For wireless receivers, low-power 1.2-V 12-bit 100-MSPS pipeline ADCs are fabricated in 90-nm CMOS technology. To achieve low-power dissipation at 1.2 V without the degradation of SNR, the configuration of 2.5 bit/stage is employed with an I/Q amplifier sharing technique. Furthermore, single-stage pseudo-differential amplifiers are used in a Sample-and-Hold (S/H) circuit and a 1st Multiplying Digital-to-Analog Converter (MDAC). The pseudo-differential amplifier with two-gain-stage transimpedance gain-boosting amplifiers realizes high DC gain of more than 90 dB with low power. The measured SNR of the 100-MSPS ADC is 66.7 dB at 1.2-V supply. Under that condition, each ADC dissipates only 55 mW.

A compact built-in handset antenna for multiple-input multiple-output (MIMO) system at 2 GHz, comprising two elements array of newly proposed L-shaped folded monopole antenna (LFMA), is evaluated under the multipath radio wave propagation environments. By analyzing the fundamental characteristics, mean effective gain (MEG), correlation, and channel capacity, the significant enhancement in the capability, as a handset MIMO antenna under practical use conditions, was confirmed. The performances were also compared to those of an array antenna comprising two planar inversed-F antenna (PIFA) elements in order to verify the effectiveness of the proposed antenna. The results show that the equivalent or improved performances can be realized, by using the proposed LFMA array with a compact size, taking only the volume of 44% of a PIFA array. The LFMA array provides almost the same bandwidth and enhanced isolation compared with a PIFA array, and the sufficiently low correlation and acceptable effective gain are obtained under the multipath radio wave propagation environments. In addition, a greater channel capacity than a PIFA array is achieved especially when the proposed LFMA array is inclined for the display-viewing mode, and moreover, an almost doubled increase in the channel capacity is obtained by using MIMO transmission compared with single-input single-output (SISO). This study also show that the MEG has much effects on the channel capacity, rather than the correlations, for the proposed antenna.

The surface amino groups of plasma-polymerized films prepared from various nitrogen-containing monomers were quantitatively characterized for bioelectronic and biomedical applications. X-ray photoelectron spectroscopy (XPS) measurements were conducted on two kinds of surfaces: pristine surfaces of plasma-polymerized film prepared using various nitrogen-containing monomers, and theirs surfaces whose amino groups had been derivatized by a primary-amine-selective reagent carrying an XPS label. The XPS data showed that the maximum surface density of amino groups for this film was 8.41013 cm-2. Amino groups constituted 14-64% of all surface nitrogen atoms (NH/N), depending on the monomer used.

As THz wave has the advantages of enough resolution and penetration to materials, it has been examined to be used for the imaging system. The propagation distance of THz wave is limited to be short. That is also the advantage for application to the indoor wireless communication etc. For the achievement of the ultra-high frequency oscillator (and concurrently transmitter) device, the properties of small, electronic excitation, the antenna constructed and being on the wafer are important. For the purpose, the Negative differential resistance Dual channel transistor (NDR-DCT) proposed by AIST is utilized. In this paper, as an initial theoretical analysis, we simulated the oscillation frequency of this device at about 100 GHz-1THz within the Terahertz band on which the above applications was expected. The equivalent circuit model of NDR-DCT was shown based on the analogy with the resonant tunnelling diode (RTDs), and the antenna as the resonance circuit part was designed by the numerical analysis. The possibility of the THz oscillation of this device was confirmed. The slit reflector that we proposed can realize the slot antenna on the device effectively and is suitable for three terminal structure semiconductor. its manufacturing is relatively easy.

A new sinusoidal modeling approach for the analysis-by-synthesis (AbS) of parameters that characterize a linear combination of damped sinusoids is proposed. In addition to the typical sinusoidal parameters, two different damping factors, which represent the time-varying nature of speech, were used to efficiently reduce the modeling error. Even though the proposed model does not employ the overlap-adding synthesis or smoothly interpolative synthesis scheme, it shows substantially better modeling performance in the synthesis of voiced and transient segments.

This letter describes a new QR-decomposition maximum likelihood detector that is combined with frequency-domain equalization for single-carrier transmission based multiple-input multiple-output systems. By utilizing the equalized substreams to adjust the frequency selectivity in corresponding substreams in subsequent stages, the packet error rate performances of the proposed detector is superior to that of the minimum mean squared error receiver by a factor of the receive antenna diversity gain.

The TFT-LCD image has non-uniform brightness that is the major difficulty of finding the visible defect called Mura in the field. To facilitate Mura detection, background signal shading should level off and Mura signal must be amplified. In this paper, Mura signal amplification and background signal flattening method is proposed based on human visual system (HVS). The proposed DC normalized contrast sensitivity function (CSF) is used for the Mura signal amplification and polynomial regression (PR) is used to level off the background signal. In the enhanced image, tri-modal thresholding segmentation technique is used for finding Dark and White Mura at the same time. To select reliable defect, falsely detected invisible region is eliminated based on Weber's Law. By the experimental results of artificially generated 1-d signal and TFT-LCD image, proposed algorithm has novel enhancement results and can be applied to real automated inspection system.

This paper investigates suitable indexing techniques to enable efficient content-based audio retrieval in large acoustic databases. To make an index-based retrieval mechanism applicable to audio content, we investigate the design of Locality Sensitive Hashing (LSH) and the partial sequence comparison. We propose a fast and efficient audio retrieval framework of query-by-content and develop an audio retrieval system. Based on this framework, four different audio retrieval schemes, LSH-Dynamic Programming (DP), LSH-Sparse DP (SDP), Exact Euclidian LSH (E2LSH)-DP, E2LSH-SDP, are introduced and evaluated in order to better understand the performance of audio retrieval algorithms. The experimental results indicate that compared with the traditional DP and the other three compititive schemes, E2LSH-SDP exhibits the best tradeoff in terms of the response time, retrieval accuracy and computation cost.

In the real world, it is not always true that neighboring houses are physically adjacent or close to each other. in other words, "neighbors" are not always "true neighbors." In this study, we propose a new Self-Organizing Map (SOM) algorithm, SOM with False-Neighbor degree between neurons (called FN-SOM). The behavior of FN-SOM is investigated with learning for various input data. We confirm that FN-SOM can obtain a more effective map reflecting the distribution state of input data than the conventional SOM and Growing Grid.

This paper studies encoding/decoding function of artificial spiking neurons. First, we investigate basic characteristics of spike-trains of the neurons and fix parameter value that can minimize variation of spike-train length for initial value. Second we consider analog-to-digital encoding based upon spike-interval modulation that is suitable for simple and stable signal detection. Third we present a digital-to-analog decoder in which digital input is applied to switch the base signal of the spiking neuron. The system dynamics can be simplified into simple switched dynamical systems and precise analysis is possible. A simple circuit model is also presented.

Both the clonal selection algorithm (CSA) and the ant colony optimization (ACO) are inspired by natural phenomena and are effective tools for solving complex problems. CSA can exploit and explore the solution space parallely and effectively. However, it can not use enough environment feedback information and thus has to do a large redundancy repeat during search. On the other hand, ACO is based on the concept of indirect cooperative foraging process via secreting pheromones. Its positive feedback ability is nice but its convergence speed is slow because of the little initial pheromones. In this paper, we propose a pheromone-linker to combine these two algorithms. The proposed hybrid clonal selection and ant colony optimization (CSA-ACO) reasonably utilizes the superiorities of both algorithms and also overcomes their inherent disadvantages. Simulation results based on the traveling salesman problems have demonstrated the merit of the proposed algorithm over some traditional techniques.

Digital video encapsulates the time series of a frame (still) images, where overall video quality can be obtained by using the quality of each frame image and the temporal information between the frame image. Coding of video produces degradation of these two types of information. These degradations can be classified as spatial degradation (static degradation) of a frame images and temporal degradation between frame image (dynamic degradation). In the framework of video quality evaluation it is necessary to consider those degradations, because their contents are strongly interdependable and quantification is problematic for these degradations. Therefore, the development of an objective video quality assessment method for single video quality requires to investigate how much static degradation and dynamic degradation affect single video quality. In this research, single video quality was predicted highly accuratly by using frame quality as static degradation and frame rate information as dynamic degradation.

In this paper, we investigated the effect of chromaticity and luminance of surround to decide subject neutral white, and conducted a mathematical model of adapting degree for environment. Factors for adapting degree consist of two parts, adapting degree of ambient chromaticity and color saturation. These can be applied to color appearance models (CAM), actually improve the performance of color matching of CAM, hence would produce the method of image reproduction to general display systems.

Spatial filtering is a useful method to suppress undesired reflection from unwanted scatters in Radar Cross Section (RCS) measurements. Actually, it is difficult to prepare an ideal field which satisfies the far-field criterion for RCS measurements of large targets. We applied the filtering method to a bistatic RCS measurement in a near field and investigated the validity of that method by varying the scanning angular span. Electromagnetic simulations show that predicted RCS profiles from near-field data with unwanted scatters closely matched far-field reference data of the test target. In conclusion, the results show that the method is effective for bistatic RCS measurements in practical field enviroments.

Auditory artifacts due to switching head-related transfer functions (HRTFs) are investigated, using a software-implemented dynamic virtual auditory display (DVAD) developed by the authors. The DVAD responds to a listener's head rotation using a head-tracking device and switching HRTFs to present a highly realistic 3D virtual auditory space to the listener. The DVAD operates on Windows XP and does not require high-performance computers. A total system latency (TSL), which is the delay between head motion and the corresponding change of the ear input signal, is a significant factor of DVADs. The measured TSL of our DVAD is about 50 ms, which is sufficient for practical applications and localization experiments. Another matter of concern is the auditory artifact in DVADs caused by switching HRTFs. Switching HRTFs gives rise to wave discontinuity of synthesized binaural signals, which can be perceived as click noises that degrade the quality of presented sound image. A subjective test and excitation patterns (EPNs) analysis using an auditory filter are performed with various source signals and HRTF spatial resolutions. The results of the subjective test reveal that click noise perception depends on the source signal and the HRTF spatial resolution. Furthermore, EPN analysis reveals that switching HRTFs significantly distorts the EPNs at the off signal frequencies. Such distortions, however, are masked perceptually by broad-bandwidth source signals, whereas they are not masked by narrow-bandwidth source signals, thereby making the click noise more detectable. A higher HRTF spatial resolution leads to smaller distortions. But, depending on the source signal, perceivable click noises still remain even with 0.5-degree spatial resolution, which is less than minimum audible angle (1 degree in front).

Although it is very important to conduct listening tests when constructing a practical sound field reproduction system based on wave field synthesis, listening tests are very expensive. A localization model of synthesized sound images that predicts the results of listening tests is proposed. This model reduces the costs of constructing a reproduction system because it makes it possible to omit the listening tests. The proposed model uses the precedence effect and predicts the direction of synthesized sound images based on the inter-aural time difference. A comparison of the results predicted by the proposed model and the localized results of listening tests shows that the model accurately predicts the localized results.

Speech dereverberation is one of the most difficult tasks in acoustic signal processing. Of the various problems involved in this task, this paper highlights "over-whitening," which flattens the characteristics of recovered speech. This distortion sometimes happens when inverse filters are directly calculated from microphone signals. This paper reviews two studies related to this problem. The first study shows the possibility of compensating for such over-whitening to achieve precise speech-dereverberation. The second study presents a new approach for approximating the original speech by removing the effect of late reflections from observed reverberant speech.

A low distortion and low noise differential amplifier using the difference between the even- and odd-mode impedances is proposed. In order to realize an amplifier with high OIP3 and low NF characteristics, the impedance of the bias circuit should be low (<300 Ω) at the difference frequency and high (>4 kΩ) at the carrier frequency. Although the frequency response of the bias circuit impedance can only meet these conditions with difficulty, owing to the 20 MHz Tx signal bandwidth for 3G LTE, the proposed amplifier can achieve the impedance difference using the properties of a differential configuration where the difference frequency signal is the even-mode and the carrier frequency is the odd-mode. It has been demonstrated that the NF of the proposed amplifier, which has been fabricated in 0.18 µm SiGe BiCMOS technology operating at 2.14 GHz, can be kept to 1.6 dB or less and an OIP3 of 9.0 dBm can be achieved, which is 3 dB higher than that of a conventional amplifier, in the condition where the power gain is greater than 18 dB.

Due to the demand of dual-band modern wireless communications, this paper presents a dual-band patch antenna for IEEE802.11 a and g wireless local area network (WLAN) system. The antenna has bidirectional patterns that can be switched by an RF switch to select the feeding probe positions. The 2.4 GHz and 5.2 GHz patches are stacked on a ground plane and are matched to the RF switch by open stubs. Analysis and design are illustrated and throughput improvement is demonstrated in an indoor environment.

Three-dimensional visualization using jigsaw-puzzle-like glyphs, or shapes, is proposed as a means of representing grammatical constraints in programming. The proposed visualization uses 3D glyphs such as convex, concave, and wireframe shapes. A semantic constraint, such as a type constraint in an assignment, is represented by an inclusive match between 3D glyphs. An application of the proposed visualization method to a subset of the Java programming language is demonstrated. An experimental evaluation showed that the 3D glyphs are easier to learn and enable users to more quickly understand their relationships than 2D glyphs and 1D symbol sequences.