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[Keyword] SSIM(14hit)

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  • A Multiobjective Optimization Dispatch Method of Wind-Thermal Power System

    Xiaoxuan GUO  Renxi GONG  Haibo BAO  Zhenkun LU  

     
    PAPER-Fundamentals of Information Systems

      Pubricized:
    2020/09/18
      Vol:
    E103-D No:12
      Page(s):
    2549-2558

    It is well known that the large-scale access of wind power to the power system will affect the economic and environmental objectives of power generation scheduling, and also bring new challenges to the traditional deterministic power generation scheduling because of the intermittency and randomness of wind power. In order to deal with these problems, a multiobjective optimization dispatch method of wind-thermal power system is proposed. The method can be described as follows: A multiobjective interval power generation scheduling model of wind-thermal power system is firstly established by describing the wind speed on wind farm as an interval variable, and the minimization of fuel cost and pollution gas emission cost of thermal power unit is chosen as the objective functions. And then, the optimistic and pessimistic Pareto frontiers of the multi-objective interval power generation scheduling are obtained by utilizing an improved normal boundary intersection method with a normal boundary intersection (NBI) combining with a bilevel optimization method to solve the model. Finally, the optimistic and pessimistic compromise solutions is determined by a distance evaluation method. The calculation results of the 16-unit 174-bus system show that by the proposed method, a uniform optimistic and pessimistic Pareto frontier can be obtained, the analysis of the impact of wind speed interval uncertainty on the economic and environmental indicators can be quantified. In addition, it has been verified that the Pareto front in the actual scenario is distributed between the optimistic and pessimistic Pareto front, and the influence of different wind power access levels on the optimistic and pessimistic Pareto fronts is analyzed.

  • A Rate Perceptual-Distortion Optimized Video Coding HEVC

    Bumshik LEE  Jae Young CHOI  

     
    PAPER-Image Processing and Video Processing

      Pubricized:
    2018/08/24
      Vol:
    E101-D No:12
      Page(s):
    3158-3169

    In this paper, a perceptual distortion based rate-distortion optimized video coding scheme for High Efficiency Video Coding (HEVC) is proposed. Structural Similarity Index (SSIM) in transform domain, which is known as distortion metric to better reflect human's perception, is derived for the perceptual distortion model to be applied for hierarchical coding block structure of HEVC. A SSIM-quantization model is proposed using the properties of DCT and high resolution quantization assumption. The SSIM model is obtained as the sum of SSIM in each Coding Unit (CU) depth of HEVC, which precisely predict SSIM values for the hierarchical quadtree structure of CU in HEVC. The rate model is derived from the entropy, based on Laplacian distributions of transform residual coefficients and is jointly combined with the SSIM-based distortion model for rate-distortion optimization in an HEVC video codec and can be compliantly applied to HEVC. The experimental results demonstrate that the proposed method achieves 8.1% and 4.0% average bit rate reductions in rate-SSIM performance for low-delay and random access configurations respectively, outperforming other existing methods. The proposed method provides better visual quality than the conventional mean square error (MSE)-based RDO coding scheme.

  • A Secure M + 1st Price Auction Protocol Based on Bit Slice Circuits

    Takuho MITSUNAGA  Yoshifumi MANABE  Tatsuaki OKAMOTO  

     
    PAPER-Cryptography and Information Security

      Vol:
    E99-A No:8
      Page(s):
    1591-1599

    This paper presents an efficient secure auction protocol for M+1st price auction. In our proposed protocol, a bidding price of a player is represented as a binary expression, while in the previous protocol it is represented as an integer. Thus, when the number of players is m and the bidding price is an integer up to p, compared to the complexity of the previous protocol which is a polynomial of m and p, the complexity of our protocol is a polynomial of m and log p. We apply the Boneh-Goh-Nissim encryption to the mix-and-match protocol to reduce the computation costs.

  • Image Arbitrary-Ratio Down- and Up-Sampling Scheme Exploiting DCT Low Frequency Components and Sparsity in High Frequency Components

    Meng ZHANG  Tinghuan CHEN  Xuchao SHI  Peng CAO  

     
    PAPER-Image Processing and Video Processing

      Pubricized:
    2015/10/30
      Vol:
    E99-D No:2
      Page(s):
    475-487

    The development of image acquisition technology and display technology provide the base for popularization of high-resolution images. On the other hand, the available bandwidth is not always enough to data stream such high-resolution images. Down- and up-sampling, which decreases the data volume of images and increases back to high-resolution images, is a solution for the transmission of high-resolution images. In this paper, motivated by the observation that the high-frequency DCT components are sparse in the spatial domain, we propose a scheme combined with Discrete Cosine Transform (DCT) and Compressed Sensing (CS) to achieve arbitrary-ratio down-sampling. Our proposed scheme makes use of two properties: First, the energy of a image concentrates on the low-frequency DCT components. Second, the high-frequency DCT components are sparse in the spatial domain. The scheme is able to preserve the most information and avoid absolutely blindly estimating the high-frequency components. Experimental results show that the proposed down- and up-sampling scheme produces better performance compared with some state-of-the-art schemes in terms of peak signal to noise ratio (PSNR), structural similarity index measurement (SSIM) and processing time.

  • Perceptually Optimized Missing Texture Reconstruction via Neighboring Embedding

    Takahiro OGAWA  Miki HASEYAMA  

     
    PAPER

      Vol:
    E98-A No:8
      Page(s):
    1709-1717

    Perceptually optimized missing texture reconstruction via neighboring embedding (NE) is presented in this paper. The proposed method adopts the structural similarity (SSIM) index as a measure for representing texture reconstruction performance of missing areas. This provides a solution to the problem of previously reported methods not being able to perform perceptually optimized reconstruction. Furthermore, in the proposed method, a new scheme for selection of the known nearest neighbor patches for reconstruction of target patches including missing areas is introduced. Specifically, by monitoring the SSIM index observed by the proposed NE-based reconstruction algorithm, selection of known patches optimal for the reconstruction becomes feasible even if target patches include missing pixels. The above novel approaches enable successful reconstruction of missing areas. Experimental results show improvement of the proposed method over previously reported methods.

  • Fretting Characteristics of Dissimilar Metal Contacts

    Tetsuya ITO  Takuya YAMANAKA  Yasuhiro HATTORI  

     
    PAPER

      Vol:
    E96-C No:9
      Page(s):
    1104-1109

    The authors previously conducted the observation of microstructures and three-dimensional SEM on fretting wear phenomena at tin-plated contacts. In this study, we report the fretting characteristics of dissimilar metal contacts by studying the relation between the contact resistance behaviors and micro structural changes of gold and tin-plated fretting contacts, through surface SEM observations and cross sectional SEM and AES analysis.

  • Efficient Secure Auction Protocols Based on the Boneh-Goh-Nissim Encryption

    Takuho MITSUNAGA  Yoshifumi MANABE  Tatsuaki OKAMOTO  

     
    PAPER-Public Key Based Protocols

      Vol:
    E96-A No:1
      Page(s):
    68-75

    This paper presents efficient secure auction protocols for first price auction and second price auction. Previous auction protocols are based on a generally secure multi-party protocol called mix-and-match protocol based on plaintext equality tests. However, the time complexity of the plaintext equality tests is large, although the mix-and-match protocol can securely calculate any logical circuits. The proposed protocols reduce the number of times the plaintext equality tests is used by replacing them with the Boneh-Goh-Nissim encryption, which enables calculation of 2-DNF of encrypted data.

  • Improving the Efficiency in Halftone Image Generation Based on Structure Similarity Index Measurement

    Aroba KHAN  Hernan AGUIRRE  Kiyoshi TANAKA  

     
    PAPER-Image Processing and Video Processing

      Vol:
    E95-D No:10
      Page(s):
    2495-2504

    This paper presents two halftoning methods to improve efficiency in generating structurally similar halftone images using Structure Similarity Index Measurement (SSIM). Proposed Method I reduces the pixel evaluation area by applying pixel-swapping algorithm within inter-correlated blocks followed by phase block-shifting. The effect of various initial pixel arrangements is also investigated. Proposed Method II further improves efficiency by applying bit-climbing algorithm within inter-correlated blocks of the image. Simulation results show that proposed Method I improves efficiency as well as image quality by using an appropriate initial pixel arrangement. Proposed Method II reaches a better image quality with fewer evaluations than pixel-swapping algorithm used in Method I and the conventional structure aware halftone methods.

  • Attacker Detection Based on Dissimilarity of Local Reports in Collaborative Spectrum Sensing

    Junnan YAO  Qihui WU  Jinlong WANG  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E95-B No:9
      Page(s):
    3024-3027

    In this letter, we propose a dissimilarity metric (DM) to measure the deviation of a cognitive radio from the network in terms of local sensing reports. Utilizing the probability mass function of the DM, we present a dissimilarity-based attacker detection algorithm to distinguish Byzantine attackers from honest users. The proposed algorithm is able to identify the attackers without a priori information of the attacking styles and is robust against both independent and dependent attacks.

  • A Complete Design of Coexistence Information Service for Autonomous Decision-Making Systems in TV White Space

    Junyi WANG  Stanislav FILIN  Tuncer BAYKAS  Mohammad Azizur RAHMAN  Chunyi SONG  Hiroshi HARADA  

     
    PAPER

      Vol:
    E95-B No:4
      Page(s):
    1230-1240

    In this paper, we present a coexistence protocol design for a coexistence information service to provide coexistence solutions among dissimilar or independently operated autonomous decision-making networks in a wireless communication environment over, specifically but not limited to, TV white space (TVWS) frequency bands. The designed coexistence protocol for the coexistence information service has three main functionalities: (1) To collect basic information of subscribed TVWS networks; (2) To support generating neighbor lists for the TVWS networks based on the geography information and/or propagation parameters; (3) To provide necessary information for TVWS networks to make coexistence decisions. Both theoretical analysis and simulation results show that the designed coexistence information service ensures harmonious communications among dissimilar networks and is able to achieve coexistence over an area with the limited number of available channels in white space.

  • A Deterministic Approximation Algorithm for Maximum 2-Path Packing

    Ruka TANAHASHI  Zhi-Zhong CHEN  

     
    PAPER

      Vol:
    E93-D No:2
      Page(s):
    241-249

    This paper deals with the maximum-weight 2-path packing problem (M2PP), which is the problem of computing a set of vertex-disjoint paths of length 2 in a given edge-weighted complete graph so that the total weight of edges in the paths is maximized. Previously, Hassin and Rubinstein gave a randomized cubic-time approximation algorithm for M2PP which achieves an expected ratio of - ε ≈ 0.5223 - ε for any constant ε > 0. We refine their algorithm and derandomize it to obtain a deterministic cubic-time approximation algorithm for the problem which achieves a better ratio (namely, 0.5265 - ε for any constant ε>0).

  • Quality and Power Efficient Architecture for the Discrete Cosine Transform

    Chi-Chia SUNG  Shanq-Jang RUAN  Bo-Yao LIN  Mon-Chau SHIE  

     
    PAPER-VLSI Architecture

      Vol:
    E88-A No:12
      Page(s):
    3500-3507

    In recent years, the demand for multimedia mobile battery-operated devices has created a need for low power implementation of video compression. Many compression standards require the discrete cosine transform (DCT) function to perform image/video compression. For this reason, low power DCT design has become more and more important in today's image/video processing. This paper presents a new power-efficient Hybrid DCT architecture which combines Loeffler DCT and binDCT in terms of special property on luminance and chrominance difference. We use Synopsys PrimePower to estimate the power consumption in a TSMC 0.25-µm technology. Besides, we also adopt a novel quality assessment method based on structural distortion measurement to measure the quality instead of peak signal to noise rations (PSNR) and mean squared error (MSE). It is concluded that our Hybrid DCT offers similar quality performance to the Loeffler, and leads to 25% power consumption and 27% chip area savings.

  • Effect of Imperfect Channel Estimation on the Performance of Pilot Channel-Aided Coherent DS-CDMA System over Rayleigh-Fading Multipath Channel

    Seokjun KO  Hyungjin CHOI  

     
    PAPER-Mobile Communication

      Vol:
    E83-B No:3
      Page(s):
    721-733

    This paper presents the bit-error rate (BER) performance of the RAKE receiver over a multipath Rayleigh fading channel. The closed-form BER in the downlink single-cell environment is obtained through the analysis of the imperfect channel estimation. We compute the BER as a function of energy-to-noise ratio per bit including the effect of multiple access interference and multipath interference, with channel and system parameters: number of diversity channels L = 1, 3, 6, 12; Doppler frequency shift with fD T = 0.008333, 0.0167, 0.025; residual carrier frequency offset Δ f = -600 600 Hz; averaging length of the channel estimator Np = 128-1536 chips. This analysis allows predicting the system's performance and helps to optimize the parameter setting for the channel estimation process. We show that even if the optimal system parameters are used, the BER performance results in a minimal 4dB degradation in comparison to the perfect channel estimation. Finally, the theoretical results are verified by using the Monte-Carlo computer simulations.

  • Color Assimilation of Strip Fields Displayed on CRT with a Dark Background

    Takashi NAKAGAWA  Yukitaka GOHARA  

     
    LETTER

      Vol:
    E78-A No:11
      Page(s):
    1559-1561

    We investigated perceptual color assimilation of a strip (test field) displayed on a CRT close to a green or red strip (inducing field) with a dark background. The maximal distance to induce assimilation was about 7 for a red inducing field, and 24 for a blue one. The intensity of assimilation was almost inversely proportional to the width of test field.