A novel Linear Prediction (LPC) based Automatic Speaker Identification (ASI) technique employing multiple representations of the LPC is presented. The proposed ASI system has two modes namely, the encoding mode, and t...
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A novel Linear Prediction (LPC) based Automatic Speaker Identification (ASI) technique employing multiple representations of the LPC is presented. The proposed ASI system has two modes namely, the encoding mode, and the Speaker Identification (SI) mode. During the encoding mode, otherwise known as the training mode, the Linear Prediction Coefficients (LPC) are extracted for each speaker as speech features. Multiple Representation Split Vector Quantization (MRSVQ) [1] is employed to form representative codebooks corresponding to each representation, for each speaker. During SI (running) mode, the ASI system identifies the codebooks of the speaker in the database that best matches the LPC extracted from the speech signal of the unknown speaker. The synthesized all pole vocal tract transfer function is used as a measure of vocal tract for ASI. Employing the normalized vocal tract transfer function error measure, the proposed technique is consistently found to obtain enhanced ASI accuracy in comparison with vector quantization employing existing LPC representation, at the expense of a modest increase in computational complexity. The ASI technique presented here can be used in a stand-alone system or as part of an ASI environment.
Point-of-load DC-DC converters for current and next generation of ICs for communication systems and microprocessors are increasingly becoming stricter than ever. This is due to the required tight dynamic tolerances al...
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Point-of-load DC-DC converters for current and next generation of ICs for communication systems and microprocessors are increasingly becoming stricter than ever. This is due to the required tight dynamic tolerances allowed for supply voltages and high dynamic performance demand coupled with very high power density. A new coupled-inductors current-doubler topology is proposed in this paper. The advantages of the proposed topology include higher voltage step-down ratio suitable for lower output voltages, better current ripple cancellation resulting in lower output current ripple, smaller isolation transformer turns ratio and lower secondary turns current when used in isolated topology, and can be designed to achieve symmetric transient response at both step-up and step-down transients when used in non-isolated topology. Theoretical analysis and simulation results are presented, and verified by experimental results.
Flooding, a common operation providing useful functions in MANET (unicast or multicast routing), could cause redundant rebroadcasts, which in result leads to the broadcast storm problem. Several flooding sch.mes have ...
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Flooding, a common operation providing useful functions in MANET (unicast or multicast routing), could cause redundant rebroadcasts, which in result leads to the broadcast storm problem. Several flooding sch.mes have been proposed to solve the broadcast storm problem, but none have been regarded as the satisfying solution. Some flooding sch.mes use the simple probabilistic method while others use neighbor knowledge for efficient flooding. Neighbor knowledge methods use periodic hello packets to acquire neighbor information that generates additional overhead to the wireless network. We propose the Implicit Neighbor Knowledge (INK) routing sch.me, which aims to reduce the flooding overhead by using the simple probability based method. INK routing sch.me uses a variable probability defined by its neighbor size. INK tries to acquire neighbor knowledge without the usage of any periodic hello packets by observing flooded packets. The proposed sch.me keeps up the reachability of blind flooding while maintaining the simplicity of probability based sch.mes.
The dual-Vτ and negative feedback mechanisms have been proposed to enhance Current Balanced Logic for low noise IC design. The detailed circuit analysis and SPICE simulations show that the dual-Vτ structure has adva...
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The dual-Vτ and negative feedback mechanisms have been proposed to enhance Current Balanced Logic for low noise IC design. The detailed circuit analysis and SPICE simulations show that the dual-Vτ structure has advantages over the conventional CBL design in many design aspects, such as gate area, delay, power dissipation, and switching noise. The negative feedback can further reduce the current spike with some tradeoffs. The design procedures of the enhancement CBL are discussed in detail. The proposed methods give the designer a better control of the current spike for mixed-signal integrated circuits.
The need for participation in an emerging Information Society has led to several research efforts for designing accessibility solutions for disabled people. In this paper we present a method for developing Human-Compu...
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The need for participation in an emerging Information Society has led to several research efforts for designing accessibility solutions for disabled people. In this paper we present a method for developing Human-computer Interfaces (HCIs) for quadriplegic people in modern programming environments. The presented method accommodates the design of scanning interfaces with modern programming tools, leading to flexible interfaces with improved appearance and it is based on the use of specially designed software objects called "wifsids" (Widgets For Single-switch Input Devices). The wifsid structure is demonstrated and 4 types of wifsids are analyzed. Developed software applications are to be operated by single-switch activations that are captured through the wifsids, with the employment of several modes of the scanning technique. We also demonstrate the "Autonomia" software application, that has been developed according to the specific methodology. The basic snapshots of this application are analyzed, in order to demonstrate how the wifsids cooperate with the scanning process in a user-friendly environment that enables a quadriplegic person to access an ordinary computer system.
In this paper, we study a practical approach to match the performance of an output-queued switch statistically. For this purpose, we propose a novel switching architecture called a multiple input/output-queued (MIOQ) ...
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In this paper, we study a practical approach to match the performance of an output-queued switch statistically. For this purpose, we propose a novel switching architecture called a multiple input/output-queued (MIOQ) switch that requires no speedup for providing sufficient switching bandwidth. To operate an MIOQ switch in a practical manner, we also propose a multi-token-based arbiter which sch.dules the switch at a high operation rate and a virtual FIFO queueing sch.me which guarantees the departure order of cells belonging to the same traffic flow at output. Additionally, we show that the proposed switch can naturally provide asymmetric bandwidth for inputs and outputs, which may be important in dealing with the links with different bandwidth demands. Finally, we compare the performance of an MIOQ switch with that of an output-queued switch and discuss the design criteria to match the performance of an output-queued switch.
Proxy servers can be used to stream video stored at a geographically separate location. This separation between the proxy server and the storage introduces a non-negligible delay in retrieving video frames in real tim...
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Proxy servers can be used to stream video stored at a geographically separate location. This separation between the proxy server and the storage introduces a non-negligible delay in retrieving video frames in real time. We develop an effective sch.me to achieve consistent, high streaming quality under such delays. Central to the sch.me is the control of buffer occupancy at the proxy server. We model the buffer as a bilinear dynamical system disturbed by a point process with stochastic state-dependent intensity, reflecting the behavior of an additive-increase/multiplicative-decrease transport protocol. Using the buffer model, we construct two controllers based on prediction of future system states, taking into account both the delay and the state-dependent disturbance. Our empirical study illustrates the effectiveness of the sch.me and shows that the controllers exploiting the buffer model perform well in overcoming the adverse impact of the retrieval delay.
The vision of nomadic computing with its ubiquitous access has stimulated much interest in the Mobile Ad Hoc Networking (MANET) technology. However, its proliferation strongly depends on the availability of security p...
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ISBN:
(纸本)1581137699
The vision of nomadic computing with its ubiquitous access has stimulated much interest in the Mobile Ad Hoc Networking (MANET) technology. However, its proliferation strongly depends on the availability of security provisions, among other factors. In the open, collaborative MANET environment practically any node can maliciously or selfishly disrupt and deny communication of other nodes. In this paper, we present and evaluate the Secure Message Transmission (SMT) protocol, which safeguards the data transmission against arbitrary malicious behavior of other nodes. SMT is a lightweight, yet very effective, protocol that can operate solely in an end-to-end manner. It exploits the redundancy of multi-path routing and adapts its operation to remain efficient and effective even in highly adverse environments. SMT is capable of delivering up to 250% more data messages than a protocol that does not secure the data transmission. Moreover, SMT outperforms an alternative single-path protocol, a secure data forwarding protocol we term Secure Single Path (SSP) protocol. SMT imposes up to 68% less routing overhead than SSP, delivers up to 22% more data packets and achieves end-to-end delays that are up to 94% lower than those of SSP. Thus, SMT is better suited to support QoS for real-time communications in the ad hoc networking environment. The security of data transmission is achieved without restrictive assumptions on the network nodes' trust and network membership, without the use of intrusion detection sch.mes, and at the expense of moderate multi-path transmission overhead only.
New dielec.ric-covered waveguide-to-microstrip transitions at Ka-band have been developed. These transitions are probe-type, but the dielec.ric material completely covers the waveguide opening in order to provide mois...
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New dielec.ric-covered waveguide-to-microstrip transitions at Ka-band have been developed. These transitions are probe-type, but the dielec.ric material completely covers the waveguide opening in order to provide moisture barrier and robustness. These transitions are also designed to be less sensitive to fabrication tolerances. The transition structures have been comprehensively analyzed using a 3-D EM software. The resonance phenomena caused by the discontinuity of waveguide-wall have been removed by placing vias around the waveguide aperture. These transitions have also been fabricated and measured. The measured insertion loss of the transition is less than 0.4 dB and the return loss is about 15 dB over entire Ka-band.
This paper proposes a method for designing a color look-up table (GLUT) that can simultaneously process gamut mapping and color space conversion without any complex computation. After constructing a LUT composed of th...
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ISBN:
(纸本)0892082461
This paper proposes a method for designing a color look-up table (GLUT) that can simultaneously process gamut mapping and color space conversion without any complex computation. After constructing a LUT composed of the scanner and printer gamuts, fictive sample points are uniformly selec.ed in CIELAB space and CMY values computed using gamut mapping. The scanner input RGB image is then converted into CIELAB using a regression function and the scanner RGB values converted into CMY values using the proposed GLUT that includes gamut mapping without any additional gamut mapping process. In experiments, the proposed method produced a similar color difference to the direct computation method, yet a reduced computational complexity when compared with discrete gamut mapping and color space conversion.
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