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11421-11440hit(42807hit)

  • AspectQuery: A Method for Identification of Crosscutting Concerns in the Requirement Phase

    Chengwan HE  Chengmao TU  

     
    PAPER-Software Engineering

      Vol:
    E96-D No:4
      Page(s):
    897-905

    Identification of early aspects is the critical problem in aspect-oriented requirement engineering. But the representation of crosscutting concerns is various, which makes the identification difficult. To address the problem, this paper proposes the AspectQuery method based on goal model. We analyze four kinds of goal decomposition models, then summarize the main factors about identification of crosscutting concerns and conclude the identification rules based on a goal model. A goal is crosscutting concern when it satisfies one of the following conditions: i) the goal is contributed to realize one soft-goal; ii) parent goal of the goal is candidate crosscutting concern; iii) the goal has at least two parent goals. AspectQuery includes four steps: building the goal model, transforming the goal model, identifying the crosscutting concerns by identification rules, and composing the crosscutting concerns with the goals affected by them. We illustrate the AspectQuery method through a case study (a ticket booking management system). The results show the effectiveness of AspectQuery in identifying crosscutting concerns in the requirement phase.

  • Machine Learning in Computer-Aided Diagnosis of the Thorax and Colon in CT: A Survey Open Access

    Kenji SUZUKI  

     
    INVITED SURVEY PAPER

      Vol:
    E96-D No:4
      Page(s):
    772-783

    Computer-aided detection (CADe) and diagnosis (CAD) has been a rapidly growing, active area of research in medical imaging. Machine leaning (ML) plays an essential role in CAD, because objects such as lesions and organs may not be represented accurately by a simple equation; thus, medical pattern recognition essentially require “learning from examples.” One of the most popular uses of ML is the classification of objects such as lesion candidates into certain classes (e.g., abnormal or normal, and lesions or non-lesions) based on input features (e.g., contrast and area) obtained from segmented lesion candidates. The task of ML is to determine “optimal” boundaries for separating classes in the multi-dimensional feature space which is formed by the input features. ML algorithms for classification include linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), multilayer perceptrons, and support vector machines (SVM). Recently, pixel/voxel-based ML (PML) emerged in medical image processing/analysis, which uses pixel/voxel values in images directly, instead of features calculated from segmented lesions, as input information; thus, feature calculation or segmentation is not required. In this paper, ML techniques used in CAD schemes for detection and diagnosis of lung nodules in thoracic CT and for detection of polyps in CT colonography (CTC) are surveyed and reviewed.

  • A Novel Imaging Method for Cell Phone Camera in Low Ambient Light Conditions Using Flash and No-Flash Image Pairs

    Lin-bo LUO  Jun CHEN  Sang-woo AN  Chang-shuai WANG  Jong-joo PARK  Ying-chun LI  Jong-wha CHONG  

     
    PAPER-Image Processing and Video Processing

      Vol:
    E96-D No:4
      Page(s):
    957-962

    In lowlight conditions, images taken by phone cameras usually have too much noise, while images taken using a flash have a high signal-noise ratio (SNR) and look unnatural. This paper proposes a novel imaging method using flash/no-flash image pairs. Through transferring the natural tone of the former to the latter, the resulting image has a high SNR and maintains a natural appearance. For realtime implementation, we use two preview images, which are taken with and without flash, to estimate the transformation function in advance. Then we use this function to adjust the tone of the image captured with flash in real time. Thus, the method does not require a frame memory and it is suitable for cell phone cameras.

  • Design of Effective Supply Voltage Monitor for Measuring Power Rails of Integrated Circuits

    Takeshi OKUMOTO  Kumpei YOSHIKAWA  Makoto NAGATA  

     
    PAPER

      Vol:
    E96-C No:4
      Page(s):
    538-545

    An effective supply voltage monitor evaluates dynamic variation of (Vdd-Vss) within power rails of integrated circuits on a die. The monitor occupies an area of as small as 10.8 14.5 µm2 and is followed by backend digitizing circuits, both using 3.3 V thick oxide transistors in a 65 nm CMOS technology for covering all power domains from core circuits to peripheral I/O rings. A prototype demonstrates capturing of effective supply voltage waveforms in digital (shift registers) as well as in analog (4 bit Flash ADC) circuits.

  • Ultimate Boundedness of Nonlinear Singularly Perturbed System with Measurement Noise

    Kyung-In KANG  Kyun-Sang PARK  Jong-Tae LIM  

     
    LETTER-Systems and Control

      Vol:
    E96-A No:4
      Page(s):
    826-829

    In this letter, we consider the ultimate boundedness of the singularly perturbed system with measurement noise. The composite controller is commonly used to regulate the singularly perturbed system. However, in the presence of measurement noise, the composite controller does not guarantee the ultimate boundedness of the singularly perturbed system. Thus, we propose the modified composite controller to show the ultimate boundedness of the singularly perturbed system with measurement noise.

  • GA-Enhanced Thin Square Array with Cyclic Difference Sets

    Gina KWON  Keum-Cheol HWANG  Joon-Young PARK  Seon-Joo KIM  Dong-Hwan KIM  

     
    BRIEF PAPER-Electromagnetic Theory

      Vol:
    E96-C No:4
      Page(s):
    612-614

    A hybrid approach for the synthesis of square thinned arrays with low sidelobes is presented. The proposed method combines the advantages of a genetic algorithm and combinatorial technique-cyclic difference sets (CDSs). The peak sidelobe level (PSL) and the thinning factor are numerically evaluated to show the effectiveness and reliability of the proposed hybrid method. In the proposed GA-enhanced square arrays with the DS and the best CDS, reductions of the PSL, of 4.16 dB and 2.45 dB, respectively, were achieved as compared to the results of conventional rectangular DS and CDS arrays.

  • A Low Complexity Precoding Transceiver Design for Double STBC System

    Juinn-Horng DENG  Shiang-Chyun JHAN  Sheng-Yang HUANG  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E96-B No:4
      Page(s):
    1075-1080

    A precoding design for double space-time block coding (STBC) system is investigated in this paper, i.e., the joint processing of STBC and dirty paper coding (DPC) techniques. These techniques are used for avoiding dual spatial streams interference and improving the transmitter diversity. The DPC system is interference free on multi-user or multi-antenna. The STBC transceiver can provide the transmit diversity. Due to the benefits about offered by the STBC and DPC techniques, we propose a new scheme called STBC-DPC system. The transceiver design involves the following procedures. First, the ordering QR decomposition of channel matrix and the maximum likelihood (ML) one-dimensional searching algorithm are proposed to acquire reliable performance. Next, the channel on/off assignment using the water filling algorithm, i.e., maximum capacity criterion, is proposed to overcome the deep fading channel problem. Finally, the STBC-DPC system with the modulus operation to limit the transmit signal level, i.e., the Tomlinson-Harashima precoding (THP) scheme, is proposed to achieve low peak-to-average power ratio (PAPR) performance. Simulation results confirm that the proposed STBC-DPC/THP with water filling ML algorithm can provide the low PAPR and excellent bit error rate (BER) performances.

  • Ensemble Learning Based Segmentation of Metastatic Liver Tumours in Contrast-Enhanced Computed Tomography Open Access

    Akinobu SHIMIZU  Takuya NARIHIRA  Hidefumi KOBATAKE  Daisuke FURUKAWA  Shigeru NAWANO  Kenji SHINOZAKI  

     
    LETTER-Medical Image Processing

      Vol:
    E96-D No:4
      Page(s):
    864-868

    This paper presents an ensemble learning algorithm for liver tumour segmentation from a CT volume in the form of U-Boost and extends the loss functions to improve performance. Five segmentation algorithms trained by the ensemble learning algorithm with different loss functions are compared in terms of error rate and Jaccard Index between the extracted regions and true ones.

  • Segmentation of Liver in Low-Contrast Images Using K-Means Clustering and Geodesic Active Contour Algorithms Open Access

    Amir H. FORUZAN  Yen-Wei CHEN  Reza A. ZOROOFI  Akira FURUKAWA  Yoshinobu SATO  Masatoshi HORI  Noriyuki TOMIYAMA  

     
    PAPER-Medical Image Processing

      Vol:
    E96-D No:4
      Page(s):
    798-807

    In this paper, we present an algorithm to segment the liver in low-contrast CT images. As the first step of our algorithm, we define a search range for the liver boundary. Then, the EM algorithm is utilized to estimate parameters of a 'Gaussian Mixture' model that conforms to the intensity distribution of the liver. Using the statistical parameters of the intensity distribution, we introduce a new thresholding technique to classify image pixels. We assign a distance feature vectors to each pixel and segment the liver by a K-means clustering scheme. This initial boundary of the liver is conditioned by the Fourier transform. Then, a Geodesic Active Contour algorithm uses the boundaries to find the final surface. The novelty in our method is the proper selection and combination of sub-algorithms so as to find the border of an object in a low-contrast image. The number of parameters in the proposed method is low and the parameters have a low range of variations. We applied our method to 30 datasets including normal and abnormal cases of low-contrast/high-contrast images and it was extensively evaluated both quantitatively and qualitatively. Minimum of Dice similarity measures of the results is 0.89. Assessment of the results proves the potential of the proposed method for segmentation in low-contrast images.

  • Model-Based Approach to Recognize the Rectus Abdominis Muscle in CT Images Open Access

    Naoki KAMIYA  Xiangrong ZHOU  Huayue CHEN  Chisako MURAMATSU  Takeshi HARA  Hiroshi FUJITA  

     
    LETTER-Medical Image Processing

      Vol:
    E96-D No:4
      Page(s):
    869-871

    Our purpose in this study is to develop a scheme to segment the rectus abdominis muscle region in X-ray CT images. We propose a new muscle recognition method based on the shape model. In this method, three steps are included in the segmentation process. The first is to generate a shape model for representing the rectus abdominis muscle. The second is to recognize anatomical feature points corresponding to the origin and insertion of the muscle, and the third is to segment the rectus abdominis muscles using the shape model. We generated the shape model from 20 CT cases and tested the model to recognize the muscle in 10 other CT cases. The average value of the Jaccard similarity coefficient (JSC) between the manually and automatically segmented regions was 0.843. The results suggest the validity of the model-based segmentation for the rectus abdominis muscle.

  • Development of a Robust and Compact On-Line Handwritten Japanese Text Recognizer for Hand-Held Devices

    Jinfeng GAO  Bilan ZHU  Masaki NAKAGAWA  

     
    PAPER-Pattern Recognition

      Vol:
    E96-D No:4
      Page(s):
    927-938

    The paper describes how a robust and compact on-line handwritten Japanese text recognizer was developed by compressing each component of an integrated text recognition system including a SVM classifier to evaluate segmentation points, an on-line and off-line combined character recognizer, a linguistic context processor, and a geometric context evaluation module to deploy it on hand-held devices. Selecting an elastic-matching based on-line recognizer and compressing MQDF2 via a combination of LDA, vector quantization and data type transformation, have contributed to building a remarkably small yet robust recognizer. The compact text recognizer covering 7,097 character classes just requires about 15 MB memory to keep 93.11% accuracy on horizontal text lines extracted from the TUAT Kondate database. Compared with the original full-scale Japanese text recognizer, the memory size is reduced from 64.1 MB to 14.9 MB while the accuracy loss is only 0.5% from 93.6% to 93.11%. The method is scalable so even systems of less than 11 MB or less than 6 MB still remain 92.80% or 90.02% accuracy, respectively.

  • Homomorphic Filtered Spectral Peaks Energy for Automatic Detection of Vowel Onset Point in Continuous Speech

    Xian ZANG  Kil To CHONG  

     
    PAPER-Speech and Hearing

      Vol:
    E96-D No:4
      Page(s):
    949-956

    During the production of speech signals, the vowel onset point is an important event containing important information for many speech processing tasks, such as consonant-vowel unit recognition and speech end-points detection. In order to realize accurate automatic detection of vowel onset points, this paper proposes a reliable method using the energy characteristics of homomorphic filtered spectral peaks. The homomorphic filtering helps to separate the slowly varying vocal tract system characteristics from the rapidly fluctuating excitation characteristics in the cepstral domain. The distinct vocal tract shape related to vowels is obtained and the peaks in the estimated vocal tract spectrum provide accurate and stable information for VOP detection. Performance of the proposed method is compared with the existing method which uses the combination of evidence from the excitation source, spectral peaks, and modulation spectrum energies. The detection rate with different time resolutions, together with the missing rate and spurious rate, are used for comprehensive evaluation of the performance on continuous speech taken from the TIMIT database. The detection accuracy of the proposed method is 74.14% for ±10 ms resolution and it increases to 96.33% for ±40 ms resolution with 3.67% missing error and 4.14% spurious error, much better than the results obtained by the combined approach at each specified time resolution, especially the higher resolutions of ±10±30 ms. In the cases of speech corrupted by white noise, pink noise and f-16 noise, the proposed method also shows significant improvement in the performance compared with the existing method.

  • Joint Motion-Compensated Interpolation Using Eight-Neighbor Block Motion Vectors

    Ran LI  Zong-Liang GAN  Zi-Guan CUI  Xiu-Chang ZHU  

     
    LETTER-Image Processing and Video Processing

      Vol:
    E96-D No:4
      Page(s):
    976-979

    Novel joint motion-compensated interpolation using eight-neighbor block motion vectors (8J-MCI) is presented. The proposed method uses bi-directional motion estimation (BME) to obtain the motion vector field of the interpolated frame and adopts motion vectors of the interpolated block and its 8-neighbor blocks to jointly predict the target block. Since the smoothness of the motion vector filed makes the motion vectors of 8-neighbor blocks quite close to the true motion vector of the interpolated block, the proposed algorithm has the better fault-tolerancy than traditional ones. Experiments show that the proposed algorithm outperforms the motion-aligned auto-regressive algorithm (MAAR, one of the state-of-the-art frame rate up-conversion (FRUC) schemes) in terms of the average PSNR for the test image sequence and offers better subjective visual quality.

  • Parallel Acceleration Scheme for Monte Carlo Based SSTA Using Generalized STA Processing Element

    Hiroshi YUASA  Hiroshi TSUTSUI  Hiroyuki OCHI  Takashi SATO  

     
    PAPER

      Vol:
    E96-C No:4
      Page(s):
    473-481

    We propose a novel acceleration scheme for Monte Carlo based statistical static timing analysis (MC-SSTA). MC-SSTA, which repeatedly executes ordinary STA using a set of randomly generated gate delay samples, is widely accepted as an accuracy reference. A large number of random samples, however, should be processed to obtain accurate delay distributions, and software implementation of MC-SSTA, therefore, takes an impractically long processing time. In our approach, a generalized hardware module, the STA processing element (STA-PE), is used for the delay evaluation of a logic gate, and netlist-specific information is delivered in the form of instructions from an SRAM. Multiple STA-PEs can be implemented for parallel processing, while a larger netlist can be handled if only a larger SRAM area is available. The proposed scheme is successfully implemented on Altera's Arria II GX EP2AGX125EF35C4 device in which 26 STA-PEs and a 624-port Mersenne Twister-based random number generator run in parallel at a 116 MHz clock rate. A speedup of far more than10 is achieved compared to conventional methods including GPU implementation.

  • An Improved Face Clustering Method Using Weighted Graph for Matched SIFT Keypoints in Face Region

    Ji-Soo KEUM  Hyon-Soo LEE  

     
    LETTER-Pattern Recognition

      Vol:
    E96-D No:4
      Page(s):
    967-971

    In this paper, we propose an improved face clustering method using a weighted graph-based approach. We combine two parameters as the weight of a graph to improve clustering performance. One is average similarity, which is calculated with two constraints of geometric and symmetric properties, and the other is a newly proposed parameter called the orientation matching ratio, which is calculated from orientation analysis for matched keypoints in the face region. According to the results of face clustering for several datasets, the proposed method shows improved results compared to the previous method.

  • A Low Power Multimedia Processor Implementing Dynamic Voltage and Frequency Scaling Technique and Fast Motion Estimation Algorithm Called “Adaptively Assigned Breaking-Off Condition (A2BC)”

    Tadayoshi ENOMOTO  Nobuaki KOBAYASHI  

     
    PAPER

      Vol:
    E96-C No:4
      Page(s):
    424-432

    A motion estimation (ME) multimedia processor was developed by employing dynamic voltage and frequency scaling (DVFS) technique to greatly reduce the power dissipation. To make full use of the advantages of DVFS technique, a fast motion estimation (ME) algorithm was also developed. It can adaptively predict the optimum supply voltage and the optimum clock frequency before ME process starts for each macro-block for encoding. Power dissipation of the 90-nm CMOS DVFS controlled multimedia processor, which contained an absolute difference accumulator as well as a small on-chip DC/DC level converter, a minimum value detector and DVFS controller, was reduced to 38.48 µW, which was only 3.261% that of a conventional multimedia processor.

  • Independent-Double-Gate FinFET SRAM Technology Open Access

    Kazuhiko ENDO  Shin-ichi OUCHI  Takashi MATSUKAWA  Yongxun LIU  Meishoku MASAHARA  

     
    INVITED PAPER

      Vol:
    E96-C No:4
      Page(s):
    413-423

    Multi-Gate device technology is the promising candidate for the enhancement of device characteristics of the scaled MOSFETs. Moreover, independent-double-gate devices have been proposed to achieve flexible Vth adjustment. It is revealed that the SRAM noise margins have been increased by introducing the independent-double-gate FinFET.

  • Early Decision of Prediction Direction with Hierarchical Correlation for HEVC Compression

    Chae Eun RHEE  Hyuk-Jae LEE  

     
    LETTER-Image Processing and Video Processing

      Vol:
    E96-D No:4
      Page(s):
    972-975

    The emerging High Efficiency Video Coding (HEVC) standard attempts to improve the coding efficiency by a factor of two over H.264/AVC through the use of new compression tools with high computational complexity. Although multipledirectional prediction is one of the features contributing to the improved compression efficiency, the computational complexity for prediction increases significantly. This paper presents an early uni-directional prediction decision algorithm. The proposed algorithm takes advantage of the property of HEVC that it supports a deep quad-tree block structure. Statistical observation shows that the correlation of prediction direction among different blocks which share same area is very high. Based on this observation, the mode of the current block is determined early according to the mode of upper blocks. Bi-directional prediction is not performed when the upper block is encoded as the uni-directional prediction mode. A simulation shows that it reduces ME operation time by about 22.7% with a marginal drop in compression efficiency.

  • A Scalable Communication-Induced Checkpointing Algorithm for Distributed Systems

    Alberto CALIXTO SIMON  Saul E. POMARES HERNANDEZ  Jose Roberto PEREZ CRUZ  Pilar GOMEZ-GIL  Khalil DRIRA  

     
    PAPER-Fundamentals of Information Systems

      Vol:
    E96-D No:4
      Page(s):
    886-896

    Communication-induced checkpointing (CIC) has two main advantages: first, it allows processes in a distributed computation to take asynchronous checkpoints, and secondly, it avoids the domino effect. To achieve these, CIC algorithms piggyback information on the application messages and take forced local checkpoints when they recognize potentially dangerous patterns. The main disadvantages of CIC algorithms are the amount of overhead per message and the induced storage overhead. In this paper we present a communication-induced checkpointing algorithm called Scalable Fully-Informed (S-FI) that attacks the problem of message overhead. For this, our algorithm modifies the Fully-Informed algorithm by integrating it with the immediate dependency principle. The S-FI algorithm was simulated and the result shows that the algorithm is scalable since the message overhead presents an under-linear growth as the number of processes and/or the message density increase.

  • Fine-Grained Run-Tume Power Gating through Co-optimization of Circuit, Architecture, and System Software Design Open Access

    Hiroshi NAKAMURA  Weihan WANG  Yuya OHTA  Kimiyoshi USAMI  Hideharu AMANO  Masaaki KONDO  Mitaro NAMIKI  

     
    INVITED PAPER

      Vol:
    E96-C No:4
      Page(s):
    404-412

    Power consumption has recently emerged as a first class design constraint in system LSI designs. Specially, leakage power has occupied a large part of the total power consumption. Therefore, reduction of leakage power is indispensable for efficient design of high-performance system LSIs. Since 2006, we have carried out a research project called “Innovative Power Control for Ultra Low-Power and High-Performance System LSIs”, supported by Japan Science and Technology Agency as a CREST research program. One of the major objectives of this project is reducing the leakage power consumption of system LSIs by innovative power control through tight cooperation and co-optimization of circuit technology, architecture, and system software designs. In this project, we focused on power gating as a circuit technique for reducing leakage power. Temporal granularity is one of the most important issue in power gating. Thus, we have developed a series of Geysers as proof-of-concept CPUs which provide several mechanisms of fine-grained run-time power gating. In this paper, we describe their concept and design, and explain why co-optimization of different design layers are important. Then, three kinds of power gating implementations and their evaluation are presented from the view point of power saving and temporal granularity.

11421-11440hit(42807hit)