This paper presents a powerful variant of the ICP (iterative closest point) algorithm for registering range images using a probability field. The probability field (p-field) represents the probability distribution of ...
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This paper presents a powerful variant of the ICP (iterative closest point) algorithm for registering range images using a probability field. The probability field (p-field) represents the probability distribution of the surface position. By capitalizing on the properties of the range image, fast construction, compact representation, and efficient query of the p-field can be achieved. Different sensor models are supported by the p-field according to the properties of the range image. Range images can be precisely aligned by maximizing the probability of overlapping surfaces via the p-field
We introduce the piecewise-linear Haar (PLHaar) transform, a reversible n-bit to n-bit transform that is based on the Haar wavelet transform. PLHaar is continuous, while all current n-bit to n-bit methods are not, and...
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We introduce the piecewise-linear Haar (PLHaar) transform, a reversible n-bit to n-bit transform that is based on the Haar wavelet transform. PLHaar is continuous, while all current n-bit to n-bit methods are not, and is therefore uniquely usable with both lossy and lossless methods (e.g. image compression). PLHaar has both integer and continuous (i.e. non-discrete) forms. By keeping the coefficients to n bits PLHaar is particularly suited for use in hardware environments where channel width is limited, such as digital video channels and graphics hardware.
It is generally believed that the queueing behavior of an arrival process is most sensitive to its first and second order statistics. In this paper, we show that this is not generally true. We consider the queueing be...
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It is generally believed that the queueing behavior of an arrival process is most sensitive to its first and second order statistics. In this paper, we show that this is not generally true. We consider the queueing behavior of two classes of sources. The first class is the superposition of multiple discrete autoregressive sources of order 1 (referred to as DAR(1) sources), and the second class is a single DAR(1) source having the same first and second order statistics as the superposed source. In particular, we show that in the homogeneous case, the mean queue lengths of the two models are identical, but the queue length variances of the two models are significantly different depending on the correlation of individual sources.
While a secure channel provides protection against interception, an authentication system is required to protect a client and an e-commerce server from fabrication attacks. By using a modified three-way authentication...
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ISBN:
(纸本)0889863806
While a secure channel provides protection against interception, an authentication system is required to protect a client and an e-commerce server from fabrication attacks. By using a modified three-way authentication, there is no need for a timeserver. Based on the modified three way authentication model, we propose a hybrid authentication protocol, whereby a strong link is created between a one-time-password e-commerce system and the hybrid authentication protocol by using a user's public key. Within a secure e-commerce framework there are two forms of authentication: (i) user-level authentication and (ii) machine-level authentication. In our proposed model, user-level authentication can be provided by one-time passwords (OTPs), while machine-level authentication is provided by the proposed hybrid authentication protocol. The strengths of the proposed authentication model are also presented.
One of the drawbacks of using PLM (Packet-pair Layered Multicast) protocol is that it only operates in a network that exhibits a Fair Scheduler paradigm, where Fair Queue (FQ) algorithm is implemented in routers that ...
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ISBN:
(纸本)0889863806
One of the drawbacks of using PLM (Packet-pair Layered Multicast) protocol is that it only operates in a network that exhibits a Fair Scheduler paradigm, where Fair Queue (FQ) algorithm is implemented in routers that maintain separate queues for packets from each individual source. This gives rise to the complexity of per-flow management, which incurs costs and overheads. To reduce the complexity, we propose in this paper a framework called Stateless Core (SCORE) network architecture for transmission of multicast layers via an integrated PLM/CSFQ (Core Stateless Fair Queueing) packet-pair mechanism. The proposed model reduces the number of routers performing per-flow management, thus reducing costs. We then evaluate the scalability of the integrated PLM/ CSFQ queueing mechanism using the NS-2 network simulator. The results from the experiments show that the integrated PLM/CSFQ scales well with the increased number of receivers joining the same session, in terms of being TCP friendly, bandwidth allocation and packet losses sustained.
Java RMI by default does not support authenticated and encrypted transport. That is, objects sent over the network are not encrypted. A firewall can be used to secure a Java RMI application. Here, the firewall must al...
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ISBN:
(纸本)0889863806
Java RMI by default does not support authenticated and encrypted transport. That is, objects sent over the network are not encrypted. A firewall can be used to secure a Java RMI application. Here, the firewall must allow access to specifically known ports. That is, these ports cannot be denied access by the firewall. SOCKS provides a partial solution to the use of RMI through firewalls in that it protects outgoing RMI calls, but incoming RMI calls as well as RMI call-backs are not protected. This may be overcome by using bi-directional RMI implementation through the firewalls. However, it requires the use of specific settings that can relax the security or application-level proxy servers, thus increasing the administrative overheads. Also, changing the security policy to allow bi-directional RMI traffic should only be done with extreme care. A better solution towards securing RMI is by means of supporting authenticated and encrypted transport, so that a network attacker cannot alter data on communication. This can be achieved by running RMI on SSL.
Java (J2EE) platform views the Internet world as one language running on different operating systems (OS), whereas .NET framework views the world running on one OS with a programmers having choice of multiple language...
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ISBN:
(纸本)0889863806
Java (J2EE) platform views the Internet world as one language running on different operating systems (OS), whereas .NET framework views the world running on one OS with a programmers having choice of multiple languages. Therefore, J2EE platform interpolates multiple operating systems, and .NET framework interpolates multiple languages. This is the fundamental difference between Microsoft and Sun's strategy. However, in longer term J2EE and .NET will converge and therefore a new integrated framework is desirable. In this paper we focus on Java's RMI, Microsoft's DCOM and SOAP for an application running on an integrated platform.
The performance of object-oriented applications in scientific computing often suffers from the inefficient use of high-level abstractions provided by underlying libraries. Since these library abstractions are user-def...
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This paper proposes a new receiver-based rate-adaptation protocol for multicasting video, called Split-Layer Video Multicast (SPLIT). Unlike existing receiver-based rate-adaptation protocols, such as Receiver-driven L...
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This paper proposes a new receiver-based rate-adaptation protocol for multicasting video, called Split-Layer Video Multicast (SPLIT). Unlike existing receiver-based rate-adaptation protocols, such as Receiver-driven Layered Multicast (RLM), the SPLIT protocol is specifically designed to take advantage of existing packet loss concealment techniques to provide end-users with increased quality of video. In an effort to gauge the performance of the SPLIT protocol, a number of experiments using the NS-2 network simulator were conducted and the results were compared with those of the RLM protocol. The results show that the proposed SPLIT protocol utilizes the available bandwidth in a more efficient way than the RLM protocol does.
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