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[Keyword] evolution(162hit)

81-100hit(162hit)

  • Page History Explorer: Visualizing and Comparing Page Histories

    Adam JATOWT  Yukiko KAWAI  Katsumi TANAKA  

     
    PAPER

      Vol:
    E94-D No:3
      Page(s):
    564-577

    Due to the increased preservation efforts, large amounts of past Web data have been stored in Web archives and other archival repositories. Utilizing this data can offer certain benefits to users, for example, it can facilitate page understanding. In this paper, we propose a system for interactive exploration of page histories. We demonstrate an application called Page History Explorer (PHE) for summarizing and visualizing histories of Web pages. PHE portrays the overview of page evolution, characterizes its typical content over time and lets users observe page histories from different viewpoints. In addition, it enables flexible comparison of histories of different pages.

  • Interactive Support System for Image Quality Enhancement Focused on Lightness, Color and Sharpness

    Kazune AOIKE  Gosuke OHASHI  Yuichiro TOKUDA  Yoshifumi SHIMODAIRA  

     
    PAPER-Evaluation

      Vol:
    E94-A No:2
      Page(s):
    500-508

    An interactive support system for image quality enhancement to adjust display equipments according to the user's own subjectivity is developed. Interactive support system for image quality enhancement enable the parameters based on user's preference to be derived by only selecting user's preference images without adjusting image quality parameters directly. In the interactive support system for image quality enhancement, the more the number of parameters is, the more effective this system is. In this paper, lightness, color and sharpness are used as the image quality parameters and the images are enhanced by increasing the number of parameters. Shape of tone curve is controlled by two image quality adjustment parameters for lightness enhancement. Images are enhanced using two image quality adjustment parameters for color enhancement. The two parameters are controlled in L* a* b* color space. Degree and coarseness of image sharpness enhancement are adjusted by controlling a radius of mask of smoothing filter and weight of adding. To confirm the effectiveness of the proposed method, the image quality and derivation time of the proposed method are compared with a manual adjustment method.

  • Impulsive Noise Removal in Color Image Using Interactive Evolutionary Computing

    Yohei KATSUYAMA  Kaoru ARAKAWA  

     
    PAPER

      Vol:
    E93-A No:11
      Page(s):
    2184-2192

    A new type of digital filter for removing impulsive noise in color images is proposed using interactive evolutionary computing. This filter is realized as a rule-based system containing switching median filters. This filter detects impulsive noise in color images with rules and applies switching median filters only at the noisy pixel. Interactive evolutionary computing (IEC) is adopted to optimize the filter parameters, considering the subjective assessment by human vision. In order to detect impulsive noise precisely, complicated rules with multiple parameters are required. Here, the relationship between color components and the degree of peculiarity of the pixel value are utilized in the rules. Usually, optimization of such a complicated rule-based system is difficult, but IEC enables such optimization easily. Moreover, human taste and subjective sense are highly considered in the filter performance. Computer simulations are shown for noisy images to verify its high performance.

  • Improving Proximity and Diversity in Multiobjective Evolutionary Algorithms

    Chang Wook AHN  Yehoon KIM  

     
    LETTER-Biocybernetics, Neurocomputing

      Vol:
    E93-D No:10
      Page(s):
    2879-2882

    This paper presents an approach for improving proximity and diversity in multiobjective evolutionary algorithms (MOEAs). The idea is to discover new nondominated solutions in the promising area of search space. It can be achieved by applying mutation only to the most converged and the least crowded individuals. In other words, the proximity and diversity can be improved because new nondominated solutions are found in the vicinity of the individuals highly converged and less crowded. Empirical results on multiobjective knapsack problems (MKPs) demonstrate that the proposed approach discovers a set of nondominated solutions much closer to the global Pareto front while maintaining a better distribution of the solutions.

  • Approach to the Unit Maintenance Scheduling Decision Using Risk Assessment and Evolution Programming Techniques

    Chen-Sung CHANG  

     
    PAPER-Artificial Intelligence, Data Mining

      Vol:
    E93-D No:7
      Page(s):
    1900-1908

    This paper applies the Evolutionary Programming (EP) algorithm and a risk assessment technique to obtain an optimal solution to the Unit Maintenance Scheduling Decision (UMSD) problem subject to economic cost and power security constraints. The proposed approach employs a risk assessment model to evaluate the security of the power supply system and uses the EP algorithm to establish the optimal unit maintenance schedule. The effectiveness of the proposed methodology is verified through testing using the IEEE Reliability Test System (RTS). The test results confirm that the proposed approach can to ensure that the system security and outperforms the existing deterministic and stochastic optimization methods both in terms of the quality of the solution and the computational effort required. Therefore, the proposed methodology represents a particular effective technique for the UMSD.

  • Evolution Analysis of Parallel Concatenated Coded IDMA Systems

    Hao WANG  Shi CHEN  Xiaokang LIN  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E93-B No:6
      Page(s):
    1620-1623

    The bit-error-rate (BER) performance predicted by the semi-analytical evolution technique proposed by Li Ping et al. becomes inaccurate for parallel concatenated coded interleave-division multiple-access (PCC-IDMA) systems. To solve this problem, we develop a novel evolution technique of such systems. Numerical results show that the predicted performance agrees well with the simulation results, and that this technique is useful for system optimization.

  • Evolutionary Game Theoretic Approach to Self-Organized Data Aggregation in Delay Tolerant Networks

    K. Habibul KABIR  Masahiro SASABE  Tetsuya TAKINE  

     
    PAPER

      Vol:
    E93-B No:3
      Page(s):
    490-500

    Custody transfer in delay tolerant networks (DTNs) provides reliable end-to-end data delivery by delegating the responsibility of data transfer among special nodes (custodians) in a hop-by-hop manner. However, storage congestion occurs when data increases and/or the network is partitioned into multiple sub-networks for a long time. The storage congestion can be alleviated by message ferries which move around the network and proactively collect data from the custodians. In such a scenario, data should be aggregated to some custodians so that message ferries can collect them effectively. In this paper, we propose a scheme to aggregate data into selected custodians, called aggregators, in a fully distributed and autonomous manner with the help of evolutionary game theoretic approach. Through theoretical analysis and several simulation experiments, taking account of the uncooperative behavior of nodes, we show that aggregators can be selected in a self-organized manner and the number of aggregators can be controlled to a desired value.

  • Evolutionary P2P Networking That Fuses Evolutionary Computation and P2P Networking Together

    Kei OHNISHI  Yuji OIE  

     
    PAPER-Network

      Vol:
    E93-B No:2
      Page(s):
    317-327

    In the present paper, we propose an evolutionary P2P networking technique that dynamically and adaptively optimizes several P2P network topologies, in which all of the nodes are included at the same time, in an evolutionary manner according to given evaluation criteria. In addition, through simulations, we examine whether the proposed evolutionary P2P networking technique can provide reliable search capability in dynamic P2P environments. In simulations, we assume dynamic P2P environments in which each node leaves and joins the network with its own probability and in which search objects vary with time. The simulation results show that topology reconstruction by the evolutionary P2P networking technique is better than random topology reconstruction when only a few types of search objects are present in the network at any moment and these search objects are not replicated. Moreover, for the scenario in which the evolutionary P2P networking technique is more effective, we show through simulations that when each node makes several links with other nodes in a single network topology, the evolutionary P2P networking technique improves the reliable search capability. Finally, the number of links that yields more reliable search capability appears to depend on how often nodes leave and join the network.

  • Circuit Design Optimization Using Genetic Algorithm with Parameterized Uniform Crossover

    Zhiguo BAO  Takahiro WATANABE  

     
    PAPER-Nonlinear Problems

      Vol:
    E93-A No:1
      Page(s):
    281-290

    Evolvable hardware (EHW) is a new research field about the use of Evolutionary Algorithms (EAs) to construct electronic systems. EHW refers in a narrow sense to use evolutionary mechanisms as the algorithmic drivers for system design, while in a general sense to the capability of the hardware system to develop and to improve itself. Genetic Algorithm (GA) is one of typical EAs. We propose optimal circuit design by using GA with parameterized uniform crossover (GApuc) and with fitness function composed of circuit complexity, power, and signal delay. Parameterized uniform crossover is much more likely to distribute its disruptive trials in an unbiased manner over larger portions of the space, then it has more exploratory power than one and two-point crossover, so we have more chances of finding better solutions. Its effectiveness is shown by experiments. From the results, we can see that the best elite fitness, the average value of fitness of the correct circuits and the number of the correct circuits of GApuc are better than that of GA with one-point crossover or two-point crossover. The best case of optimal circuits generated by GApuc is 10.18% and 6.08% better in evaluating value than that by GA with one-point crossover and two-point crossover, respectively.

  • Modular Conformance Testing and Assume-Guarantee Verification for Evolving Component-Based Software

    Ngoc Hung PHAM  Toshiaki AOKI  Takuya KATAYAMA  

     
    PAPER

      Vol:
    E92-A No:11
      Page(s):
    2772-2780

    This paper proposes a framework for modular verification of evolving component-based software. This framework includes two stages: modular conformance testing for updating inaccurate models of the evolved components and modular verification for evolving component-based software. When a component is evolved after adapting some refinements, the proposed framework focuses on this component and its model in order to update the model and recheck the whole evolved system. The framework also reuses the previous verification results and the previous models of the evolved components to reduce the number of steps required in the model update and modular verification processes. An implementation and some experimental results are presented.

  • An Inter-Cell Interference Mitigation Method for OFDM-Based Cellular Systems Using Independent Component Analysis

    Hui ZHANG  Xiaodong XU  Xiaofeng TAO  Ping ZHANG  Ping WU  

     
    PAPER

      Vol:
    E92-B No:10
      Page(s):
    3034-3042

    Orthogonal frequency division multiplexing (OFDM) is a critical technology in 3G evolution systems, which can effectively avoid intra-cell interference, but may bring with serious inter-cell interference. Inter-cell interference cancellation is one of effective schemes taken in mitigating inter-cell interference, but for many existing schemes in inter-cell interference cancellation, various generalized spatial diversities are taken, which always bring with extra interference and blind spots, or even need to acquire extra information on source and channel. In this paper, a novel inter-cell interference mitigation method is proposed for 3G evolution systems. This method is based on independent component analysis in blind source separation, and the input signal to interference plus noise ratio (SINR) is set as objective function. By generalized eigenvalue decomposition and algorithm iterations, maximum signal noise ratio (SNR) can be obtained in output. On the other hand, this method can be worked with no precise knowledge of source signal and channel information. Performance evaluation shows that such method can mitigate inter-cell interference in a semi-blind state, and effectively improve output SNR with the condition that lower input SINR, higher input SNR and longer lengths of the processing frame.

  • Convergence Speed Analysis of Layered Decoding of Block-Type LDPC Codes

    Min-Ho JANG  Beomkyu SHIN  Woo-Myoung PARK  Jong-Seon NO  Dong-Joon SHIN  

     
    LETTER-Fundamental Theories for Communications

      Vol:
    E92-B No:7
      Page(s):
    2484-2487

    In this letter, we analyze the convergence speed of layered decoding of block-type low-density parity-check codes and verify that the layered decoding gives faster convergence speed than the sequential decoding with randomly selected check node subsets. Also, it is shown that using more subsets than the maximum variable node degree does not improve the convergence speed.

  • 3G Radio Access Evolution -- HSPA and LTE for Mobile Broadband -- Open Access

    Erik DAHLMAN  Ylva JADING  Stefan PARKVALL  Hideshi MURAI  

     
    INVITED PAPER

      Vol:
    E92-B No:5
      Page(s):
    1432-1440

    This paper provides an overview of the 3GPP radio-access technologies for mobile broadband -- HSPA and its evolution, and LTE. The paper also discusses the current stage of the 3GPP activities on evolving LTE towards LTE-Advanced and full IMT-Advanced compliance.

  • An XML Transformation Algorithm Inferred from an Update Script between DTDs

    Nobutaka SUZUKI  Yuji FUKUSHIMA  

     
    PAPER-Database

      Vol:
    E92-D No:4
      Page(s):
    594-607

    Finding an appropriate data transformation between two schemas has been an important problem. In this paper, assuming that an update script between original and updated DTDs is available, we consider inferring a transformation algorithm from the original DTD and the update script such that the algorithm transforms each document valid against the original DTD into a document valid against the updated DTD. We first show a transformation algorithm inferred from a DTD and an update script. We next show a sufficient condition under which the transformation algorithm inferred from a DTD d and an update script is unambiguous, i.e., for any document t valid against d, elements to be deleted/inserted can unambiguously be determined. Finally, we show a polynomial-time algorithm for testing the sufficient condition.

  • Detailed Evolution of Degree Distributions in Residual Graphs with Joint Degree Distributions

    Takayuki NOZAKI  Kenta KASAI  Tomoharu SHIBUYA  Kohichi SAKANIWA  

     
    PAPER-Coding Theory

      Vol:
    E91-A No:10
      Page(s):
    2737-2744

    Luby et al. derived evolution of degree distributions in residual graphs for irregular LDPC code ensembles. Evolution of degree distributions in residual graphs is important characteristic which is used for finite-length analysis of the expected block and bit error probability over the binary erasure channel. In this paper, we derive detailed evolution of degree distributions in residual graphs for irregular LDPC code ensembles with joint degree distributions.

  • Density Evolution Analysis of Robustness for LDPC Codes over the Gilbert-Elliott Channel

    Manabu KOBAYASHI  Hideki YAGI  Toshiyasu MATSUSHIMA  Shigeichi HIRASAWA  

     
    PAPER-Coding Theory

      Vol:
    E91-A No:10
      Page(s):
    2754-2764

    In this paper, we analyze the robustness for low-density parity-check (LDPC) codes over the Gilbert-Elliott (GE) channel. For this purpose we propose a density evolution method for the case where LDPC decoder uses the mismatched parameters for the GE channel. Using this method, we derive the region of tuples of true parameters and mismatched decoding parameters for the GE channel, where the decoding error probability approaches asymptotically to zero.

  • Automatic Cell Segmentation Using a Shape-Classification Model in Immunohistochemically Stained Cytological Images

    Shishir SHAH  

     
    PAPER

      Vol:
    E91-D No:7
      Page(s):
    1955-1962

    This paper presents a segmentation method for detecting cells in immunohistochemically stained cytological images. A two-phase approach to segmentation is used where an unsupervised clustering approach coupled with cluster merging based on a fitness function is used as the first phase to obtain a first approximation of the cell locations. A joint segmentation-classification approach incorporating ellipse as a shape model is used as the second phase to detect the final cell contour. The segmentation model estimates a multivariate density function of low-level image features from training samples and uses it as a measure of how likely each image pixel is to be a cell. This estimate is constrained by the zero level set, which is obtained as a solution to an implicit representation of an ellipse. Results of segmentation are presented and compared to ground truth measurements.

  • A Low Distortion and Low Noise Differential Amplifier Suitable for 3G LTE Applications Using the Even- and Odd-Mode Impedance Differences of a Bias Circuit

    Toshifumi NAKATANI  Koichi OGAWA  

     
    PAPER

      Vol:
    E91-C No:6
      Page(s):
    844-853

    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.

  • A Real-Time Decision Support System for Voltage Collapse Avoidance in Power Supply Networks

    Chen-Sung CHANG  

     
    PAPER-Artificial Intelligence and Cognitive Science

      Vol:
    E91-D No:6
      Page(s):
    1740-1747

    This paper presents a real-time decision support system (RDSS) based on artificial intelligence (AI) for voltage collapse avoidance (VCA) in power supply networks. The RDSS scheme employs a fuzzy hyperrectangular composite neural network (FHRCNN) to carry out voltage risk identification (VRI). In the event that a threat to the security of the power supply network is detected, an evolutionary programming (EP)-based algorithm is triggered to determine the operational settings required to restore the power supply network to a secure condition. The effectiveness of the RDSS methodology is demonstrated through its application to the American Electric Power Provider System (AEP, 30-bus system) under various heavy load conditions and contingency scenarios. In general, the numerical results confirm the ability of the RDSS scheme to minimize the risk of voltage collapse in power supply networks. In other words, RDSS provides Power Provider Enterprises (PPEs) with a viable tool for performing on-line voltage risk assessment and power system security enhancement functions.

  • δ-Similar Elimination to Enhance Search Performance of Multiobjective Evolutionary Algorithms

    Hernan AGUIRRE  Masahiko SATO  Kiyoshi TANAKA  

     
    LETTER-Artificial Intelligence and Cognitive Science

      Vol:
    E91-D No:4
      Page(s):
    1206-1210

    In this paper, we propose δ-similar elimination to improve the search performance of multiobjective evolutionary algorithms in combinatorial optimization problems. This method eliminates similar individuals in objective space to fairly distribute selection among the different regions of the instantaneous Pareto front. We investigate four eliminating methods analyzing their effects using NSGA-II. In addition, we compare the search performance of NSGA-II enhanced by our method and NSGA-II enhanced by controlled elitism.

81-100hit(162hit)