We report a flexible and lightweight wearable microstrip antenna that can be sewn into clothing and hats. This antenna is composed of felt and a conductive woven fabric. Experimental results clearly show that this antenna operates normally as a conventional microstrip antenna, and is practical and feasible for personal satellite communications.

By modelling the quantization error as additive white noise in the transform domain, Wiener filter is used to reduce quantization noise for DCT coded images in DCT domain. Instead of deriving the spectrum of the transform coefficient, a DPCM loop is used to whiten the quantized DCT coefficients. The DPCM loop predicts the mean for each coefficient. By subtracting the mean, the quantized DCT coefficient is converted into the sum of prediction error and quantization noise. After the DPCM loop, the prediction error can be assumed uncorrelated to make the design of the subsequent Wiener filter easy. The Wiener filter is applied to remove the quantization noise to restore the prediction error. The original coefficient is reconstructed by adding the DPCM predicted mean with the restored prediction error. To increase the prediction accuracy, the decimated DCT coefficients in each subband are interpolated from the overlapped blocks.

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.

In this paper the correlation spectrum of antenna array is introduced. Based on the relationship between the correlation spectrum and space spectrum of MUSIC, we proposed a novel approach to improve the DOA estimation by arranging the linear antenna array elements using genetic algorithm (GA) in optimizing the correlation spectrum. The DOA estimation performance of the optimized array is validated by Monte Carlo simulation and Cramer-Rao bound (CRB), which are improved compared with that of the traditional uniform linear array and the Minimum-Redundancy array (MRA).

A principal attraction of ATM networks, in both wired and wireless realizations, is that the key quality of service (QoS) parameters of every call, including end-to-end delay, jitter, and loss are guaranteed by the network when appropriate cell-level traffic controls are imposed at the user network interface (UNI) on a per call basis, utilizing the peak cell rate (PCR) and the sustainable cell rate (SCR) values for the multimedia--voice, video, and data, traffic sources. There are three practical difficulties with these guarantees. First, while PCR and SCR values are, in general, difficult to obtain for traffic sources, the typical user-provided parameter is a combination of the PCR, SCR, and the maximum burstiness over the entire duration of the traffic. Second, the difficulty in accurately defining PCR arises from the requirement that the smallest time interval must be specified over which the PCR is computed which, in the limit, will approach zero or the network's resolution of time. Third, the literature does not contain any reference to a scientific principle underlying these guarantees. Under these circumstances, the issue of providing QoS guarantees in the real world, through traffic controls applied on a per call basis, is rendered uncertain. This paper adopts a radically different, high level approach to the issue of QoS guarantees. It aims at uncovering through systematic experimentation a relationship, if any exists, between the key high level user traffic characteristics and the resulting QoS measures in a realistic operational environment. It may be observed that while each user is solely interested in the QoS of his/her own traffic, the network provider cares for two factors: (1) Maximize the link utilization in the network since links constitute a significant investment, and (2) ensure the QoS guarantees for every user traffic, thereby maintaining customer satisfaction. Based on the observations, this paper proposes a two-phase strategy. Under the first phase, the average "link utilization" computed over all the links in a network is maintained within a range, specified by the underlying network provider, through high level call admission control, i.e. by limiting the volume of the incident traffic on the network, at any time. The second phase is based on the hypothesis that the number of traffic sources, their nature--audio, video, or data, and the bandwidth distribution of the source traffic, admitted subject to a specific chosen value of "link utilization" in the network, will exert a unique influence on the cumulative delay distribution at the buffers of the representative nodes and, hence, on the QoS guarantees of each call. The underlying thinking is as follows. The cumulative buffer delay distribution, at any given node and at any time instant, will clearly reflect the cumulative effect of the traffic distributions of the multiple connections that are currently active on the input links. Any bounds imposed on the cumulative buffer delay distribution at the nodes of the network will also dominate the QoS bounds of each of the constituent user traffic. Thus, for each individual traffic source, the buffer delay distributions at the nodes of the network, obtained for different traffic distributions, may serve as its QoS measure. If the hypothesis is proven true, in essence, the number of traffic sources and their bandwidth distribution will serve asa practically realizable high level traffic control in providing realistic QoS guarantees for every call. To verify the correctness of the hypothesis, an experiment is designed that consists of a representative ATM network, traffic sources that are characterized through representative and realistic user-provided parameters, and a given set of input traffic volumes appropriate for a network provider approved link utilization measure. The key source traffic parameters include the number of sources that are incident on the network and the constituent links at any given time, the bandwidth requirement of the sources, and their nature. For each call, the constituent cells are generated stochastically, utilizing the typical user-provided parameter as an estimate of the bandwidth requirement. Extensive simulations reveal that, for a given link utilization level held uniform throughout the network, while the QoS metrics--end-to-end cell delay, jitter, and loss, are superior in the presence of many calls each with low bandwidth requirement, they are significantly worse when the network carries fewer calls of very high bandwidths. The findings demonstrate the feasibility of guaranteeing QoS for each and every call through high level traffic controls. As for practicality, call durations are relatively long, ranging from ms to even minutes, thereby enabling network management to exercise realistic controls over them, even in a geographically widely dispersed ATM network. In contrast, current traffic controls that act on ATM cells at the UNI face formidable challenge from high bandwidth traffic where cell lifetimes may be extremely short, in the range of µs. The findings also underscore two additional important contributions of this paper. First, the network provider may collect data on the high level user traffic characteristics, compute the corresponding average link utilization in the network, and measure the cumulative buffer delay distributions at the nodes, in an operational network. The provider may then determine, based on all relevant criteria, a range of input and system parameters over which the network may be permitted to operate, the intersection of all of which may yield a realistic network operating point (NOP). During subsequent operation of the network, the network provider may guide and maintain the network at a desired NOP by exercising control over the input and system parameters including link utilization, call admittance based on the requested bandwidth, etc. Second, the finding constitutes a vulnerability of ATM networks which a perpetrator may exploit to launch a performance attack.

In the optimum design of AC contactors, it is necessary to analyze the dynamic behavior. Moreover, movable contacts and core bounce have remarkable effect on the lifetime of contactors. A set of differential equations describes the coupling of the electric circuit, electromagnetic field and mechanical system taking account into bounce and the influence of friction. With virtual prototyping technology, the dynamic behavior, especially for contacts bounce, has been investigated according to different electrical circuit parameters. Two approaches are introduced to solve electromagnetic parameters. Based on 3D finite element static nonlinear analysis, the flux linkage and electromagnetic force can be evaluated with different air gap and exciting current for larger gap. In addition, concerning to the shading coil for smaller gap, magnetic circuit can facilitate the calculation. The validity of the proposed method is confirmed by experiments.

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.

A high-attenuation waveguide filter using electromagnetic bandgap (EBG) substrates is introduced. With a simple design modification on the EBG covers, the waveguide filter produced an almost full Ku-band rejection bandwidth showing better than 20 dB input-to-output isolation from 12.3 to 17.2 GHz.

In this letter, adaptive multi-stage parallel interference cancellation (PIC) receiver is considered for multi-rate DS-CDMA system. In each stage of the adaptive multi-stage PIC receiver, multiple access interference (MAI) estimates are obtained by the sub-bit estimates from the previous stage and the adaptive weights for the sub-bit estimates. The adaptive weights are obtained by minimizing the mean squared error between the received signal and its estimate through normalized least mean square (LMS) algorithm. It is shown that the adaptive multi-stage PIC receiver achieves smaller BER than the matched filter receiver, multi-stage PIC receiver, and multi-stage partial PIC receiver for the multi-rate DS-CDMA system in a Rayleigh fading channel.

Automotive fuel pumps are driven by small DC motor. Commutation is carried out in gasoline, and arc voltage and duration are different from that in air. Our laboratory have analyzed commutation phenomenon in gasoline quantitatively and we have considered brush materials. To develop high power motor, we need to examine materials that are less arc abrasion and good sliding condition. In this research, we attend to characteristics of flat carbon commutator. As a result, it is possible to drive longer time, like established cylindrical copper commutator.

Cutoff rate of m-ary PPM is derived for an avalanche photodiode (APD) based receiver. The cutoff rate is compared among m=8-256 under the condition of the same total signal energy in 256 slots, where the effects of the timing jitter and atmospheric turbulence are included. Numerical results are shown for the illustrative examples of the cutoff rate.

For detecting the anomalous behavior of a user effectively, most researches have concentrated on statistical techniques. However, since statistical techniques mainly analyze the average behavior of a user's activities, some anomalies can be detected inaccurately. In addition, it is difficult to model intermittent activities performed periodically. In order to model the normal behavior of a user closely, a set of various features can be employed. Given an activity of a user, the values of those features that are related to the activity represent the behavior of the activity. Furthermore, activities performed in a session of a user can be regarded as a semantically atomic transaction. Although it is possible to apply clustering technique to these values to extract the normal behavior of a user, most of conventional clustering algorithms do not consider any transactional boundary in a data set. In this paper, a transaction-based clustering algorithm for modeling the normal behavior of a user is proposed. Based on the activities of the past transactions, a set of clusters for each feature can be found to represent the normal behavior of a user as a concise profile. As a result, any anomalous behavior in an online transaction of the user can be effectively detected based on the profile of the user.

We newly propose a novel blind separation framework for Single-Input Multiple-Output (SIMO)-model-based acoustic signals using an extended ICA algorithm, SIMO-ICA. The SIMO-ICA consists of multiple ICAs and a fidelity controller, and each ICA runs in parallel under the fidelity control of the entire separation system. The SIMO-ICA can separate the mixed signals, not into monaural source signals but into SIMO-model-based signals from independent sources as they are at the microphones. Thus, the separated signals of SIMO-ICA can maintain the spatial qualities of each sound source. In order to evaluate its effectiveness, separation experiments are carried out under both nonreverberant and reverberant conditions. The experimental results reveal that the signal separation performance of the proposed SIMO-ICA is the same as that of the conventional ICA-based method, and that the spatial quality of the separated sound in SIMO-ICA is remarkably superior to that of the conventional method, particularly for the fidelity of the sound reproduction.

This paper addresses the issue of reconfiguring multi-layer neural networks implemented in single or multiple VLSI chips. The ability to adaptively reconfigure network configuration for a given application, considering the presence of faulty neurons, is a very valuable feature in a large scale neural network. In addition, it has become necessary to achieve systems that can automatically reconfigure a network and acquire optimal weights without any help from host computers. However, self-reconfigurable architectures for neural networks have not been studied sufficiently. In this paper, we propose an architecture for a self-reconfigurable multi-layer neural network employing both reconfiguration with spare neurons and weight training by GAs. This proposal offers the combined advantages of low hardware overhead for adding spare neurons and fast weight training time. To show the possibility of self-reconfigurable neural networks, the prototype system has been implemented on a field programmable gate array.

The three major failures of electrical contacts for automotive relay applications are: contact welding (or contact sticking), high contact resistance and severe contact erosion due to switching arcing. With the demand of high power and multiple functions of automotive vehicles, the switching current has be dramatically increased, it results in higher failing rate, in particular for contact welding. On the other hand, the miniaturization of electromechanical relays has lead to the reduction of mechanical spring force. This not only results in the earlier contact welding but also makes the relay more susceptible to the contact resistance and arc erosion failures. This paper is a review of most recent studies on these three failure aspects. It describes the progress in the understanding of contact welding caused by short arcing and high contact resistance due to contamination of particles and films in relay manufacturing process and also it review the material transfer due to switching arcing. At the end, the brief considerations of electromechanical relays used in 42 volts have also been given.

A new and fast fingerprint classification method based on direction patterns is presented in this paper. This method is developed to be applicable to today's embedded fingerprint authentication system, in which small area sensors are widely used. Direction patterns are well treated in the direction map at block level, where each block consists of 88 pixels. It is demonstrated that the search of directions pattern in specific area, generally called as pattern area, is able to classify fingerprints clearly and quickly. With our algorithm, the classification accuracy of 89% is achieved over 4000 images in the NIST-4 database, slightly lower than the conventional approaches. However, the classification speed is improved tremendously up to about 10 times as fast as conventional singular point approaches.

Plastic ferrules for single-mode (SM) MU-type simplified receptacles are fabricated with a precise injection-molding technique using a liquid crystalline polymer (LCP). The fabricated plastic ferrules exhibit an eccentricity of < 0.6 µm and outer diameter variation of 1 µm. MU-type simplified plugs incorporating the plastic ferrules have an average insertion loss of 0.13 dB and a return loss of > 46 dB. The plastic ferrules exhibit good resistance in 500-cycle mating tests, and in vibration and impact tests as well. The initial optical characteristics are maintained during a temperature and humidity cycling test and a heat-cycling test.

This paper proposes the tile size conversion method for the wavelet image transcoding gateway and a set of methods to reduce the tile boundary artifacts caused by the conversion. In the wavelet image coding system represented by JPEG 2000, pictures are usually divided into one or more tiles and each tile is then transformed separately. On low memory terminals such as mobile terminals, some decoders are likely to have limits on what tile sizes they can decode. Assuming a system using these limited decoders, methods were investigated for converting the tile size quickly and automatically at the gateway when image data with a non-decodable tile size is received at the gateway from another system. Furthermore, tile boundary artifacts reduction methods are investigated. This paper verifies the validity of the proposed scheme by implementing it with a (5, 3) reversible filter and a (9, 7) irreversible filter. In addition, we implemented the tile size conversion gateway and evaluated the performance of the processing time. The results show the validity of the conversion gateway.

Design points and the results seen in the development of a dynamically reconfigurable logic LSI, PCA-2, are described. PCA-2 enables the realization of flexible parallel processing based on the autonomous reconfiguration of logic circuits. To realize this feature, we introduce an asynchronous circuit design and a homogeneous cell array structure. PCA-2 represents an advance on the earlier LSI, PCA-1. Cutting edge CMOS technology is used to realize the structural merits of PCA hardware. Compared to PCA-1, PCA-2 offers 16 times greater integration level for programmable logic. Due to miniaturization and design refinement, PCA-2 provides a 6-fold increase in the circuit frequency of the configuration controller and a 3-fold increase in the operating frequency of the programmable logic. The results gained confirm the effects of refinement and the suitability of our architecture for device miniaturization.

Common-mode (CM) current on a feed cable attached to printed circuit board (PCB), which is one of main source of undesired electromagnetic radiation problem, is investigated by experimental and finite-difference time-domain (FDTD) modeling. In this paper, frequency responses of CM current on PCB and feed cable are modeled and analyzed as an electromagnetic interference (EMI) antenna, which depends on the configuration of PCB with a wire cable. Several different configurations are prepared to demonstrate the effect of PCB dimension on resonance frequencies of CM current. In the results, EMI antenna in the frequency band around the first resonance frequency was comprised of the ground plane and cable. In order to explain the frequency response of CM current, two EMI antenna models are proposed and demonstrated. EMI antenna is comprised of the ground plane and cable, and the other EMI antenna is comprised of the trace on the ground plane. It is suggested that the result is one of basic consideration for the ground plane with cable that have high EMI problem and resonance frequency of CM current.