In this paper, a novel continuous complementary sliding control was proposed to improve the tracking performance given the available control bandwidth and the extend of parameter uncertainty. With this control law, the ultimate bound of tracking error was shown to be reduced at least by half, as compared with the conventional continuous sliding control. More strikingly, the proposed control can effectively improve the error transient response during the reaching phase. We presented a composite complementary sliding control scheme for a class of uncertain nonlinear systems including the nonlinear electrohydraulic position servo control system, which will be used as an illustrated example. Simulation results indicated exceptional good tracking performance to step and sine wave reference inputs can be obtained. In addition, the disturbance rejection property of the controller to single-frequency sinusoidal disturbances is also outstanding.

We examine a concatenated code which consists of a rate 1/2, 4-state turbo code (an inner code) and a single-parity-check product code (an outer code), and discuss the decoding structure called a double concatenated decoding scheme. From our Monte Carlo simulation trials, we show the advantage of the concatenated codes over turbo codes alone. Specifically, when we use an interleaver of 4096 bits, the Eb/No to obtain a BER of 10-6 is about 1.45 dB for the concatenated code. On the other hand, it is more than 2.5 dB for the turbo code alone. So, the Eb/No improvement can be achieved by about 1 dB. This improvement in Eb/No was also obtained for the interleavers of 8192 and 2048 bits. Therefore, the concatenated codes using a double concatenated decoding scheme can solve the problem of the BER flattening in decoding of turbo codes.

We have recently developed a programmable composite noise generator (P-CNG) which can easily control noise parameters such as average power, time-based amplitude probability distribution (APD), crossing rate distribution, occurrence frequency distribution and burst duration. Two applications of the P-CNG are demonstrated to show its usefulness. For the first application, Middleton's Class A noise is simulated. A method of setting parameters for Class A noise is demonstrated. The APD of P-CNG output is in good agreement with that of true Class A noise. In the second application, the P-CNG is used for subjective evaluation test (opinion test) of TV picture degradation. Five simple composite noise models with two kinds of APD are used. Other parameters such as average power are kept constant. Experimental results show that the envelope and APD of composite noises do not greatly influence the subjective evaluation. Finally the capabilities of the P-CNG are shown.

This paper proposes a fast method for the calculation of exponential B-splines sampled at regular intervals. This algorithm is based on a combination of FIR and IIR filters which enables a fast decomposition and reconstruction of a signal. When complex values are selected for the parameters of the exponentials, complex trigonometric functions are obtained. Only the real part of these functions are used for the interpolation of real signals, leading less bandlimited signals when they are compared with the polynomial B-spline counterparts. These characteristics were verified with 1-D and 2-D examples. This paper also discusses the effectiveness of exponential B-splines, when they are applied to image processing.

Polyurea thin films containing azo-based nonlinear optical (NLO) chromophore were prepared by co-deposition of 4,4'-diphenylmethane diisocyanate and 2,4-diamino-4'-nitroazobenzene monomers using the ionization-assisted method. The co-deposited film reacted to form polyurea after annealing in the air. The dichroic optical absorption spectra indicated the preferential orientation of dipole moments in the as-deposited film. The substrate bias voltage influenced the optical anisotropy. Maker fringe measurement showed that the films have NLO activity without the poling process.

Soft bit speech decoding, as a new approach of error concealment, is applied to the mixed excitation linear prediction (MELP) algorithm. Average residual redundancies of the quantized parameters are exploited in the error concealment process as an a priori knowledge of the source. Results show a significant SNR improvement for parameters decoded using the error concealment scheme.

In positioning systems NLOS (Non-Line of Sight) errors always cause remarkable positive bias and directly increase range measurement errors. In this paper, a new method is proposed to calibrate NLOS errors in positioning systems by using the relationship between mean excess delay and delay spread measured at a mobile station. The computer simulations showed that the proposed calibration technique effectively reduces the positioning error caused by urban NLOS environment.

With increasing Internet traffic congestion, the provision of reliable transmission and packet loss recovery continues to be of substantial importance. In this paper, we analyze a new recovery method using punctured convolutional codes, demonstrating the simplicity and efficiency of the proposed method for the recovery of lost packets. The analysis provides a method for determining the recoverability and the post-reconstruction receiving rate for a given convolutional code. The exact expressions for calculating the recovery rate are derived for a number of convolutional codes and the (2, 1, m) punctured convolutional code. Where packet loss probabilities are in the range typically found in Internet transmissions, the convolutional code-based method delivers superior performance over the traditional parity method with the same redundancy.

Blind adaptive channel identification of communication channels is a problem of important current theoretical and practical concerns. Recently proposed solutions for this problem exploit the diversity induced by antenna array or time oversampling, leading to the so-called, second order statistics techniques. Adaptive blind channel identification techniques based on a off-line least-squares approach have been proposed but this method assumes noise-free case. The method resorts to an adaptive filter with a linear constraint. This paper proposes a new approach based on eigenvalue decomposition. Indeed, the eigenvector corresponding to the minimum eigenvalue of the covariance matrix of the received signals contains the channel impulse response. And we present a adaptive algorithm to solve this problem. The performance of the proposed technique is evaluated over real measured channel and is compared to existing algorithms.

This paper presents a high quality 4-kbit/s speech coding algorithm based on a CELP algorithm. The coder operates on speech frames of 20 ms. The algorithm has following four main features: multiple sub-codebooks, backward adaptive mode switching, dispersed-pulse structure, and noise post-processing. The multiple sub-codebooks consist of a pulse-codebook and a random-codebook so that they can handle both signals, noise-like (e.g. unvoiced, stationary noise) and pulse-like (e.g. voiced). The backward adaptive mode switching is performed using decoded parameters; therefore, no additional mode bit is transmitted. The random-codebook size is switched with the backward adaptively selected mode. The subjective quality of unvoiced speech or noise-like signal can be improved by this switching operation because the random-codebook size is greatly increased in such signal mode. The dispersed-pulse structure provides better performance of sparse pulse excitation using dispersed pulses instead of simple unit pulses. The noise post-processing employs a stationary background noise generator for producing stationary noise signal. It significantly improves subjective quality of decoded signal under various background noise conditions. Subjective listening tests are conducted in accordance with ACR and DCR tests. The ACR test results indicate that the fundamental performance of the MDP-CELP is equivalent to that of 32-kbit/s adaptive differential pulse code modulation (ADPCM). The DCR test results show that the performance of the MDP-CELP is equivalent to or better than that of 8-kbit/s conjugate-structure algebraic code excited linear prediction (CS-ACELP) under several background noise conditions.

In this paper, we discuss the impossible differential cryptanalysis for the block cipher Zodiac. The main design principles of Zodiac include simplicity and efficiency. However, the diffusion layer in its round function is too simple to offer enough security. The impossible differential cryptanalysis exploits such weakness in Zodiac. Our attack using a 14-round impossible characteristic derives the 128-bit master key of the full 16-round Zodiac faster than the exhaustive search. The efficiency of the attack compared with exhaustive search increases as the key size increases.

In this paper, we examine the polarimetric characteristics and the potential of the coherent decomposition in polarimetric synthetic aperture radar (SAR) interferometry. Coherent scattering decomposition based on the coherence optimization can separate effective phase center of different scattering mechanisms and can be used to generate canopy digital elevation model (DEM). This decomposition is applied to a simplified stochastic scattering model such as forest canopy. However, since the polarimetric characteristics are not well understood when the decomposition is carried out, we investigate its characteristics and potential using polarimetric entropy-alpha and three-component scattering matrix decomposition. The results show that the first and third components correspond to the lower and upper layer, respectively, in ideal case. In this investigation, SIR-C/X-SAR data of the Tien Shan flight-pass are used.

This paper proposes a linear algorithm for metric reconstruction from projective reconstruction. Metric reconstruction problem is equivalent to estimating the projective transformation matrix that converts projective reconstruction to Euclidean reconstruction. We build a quadratic form from dual absolute conic projection equation with respect to the elements of the transformation matrix. The matrix of quadratic form of rank 2 is then eigen-decomposed to produce a linear estimate. The algorithm is applied to three different sets of real data and the results show a feasibility of the algorithm. Additionally, our comparison of results of the linear algorithm to results of bundle adjustment, applied to sets of synthetic image data having Gaussian image noise, shows reasonable error ranges.

Let t and n be positive integers. We show that the necessary and sufficient condition for the existence of a balanced t-foil decomposition of the complete graph Kn is n 1 (mod 6t). Decomposition algorithms are also given.

A novel in vivo exposure setup has been developed for testing the possible promoting effects of 1.5 GHz digital cellular phones on mouse skin carcinogenesis. The exposure setup has two main features: one is the employment of an electrically short monopole antenna with capacitive-loading, which supplies the ability to realize a highly localized peak SAR above 2 W/kg without any thermal stress for a mouse; the other is the use of a transparent absorber to allow real-time observation of both the exposure process as well as mouse activities during the exposure. Dosimetric analyses for the exposure setup have been carried out both numerically and experimentally. Good agreement was confirmed between the numerical and experimental results, thereby demonstrating the validity of the novel exposure setup.

This paper presents a new framework for synthesizing look-up table (LUT) networks. Some of the existing LUT network synthesis methods are based on one or two functional (Boolean) decompositions. Our method also uses functional decompositions, but we try to use various decomposition methods, which include algebraic decompositions. Therefore, this method can be thought of as a general framework for synthesizing LUT networks by integrating various decomposition methods. We use a cost database file which is a unique characteristic in our method. We also present comparisons between our method and some well-known LUT network synthesis methods, and evaluate the final results after placement and routing. Although our method is rather heuristic in nature, the experimental results are encouraging.

We propose a transistor sizing method that downsizes MOSFETs inside a cell to eliminate redundancy of cell-based circuits as much as possible. Our method reduces power dissipation of detail-routed circuits while preserving interconnects. The effectiveness of our method is experimentally evaluated using 3 circuits. The power dissipation is reduced by 75% maximum and 60% on average without delay increase. Compared with discrete cell sizing, the proposed method reduces power dissipation furthermore by 30% on average.

Tree-based approach has been proven to be most scalable for one-to-many reliable multicast. It efficiently combines distributed recovery with local recovery over a logical tree of the sender and receivers. It has also been known that the performance of the tree-based protocols heavily depends upon the quality of the logical tree. In this paper, we propose an end-to-end scheme to further enhance the scalability of the tree-based approach. By exchanging packet loss information observed at the end hosts, the scheme constructs and maintains a logical tree congruent with the underlying multicast routing tree even in the presence of session membership and multicast route changes. The scheme also groups the tree nodes and assigns separate multicast addresses to them in order to enable efficient multicast retransmission for reducing both delay and exposure. We compare the proposed scheme with Tree-based Multicast Transport Protocol (TMTP), a static tree-based protocol. Extensive simulations up to 300 node sessions reveal that the proposed scheme reduces implosion and exposure more than 20% and 50%, respectively. The results also indicate that the scheme is highly scalable such that the improvement gets more significant as the size of the session increases.

A high assurance on-line recovery technology for a space on-board computer that can be realized using commercial devices is proposed whereby a faulty processor node confirms its normality and then recovers without affecting the other processor nodes in operation. Also, the result of an evaluation test using the breadboard model implementing this technology is reported. Because this technology enables simple and assured recovery of a faulty processor node regardless of its degree of redundancy, it can be applied to various applications, such as a launch vehicle, a satellite, and a reusable launch vehicle. As a result, decreasing the cost of an on-board computer is possible while maintaining its high reliability.

Characteristics of the optical feedback noise in semiconductor lasers under superposition of the HF (High Frequency) current were experimentally examined and theoretically analyzed. The feedback noise was mostly suppressed by superposition of HF current, but still remained when frequency of the HF current coincided with a rational number of the round trip time period for the optical feedback in experimental measurement. Theoretical analysis was also given to explain these characteristic based on the mode competition theory of the semiconductor laser.