This paper presents a new technique for modeling High-Voltage lightly-doped-drain MOS (HV MOS) devices accurately with the BSIM3v3 SPICE model. Standard SPICE models do not model the voltage dependency of Rs and Rd in HV MOS devices; this causes large discrepancies between the simulated and measured I-V characteristics of HV MOS devices. We propose to assign physical meanings and values different from the original BSIM3v3 model to three of its parameters to represent the voltage dependency of Rs and Rd. With this method, we have succeeded in highly accurate parameter extraction, and the simulated I-V characteristics of HV MOS devices using the extracted parameters match the measured results well. The relationship between the proposed modeling technique and the physical mechanism of HV MOS devices is also discussed based on measurement and device simulation results. Since our method does not change any model equations of BSIM3v3, it can be applied to any SPICE simulator on which the BSIM3v3 model runs, so we can use SPICE simulation for accurate circuit design of complex circuits using HV MOS devices.

A new method using new test structure, which is connected 15.4 million MOS transistor, for evaluating extrinsic oxide breakdown is proposed. The active gate area which is needed to predict reliability will be shown. And by using this new method, activation energy not only for the intrinsic breakdown but also for the extrinsic breakdown are obtained.

In highly reliable communication network design, disjoint paths between pairs of nodes are often needed in the design phase. The problem of finding k paths which are as diverse as possible and have the lowest total cost is called a k-best paths problem. We propose an algorithm for finding the k-best paths connecting a pair of nodes in a graph G. Graph extension is used to transfer the k-best paths problem to a problem which deploits well-known maximum flow (MaxFlow) and minimum cost network flow (MCNF) algorithms. We prove the k-best paths solution of our algorithm to be an optimal one and the time complexity is the same as MCNF algorithm. Our computational experiences show that the proposed algorithm can solve k-best paths problem for a large network within reasonable computation time.

This paper proposes an adaptive microphone array using blind deconvolution. The method realizes an signal enhancement based on the combination of blind deconvolution, synchronized summation and DSA (Delay-and-Sum Array) method. The proposed method improves performance of estimation by the iterative operation of blind deconvolution using a cost-function based on the coherency function.

This paper presents a contact-less connector using proximity coupling through a parasitic element. For example, proximity coupling is used for interconnect of microstrip lines for DC-break structure. We also present a cross wiring structure using this interconnect.

This paper proposes a newly developed dual-frequency antenna for 800 MHz and 1500 MHz band use. A uniformly spaced array configuration, originally designed for a 800 MHz analog system, is extended to yield dual frequencies operations. An important characteristic of a base station antenna is low sidelobe level in order to suppress inter-cell interference. In the case of a uniformly spaced array configuration, sidelobe levels are increased by the emergence of grating lobes at higher frequencies. Electrical beam tilt also degrades the sidelobe level. As does the change in the excitation coefficients of the array elements at higher frequencies. These three factors are studied theoretically to yield practical sidelobe levels. One more important beam characteristic is the sector beam in the horizontal plane. The same beam width in two frequency bands is achieved by designing the novel reflector shape and determining the proper array element positions in front of the reflector. Practical antenna characteristics are confirmed by designing, manufacturing, and testing a base station antenna.

An Acoustic echo canceller has problems adaptating under noisy or double-talk conditions. The adaptation process requires a precise identification of the temporarily changed room impulse response. To do this, both minimizing the step size parameter of the Least Mean Square (LMS) method to be as small as possible and giving up on updating the adaptive filter coefficients have been considered. This paper describes an adaptive cross-spectral technique that is robust to adaptive filtering under noisy or double-talk conditions and for colored signals such a speech signal. The cross-spectral technique was originally developed to measure the impulse response in a linear system. Here we apply in the adaptive cross-spectral technique to solve the acoustic echo cancelling problem. This cross-spectral technique takes the ensemble average of the cross spectrum between input and error signals and the averaged cross spectrum is divided by the averaged power spectrum of the input signal to update the filter coefficients. We have confirmed that the echo signal is suppressed by about 15 dB even under double-talk conditions. We also explain that this method has a systematic error due to using a short time block for estimating the room impulse response. Then we investigate overlapping every last half block by the following first half block in order to reduce the effect of the systematic error. Finally, we compare our method with the Frequency-domain Block LMS (FBLMS) method because both methods are implemented in the frequency domain using a short time block.

We show by numerical calculations that a chaotic neuron model driven by a weak sinusoid has resonance. This resonance phenomenon has a peak at a drive frequency similar to that of noise-induced stochastic resonance (SR). This neuron model was proposed from biological studies and shows a chaotic response when a parameter is varied. SR is a noise induced effect in driven nonlinear dynamical systems. The basic SR mechanism can be understood through synchronization and resonance in a bistable system driven by a subthreshold sinusoid plus noise. Therefore, background noise can boost a weak signal using SR. This effect is found in biological sensory neurons and obviously has some useful sensory function. The signal-to-noise ratio (SNR) of the driven chaotic neuron model is improved depending on the drive frequency; especially at low frequencies, the SNR is remarkably promoted. The resonance mechanism in the model is different from the noise-induced SR mechanism. This paper considers the mechanism and proposes possible explanations. Also, the meaning of chaos in biological systems based on the resonance phenomenon is considered.

A new method of designing a microphone array with two outputs preserving binaural information is proposed in this paper. This system employs adaptive beamforming using multiple constraints. The binaural cues may be preserved in the two outputs by use of these multiple constraints with simultaneous beamforming to enhance target signals is also available. A computer simulation was conducted to examine the performance of the beamforming. The results showed that the proposed array can perform both the generation of the binaural cues and the beamforming as intended. In particular, beamforming with double-constraints exhibits the best performance; DI is around 7 dB and good interchannel (interaural) time/phase and level differences are generated within a target region in front. With triple-constraints, however, the performance of the beamforming becomes poorer while the binaural information is better realized. Setting of the desired responses to give proper binaural information seems to become critical as the number of the constraints increases.

Profiles of photoemission induced by hot electrons in LDD-type n-MOSFETs with L = 0.35-2.0 µm were measured with a photoemission microscope, which had a capability of 1000 magnification and a spatial resolution of 27 nm/pixel on a CCD imager sufficient to detect profile changes in the channel length direction. Under the bias condition of maximum substrate current, photoemission peaks were located at the LDD-drain edge and the n+-drain edge for the devices with L = 0.35 and L 0.40 µm, respectively. A peak position, only in the case of the 0.35 µm device, shifted toward the drain side by about 80 nm at VD = 7.0 V. Since VD did not affect peak positions in L 0.40 µm devices, the photoemission mechanisms may be different between L = 0.35 µm and L 0.40 µm devices. The photoemission points due to p-n junction breakdown were located at the cylindrical curvature edge of the n+-drain region. Two-dimensional device simulation, even when the lateral electric field, electron temperature and radiative recombination rate were taken into account, could not explain the experimental results completely.

A novel method to enhance the practical security of interferometric quantum cryptography is proposed, giving the protocol and detailed constructions including a controlled spontaneous photon emitter, a superradiance amplifier, beam splitters, phase shifters, and a pair of Mach-Zehnder interferometers. The intrinsic uncertainty due to the random phase selection out of three, leads to the detection of eavesdropping. The physical uncertainty of the controlled spontaneous emission of coherent photons also adds temporal equivocation to confuse eavesdroppers.

Under a contamination of background sound noises, it seems difficult especially in a real working situation to evaluate various type statistics of only an objective sound signal fluctuation. In many cases of the noise evaluation, some signal processing method have been employed to eliminate the effect of background sound noises by first measuring emitted sound levels. In this study, a new evaluation method of sound level fluctuation is proposed in principle on the basis of the measurement of heterogeneous physical quantity other than sound pressures or sound levels to eliminate the effect of background sound noises. Though the theoretical analysis on acoustical emission caused by a mechanical vibration seems very difficult in a working situation, the sound noise fluctuation emitted only from an objective sound source can be effectively evaluated through its related vibration measurement by employing a fairly unified stochastic method proposed on the basis of a generalized regression analysis between sound and vibration. Here, the regression coefficients are determined by employing the least squares error method to minimize the mean square of estimation error to illustrate well the sound data by means of vibration data. Finally, the effectiveness of proposed method has been experimentally applied to the sound noise evaluation of a jigsaw.

We proposed Reversible Energy Recovery Logic (RERL) using an 8-phase clocking scheme, which is a dual-rail reversible adiabatic logic for ultra-low-energy applications. Because we eliminated non-adiabatic energy loss in RERL by using the concept of reversible logic, RERL has only adiabatic and leakage losses. In this paper we explain its operation and logic design and present its simulation and experimental results. We also present an energy-efficient 8-phase, clocked power generator that uses an off-chip inductor. With simulation results for the full adder, we confirmed that the RERL circuit consumed substantially less energy than other logic circuits at low-speed operation. We evaluated a test chip implemented with a 0.6-µm CMOS technology, which integrated a chain of inverters with a clocked power generator. In the experimental results, the RERL circuit consumed only 4.5% of the dissipated energy of a static CMOS circuit at an optimal operating speed of 40 kHz. In conclusion, RERL is suitable for the applications that do not require high performance but low-energy consumption because its energy consumption can be decreased to the minimum by reducing the operating frequency until adiabatic and leakage losses are equal.

Today, many kinds of real-time applications are available over IP networks. It is important to measure the network performance for such applications before making use of real applications. Authors developed the general purpose traffic measurement tool for IP networks. This system can generate any kinds of traffic flexibly and calculate the network performance such as throughput, delay and loss ratio according to received packets. In this paper, the concept of this traffic measurement tool is described in detail, and several examples of network measurements are shown.

This paper evaluates the performance of a reliable multicast protocol for bulk-data transfer over unreliable networks via IP-multicast. Bulk-data type reliable multicast appears promising for commercial publishing and large-scale data replication. The proposed reliable multicast transport protocol (RMTP) provides high-performance due to the use of IP multicast while also providing confirmed and error free transfer by end-to-end controls. The protocol includes a multi-round selective repeat scheme dedicated for bulk-data multicast applications. This paper examines the multicast retransmission procedures in RMTP through analysis and tests on an implemented system and clarifies the basic performance behavior of the protocol. Evaluations are conducted with regard to retransmission redundancy, transfer time, and packet processing load with various error conditions and number of receivers. Against the response concentration problem seen in end-to-end communication, the backoff time algorithm is applied to the protocol; the limits it places on system scalability are clarified.

This paper presents a high-speed CAC scheme, called PERB CAC (CAC based on Prior Estimation for Residual Bandwidth). This scheme estimates the residual bandwidth in advance by generating virtual requests for connection. When an actual new request occurs, PERB CAC can instantaneously judge if the required bandwidth is larger than the estimated residual bandwidth. PERB CAC provides very rapid response time both for statistical and deterministic bandwidth allocation services, while keeping statistical multiplexing gain for the former service. Numerical results indicate that PERB CAC provides reasonably accurate and conservative values of residual bandwidth. In addition, by using PERB CAC, both services are able to be accommodated into a single VP. VP capacity control is more relaxed than is true with conventional VP-separation management. This is another merit of PERB CAC. Therefore, PERB CAC can achieve high-speed connection set-up while utilizing network resources in a cost-effective manner.

This paper proposes a medium access control (MAC) protocol for single-hop WDM star-coupler networks, in which the number of stations is larger than the number of channels and the stations have arbitrary distances to the star coupler. The proposed protocol has one control channel for reserving the slots of data channels and several data channels which are used to transmit traffic. This paper also suggests a scheme that accomplishes load balancing among data channels for arbitrary traffic patterns between stations. Since this load balancing scheme diminishes an influence that traffic patterns have on the performance of the proposed MAC protocol, the proposed system is appropriate for systems which have asymmetric traffic intensity between stations. Throughput and mean message delay of the MAC protocol are analyzed using a discrete time Markov process and a D/G/1 queue with batch arrivals. The numerical results show that the performance is improved as the message length increases, the maximum round-trip propagation delay decreases, and the number of data channels increases.

Feedback of class memberships is incorporated into multimodal pattern classifiers and their unsupervised learning algorithm is presented. Classification decision at low levels is revised by the feedback information which also enables the reconstruction of patterns at low levels. The effects of the feedback are examined for the McGurk effect by using a simple model.

In this paper, we consider the steady state mean square error (MSE) analysis for 2-D LMS adaptive filtering algorithm in which the filter's weights are updated along both vertical and horizontal directions as a doubly-indexed dynamical system. The MSE analysis is conducted using the well-known independence assumption. First we show that computation of the weight-error covariance matrix for doubly-indexed 2-D LMS algorithm requires an approximation for the weight-error correlation coefficients at large spatial lags. Then we propose a method to solve this problem. Further discussion is carried out for the special case when the input signal is white Gaussian. It is shown that the convergence in the MSE sense occurs for step size range that is significantly smaller than the one necessary for the convergence of the mean. Simulation experiments are presented to support the obtained analytical results.

A new dynamic programming (DP) based algorithm for monotonic and continuous two-dimensional warping (2DW) is presented. This algorithm searches for the optimal pixel-to-pixel mapping between a pair of images subject to monotonicity and continuity constraints with by far less time complexity than the algorithm previously reported by the authors. This complexity reduction results from a refinement of the multi-stage decision process representing the 2DW problem. As an implementation technique, a polynomial order approximation algorithm incorporated with beam search is also presented. Theoretical and experimental comparisons show that the present approximation algorithm yields better performance than the previous approximation algorithm.