This paper describes a new probabilistic sentence reduction method using maximum entropy model. In contrast to previous methods, the proposed method has the ability to produce multiple best results for a given sentence, which is useful in text summarization applications. Experimental results show that the proposed method improves on earlier methods in both accuracy and computation time.

This paper proposes a new robust adaptive processing algorithm that is based on the extended least squares (ELS) method with running spectrum filtering (RSF). By utilizing the different characteristics of running spectra between speech signals and noise signals, RSF can retain speech characteristics while noise is effectively reduced. Then, by using ELS, autoregressive moving average (ARMA) parameters can be estimated accurately. In experiments on real speech contaminated by white Gaussian noise and factory noise, we found that the method we propose offered spectrum estimates that were robust against additive noise.

In this paper, we propose a new algorithm for calculating the exact poles of the admittance matrix of RLCG interconnects. After choosing dominant poles and corresponding residues, each element of the exact admittance matrix is approximated by partial fraction. A procedure to obtain the residues that guarantee the passivity is also provided, based on experimental studies. In the procedure the residues are calculated by using the least squares method so that the partial fraction matches each element of the exact admittance matrix in the frequency-domain. From the partial fraction representation, the asymptotic equivalent circuit models which can be easily simulated with SPICE are synthesized. It is shown that an efficient model-order reduction is possible for short-length interconnects.

A noise reduction technique to reduce background noise in noisy speech is proposed. We have proposed the noise reduction method which uses a noise reconstruction system. However, since a residual speech signal is included in the input signal of a noise reconstruction filter (NRF) used for reconstructing the background noise, the long time average value of error signal for estimating the background noise is needed not to estimate the speech signal. Therefore, the ability of tracking the non-stationary noise is decreased. In order to solve this problem, we propose the noise reconstruction system with adaptive line enhancer (ALE). Since ALE works to obtain the signal occupied by noise components, the input signal of the NRF includes only a few speech components. Therefore, we can give the high tracking ability to NRF.

In this paper, we present a noble pattern synthesis method of linear and planar array antennas, with non-uniform spacing, for simultaneous reduction of their side-lobe level and pattern distortion during beam steering. In the case of linear array, the Gauss-Newton method is applied to adjust the positions of elements, providing an optimal linear array in the sense of side-lobe level and pattern distortion. In the case of planar array, the concept of thinned array combined with non-uniformly spaced array is applied to obtain an optimal two dimensional (2-D) planar array structure under some constraints. The optimized non-uniformly spaced linear array is extended to the 2-D planar array structure, and it is used as an initial planar array geometry. Next, we further modify the initial 2-D planar array geometry with the aid of thinned array theory in order to reduce the maximum side-lobe level. This is implemented by a genetic algorithm under some constraints, minimizing the maximum side-lobe level of the 2-D planar array. It is shown that the proposed method can significantly reduce the pattern distortion as well as the side-lobe level, although the beam direction is scanned.

In this letter, we propose a fast modular reduction method over Euclidean rings, which is a generalization of Barrett's reduction algorithm over the ring of integers. As an application, we construct new universal hash function families whose operations are modular arithmetic over a Euclidean ring, which can be any of three rings, the ring of integers, the ring of Gauss integers and the ring of Eisenstein integers. The implementation of these families is efficient by using our method.

In this paper, a novel type of the step-up high frequency transformer linked full-bridge soft-switching phase-shift PWM DC-DC power converter with ZVS and ZCS bridge legs is proposed for small scale fuel cell power generation systems, automotive AC power supplies. A tapped inductor filter with a freewheeling diode is implemented in the proposed soft-switching DC-DC power converter to minimize the circulating current in the high-frequency step-up transformer primary side and high-frequency inverter stage. Using a tapped inductor filter with a freewheeling diode makes possible to reduce the circulating current without any active switches and theirs gate-drive circuits. The operating principle of the proposed DC-DC power converter with each operation mode during a half cycle of the steady state operation is explained. The optimum design of the tapped inductor turns ratio is described on the basis of the circuit simulation results. Developing 1 kW 100 kHz prototype with power MOSFETs and 36 V DC source verifies the practical effectiveness of the proposed soft-switching DC-DC power converter. The actual efficiency of the proposed DC-DC power converter is obtained 94% for the wide load and output voltage variation ranges.

We propose a multiple-subcarrier (MS) optical communication system using intensity modulation with direct detection (IM/DD) with peak reduction carriers (PRCs) to improve the power efficiency of IM/DD MS systems. The proposed system transmits L subcarriers referred to as PRCs among N subcarriers for the d.c. bias reduction so that the optical power is reduced. Since information bits are mapped onto each subcarrier other than PRCs independently, the information bits of each subcarrier can be detected independently and the error rate of the proposed system is unaffected by PRCs.

There have been numerous studies on the enhancement of the noisy speech signal. In this paper, We propose a new speech enhancement method, that is, a DFF (Dissonant Frequency Filtering) scheme combined with NR (noise reduction) algorithm. The simulation results indicate that the proposed method provides a significant gain in perceptual quality compared with the conventional method. Therefore if the proposed enhancement scheme is used as a pre-filter, the output speech quality would be enhanced perceptually.

In this paper, we propose a new method which makes transient simulation faster for the circuit including both nonlinear and linear elements. First, the method for generating the projection matrix with Krylov-subspace technique is described. The order of the circuit equation is reduced by congruence transformation with the projection matrix. Next, we suggest a method which can calculate the reduced Jacobian matrix directly in each Newton-Raphson iteration. Since this technique does not need to calculate the original size of Jacobian matrix, the calculation cost is reduced drastically. Therefore, efficient circuit simulation can be achieved. Finally, our method is applied to some example circuits and the validity of the nonlinear circuit reduction technique is verified.

We propose a post-filter (digital filter applied after the correlator) to reduce multiple-access interference (MAI) in the correlator output in asynchronous communications. Optimum filter coefficients are derived for Markov and i.i.d. codes. It is shown that post-filter is not needed for Markov case. Variance of MAI is reduced in i.i.d. codes and it becomes equal to that of Markov codes; thus, both will have the same bit error rate (BER) performance. This post-filter reduces level of MAI in the correlator output for Gold codes as well.

In this proposed method, CRC coding is only applied to data unit, not to padded zeros that are to fill up the fixed length of data unit. So improved frame error rate and protocol efficiency are possible instead of increment of receiver complexity.

In this paper, we consider a location management scheme using Limited Pointer forwarding from Commonly visited sites (LPC) strategy for Personal Communication Services (PCS) networks. The Commonly Visited Site (CVS) is defined as a site in which a mobile user is found with high probability. A feature of the strategy is that it skips updating location information of the mobile user, provided that the mobile user moves within its CVSs. Such a strategy is expected to significantly reduce the location update cost. We evaluate the location management cost of the LPC scheme by employing a Continuous-Time Markov Chain (CTMC) model. We show that the LPC scheme can reduce the location management cost of a highly mobile user who is found in its CVS with high probability.

We propose a novel mobility reduction cancellation technique for an OTA (Operational Transconductance Amplifier). The proposed technique can be easily realized by using conventional OTAs. The proposed OTAs have good linearity. The simulation results show that the THD is less than 1% for 1.8 Vp-p at 3 V supply voltage.

A new state reduction method of incompletely specified sequential machines is proposed in this paper. The method is based on a genetic algorithm implementing a dormant mechanism. MCNC benchmark machines are simplified by using this method to evaluate the method. The experimental results show that machines of almost the same number of states as the minimum ones can be derived by this method.

This paper presents the improvement of the transient response and stability for a two-stage DC-DC converter by removing the output inductor. The conventional two-stage converter consists of a buck converter used as the first stage and a half-bridge converter used as the second stage. The proposed circuit topology removing the output inductor and the conventional topology are compared. Removing the output inductor results in the system-order reduction of the transfer function. As a result, the stability is improved, and the crossover frequency of the open-loop transfer function becomes higher. The effectiveness of the proposed circuit topology was experimentally confirmed.

Orthogonal frequency division multiplexing (OFDM) is a possible candidate for the modulation used in mobile multimedia communications because of its robustness to fading and flexibility of transmission rate. Partial transmit sequence (PTS) is an effective technique for reducing the peak power of OFDM signals by means of phase rotation. In PTS, side information (SI) is transmitted to correct the effects of the phase rotation. We propose a new method based on rotationally invariant trellis coded modulation for coded OFDM with PTS. In this method, no SI is required and the few information bits affected by the phase rotation are not used as data. (They are regarded as dummy bits). It is shown that the proposed method yields better bit error rate (BER) performance than other methods using side information under the condition of almost the same transmission rate.

We propose a method for reducing the size of a share in visual secret sharing schemes. The proposed method does not cause the leakage and the loss of the original image. The quality of the recovered image is almost same as that of previous schemes.

A multiple channel active noise control (ANC) system with several secondary sources, error sensors, and reference sensors has been used for complicated noise fields. Centralized multiple channel ANC systems have been proposed, however implementation of such systems becomes difficult according to increase of control points. Distributed multiple channel ANC systems which have more than a controller are considered. This paper proposes a new implementation of distributed multiple channel ANC systems based on simultaneous equations methods. In the proposed algorithm, communications between controllers are permitted to distribute the computational burden and to improve the performance of noise reduction. This algorithm shows good performances for noise cancellation and tracking of changes in the error paths.

We investigated growth conditions of the ReO3 thin films, as a first step of establishment of artificial superconducting multi-layer with the infinite layer cuprate and ReO3. The layers of ReO3 were expected to work as a charge reservoir block. The films were deposited from a Re metal target by off-axis reactive sputtering. Conductive and preferentially (100) oriented ReO3 thin films were obtained by in-situ post-annealing. The lowest resistivity was 4.4 10-5 ohmcm at room temperature.