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6121-6140hit(20498hit)

  • A Fully Automatic Player Detection Method Based on One-Class SVM

    Xuefeng BAI  Tiejun ZHANG  Chuanjun WANG  Ahmed A. ABD EL-LATIF  Xiamu NIU  

     
    LETTER-Image Recognition, Computer Vision

      Vol:
    E96-D No:2
      Page(s):
    387-391

    Player detection is an important part in sports video analysis. Over the past few years, several learning based detection methods using various supervised two-class techniques have been presented. Although satisfactory results can be obtained, a lot of manual labor is needed to construct the training set. To overcome this drawback, this letter proposes a player detection method based on one-class SVM (OCSVM) using automatically generated training data. The proposed method is evaluated using several video clips captured from World Cup 2010, and experimental results show that our approach achieves a high detection rate while keeping the training set construction's cost low.

  • A Digitally-Controlled SMPS Using a Novel High-Resolution DPWM Generator Based on a Pseudo Relaxation-Oscillation Technique

    Ji-Hoon LIM  Won-Young JUNG  Yong-Ju KIM  Inchae SONG  Jae-Kyung WEE  

     
    PAPER-Electronic Circuits

      Vol:
    E96-C No:2
      Page(s):
    277-284

    We suggest a novel digitally-controlled SMPS using a high-resolution DPWM generator. In the proposed circuit, the duty ratio of the DPWM is determined by the voltage slope control of an internal capacitor using a pseudo relaxation-oscillation technique. This new control method has a simpler structure, and consumes less power compared to a conventional digitally-controlled SMPS. Therefore, the proposed circuit is able to operate at a high switching frequency (1 MHz10 MHz) obtained from a relatively low internal operating frequency (10 MHz100 MHz) with a small area. The maximum current of the core circuit is 2.7 mA, and the total current of the entire circuit, including the output buffer driver, is 15 mA at 10 MHz switching frequency. The proposed circuit is designed to supply a maximum 1A with maximum DPWM duty ratio of 90%. The output voltage ripple is 7 mV at 3.3 V output voltage. To verify the operation of the proposed circuit, we performed a simulation with Dongbu Hitek BCD 0.35 µm technology.

  • Adaptive Block-Wise Compressive Image Sensing Based on Visual Perception

    Xue ZHANG  Anhong WANG  Bing ZENG  Lei LIU  Zhuo LIU  

     
    LETTER-Image Processing and Video Processing

      Vol:
    E96-D No:2
      Page(s):
    383-386

    Numerous examples in image processing have demonstrated that human visual perception can be exploited to improve processing performance. This paper presents another showcase in which some visual information is employed to guide adaptive block-wise compressive sensing (ABCS) for image data, i.e., a varying CS-sampling rate is applied on different blocks according to the visual contents in each block. To this end, we propose a visual analysis based on the discrete cosine transform (DCT) coefficients of each block reconstructed at the decoder side. The analysis result is sent back to the CS encoder, stage-by-stage via a feedback channel, so that we can decide which blocks should be further CS-sampled and what is the extra sampling rate. In this way, we can perform multiple passes of reconstruction to improve the quality progressively. Simulation results show that our scheme leads to a significant improvement over the existing ones with a fixed sampling rate.

  • Direction-of-Arrival Estimation for Near-Field Sources with Multiple Symmetric Subarrays

    Tomoyuki KITADA  Jun CHENG  Yoichiro WATANABE  

     
    PAPER-Antennas and Propagation

      Vol:
    E96-B No:2
      Page(s):
    553-560

    A direction-of-arrival estimation (DoA) scheme that uses a uniform circular array (UCA) is proposed for near-field sources, where multiple pairs-of-subarrays exist with central symmetry. First, multiple generalized ESPRIT (G-ESPRIT) spectrums are obtained by applying the conventional G-ESPRIT algorithm to each of multiple pairs-of-subarrays. Second, a parallel spectrum is found by adding up the reciprocals of these G-ESPRIT spectrums and taking the reciprocal of the total. The locations of peaks in the parallel spectrum give the DoAs being estimated. When a DoA approaches the translation direction of two subarrays, the conventional G-ESPRIT spectrum is broken by a false peak. Since the translation directions of pairs-of-subarrays are different from each other, the false peak, due to the DoA approaching one of translation directions, does not exist simultaneously in all G-ESPRIT spectrums. The parallel concatenation of the spectrums suppresses the false peak and enhances the true DoA peaks. Simulation shows that the proposed scheme reduces the root mean square error of the DoA estimation, compared with the conventional G-ESPRIT algorithm.

  • Device-Parameter Estimation through IDDQ Signatures

    Michihiro SHINTANI  Takashi SATO  

     
    PAPER-Dependable Computing

      Vol:
    E96-D No:2
      Page(s):
    303-313

    We propose a novel technique for the estimation of device-parameters suitable for postfabrication performance compensation and adaptive delay testing, which are effective means to improve the yield and reliability of LSIs. The proposed technique is based on Bayes' theorem, in which the device-parameters of a chip, such as the threshold voltage of transistors, are estimated by current signatures obtained in a regular IDDQ testing framework. Neither additional circuit implementation nor additional measurement is required for the purpose of parameter estimation. Numerical experiments demonstrate that the proposed technique can achieve 10-mV accuracy in threshold voltage estimations.

  • Impact of the Primary User's Power Allocation on the Performance of the Secondary User in Cognitive Radio Networks

    Ding XU  Zhiyong FENG  Ping ZHANG  

     
    LETTER-Terrestrial Wireless Communication/Broadcasting Technologies

      Vol:
    E96-B No:2
      Page(s):
    668-672

    In spectrum sharing cognitive radio (CR) networks, secondary user (SU) is allowed to share the same spectrum band concurrently with primary user (PU), with the condition that the SU causes no harmful interference to the PU. In this letter, the ergodic and outage capacity loss constraints are proposed to protect the PU according to its service types. We investigate the performance of the SU in terms of ergodic capacity under various power allocation policies of the PU. Specifically, three PU power allocation policies are considered, namely waterfilling, truncated channel inversion with fixed rate (TIFR) and constant power allocation. We obtain the ergodic capacities of the SU under the three PU power allocation policies. The numerical results show that the PU waterfilling and TIFR power allocation policies are superior to the PU constant power allocation in terms of the capacity of the PU. In particular, it is shown that, with respect to the ergodic capacity of the SU, the PU waterfilling power allocation is superior to the PU constant power allocation, while the PU TIFR power allocation is inferior to the PU constant power allocation.

  • Quadrature-Phase-Shift-Keying Radio-over-Fiber Transmission for Coherent Optical and Radio Seamless Networks Open Access

    Atsushi KANNO  Pham TIEN DAT  Toshiaki KURI  Iwao HOSAKO  Tetsuya KAWANISHI  Yoshihiro YASUMURA  Yuki YOSHIDA  Ken-ichi KITAYAMA  

     
    INVITED PAPER

      Vol:
    E96-C No:2
      Page(s):
    156-162

    We propose a coherent optical and radio seamless network concept that allows broadband access without deployment of additional optical fibers within an optical fiber dead zone while enhancing network resilience to disasters. Recently developed radio-over-fiber (RoF) and digital coherent detection technologies can seamlessly convert between optical and radio signals. A millimeter-wave radio with a capacity greater than 10 Gb/s and high-speed digital signal processing is feasible for this purpose. We provide a preliminary demonstration of a high-speed, W-band (75–110 GHz) radio that is seamlessly connected to an optical RoF transmitter using a highly accurate optical modulation technique to stabilize the center frequencies of radio signals. Using a W-band digital receiver with a sensitivity of -37 dBm, we successfully transmitted an 18.6 Gb/s quadrature-phase-shift-keying signal through both air and an optical fiber.

  • Mobile Backhaul Optical Access Networks for Coordinated Multipoint Transmission/Reception (CoMP) Techniques in Future Cellular Systems Open Access

    Changsoon CHOI  Thorsten BIERMANN  Qing WEI  Kazuyuki KOZU  Masami YABUSAKI  

     
    INVITED PAPER

      Vol:
    E96-C No:2
      Page(s):
    147-155

    This paper describes mobile backhaul optical access network designs for future cellular systems, in particular, for those systems that exploit coordinated multipoints (CoMP) transmission/reception techniques. Wavelength-division-multiplexing passive optical networks (WDM-PON) are primarily considered and two proposals to enhance mobile backhaul capability of WDM-PONs for CoMP are presented. One is physical X2 links that support dedicated low latency and high capacity data exchange between base stations (BSs). The other is multicasting in WDM-PONs. It effectively reduces data/control transmission time from central node to multiple BSs joining CoMP. Evaluation results verify that the proposed X2 links and the multicasting enable more BSs to join CoMP by enhancing the mobile backhaul capability, which results in improved service quality for users.

  • A 120 GHz/140 GHz Dual-Channel OOK Receiver Using 65 nm CMOS Technology

    Ryuichi FUJIMOTO  Mizuki MOTOYOSHI  Kyoya TAKANO  Minoru FUJISHIMA  

     
    PAPER

      Vol:
    E96-A No:2
      Page(s):
    486-493

    The design and measured results of a 120 GHz/140 GHz dual-channel OOK (ON-OFF Keying) receiver are presented in this paper. Because a signal with very wide frequency width is difficult to process in a single-channel receiver, a dual-channel configuration with channel selection is adopted in the proposed receiver. The proposed receiver is fabricated using 65 nm CMOS technology. The measured data rate of 3.0 and 3.6 Gbps, minimum sensitivity of -25.6 and -27.1 dBm, communication distance of 0.30 and 0.38 m are achieved in the 120- and 140-GHz receiver, respectively. The correct channel selection is achieved in the 120-GHz receiver. These results indicate the possibility of the CMOS multiband receiver operating at over 100 GHz for low-power high-speed proximity wireless communication systems.

  • Subjective Quality Metric for 3D Video Services

    Kazuhisa YAMAGISHI  Taichi KAWANO  Takanori HAYASHI  Jiro KATTO  

     
    PAPER

      Vol:
    E96-B No:2
      Page(s):
    410-418

    Three-dimensional (3D) video service is expected to be introduced as a next-generation television service. Stereoscopic video is composed of two 2D video signals for the left and right views, and these 2D video signals are encoded. Video quality between the left and right views is not always consistent because, for example, each view is encoded at a different bit rate. As a result, the video quality difference between the left and right views degrades the quality of stereoscopic video. However, these characteristics have not been thoroughly studied or modeled. Therefore, it is necessary to better understand how the video quality difference affects stereoscopic video quality and to model the video quality characteristics. To do that, we conducted subjective quality assessments to derive subjective video quality characteristics. The characteristics showed that 3D video quality was affected by the difference in video quality between the left and right views, and that when the difference was small, 3D video quality correlated with the highest 2D video quality of the two views. We modeled these characteristics as a subjective quality metric using a training data set. Finally, we verified the performance of our proposed model by applying it to unknown data sets.

  • Exact Design of RC Polyphase Filters and Related Issues

    Hiroshi TANIMOTO  

     
    INVITED PAPER

      Vol:
    E96-A No:2
      Page(s):
    402-414

    This paper presents analysis and design of passive RC polyphase filters (RCPFs) in tutorial style. Single-phase model of a single-stage RCPF is derived, and then, multi-stage RCPFs are analyzed and obtained some restrictions for realizable poles and zeros locations of RCPFs. Exact design methods of RCPFs with equal ripple type, and Butterworth type responses are explained for transfer function design and element value design along with some design examples.

  • PCA-Based Retinal Vessel Tortuosity Quantification

    Rashmi TURIOR  Danu ONKAEW  Bunyarit UYYANONVARA  

     
    PAPER-Pattern Recognition

      Vol:
    E96-D No:2
      Page(s):
    329-339

    Automatic vessel tortuosity measures are crucial for many applications related to retinal diseases such as those due to retinopathy of prematurity (ROP), hypertension, stroke, diabetes and cardiovascular diseases. An automatic evaluation and quantification of retinal vascular tortuosity would help in the early detection of such retinopathies and other systemic diseases. In this paper, we propose a novel tortuosity index based on principal component analysis. The index is compared with three existant indices using simulated curves and real retinal images to demonstrate that it is a valid indicator of tortuosity. The proposed index satisfies all the tortuosity properties such as invariance to translation, rotation and scaling and also the modulation properties. It is capable of differentiating the tortuosity of structures that visually appear to be different in tortuosity and shapes. The proposed index can automatically classify the image as tortuous or non tortuous. For an optimal set of training parameters, the prediction accuracy is as high as 82.94% and 86.6% on 45 retinal images at segment level and image level, respectively. The test results are verified against the judgement of two expert Ophthalmologists. The proposed index is marked by its inherent simplicity and computational attractiveness, and produces the expected estimate, irrespective of the segmentation approach. Examples and experimental results demonstrate the fitness and effectiveness of the proposed technique for both simulated curves and retinal images.

  • Adaptive Analog-to-Information Converter Design with Limited Random Sequence Modulation

    Chao ZHANG  Jialuo XIAO  

     
    PAPER

      Vol:
    E96-A No:2
      Page(s):
    469-476

    Compressive sensing enables quite lower sampling rate compared with Nyquist sampling. As long as the signal is sparsity in some basis, the random sampling with CS can be employed. In order to make CS applied in the practice, the Analog to Information Converter (AIC) should be involved. Based on the Limited Random Sequence (LRS) modulation, the AIC with LRS can be designed with high performance according to the fixed sparsity. However, if the sparsity of the signal varies with time, the original AIC with LRS is not efficient. In this paper, the adaptive AIC which adapts its scheme of LRS according to the variation of the sparsity is proposed and the prototype system is designed. Due to the adaption of the AIC with the scheme of LRS, the sampling rate can be further reduced. The simulation results confirm the performance of the proposed adaptive AIC scheme. The prototype system can successfully fulfil the random sampling and adapt to the variation of sparsity, which verify and consolidate the validity and feasibility for the future implementation of adaptive AIC on chip.

  • On the Balanced Elementary Symmetric Boolean Functions

    Longjiang QU  Qingping DAI  Chao LI  

     
    LETTER-Cryptography and Information Security

      Vol:
    E96-A No:2
      Page(s):
    663-665

    In this paper, we give some results towards the conjecture that σ2t+1l-1,2t are the only nonlinear balanced elementary symmetric Boolean functions where t and l are positive integers. At first, a unified and simple proof of some earlier results is shown. Then a property of balanced elementary symmetric Boolean functions is presented. With this property, we prove that the conjecture is true for n=2m+2t-1 where m,t (m>t) are two non-negative integers, which verified the conjecture for a large infinite class of integer n.

  • A 4–10 bit, 0.4–1 V Power Supply, Power Scalable Asynchronous SAR-ADC in 40 nm-CMOS with Wide Supply Voltage Range SAR Controller

    Akira SHIKATA  Ryota SEKIMOTO  Kentaro YOSHIOKA  Tadahiro KURODA  Hiroki ISHIKURO  

     
    PAPER

      Vol:
    E96-A No:2
      Page(s):
    443-452

    This paper presents a wide range in supply voltage, resolution, and sampling rate asynchronous successive approximation register (SAR) analog-to-digital converter (ADC). The proposed differential flip-flop in SAR logic and high efficiency wide range delay element extend the flexibility of speed and resolution tradeoff. The ADC fabricated in 40 nm CMOS process covers 4–10 bit resolution and 0.4–1 V power supply range. The ADC achieved 49.8 dB SNDR and the peak FoM of 3.4 fJ/conv. with 160 kS/sec at 0.4 V single power supply voltage. At 10 bit mode and 1 V operation, up to 10 MS/s, the FoM is below 10 fJ/conv. while keeping ENOB of 8.7 bit.

  • Query-by-Sketch Image Retrieval Using Edge Relation Histogram

    Yoshiki KUMAGAI  Gosuke OHASHI  

     
    PAPER-Image Processing and Video Processing

      Vol:
    E96-D No:2
      Page(s):
    340-348

    There has recently been much research on content-based image retrieval (CBIR) that uses image features including color, shape, and texture. In CBIR, feature extraction is important because the retrieval result depends on the image feature. Query-by-sketch image retrieval is one of CBIR and query-by-sketch image retrieval is efficient because users simply have to draw a sketch to retrieve the desired images. In this type of retrieval, selecting the optimum feature extraction method is important because the retrieval result depends on the image feature. We have developed a query-by-sketch image retrieval method that uses an edge relation histogram (ERH) as a global and local feature intended for binary line images. This histogram is based on the patterns of distribution of other line pixels centered on each line pixel that have been obtained by global and local processing. ERH, which is a shift- and scale-invariant feature, focuses on the relation among the edge pixels. It is fairly simple to describe rotation- and symmetry-invariant features, and query-by-sketch image retrieval using ERH makes it possible to perform retrievals that are not affected by position, size, rotation, or mirroring. We applied the proposed method to 20,000 images in the Corel Photo Gallery. Experimental results showed that it was an effective means of retrieving images.

  • 10-GHz High-Repetition Optical Short Pulse Generation from Wavelength-Tunable Quantum Dot Optical Frequency Comb Laser

    Naokatsu YAMAMOTO  Kouichi AKAHANE  Tetsuya KAWANISHI  Hideyuki SOTOBAYASHI  Yuki YOSHIOKA  Hiroshi TAKAI  

     
    PAPER

      Vol:
    E96-C No:2
      Page(s):
    187-191

    The quantum dot optical frequency comb laser (QD-CML) is an attractive photonic device for generating a stable emission of fine multiple-wavelength peaks. In the present paper, 1.0-GHz and 10-ps-order short optical pulsation is successfully demonstrated from a hybrid mode-locked QD-CML with an ultrabroadband wavelength tuning range in the T+O band. In addition, 10-GHz high-repetition intensity-stable short optical pulse generation with a high S/N ratio is successfully demonstrated using an external-cavity QD-CML with a 10th-harmonic mode-locking technique.

  • An Opampless Second-Order MASH ΔΣ ADC with Using Gated Ring Oscillator Time-to-Digital Converter

    Toshihiro KONISHI  Keisuke OKUNO  Shintaro IZUMI  Masahiko YOSHIMOTO  Hiroshi KAWAGUCHI  

     
    PAPER

      Vol:
    E96-A No:2
      Page(s):
    434-442

    This paper presents a second-order ΔΣ analog-to-digital converter (ADC) operating in a time domain. In the proposed ADC architecture, a voltage-controlled delay unit (VCDU) converts an input analog voltage to a delay time. Then, the clocks outputs from a gated ring oscillator (GRO) are counted during the delay time. No switched capacitor or opamp is used. Therefore, the proposed ADC can be implemented in a small area and with low power. For that reason, it has process scalability: it can keep pace with Moore's law. A time error is propagated to the second GRO by a multi-stage noise-shaping (MASH) topology, which provides second-order noise-shaping. In a standard 40-nm CMOS process, a SNDR of 45 dB is achievable at input bandwidth of 16 kHz and a sampling rate of 8 MHz, where the power is 408.5 µW. Its area is 608 µm2.

  • Texturization for Multi-Crystalline Silicon Solar Cells with Chlorine Trifluoride Gas and Acid Solution

    Takahiro SANDA  Yoji SAITO  

     
    BRIEF PAPER-Semiconductor Materials and Devices

      Vol:
    E96-C No:2
      Page(s):
    289-291

    We have investigated on a random-texturing process for multi-crystalline Si solar cells by plasmaless dry etching, with chlorine trifluoride (ClF3) gas treatments. The reflectance of textured surfaces was reduced to below 20% at a wavelength of 600 nm. In this study, we tried to improve the electrical characteristics by modifying the fabrication process. The substrate surfaces were dry etched by chlorine trifluoride gas and subsequently etched with an acid solution to form appropriate textured structures. The improved electrical characteristics were demonstrated.

  • An Efficient I/O Aggregator Assignment Scheme for Multi-Core Cluster Systems

    Kwangho CHA  

     
    PAPER-Fundamentals of Information Systems

      Vol:
    E96-D No:2
      Page(s):
    259-269

    As the number of nodes in high-performance computing (HPC) systems increases, parallel I/O becomes an important issue: collective I/O is the specialized parallel I/O that provides the function of single-file based parallel I/O. Collective I/O in most message passing interface (MPI) libraries follows a two-phase I/O scheme in which the particular processes, namely I/O aggregators, perform important roles by engaging the communications and I/O operations. This approach, however, is based on a single-core architecture. Because modern HPC systems use multi-core computational nodes, the roles of I/O aggregators need to be re-evaluated. Although there have been many previous studies that have focused on the improvement of the performance of collective I/O, it is difficult to locate a study regarding the assignment scheme for I/O aggregators that considers multi-core architectures. In this research, it was discovered that the communication costs in collective I/O differed according to the placement of the I/O aggregators, where each node had multiple I/O aggregators. The performance with the two processor affinity rules was measured and the results demonstrated that the distributed affinity rule used to locate the I/O aggregators in different sockets was appropriate for collective I/O. Because there may be some applications that cannot use the distributed affinity rule, the collective I/O scheme was modified in order to guarantee the appropriate placement of the I/O aggregators for the accumulated affinity rule. The performance of the proposed scheme was examined using two Linux cluster systems, and the results demonstrated that the performance improvements were more clearly evident when the computational node of a given cluster system had a complicated architecture. Under the accumulated affinity rule, the performance improvements between the proposed scheme and the original MPI-IO were up to approximately 26.25% for the read operation and up to approximately 31.27% for the write operation.

6121-6140hit(20498hit)