide an overview of the main features of both versions of the Kinect sensor together with the depth sensing technologies used, and review literatures on human motion recognition techniques used in Kinect applications. We provide a classification of motion recognition techniques to highlight the different approaches used in human motion recognition. Furthermore, we compile a list of publicly available Kinect datasets. These datasets are valuable resources for researchers to investigate better methods for human motion recognition and lower-level computer vision tasks such as segmentation, object detection, and human pose estimation.
We present a lightweight Byzantine fault tolerance (BFT) algorithm, which can be used to render t... more We present a lightweight Byzantine fault tolerance (BFT) algorithm, which can be used to render the coordination of Web Services Business Activities (WS-BA) more trustworthy. The lightweight design of the BFT algorithm is the result of a comprehensive study of the threats to the WS-BA Coordination services and a careful analysis of the state model of WS-BA. The lightweight BFT algorithm uses source ordering, rather than total ordering, of incoming requests to achieve Byzantine fault tolerant, state-machine replication of the WS-BA Coordination services. We have implemented the lightweight BFT algorithm, and incorporated it into the open-source Kandula framework which implements the WS-BA specification with the WS-BA-I extension.
Proceedings 26th Annual International Computer Software and Applications, 2002
Critical components of a distributed system must be replicated to achieve high availability and f... more Critical components of a distributed system must be replicated to achieve high availability and fault tolerance. Current faulttolerant CORBA infrastructures have concentrated on mechanisms for object replication and recovery, while rarely considering practical issues related to the context, i.e., the CORBA middleware within the process in which the object runs. Our study shows that to replicate and recover complex CORBA applications, the behavior of the process that hosts the CORBA objects, in particular, the bootstrapping of an application, must be taken into account. In this paper, we discuss the challenges that arose when bootstrapping CORBA applications in some common scenarios, and we provide strategies to handle such difficulties so that CORBA applications can be rendered fault-tolerant.
In this paper, we argue for the need and benefits for providing Byzantine fault tolerance as a se... more In this paper, we argue for the need and benefits for providing Byzantine fault tolerance as a service to mission critical Web applications. In this new approach to Byzantine fault tolerance, an application server can partition the incoming requests into different domains for concurrent processing, decide which set of messages that should be totally ordered, or not at all, based its application semantics. This flexibility would reduce the end-to-end latency experienced by the clients and significantly increase the system throughput. Perhaps most importantly, we propose a middleware framework that provides a uniform interface to the applications so that they are not strongly tied to any particular Byzantine fault tolerance algorithm implementation.
Communications in Computer and Information Science, 2012
In this paper, we present a catalog of application interaction patterns with the corresponding me... more In this paper, we present a catalog of application interaction patterns with the corresponding message ordering and execution rules for Byzantine fault tolerance computing. For each pattern, a set of rules are defined to determine whether or not an inbound message should be ordered and in what particular order, and which set of messages should be delivered sequentially, concurrently, or selectively concurrently under various scenarios. This catalog could serve as the design patterns for constructing practical Byzantine fault tolerance applications that may use much more sophisticated system models than the basic client-server state machine model. The set of patterns will make it easier and less error-prone when applying the Byzantine fault tolerance techniques for practical systems, in particular, Web based applications.
Communications in Computer and Information Science, 2012
In this paper, we argue for the need and benefits for providing Byzantine fault tolerance as a se... more In this paper, we argue for the need and benefits for providing Byzantine fault tolerance as a service to mission critical Web applications. In this new approach to Byzantine fault tolerance, an application server can partition the incoming requests into different domains for concurrent processing, decide which set of messages that should be totally ordered, or not at all, based its application semantics. This flexibility would reduce the end-to-end latency experienced by the clients and significantly increase the system throughput. Perhaps most importantly, we propose a middleware framework that provides a uniform interface to the applications so that they are not strongly tied to any particular Byzantine fault tolerance algorithm implementation.
2013 IEEE 33rd International Conference on Distributed Computing Systems Workshops, 2013
Mobile device utilization continues to experience considerable growth and the privacy and securit... more Mobile device utilization continues to experience considerable growth and the privacy and security of these devices are becoming more critical with their continued rise in utilization. In this paper, we discuss the components of a mobile device that require enhancements in the security and privacy controls that are inherent in modern mobile operating systems. We then propose a policy that can be used to provide the semantics of defining additional security and privacy controls. From this policy, we propose a framework that can be utilized by an application to enforce a user-defined policy while taking into account the computing constraints of a mobile platform. We then evaluate the results of implementing a limited prototype of this framework and demonstrate its effectiveness in enforcing a userdefined policy.
Many e-commerce companies such as Amazon.com, Yahoo. com, and eBay.com started to offer Web servi... more Many e-commerce companies such as Amazon.com, Yahoo. com, and eBay.com started to offer Web services to their partners and customers. Through such Web services, new value-added services could be provided and hence higher revenues would be generated. Essentially, ...
This article presents a lightweight Byzantine fault tolerance (BFT) framework for session-oriente... more This article presents a lightweight Byzantine fault tolerance (BFT) framework for session-oriented multi-tiered applications. We conclude that it is sufficient to use a lightweight BFT algorithm instead of a traditional BFT algorithm, based on a comprehensive study of the threat model to, and the state model of, the session-oriented multi-tiered applications. The lightweight BFT algorithm uses source ordering, rather than total ordering, of incoming requests to achieve Byzantine fault tolerant state-machine replication of such type of applications. The performance of the lightweight BFT framework is evaluated using a shopping cart application prototype built on the web services platform. The same shopping cart application is used as a running example to illustrate the problem we address and our proposed solution. Performance evaluation results obtained from the prototype implementation show that indeed our lightweight BFT algorithm incurs very insignificant overhead.
2014 IEEE 12th International Conference on Dependable, Autonomic and Secure Computing, 2014
Event stream processing has been used to construct many mission-critical event-driven application... more Event stream processing has been used to construct many mission-critical event-driven applications, such as business intelligence applications and collaborative intrusion detection applications. In this paper, we argue that event stream processing is also a good fit for autonomic computing and describe how to design such a system that is resilient to both hardware failures and malicious attacks. Based on a comprehensive threat analysis of event stream processing, we propose a set of lightweight mechanisms that help achieve Byzantine fault tolerant event processing for autonomic computing. The mechanisms consist of voting at the event consumers and an on-demand state synchronization mechanism triggered when an event consumer fails to collect a quorum of matching decision messages. We also introduce an evidence-based safe-guarding mechanism that prevents a faulty event consumer from inducing unnecessary rounds of state synchronization.
International Journal of Pattern Recognition and Artificial Intelligence
Microsoft Kinect, a low-cost motion sensing device, enables users to interact with computers or g... more Microsoft Kinect, a low-cost motion sensing device, enables users to interact with computers or game consoles naturally through gestures and spoken commands without any other peripheral equipment. As such, it has commanded intense interests in research and development on the Kinect technology. In this article, we present a comprehensive survey on Kinect applications, and the latest research and development on motion recognition using data captured by the Kinect sensor. On the applications front, we review the applications of the Kinect technology in a variety of areas, including healthcare, education and performing arts, robotics, sign language recognition, retail services, workplace safety training, as well as 3D reconstructions. On the technology front, we provide an overview of the main features of both versions of the Kinect sensor together with the depth sensing technologies used, and review literatures on human motion recognition techniques used in Kinect applications. We provide a classification of motion recognition techniques to highlight the different approaches used in human motion recognition. Furthermore, we compile a list of publicly available Kinect datasets. These datasets are valuable resources for researchers to investigate better methods for human motion recognition and lower-level computer vision tasks such as segmentation, object detection, and human pose estimation.
We present a lightweight Byzantine fault tolerance (BFT) algorithm, which can be used to render t... more We present a lightweight Byzantine fault tolerance (BFT) algorithm, which can be used to render the coordination of Web Services Business Activities (WS-BA) more trustworthy. The lightweight design of the BFT algorithm is the result of a comprehensive study of the threats to the WS-BA Coordination services and a careful analysis of the state model of WS-BA. The lightweight BFT algorithm uses source ordering, rather than total ordering, of incoming requests to achieve Byzantine fault tolerant, state-machine replication of the WS-BA Coordination services. We have implemented the lightweight BFT algorithm, and incorporated it into the open-source Kandula framework which implements the WS-BA specification with the WS-BA-I extension.
Proceedings 26th Annual International Computer Software and Applications, 2002
Critical components of a distributed system must be replicated to achieve high availability and f... more Critical components of a distributed system must be replicated to achieve high availability and fault tolerance. Current faulttolerant CORBA infrastructures have concentrated on mechanisms for object replication and recovery, while rarely considering practical issues related to the context, i.e., the CORBA middleware within the process in which the object runs. Our study shows that to replicate and recover complex CORBA applications, the behavior of the process that hosts the CORBA objects, in particular, the bootstrapping of an application, must be taken into account. In this paper, we discuss the challenges that arose when bootstrapping CORBA applications in some common scenarios, and we provide strategies to handle such difficulties so that CORBA applications can be rendered fault-tolerant.
In this paper, we argue for the need and benefits for providing Byzantine fault tolerance as a se... more In this paper, we argue for the need and benefits for providing Byzantine fault tolerance as a service to mission critical Web applications. In this new approach to Byzantine fault tolerance, an application server can partition the incoming requests into different domains for concurrent processing, decide which set of messages that should be totally ordered, or not at all, based its application semantics. This flexibility would reduce the end-to-end latency experienced by the clients and significantly increase the system throughput. Perhaps most importantly, we propose a middleware framework that provides a uniform interface to the applications so that they are not strongly tied to any particular Byzantine fault tolerance algorithm implementation.
Communications in Computer and Information Science, 2012
In this paper, we present a catalog of application interaction patterns with the corresponding me... more In this paper, we present a catalog of application interaction patterns with the corresponding message ordering and execution rules for Byzantine fault tolerance computing. For each pattern, a set of rules are defined to determine whether or not an inbound message should be ordered and in what particular order, and which set of messages should be delivered sequentially, concurrently, or selectively concurrently under various scenarios. This catalog could serve as the design patterns for constructing practical Byzantine fault tolerance applications that may use much more sophisticated system models than the basic client-server state machine model. The set of patterns will make it easier and less error-prone when applying the Byzantine fault tolerance techniques for practical systems, in particular, Web based applications.
Communications in Computer and Information Science, 2012
In this paper, we argue for the need and benefits for providing Byzantine fault tolerance as a se... more In this paper, we argue for the need and benefits for providing Byzantine fault tolerance as a service to mission critical Web applications. In this new approach to Byzantine fault tolerance, an application server can partition the incoming requests into different domains for concurrent processing, decide which set of messages that should be totally ordered, or not at all, based its application semantics. This flexibility would reduce the end-to-end latency experienced by the clients and significantly increase the system throughput. Perhaps most importantly, we propose a middleware framework that provides a uniform interface to the applications so that they are not strongly tied to any particular Byzantine fault tolerance algorithm implementation.
2013 IEEE 33rd International Conference on Distributed Computing Systems Workshops, 2013
Mobile device utilization continues to experience considerable growth and the privacy and securit... more Mobile device utilization continues to experience considerable growth and the privacy and security of these devices are becoming more critical with their continued rise in utilization. In this paper, we discuss the components of a mobile device that require enhancements in the security and privacy controls that are inherent in modern mobile operating systems. We then propose a policy that can be used to provide the semantics of defining additional security and privacy controls. From this policy, we propose a framework that can be utilized by an application to enforce a user-defined policy while taking into account the computing constraints of a mobile platform. We then evaluate the results of implementing a limited prototype of this framework and demonstrate its effectiveness in enforcing a userdefined policy.
Many e-commerce companies such as Amazon.com, Yahoo. com, and eBay.com started to offer Web servi... more Many e-commerce companies such as Amazon.com, Yahoo. com, and eBay.com started to offer Web services to their partners and customers. Through such Web services, new value-added services could be provided and hence higher revenues would be generated. Essentially, ...
This article presents a lightweight Byzantine fault tolerance (BFT) framework for session-oriente... more This article presents a lightweight Byzantine fault tolerance (BFT) framework for session-oriented multi-tiered applications. We conclude that it is sufficient to use a lightweight BFT algorithm instead of a traditional BFT algorithm, based on a comprehensive study of the threat model to, and the state model of, the session-oriented multi-tiered applications. The lightweight BFT algorithm uses source ordering, rather than total ordering, of incoming requests to achieve Byzantine fault tolerant state-machine replication of such type of applications. The performance of the lightweight BFT framework is evaluated using a shopping cart application prototype built on the web services platform. The same shopping cart application is used as a running example to illustrate the problem we address and our proposed solution. Performance evaluation results obtained from the prototype implementation show that indeed our lightweight BFT algorithm incurs very insignificant overhead.
2014 IEEE 12th International Conference on Dependable, Autonomic and Secure Computing, 2014
Event stream processing has been used to construct many mission-critical event-driven application... more Event stream processing has been used to construct many mission-critical event-driven applications, such as business intelligence applications and collaborative intrusion detection applications. In this paper, we argue that event stream processing is also a good fit for autonomic computing and describe how to design such a system that is resilient to both hardware failures and malicious attacks. Based on a comprehensive threat analysis of event stream processing, we propose a set of lightweight mechanisms that help achieve Byzantine fault tolerant event processing for autonomic computing. The mechanisms consist of voting at the event consumers and an on-demand state synchronization mechanism triggered when an event consumer fails to collect a quorum of matching decision messages. We also introduce an evidence-based safe-guarding mechanism that prevents a faulty event consumer from inducing unnecessary rounds of state synchronization.
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Papers by Wenbing Zhao