In terms of the formulation of the optimality, image restoration filters can be divided into two streams. One is formulated as an optimization problem in which the fidelity of a restored image is indirectly evaluated, and the other is formulated as an optimization problem based on a direct evaluation. Originally, the formulation of the optimality and the solutions derived from the formulation are identical each other. However in many studies adopting the former stream, an arbitrary choice of a solution without a mathematical ground passes unremarked. In this paper, we discuss the relation between the formulation of the optimality and the solution derived from the formulation from a mathematical point of view, and investigate the relation between a direct style formulation and an indirect one. Through these analyses, we show that the both formulations yield the identical filter in practical situations.

This paper deals with a design problem of an adaptive robust control system for linear systems with structured uncertainties. The control law consists of a state feedback with a fixed gain designed by using the nominal system, a state feedback with an adaptive gain tuned by a parameter adjustment law and a compensation input. We show the parameter adjustment law and that sufficient conditions for the existence of the compensation input are given in terms of linear matrix inequalities (LMIs). Finally, a numerical example is included.

Matching Pursuits (MP), a technique for signal decomposition using a dictionary of functions, is applied to ground penetrating radar (GPR) signals in order to remove noise and clutter included in the signals and to extract target responses. A wave-based dictionary composed of wavefronts and resonances is employed. Noise reduction performance and the removal of ground-surface reflection are evaluated through numerical simulations. The results show that the MP approach performs well and offers an effective method for feature extraction from GPR signals.

All power electronic circuits with state feedback controlled switching can be described as nonlinear time-varying dynamical systems. The occurrence of chaos--where the ripple waveforms become aperiodic--is common in such systems. It is shown here that this natural phenomenon may be effectively used in minimizing electromagnetic interference problems in power electronic circuits. This is because converters operating chaotically tend to spread the spectrum, thereby reducing the interference power at any target frequency. We also present the ways of calculating the average values of state variables and the power spectrum under chaotic operation.

This paper proposes a learning classifier based on Support Vector Domain Description (SVDD) for two-class problem. First, by the description of the training samples from one class, a sphere boundary containing these samples is obtained; then, this boundary is used to classify the test samples. In addition, instead of the traditional quadratic programming, multiplicative updates is used to solve the Lagrange multiplier in optimizing the solution of the sphere boundary. The experiment on CBCL face database illustrates the effectiveness of this learning algorithm in comparison with Support Vector Machine (SVM) and Sequential Minimal Optimization (SMO).

Motion estimation is the key issue in video compressing. Several methods for motion estimation based on the center biased strategy and minimum mean square error trend searching have been proposed, such as TSS, FSS, UCBDS and MIBAS, but these methods yield poor estimates or find local minima. Many other methods predict the starting point for the estimation; such methods include PMEA, PSA and GPS: these can be fast but are inaccurate. This study addresses the causes of wrong estimates, local minima and incorrect predictions in the prior estimation methods. The Multiple Searching Trend (MST) is proposed to overcome the problems of ineffective searches and local minima, and the Adaptive Dilated Searching Field (ADSF) is described to prevent prediction from wrong location. Applying MST and ADSF to the listed estimating methods, such as UCBDS, a fast and accurate can be reached. For this this reason, the method is called CockTail Searching (CTS).

This letter studies the impact of chip waveform shaping on the multiple access interference (MAI) in band-limited direct sequence code-division multiple access (DS-CDMA) systems. The family of band-limited waveforms with zero interchip interference (ICI) and with an excess bandwidth β in the range 0β 1 is considered. A criterion for the performance comparison of various band-limited chip waveforms based on the elementary density function is established. The effect of varying the roll-off factor of a band-limited chip waveform on the MAI level is also investigated.

Diagonal algebraic space time (DAST) block codes was proved to achieve the full transmit diversity over a quasi-static fading channel and to maintain 1 symbol/s/Hz. When the number of transmit antennas employed is larger than 2, DAST codes outperform the codes from orthogonal design with the equivalent spectral efficiency. However, due to the limitation on the signal constellation with complex integer points, no good 3bits/symbol DAST block code was given previously. In this paper, we propose a general form of 8-star-PSK constellations with integer points and present some theoretical results on the performance of the equivalent 8-star-PSK modulations. By using our proposed 8-star-PSKs, we present a searching algorithm to construct DAST codes with 3 bits per symbol under some criteria and investigate their performances over flat Rayleigh fading channels. It is shown that (5,2) 8-star-PSK scheme has a comparable performance to conventional 8PSK over additive white Gaussian noise (AWGN) channel and the corresponding DSAT codes constructed can achieve significant performance gain over flat Rayleigh fading channel.

In this letter, DAB system employing multiple antenna scheme is considered for high capacity transmission. In the MIMO-DAB system, the transmission rate is augmented efficiently by increasing the number of antennas, and thus the multi-channel estimation process is required. So, this letter proposes a new phase reference symbol structure which can be adapted to the multi-channel estimation, and investigates the channel estimation performance based on the semi-blind processing using the time-domain windowing. Simulation results have been shown that the MIMO-DAB system with multi-antennas can achieve the high-rate transmission for multimedia broadcasting.

Development of new sliding contact, usable under sever conditions such as high-temperature, extremely low-temperature or high vacuum, has recently become an urgent necessity. This research mainly examined the contact resistance and coefficient of friction of 3 kinds of self-lubricant composite materials with electrical conductivity and mechanical stiffness. The result showed that a composite material (CMML-1) containing the least quantity of solid lubricants [WS2, Gr.(Graphite)] among them was low in both contact resistance and coefficient of friction and less in fluctuation. By EPMA analysis, contribution of Sn to electrical conductivity was suggested.

Software rejuvenation is a preventive and proactive solution that is particularly useful for counteracting the phenomenon of software aging. In this paper, we consider both the periodic and non-periodic software rejuvenation policies under different dependability measures. As is well known, the steady-state system availability is the probability that the software system is operating in the steady state and, at the same time, is often regarded as the mean up rate in the system operation period. We show that the mean up rate should be defined as the mean value of up rate, but not as the mean up time per mean operation time. We derive numerically the optimal software rejuvenation policies which maximize the steady-state system availability and the mean up rate, respectively, for each periodic or non-periodic model. Numerical examples show that the real mean up rate is always smaller than the system availability in the steady state and that the availability overestimates the ratio of operative time of the software system.

This paper describes the design of a programmable QAM transceiver for VDSL applications. A 12-b DAC with 64-dB spurious-free dynamic range (SFDR) at 75-MS/s and an 11-b ADC with 72.3-dB SFDR at 70-MS/s are integrated in this complete physical layer IC. A digital IIR notch filter is included in order to not interrupt existing amateur radio bands. The proposed dual loop AGC adjusts the gain of a variable gain amplifier (VGA) to obtain maximum SNR while avoiding saturation. Using several low power techniques, the total power consumption is reduced to 300-mW at 1.8-V core and 3.3-V I/O supplies. The transceiver is fabricated in a 0.18-µm CMOS process and the chip size is 5-mm 5-mm. This VDSL transceiver supports 13-Mbps data rate over a 9000-ft channel with a BER < 10-7.

In this paper, the design of a mobile satellite Internet access (MSIA) system and a mobile broadband satellite access system, called Mobile Broadband Interactive Satellite Multimedia Access Technology System (MoBISAT) are presented. MSIA system provides Internet service, broadcasting, and digital A/V service in both fixed and mobile environments using Ku-band geostationary earth orbit (GEO) satellite. A Ku-band two-way active phased array antenna installed on top of the transportation vehicles can enable the transmission of signals to satellite as well as signal tracking and reception. The forward link and return link are a high speed Time Division Multiplex (TDM) and TDMA transmission media, respectively, both of which carry signaling and user traffic. The MoBISAT, which is a next generation mobile broadband satellite access system, provides both Ku-band satellite TV and Ka-band high-speed Internet to the passengers and crews for land, maritime, and air vehicles. This paper addresses the main technological solutions adopted for the implementation and test results for the MSIA system and the main design features of the MoBISAT system.

This paper presents a novel blind multiple access interference (MAI) suppression filter in DS/CDMA systems. The filter is adaptively updated by parallel projections onto a series of convex sets. These sets are defined based on the received signal as well as a priori knowledge about the desired user's signature. In order to achieve fast convergence and good performance at steady state, the adaptive projected subgradient method (Yamada et al., 2003) is applied. The proposed scheme also jointly estimates the desired signal amplitude and the filter coefficients based on an approximation of an EM type algorithm, following the original idea proposed by Park and Doherty, 1997. Simulation results highlight the fast convergence behavior and good performance at steady state of the proposed scheme.

A novel binary line-pattern algorithm for embedded fingerprint authentication system is introduced in this paper. In this algorithm, each line-pattern is a one-dimension binary matrix that describes the alternation pattern of ridge and valley in fingerprint image. Two parallel lines or two cross lines in a certain scope make up related line-pattern pair. Several such line-pattern pairs at different parts of a fingerprint image can describe another intrinsic feature besides traditional minutiae feature. Experimental results showed this algorithm was not only efficient but also effective. Furthermore, a hybrid fingerprint match scheme is also introduced in this paper. It has the following features: (i) minutiae matching is firstly carried out to calculate the similarity score between the query fingerprint and the template fingerprint, and moreover, the translation and rotation parameters are obtained at the same time; (ii) line-pattern algorithm is immediately performed based on the parameters obtained after minutiae matching to get another similarity score; (iii) the final matching score is the combination of the minutiae matching score and the line-pattern matching score. Experiments were conducted on the FVC2002 database and our private database respectively. Both of the results were inspiring. In detail, at the same FAR value, the FRR of this hybrid match algorithm is to be 2-8% lower than only minutiae-based matching algorithm.

This letter proposes a low-power tournament branch predictor, in which the number of accesses to the branch predictors (local predictor or global predictor) is reduced. Analysis results with Samsung Memory Compiler show that the proposed branch predictor reduces the power consumption by 24-45%, compared to the conventional tournament branch predictor, not requiring any additional storage arrays, not incurring any additional delay and never harming accuracy.

In this report we present all-optical switches and modulators based on the intersubband transition in semiconductor quantum wells. The use of InGaAs/AlAsSb coupled double quantum well structures is proposed to facilitate intersubband transitions in the optical-communication band, and to reduce the intersubband absorption recovery time from several picoseconds to a few hundred femtoseconds by utilizing enhanced electron-phonon scattering. Subpicosecond all-optical gating and modulation in coupled double quantum wells are observed using pump-probe experiments at optical-communication wavelengths. The results indicate that the intersubband transition in this structure is very useful for ultrafast all-optical switching devices.

A very general form of the probability density distribution of the fading envelope has been presented by M.Nakagami, including the Nakagami-Rice and Nakagami-Hoyt distributions as special cases. This paper gives the series form expanded in positive terms of the m-distribution for it. Previously, the feasibility of such an expansion was predicted, but there has been no explicit description to date. The properties of the well-known m-distribution and the positive sign in each term of this series make it practical for numerical calculation, approximation and analysis.

A routing algorithm, utilizing two-hop relaying when necessary, is proposed to enhance the system capacity of code division multiple access (CDMA) cellular systems. Up to now, multihop relaying is applied to cellular systems mainly with the aim of decreasing the transmit power of each mobile station or extending the cell coverage area. Here, in this paper, potential benefit of multihop relaying is studied so as to increase the system capacity. A condition for the interference to be reduced by changing single-hop connections to two-hop connections is analyzed. In addition, a new route selection criterion maximizing the amount of interference reduction is proposed. Simulation results reveal that the proposed criterion is superior to the conventional criterion minimizing the total transmit power in respect of the amount of interference reduction. By using this criterion, an efficient routing algorithm for two-hop CDMA cellular systems is proposed to enhance the system capacity. Simulation results also indicate that by using the proposed routing algorithm in combination with a call admission control, the system capacity is increased even under heavy traffic conditions.

The market for IP convergence services is expanding rapidly due to the rising number of Internet users. To respond to market trends, service systems must provide services quickly. This paper discusses that application server called the service agent which provides IP convergence services. The service agent meets the requirements for four application servers, centralized intelligence, supporting various interfaces: service creativity and scalability. The architecture is based on that of AIN systems, but whole system is written in Java especially to achieve service creativity and scalability. As a result of trial manufacture, feasibility of the service agent and scalability was achieved. Enough performance was also confirmed to obtain for commercial services.