UNITS, the successor of GSM, is evolving toward a future wireless all-IP network. In this paper we present how it supports real-time IP multimedia services, as these services are expected to drive the adoption of wire...
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ISBN:
(纸本)0780390199
UNITS, the successor of GSM, is evolving toward a future wireless all-IP network. In this paper we present how it supports real-time IP multimedia services, as these services are expected to drive the adoption of wireless all-IP networks. The scheme of real time streaming video is one of the newcomers in wireless data communication and in particular in UNITS, raising a number of novel requirements in both telecommunication and data communication systems. This scheme applies when the mobile user is experiencing real time multimedia content. In this paper, we describe the design and the implementation of a decision feedback scheme, which is based on real time protocols and it is used for streaming video over UNITS transport channels. The decision feedback scheme uses a friendly, to the mobile users, congestion control mechanism to control the transmission rate of the real time video sequence. Furthermore, we evaluate this mechanism through a number of experiments. During these experiments we demonstrate the friendly behavior of the decision feedback scheme to TCP and UDP data streams that coexist in the same channel with the video sequence.
This work aims a two-fold contribution: it presents a software to analyse logfiles and visualize popular web hot spots and, additionally, presents an algorithm to use this information in order to identify subsets of t...
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ISBN:
(纸本)1595930515
This work aims a two-fold contribution: it presents a software to analyse logfiles and visualize popular web hot spots and, additionally, presents an algorithm to use this information in order to identify subsets of the website that display large access patterns. Such information is extremely valuable to the site maintainer, since it indicates points that may need content intervention or/and site graph restructuring. Experimental validation verified that the visualization tool, when coupled with algorithms that infer frequent traversal patterns, is both effective in indicating popular hot spots and efficient in doing so by using graph-based representations of popular traversals.
We present data illustrating the effects of direct electrical stimulation on the spinal central pattern generator (CPG) for locomotion. Discrete current pulses were applied to isolated lamprey spinal cords during &quo...
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We consider the problem of maximizing the lifetime of a given multicast connection in a wireless network of energy-constrained (e.g., battery-operated) nodes, by choosing ideal transmission power levels for the nodes ...
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We consider the problem of maximizing the lifetime of a given multicast connection in a wireless network of energy-constrained (e.g., battery-operated) nodes, by choosing ideal transmission power levels for the nodes relaying the connection. We distinguish between two basic operating modes: In a static power assignment, the power levels of the nodes are set at the beginning and remain unchanged until the nodes are depleted of energy. In a dynamic power schedule, the powers can be adjusted during operation. We show that while lifetime-maximizing static power assignments can be found in polynomial time, for dynamic schedules the problem becomes NP-hard. We introduce two approximation heuristics for the dynamic case, and experimentally verify that the lifetime of a dynamically adjusted multicast connection can be made several times longer than what can be achieved by the best possible static assignment.
Many of the cryptographic schemes over small characteristic finite fields are efficiently implemented by using a trinomial basis. In this paper, we present new linear systolic arrays for multiplication in GF(2m] for c...
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Collection of Taiwanese text corpus with phonetic transcription suffers from the problems of multiple pronunciation, or pronunciation variation. By further augmenting the text with read speech, and using automatic spe...
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Collection of Taiwanese text corpus with phonetic transcription suffers from the problems of multiple pronunciation, or pronunciation variation. By further augmenting the text with read speech, and using automatic speech recognition with a sausage searching net constructed from the multiple pronunciations of the text corresponding to its speech utterance, we are able to reduce the effort for phonetic transcription. Compared to general method for pronunciation variation such as the relabeling of training corpus of [1], the sausage searching net shows advantages. Two experiments are conducted using a Taiwanese Buddhist Sutra speech and text corpus.
In this paper, we compare the performance of a speech recognition system trained with two speech corpora. We select two set of words such that they covered all the cross-syllable bi-phones and tri-phones, and are call...
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In this paper, we compare the performance of a speech recognition system trained with two speech corpora. We select two set of words such that they covered all the cross-syllable bi-phones and tri-phones, and are called phonetically bi-phone-rich and tri-phone-rich respectively. It is required about 10 times more words than that of cross-syllable bi-phones to cover all the cross-syllable tri-phones. To facilitate fair comparison, the bi-phone-rich corpus is thus consisted often sets of words that each covers all the cross-syllable bi-phones. With those words as data sheets, a male Taiwanese speaker recorded all the words as microphone speech. The resulting speech corpora, about 100 minutes for each set, are used to train for the acoustic models. Although both perform quite well in tasks with recognition networks of linear net and free syllable net the tri-phone-rich corpus does not show much advantages over the bi-phone-rich corpus.
In this paper, we describe a bi-lingual Text-to-speech (ITS) translational system, which converts Chinese Text into Taiwanese speech, by using bilingual lexicon information. This TTS system is organized as three funct...
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In this paper, we describe a bi-lingual Text-to-speech (ITS) translational system, which converts Chinese Text into Taiwanese speech, by using bilingual lexicon information. This TTS system is organized as three functional modules, which contain a text analysis module, a prosody module, and a waveform synthesis module. We conducted an experiment to evaluate the text analysis and tone-sandhi modules. About 90% labeling accuracy and 65% tone-sandhi accuracy can be achieved. With this proposed Taiwanese TTS component, a talking electronic lexicon system can be built to help those who want to learn these 2 languages.
This paper discusses a visual attack to BPCS-Steganography (Bit-Plane Complexity Segmentation-Steganography) and presents a countermeasure. BPCS categorizes each small block within cover images into either a "noi...
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DiffServ is the basis of contemporary QoS-enabled networks. Setting up DiffServ QoS requires extensive engineering effort in dimensioning and provisioning, especially for adjacent networks under different administrati...
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ISBN:
(纸本)0780395654
DiffServ is the basis of contemporary QoS-enabled networks. Setting up DiffServ QoS requires extensive engineering effort in dimensioning and provisioning, especially for adjacent networks under different administrations linked in a "federated" hierarchy. In this paper we present a case study for QoS techniques employed in the GRNET MAN networks of Athens and Crete. After introducing the supported QoS mechanisms and service types, we discuss our dimensioning methodology and present two algorithms for worst-case dimensioning. We explain the provisioning mechanisms of GRNET and we present in brief our new automated provisioning ANS tool. Finally, we deal with the extension of our mechanisms and tools in hierarchically federated networks and give some future directions of our work.
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