A huge amount of information is being accumulated on the Internet as the Internet usage spreads and numbers of Web pages increase. However, it is also becoming very difficult to find required information, even when the information exists. The actual value of the Web is thus much lower than its potential value. In order to solve this problem, technologies which allow machines to handle Web content in an efficient, accurate, and flexible way by using machine-readable metadata are being developed. This paper is a survey of knowledge representation on the Web, and the utilization of metadata and ontology for data integration and information sharing, with a focus on the Semantic Web concept.

We propose a new cell configuration which newly employs discharge deactivation film (DDF). DDF is formed on MgO surface in stripe figure to cover it around the boundary of neighboring display lines. DDF prevents discharge cross talk between the lines even in case of stripe rib structure by virtue of its low secondary electron emission coefficient (γi). DDF also makes better address discharge response because it presumably moves address discharge closer to the surface dischage gap. On behalf of mass productivity for large size PDPs DDF is formed by simple screen-printing and firing method. And it consists of very fine Al2O3 grains without any inorganic binder. Such DDF is visually transparent and then helpful for high luminance and luminous efficiency. In addition to it, such DDF is presumably equipped with gas purifying character and then helpful for deep blue color and good white color balance accordingly. Further, DDF combined with sustain electrodes in specific figure which we call "CAPABLE DDF" brings about so high luminous efficiency for stripe rib structure as it may surpass box rib one. This probably means that vertically open discharge space in stripe rib structure is advantageous for high luminous efficiency. In our latest work for 46 inch-high definition PDPs, 2.1 lm/W and 1200 cd/m2 were both achieved under practical driving condition. Still it will be as high as 2.4 lm/W if each sustain electrode is shared by neighboring display lines. CAPABLE DDF allows more tolerance in DDF printing process. It also makes optical cross talk negligible even in stripe rib structure. And its durability against long time operation proved to have no specific problem. This presumably means that re-landing of sputtered MgO never reaches DDF surface. We believe this new technology can promise the future of stripe rib.

One of the categories of decoding techniques for DFT codes in erasure channels is the class of iterative algorithms. Iterative algorithms can be considered as kind of alternating mapping methods using the given information in a repetitive way. In this paper, we propose a new iterative method for decoding DFT codes. It will be shown that the proposed method outperforms the well-known methods such as Wiley/Marvasti, and ADPW methods in the decoding of DFT codes in erasure channels.

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.

A single solid-state magnetic sensor can be used to measure a current by sensing the field near the conductor in a non-contact way. In order to improve the accuracy of the measuring system, magnetic sensor arrays have been introduced in the current measurement around the conductor. An analytical algorithm based on Discrete Fourier Transform (DFT) is presented in this paper, which can separate the effects of the field generated by the current under measurement from the interference fields. A general mathematical model of the interference analysis is set up, which can be used for both DC and AC current measurement and has no restriction on the shape and number of the current conductors. Numerical simulations associated with preliminary experimental results confirm the validity of the approach.

It is a critical design process to estimate the fractional errors of the Synthetic Aperture Radar (SAR) processor before implementation. The contribution of this paper is to identify the chief sources and types and to suggest an estimation technique for overall fractional errors of the space-based SAR processor using Range-Doppler Algorithm (RDA). Also, simulation is performed to the Experimental-SAR (E-SAR) processor to examine the practicability and efficiency of the technique, the results are discussed, and the solutions for problems are recommended. Therefore, this technique can be used to estimate the fractional errors of the space-based SAR processor using RDA.

We propose a new orthogonal frequency division multiplexing transmission scheme using orthogonal code multiplexing. This scheme makes all modulation symbols have the same reliability even in a frequency selective fading channel, through a distributed transmission of each symbol over the whole effective subcarriers using a distinct orthogonal code. As an appropriate set of orthogonal multiplexing codes, we use the set of discrete Fourier transform code sequences that hold the orthogonality irrespective of the length. Using this set, we also can greatly reduce the peak-to-average-power ratio (PAR) of the resulting signal. Simulation results show that the proposed scheme can significantly reduce the required signal-to-noise ratio at a given bit error rate over the existing schemes. The scheme can maintain the PAR within a reasonable range of about 6 dB even up to 512 subcarriers and works well even with PAR clipping of 1.5 dB.

We analyze the timing design methodology for testing chips using a multiple-clock domain scheme. We especially focus on the layout design of the design-for-test (DFT) circuits and the clock network. First, we demonstrate the built-in-self-testing (BIST) scheme for multiple-clock domains. Then, we discuss the layout method that achieves a low clock-skew between different clock domains with a small modification of the original user logic layout. Finally, we evaluate the fault coverage of our large ASIC chips designed using our new methodology. The short design period and high fault coverage of our methodology are confirmed using actual industrial designs. We introduce a viable approach for industrial designs because designers don't have to pay much attention to DFT. Our approach also provides designers with an easy method for LSI debugging and diagnostics.

Asynchronous controllers effectively control high concurrence of datapath operations for high speed. Signal Transition Graphs (STGs) can effectively represent these concurrent events. However, highly concurrent STGs cause the state explosion problem in asynchronous synthesis tools. Many small but highly concurrent STGs cannot be synthesized to obtain control circuits. Moreover, STGs also lead to some control-time overhead of the four-phase handshake protocol. In this paper, we propose a method for deriving the serial control nodes from Control Data Flow Graphs (CDFGs) such that the concurrence of datapath operations is still preserved. The STGs derived from the serialized control nodes are serial STGs which are simpler for synthesis than the concurrent STGs. We also propose an implementation using these serialized controllers to generate local clocks at any necessary times. The implementation results in very small control-time overhead. The experimental results show that the number of synthesis states is proportional to the number of control signals, and the circuits with satisfiable small control-time overhead are obtained.

Weight divided adaptive control method for a microwave FeedForward Power Amplifier (FFPA) is presented. In this adaptive controller, an output signal of a power amplifier is used as reference signal. Additionally, reference signal is divided by the weight of adaptive filter, so that characteristics of the power amplifier, such as temperature dependence, do not have influence on the convergence performances. The proposed adaptive algorithm and the convergence condition are derived analytically and we clarify that the proposed weight divided adaptive algorithm is more stable than the conventional Normalized Least Mean Square (NLMS) algorithm. Then, the convergence condition considering phase calibration error is discussed. The effectiveness of the proposed algorithm are also verified by the nonlinear simulations of the FFPA having AM-AM and AM-PM nonlinearity of GaAsFET.

Passification of a non-square linear system is considered by using a parallel feedforward compensator (PFC) and a squaring gain matrix. In contrast to the previous result, a technical assumption is removed by modifying the structure of the PFC. As a result, the broader class of non-square systems can be made passive by the proposed design method. Using the static output feedback (SOF) algorithms, the input-dimensional PFC and the squaring matrix can be designed systematically. The effectiveness of the proposed method is illustrated by practical system examples in the control literature.

This paper presents a frequency domain simultaneous equations method capable of automatically recovering noise reduction effect degraded by secondary path changes. The simultaneous equations method has been studied, first in time domain. Accordingly to the study, in the time domain, the simultaneous equations method requires an additional filter and a system identification circuit used for transforming the solution of the simultaneous equations into the coefficients of noise control filter, which increase the processing cost. To reduce the processing cost, this paper studies on the application of a frequency domain processing technique, the cross spectrum method, to the simultaneous equations method. By directly applying the equation defining the cross spectrum method to the solution, the additional filter becomes unnecessary. In addition, the system identification circuit is replaced with the inverse Fourier transform. Thereby, the processing cost drastically decreases. This paper also presents simulation results to confirm that the proposed method can automatically recover the noise reduction effect degraded by a path change and provides much higher convergence speed than that of the filtered-x NLMS algorithm with the perfectly modeled secondary path filter.

This paper proposes the IMADF (improved multiplication-free adaptive digital filter) algorithm to cancel the background noise that spans nearly all frequency bandwidths in biomedical signals. Under conditions of zero-mean, wide-sense stationary and white Gaussian noise, we analyze the convergence characteristics of the IMADF with a FSE (fractionally-spaced equalizer). In the experimental results, the IMADF algorithm has the advantage in which has superior to a condition of low-frequency and slow data speed. This application gives an important significance in ensuring the objectivity of clinical information and in promoting the representation and the disease diagnosis.

Beaulieu has proposed four signal-to-noise ratio (SNR) estimators for quadrature phase shift keying (QPSK) signaling in time domain. In this letter, we propose SNR estimators for QPSK signaling in frequency domain. A discrete Fourier transform (DFT) algorithm is used for the frequency domain analysis of the received signal. The frequency spectrum enables biased SNR estimation in the frequency domain. Circular convolution is used for robust and fast SNR estimation when the received signal exhibits a frequency offset. Simulation results show that the new estimators present good performance even when the received signal exhibits a large frequency offset.

A high efficiency feedforward power amplifier (FFPA) with a series diode linearizer for cellular base stations is presented. In order to achieve the highest overall efficiency of an FFPA, an improved pre-distortion diode linearizer has been used and the bias condition of the main amplifier has been optimized. The optimum bias condition has been derived from the overall efficiency analysis of the FFPA with a pre-distortion linearizer. From measured overall performances of the FFPA, efficiency enhancement of the series diode linearizer has been verified. The developed FFPA achieved the efficiency of 10% and output power of 45.6 dBm at 10 MHz offset Adjacent Channel leakage Power Ratio (ACPR) -50 dBc under Wide-band Code-Division Multiple-Access (W-CDMA) modulated 2 carriers signal. This design method can be also used to optimize the source and load impedances condition of the main amplifier FET.

When we want to know if it is a win or a loss at a given position of a game (e.g. chess endgame), the process to figure out this problem corresponds to searching an AND/OR tree. AND/OR-tree search is a method for getting a proof solution (win) or a disproof solution (loss) for such a problem. AO* is well-known as a representative algorithm for searching a proof solution in an AND/OR tree. AO* uses only the idea of proof number. Besides, Allis developed pn-search which uses the idea of proof number and disproof number. Both of them are best-first algorithms. There was no efficient depth-first algorithm using (dis)proof number, until Seo developed his originative algorithm which uses only proof number. Besides, Nagai recently developed PDS which is a depth-first algorithm using both proof number and disproof number. In this paper, we give a proof for the equivalence between AO* which is a best-first algorithm and Seo's depth-first algorithm in the meaning of expanding a certain kind of node. Furthermore, we give a proof for the equivalence between pn-search which is a best-first algorithm and df-pn which is a depth-first algorithm we propose in this paper.

A new blind restoration method applying Real-coded genetic algorithm (RcGA) will be proposed, and this method will be proven valid for the blurred image restoration with unidentified degradation in the experiments. In this restoration method, the degraded and blurred image is going to get restricted to the images possible to be expressed in the point spread function (PSF), then the restoration filter for this degraded image, which is also the 2-dimentional inverse filter, will be searched among several points applying RcGA. The method will enable to seek efficiently among vast solution space consists of numeral coefficient filters. And perceiving the essential features of the spectrum in the frequency space, an evaluation function will be proposed. Also, it will be proposed to apply the Rolling-ball transform succeeding an appropriate Gaussian degrade function against the dual degraded image with blur convoluting impulse noise. By above stated features of this restoration method, it will enable to restore the degraded image closer to the original within a practical processing time. Computer simulations verify this method for image restoration problem when the factors causing image distortions are not identified.

This paper suggests that a watermarking technique based on the number theoretic transform (NTT) may effectively be employed for detecting alterations on lossless digital master images. Due to its fragility, the NTT-based technique is sensitive to detecting alterations, compared with that based on the discrete Fourier transform (DFT).

Various types of wavelength-selectable light sources (WSLs) and wavelength-tunable laser diodes (LDs) have been developed, and the one based on an array of distributed feedback (DFB) laser diodes (LDs) has the advantage of tuning that is both simple and stable tuning. It requires only the selection of a DFB-LD and a temperature control. We report on monolithically integrated WSLs with a DFB-LD array, multimode interference (MMI) coupler, semiconductor optical amplifier (SOA), and electro-absorption (EA) modulator. To make them compact, we introduced microarray structures and to ensure that they were easy to fabricate, we used selective area growth. For the WSL with an integrated EA modulator, we developed a center-temperature-shift method that optimizes the detuning wavelength between the lasing wavelength and the absorption edge wavelength of the EA-modulator. Using this method, we obtained a uniform extinction ratio and were able to demonstrate error-free 2.5-Gb/s transmission over a 600-km fiber span. A CW-WSL without an EA-modulator should provide enough output power to compensate the loss caused by the external modulators, but the high-power operation of a CW-WSL is sensitive to optical feedback from the front facet. We therefore used an angled facet in our WSLs and eliminated a mode hop problem. More than 20 mW of fiber-coupled power was obtained over 23 ITU-T channels on a 50-GHz grid.

In modern high-capacity wavelength division multiplexing (WDM) transmission systems, there is increasing demand for large transmission capacity. To achieve this purpose, an L-band (1565-1625 nm) erbium-doped fiber amplifier (EDFA) is very effective method because the conventional silica-based EDF can be used. In EDFAs that used in WDM transmission systems, the gain flatness of EDFA is very important. A passive gain equalizer flattens the gain profile of EDFA. But the gain flatness in L-band deteriorates due to dynamic gain-tilt (DGT) and temperature gain-tilt (TGT) when the operating condition of the EDFA changes, while the EDFAs should maintain the gain flatness even if the operating condition has changed. To solve this problem, we propose an active gain-slope compensation technique for the L-band EDFA using a thulium-doped fiber (TDF). The EDFA actively gain-slope compensated by the TDF compensator keeps the gain profile constant for the wide input power range of more than 8 dB, a wide temperature range of 65 without gain-tilt in a wavelength band between 1575 nm and 1610 nm. Furthermore, the EDFA keeps a low noise figure of less than 7.5 dB.