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).
This paper first discusses the misinterpretation of the concept of "ubiquitous computing" that Mark Weiser originally proposed in 1991. Weiser's main message was not the ubiquity of computers, but the transparency of interface that determines users' perception of digital technologies embedded in our physical environment seamlessly. To explore Weiser's philosophy of transparency in interfaces, this paper presents the design of an interface that uses glass bottles as "containers" and "controls" for digital information. The metaphor is a perfume bottle: Instead of scent, the bottles have been filled with music -- classical, jazz, and techno music. Opening each bottle releases the sound of a specific instrument accompanied by dynamic colored light. Physical manipulation of the bottles -- opening and closing -- is the primary mode of interaction for controlling their musical contents. The bottles illustrates Mark Weiser's vision of the transparent (or invisible) interface that weaves itself into the fabric of everyday life. The bottles also exploits the emotional aspects of glass bottles that are tangible and visual, and evoke the smell of perfume and the taste of exotic beverages. This paper describes the design goals of the bottle interface, the arrangement of musical content, the implementation of the wireless electromagnetic tag technology, and the feedback from users who have played with the system.
Chung-Seok (Andy) SEO Abhijit CHATTERJEE
A new approach to optical clock distribution utilizing optical waveguide interconnect technology is introduced. In this paper, we develop a new algorithm for design and optimization of embedded optical clock distribution networks for printed wiring boards. The optimization approach takes into account bending and propagation losses of optical waveguides. Less than 26.1 psec in signal timing skew is obtained for a signal flight time of 614.38 psec. About 15% reduction in optical power consumption is also obtained over clock nets routed with existing (optical) methods.
Jinhwan KOH Dongmin LIM Tapan K. SARKAR
The objective of this research is to compare the performance of the Matrix Pencil Method (MPM) and well known root-MUSIC algorithm for high resolution DOA estimation. Performance of each technique in terms of the probability of resolution and SNR in the presence of noise is investigated. Simulation results show that the MPM has a superior resolution to the root-MUSIC algorithm.
We present a new space-time successive interference cancellation (ST-SIC) scheme with multiple transceiver antennas for direct-sequence code division multiple access (DS-CDMA) systems. The proposed scheme is computationally very efficient, while maintains the performance close to the previous space-time multiuser detection (ST-MUD) scheme. The bit error rate (BER) performance of the ST-SIC scheme for coherent phase shift keying (PSK) modulation is analytically examined in Rayleigh fading channels, and its validity and usefulness are demonstrated by computer simulations.
In low-power embedded processors design, stand-by power constraint is also important with average power and operation frequency. Multi-threshold-voltage cells are used in the design and the ratio of low-Vth cells should be controlled. On the other hand, physical synthesis flow is indispensable to achieve high performance and short design time. This paper proposes a physical synthesis methodology under the restriction of maximum low-Vth cell ratio. The experimental results show that our method can achieve only 4 MHz slower logic within 5% margin of the target low-Vth ratio. We have applied this design flow in an application processor design and the designed processor demonstrates 360 MIPS at 200 MHz only with 80 mW at 1.0 V, namely 4500 MIPS/W and 4.2 mA leakage current without any power-cut mode.
Zonghuang YANG Yoshifumi NISHIO Akio USHIDA
The paper discusses the spatio-temporal phenomena in autonomous two-layer Cellular Neural Networks (CNNs) with mutually coupled templates between two layers. By computer calculations, we show how pattern formations, autowaves and classical waves can be regenerated in the networks, and describe the properties of these phenomena in detail. In particular, we focus our discussion on the necessary conditions for generating these spatio-temporal phenomena. In addition, the influences of the template parameters and initial state conditions of CNNs on the spatio-temporal phenomena are investigated.
In this letter, we propose a groupwise successive interference cancellation (GSIC) receiver with gradient descent search for multi-rate DS-CDMA system. Proposed receiver incorporates iterative gradient descent search algorithm into conventional GSIC receiver for multi-rate DS-CDMA system. It is shown that the receiver achieves significant performance improvement over the matched filter (MF) receiver, GSIC receiver, multi-stage parallel interference cacnellation (PIC) receiver, multi-stage partial PIC receiver, and GSIC receiver with PIC in a Rayleigh fading channel.
This paper presents a Quiet-Noisy scan technique for low power delay fault testing. The novel scan cell design provides both the quiet and noisy scan modes. The toggling of scan cell outputs is suppressed in the quiet scan mode so the power is saved. Two-pattern tests are applied in the noisy scan mode so the delay fault testing is possible. The experimental data shows that the Quiet-Noisy scan technique effectively reduces the test power to 56% of that of the regular scan. The transition fault coverage is improved by 19.7% compared to an existing toggle suppression low power technique. The presented technique requires very minimal changes in the existing MUX-scan Design For Testability (DFT) methodology and needs virtually no computation. The penalties are area overhead, speed degradation, and one extra control in test mode.
This paper presents a new technique to implement a convolutional codec in VLSI. The code is used in the Trellis Code Modulation. The technique aims to reduce hardware complexity and increase throughput to decode the convolutional code using Viterbi algorithm. To simplify decoding algorithm and calculation, branch cost distances are pre-calculated and stored in a Distance Look Up Table (DLUT). By using the DLUT to get each branch cost in the algorithm, the hardware implementation of the algorithm does not require any calculation circuits. Furthermore, based on the trellis diagram, an Output Look-Up-Table (OLUT) is also constructed for decoding output generation. This table reduces the amount of storage in the algorithm. The use of look-up tables reduces hardware complexity and increases throughput of the decoder. Using this technique, a 16-states, radix-4 TCM codec with 2-D and 4-D was designed and implemented in both FPGA and ASIC after mathematically simulated. The tested ASIC has a core area of 1.1 mm2 in 0.18 µm CMOS technology and yields a decoding speed over 500 Mbps. Implementation results have shown that LUT can be used to decrease hardware requirement and to increase decoding speed. The designed codec can be used as an IP core to be integrated into system-on-chip applications and the technique can be explored to use to decode the turbo code.
Lan ZHANG Masataka MORIYA Tadayuki KOBAYASHI Masashi MUKAIDA Toshinari GOTO
In-plane-aligned a-axis-oriented YBa2Cu3O7-δ (YBCO) thin films are attractive for the formation of planar intrinsic Josephson devices. In this study, these films were deposited by dc sputtering on LaSrGaO4 (LSGO) (100) substrates and the dependence of the characteristics on the deposition conditions was investigated. In-plane-aligned a-axis-oriented YBCO thin films were successfully grown in the substrate temperature range of 555-615. With the temperature gradient method, it was seen that the critical temperature of the film increased to 81 K. The current-voltage characteristic along the c-axis exhibited clear multibranch structures. These results indicate that ion-cleaning of the substrate surface broadens the growth temperature range of these films and planar intrinsic Josephson devices can be fabricated from these films.
Kazuhiro HATTANDA Shuichi ICHIKAWA
Davidson's scheme utilizes the order of basic blocks to embed a digital signature in a computer program. To preserve the function of the original program, additional jump instructions are inserted. This involves some overhead in both size and performance. In our implementation, the increase in size was between 9% and 24%. The performance of benchmark programs was 86-102% of the original.
Youngha CHANG Suguru SAITO Masayuki NAKAJIMA
Usually, paintings are more appealing than photographic images. This is because paintings can incorporate styles based on the artist's subjective view of motif. This style can be distinguished by looking at elements such as motif, color, shape deformation and brush texture. In our work, we focus on the effect of "color" element and devise a method for transforming the color of an input photograph according to a reference painting. To do this, we consider basic color category concepts in the color transformation process. We assume that color transformations from one basic color category to another may cause peculiar feelings. Therefore, we restrict each color transformation within the same basic color category. For this, our algorithm first categorizes each pixel color of a photograph into one of eleven basic color categories. Next, for every pixel color of the photograph, the algorithm finds its corresponding color in the same category of a reference painting. Finally, the algorithm substitutes the pixel color with its corresponding color. In this way, we achieve large but natural color transformations of an image.
Hiroyuki MATSUNAMI Tsunenobu KIMOTO Hiroshi YANO
Hetero-interface properties of SiO2/4H-SiC on (0001), (11-20), and (03-38) crystal orientations are presented. Epitaxial growth on new crystal orientations, (11-20) and (03-38), is described by comparing with the growth on (0001). Using thermal oxidation with wet oxygen, metal-oxide-SiC (MOS) structure was fabricated. From high-frequency capacitance-voltage characteristics measured at 300 K and 100 K, the interface properties were characterized semi-quantitatively. The interface state density was precisely determined using the conductance method for the MOS structure at 300 K. The new crystal orientations have the lower interface state density near the conduction band edge than (0001). From the characteristics of inversion-type planar MOSFETs, higher channel mobilities were obtained on (03-38) and (11-20) than on (0001). The cause of the difference in the channel mobility is speculated by the difference bond configuration of the three crystal orientations.
Young Han NAM Tae Kyoon HA Yunho JEON Jae Soo KIM Seop Hyeong PARK
In this paper, a preprocessing approach to improving the quality of the music on a mobile phone using Enhanced variable rate codec (EVRC) is presented. Our approach works well on music signals considerably reducing the number of time-clipped frames.
This paper describes a method of analyzing musical sound using a self-organizing map. To take compound factors into account, energy spectra whose frequency ranges were based on the psycho-acoustic experiments were used as input data. Results for music compact discs confirmed that our method could effectively display the positioning and relationships among musical sounds on a map.
In this letter, we present groupwise successive interference cancellation (GSIC) receiver with adaptive minimum mean squared error (MMSE) detection and extended GSIC (EGSIC) receiver with adaptive MMSE detection for dual-rate DS-CDMA system. The receivers are GSIC receiver and EGSIC receiver combined with adaptive MMSE detection which is introduced to make initial bit detection more reliable. Furthermore, a multi-user detection scheme is introduced to mitigate the effect of multiple access interference (MAI) between users in a group which is usually ignored in conventional GSIC receiver and EGSIC receiver. Specifically, parallel interference cancellation (PIC) is adopted as a multi-user detection scheme within a group. It is shown that performance of the GSIC receiver and EGSIC receiver is significantly improved by employing adaptive MMSE detection. It is also shown that the performance of the receivers can be improved further by using PIC within a group.
Yoshiyuki KUSUNOKI Makoto FUKUMOTO Tomomasa NAGASHIMA
The cardio-music synchrogram, which is a visualization tool that helps us observe the phase synchronization between heartbeats and beats of music, is originated in cardio-respiratory synchrogram. In this paper, we proposed a novel statistical method for detecting synchronization periods in cardio-music synchrogram (CMS), and reported the synchronization periods of the cardiac activity for 8 subjects in a listening experiments. Our approach focused on the difference between the statistical distributions of the correlation coefficient calculated for the CMS in a control experiment and in the CMS in the listening experiment.
One of the most basic characteristics of the image is accompanied by its blur. It was 1962 that I had discovered for the first time in the world that the blur was a Gaussian type. In this paper the outline is described about historical details concerning this circumstances.
Tsutomu MORIUCHI Satoshi UEHARA Takayasu KAIDA Kyoki IMAMURA
In this paper, we will show that some families of periodic sequences over Z4 and Z8 with period multiple of 2r-1 generated by r-th degree basic primitive polynomials assorted by the root of each polynomial, and give the exact distribution of sequences for each family. We also point out such an instability as an extreme increase of their linear complexities for the periodic sequences by one-symbol substitution, i.e., from the minimum value to the maximum value, for all the substitutions except one.