This paper presents the design of a novel method for improvement of the operation of distance relays during capacitive voltage transformer transients using artificial neural network. The proposed module uses voltage and current signals to learn the hidden relationship existing in the input patterns. Simulation studies are preformed and the influence of changing system parameters, such as fault resistance and source impedance is studied. Details of the design procedure and the results of performance studies with the proposed relay are given in the paper. Performance studies results show that the proposed algorithm decreases the effects of CVT transients and is fast and accurate.

In recent years, the Internet has come to be able to be used at higher speed and more cheaply everywhere as the broadband service and the wireless LAN service have been provided by various ISPs. In such a ubiquitous environment, a demand for mobile computing environments in the intranet and easy access from remote sites has been increasing greatly as well as the Internet. To meet this requirement, we have proposed a Logical Office service, which is a kind of the mobile VLAN, and enables terminal plug and play, layer two tunneling, and ubiquitous communication. This paper newly proposes that the offer of the IP mobility to not only the movement of the terminal but also existing network services be possible the Logical Office service which we developed. As a result, it was verified to operate existing network services such as wirelesses LAN on the Logical Office service, and for newly existing network services to able to have the IP mobility.

A policy is an execution rule (or constraint) for objects in a system to retain security and integrity of the system. We introduce a simple policy specification language and define its operational semantics. A new NFA construction algorithm that works in linear time is proposed and a model checking method for policy controlled system (PCS) is presented. We conducted verification of a sample PCS for hotel reservation by our automatic verification tool and the experimental results showed the efficiency of the proposed method.

In this letter, a new computation method for the noise parameters of a linear noisy two-port network is introduced. A new error function, which considers noise figure and source admittance error simultaneously, is proposed to estimate the four noise parameters. The global optimization of the error function is searched directly by using a genetic algorithm.

When a dependency parser analyzes long sentences with fewer subjects than predicates, it is difficult for it to recognize which predicate governs which subject. To handle such syntactic ambiguity between subjects and predicates, we define an "a subject clause (s-clause)" as a group of words containing several predicates and their common subject. This paper proposes a two-phase method for S-clause segmentation. The first phase reduces the number of candidates of S-clause boundaries, and the second performs S-clause segmentation using decision trees. In experimental evaluation, the S-clause information turned out to be effective for determining the governor of a subject and that of a predicate in dependency parsing. Further syntactic analysis using S-clauses achieved an improvement in precision of 5 percent.

In a multi-layered RF circuit, it is important to avoid unexpected coupling caused by a parallel plate mode excited between different ground layers. Ground via-holes that short-circuit different ground layers are used for suppressing this mode. Quantitative evaluation of relations between suppression effect and ground via-hole disposition is required for optimal design. In this paper, a simple design formula that describes the suppression ratio is derived by mode-matching technique. The results of comparison with an FEM simulation validate our proposed formula. It is shown that the technique is indispensable for designing optimal disposition of via-holes to minimize the area of the ground via-holes for desired performance.

This paper compared the approaches concerning the pinball routing problem that occurs in the nested network in network mobility environment and developed the analytic framework to model. Each model was evaluated of transmission latency, memory usage, and BU's occurrence number at routing optimization process. The estimation result showed that the optimization mechanism achievement overhead existed in each model, and the full optimization of the specific model was not attained because of it. Therefore, the most appropriate approach for routing optimization in nested NEMO can be determined only after a careful evaluation, and the proposals must consider using it in combination with other approaches. The modeling framework presented in this paper is intended to quantity the relative merits and demerits of the various approaches.

A millimeter wave BPF constructed from the WG mode dielectric disk resonators is presented. The design chart for the high Q WG mode resonator is obtained from Qu calculation of some WG modes. By using the design chart, high Q WG mode resonator having no influence of unwanted higher order resonances is designed. Designed resonators have different diameter and various Resonance Frequency Separation respectively. A 3 stage maximally flat BPF is constructed so that each resonator may be coupled laterally on the edge of the disk. Designed center frequency is 62.47 GHz and 3 dB bandwidth is 100 MHz. As a result, this BPF has insertion loss of 1.5 dB and some spurious responses which were existed conventional WG mode BPF are reduced considerably.

Noise characteristics of GaAs metal-semiconductor field effect transistors (GaAs-MESFETs) with scaled-down dimensions are analyzed and modeled using a physics-based circuit simulator employing the Monte Carlo (MC) particle technique. The microscopic dynamics of electrons is also analyzed to investigate the mechanism of noise generation in a channel. Noise spectral densities of GaAs-MESFETs with two different geometries are estimated by evaluating fluctuations in instantaneous terminal currents. Then, minimum noise figures, F min, and noise figure circles are estimated using the noise spectral densities and Y-parameters. Because of an increase in y21 and suppression of an increase of noise spectral density, the device with an n+-region extending to below the drain-side edge of the gate contact exhibits a smaller noise figure. Suppression of the electron velocity fluctuation caused by electron transitions to higher valleys in a high electric field region is responsible for the noise suppression.

In adaptive motion estimation, spatial-temporal correlation based motion type inference has been recognized as an effective way to guide the motion estimation strategy adjustment according to video contents. However, the complexity and the reliability of those methods remain two crucial problems. In this paper, a motion vector field model is introduced as the basis for a new spatial-temporal correlation based motion type inference method. For each block, Full Search with Adaptive Search Window (ASW) and Three Step Search (TSS), as two search strategy candidates, can be employed alternatively. Simulation results show that the proposed method can constantly reduce the dynamic computational cost to as low as 3% to 4% of that of Full Search (FS), while remaining a closer approximation to FS in terms of visual quality than other fast algorithms for various video sequences. Due to its efficiency and reliability, this method is expected to be a favorable contribution to the mobile video communication where low power real-time video coding is necessary.

A rotator graph was proposed as a topology for interconnection networks of parallel computers, and it is promising because of its small diameter and small degree. However, a rotator graph is a directed graph that sometimes behaves harmfully when it is applied to actual problems. A bi-rotator graph is obtained by making each edge of a rotator graph bi-directional. In a bi-rotator graph, average distance is improved against a rotator graph with the same number of nodes. In this paper, we give an algorithm for the container problem in bi-rotator graphs with its evaluation results. The solution achieves some fault tolerance such as file distribution based information dispersal technique. The algorithm is of polynomial order of n for an n-bi-rotator graph. It is based on recursion and divided into two cases according to the position of the destination node. The time complexity of the algorithm and the maximum length of paths obtained are estimated to be O(n3) and 4n-5, respectively. Average performance of the algorithm is also evaluated by computer experiments.

The authors realize a 50% length reduction of short-slot couplers in a post-wall dielectric substrate by two techniques. One is to introduce hollow rectangular holes near the side walls of the coupled region. The difference of phase constant between the TE10 and TE20 propagating modes increases and the required length to realize a desired dividing ratio is reduced. Another is to remove two reflection-suppressing posts in the coupled region. The length of the coupled region is determined to cancel the reflections at both ends of the coupled region. The total length of a 4-way Butler matrix can be reduced to 48% in comparison with the conventional one and the couplers still maintain good dividing characteristics; the dividing ratio of the hybrid is less than 0.1 dB and the isolations of the couplers are more than 20 dB.

This paper describes how to integrate interaction in wallpaper using vector graphics solution VIS (Vector Image Solution). By using dedicated key action for toggling input mode and VIS functionality such as action script support, pause-resume interface, etc., we can achieve direct interactivity for rich media services without deteriorating stability of the integrated program of mobile handset.

This paper presents a novel low-power register file based on adiabatic logic. The register file consists of a storage-cell array, address decoders, read/write control circuits, sense amplifiers, and read/write drivers. The storage-cell array is based on the conventional memory cell. All the circuits except the storage-cell array employ CPAL (complementary pass-transistor adiabatic logic) to recover the charge of large node capacitance on address decoders, bit-lines and word-lines in fully adiabatic manner. The minimization of energy consumption was investigated by choosing the optimal size of CPAL circuits for large load capacitance. The power consumption of the proposed adiabatic register file is significantly reduced because the energy transferred to the large capacitance buses is mostly recovered. The energy and functional simulations are performed using the net-list extracted from the layout. HSPICE simulation results indicate that the proposed register file attains energy savings of 65% to 85% as compared to the conventional CMOS implementation for clock rates ranging from 25 to 200 MHz.

With reference to video motion estimation in the framework of the new H.264/AVC video coding standard, this paper presents algorithmic and architectural solutions for the implementation of context-aware coprocessors in real-time, low-power embedded systems. A low-complexity context-aware controller is added to a conventional Full Search (FS) motion estimation engine. While the FS coprocessor is working, the context-aware controller extracts from the intermediate processing results information related to the input signal statistics in order to automatically configure the coprocessor itself in terms of search area size and number of reference frames; thus unnecessary computations and memory accesses can be avoided. The achieved complexity saving factor ranges from 2.2 to 25 depending on the input signal while keeping unaltered performance in terms of motion estimation accuracy. The increased efficiency is exploited both for (i) processing time reduction in case of software implementation on a programmable platform; (ii) power consumption reduction in case of dedicated hardware implementation in CMOS technology.

A technique to control the radiation pattern of an NRD-guide-compatible pyramidal horn antenna, which consists of a tapered dielectric rod inserted into the horn, was developed for multiple access LAN applications at 60 GHz. By using this simple technique, the half-power beamwidth can be controlled from 11to 40.

In a CDMA non-linear interference canceller, a generated replica of an interference signal is multiplied by a positive number smaller than unity, which is called cancellation moderating factor (CMF), to prevent interference enhancement due to inaccurate replica subtraction. In this paper, two CMF controlling schemes applicable to a multistage parallel interference canceller with multi-antenna (spatial diversity) reception are proposed. They control CMF by using the mean square error of the complex channel gain or by using the ratio of the estimated power of each interference signal to remaining interference signals' power, in order to mitigate the replica subtraction error due to inaccurate channel estimation. The performance of the proposed schemes are evaluated by computer simulations assuming an asynchronous uplink single chip-rate variable spreading factor DS-CDMA system. The simulation results show that the proposed schemes with higher order diversity reception improve the bit error rate (BER) performance compared with a conventional scheme considering the tentative decision error or fixed CMF settings. Their performance improvement is by 0.1-0.9 dB in terms of the required Eb/N0 at an average BER of 10-5 over exponentially decaying 5-path Rayleigh distributed channels when the number of receiving antennas is 6.

This paper focuses on the underdetermined blind source separation (BSS) of three speech signals mixed in a real environment from measurements provided by two sensors. To date, solutions to the underdetermined BSS problem have mainly been based on the assumption that the speech signals are sufficiently sparse. They involve designing binary masks that extract signals at time-frequency points where only one signal was assumed to exist. The major issue encountered in previous work relates to the occurrence of distortion, which affects a separated signal with loud musical noise. To overcome this problem, we propose combining sparseness with the use of an estimated mixing matrix. First, we use a geometrical approach to detect when only one source is active and to perform a preliminary separation with a time-frequency mask. This information is then used to estimate the mixing matrix, which allows us to improve our separation. Experimental results show that this combination of time-frequency mask and mixing matrix estimation provides separated signals of better quality (less distortion, less musical noise) than those extracted without using the estimated mixing matrix in reverberant conditions where the reverberant time (TR) was 130 ms and 200 ms. Furthermore, informal listening tests clearly show that musical noise is deeply lowered by the proposed method comparatively to the classical approaches.

Orthogonal space-time block codes (STBCs) appear to be a very fascinating means of enhancing reception quality in quasi-static MIMO channels due to their full diversity, and especially their simple maximum-likelihood (ML) decoders. However, full-rate full-diversity orthogonal STBCs do not exist for more than two transmit antennas. Vertical layered space-time architecture (so-called the V-BLAST) with a nulling- and cancelling-based detection algorithm, in contrast, has an ability of achieving high transmission rates at the cost of having very low diversity gain, an undesirable consequence caused by the interference nulling and cancelling processes. The uncoded V-BLAST system is able to reach its ML performance with the aid of the sphere decoder algorithm at the expense of higher detection complexity. Undoubtedly, the tradeoff between transmission rates, diversity, and complexity is inherent in designing space-time codes. This paper investigates a method to increase the "nulling diversity gains" for a general high-rate space-time code and introduces a new design strategy for high-rate space-time codes detected based on interference nulling and cancelling processes, thanks to which high-rate quasi-orthogonal space-time codes for MIMO applications are proposed. We show that when nT transmit and nR=nT receive antennas are deployed, the first code offers a transmission rate of (nT-1) with a minimum nulling diversity order of 3, whereas the second one offers a transmission rate of (nT-2) with a minimum nulling diversity order of 5. Therefore, the proposed codes significantly outperform the V-BLAST as nR=nT. Simulation results and discussions on the performance of the proposed codes are provided.

A speech signal captured by a distant microphone is generally smeared by reverberation, which severely degrades both the speech intelligibility and Automatic Speech Recognition (ASR) performance. Previously, we proposed a single-microphone dereverberation method, named "Harmonicity based dEReverBeration (HERB)." HERB estimates the inverse filter for an unknown room transfer function by utilizing an essential feature of speech, namely harmonic structure. In previous studies, improvements in speech intelligibility was shown solely with spectrograms, and improvements in ASR performance were simply confirmed by matched condition acoustic model. In this paper, we undertook a further investigation of HERB's potential as regards to the above two factors. First, we examined speech intelligibility by means of objective indices. As a result, we found that HERB is capable of improving the speech intelligibility to approximately that of clean speech. Second, since HERB alone could not improve the ASR performance sufficiently, we further analyzed the HERB mechanism with a view to achieving further improvements. Taking the analysis results into account, we proposed an appropriate ASR configuration and conducted experiments. Experimental results confirmed that, if HERB is used with an ASR adaptation scheme such as MLLR and a multicondition acoustic model, it is very effective for improving ASR performance even in unknown severely reverberant environments.