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[Author] Wei WU(25hit)

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  • Fabrication of an X-Band Dual Mode Bandpass Filter Using Low Cost FR4 Substrate

    Min-Hung WENG  Cheng-Yuan HUNG  Hung-Wei WU  

     
    LETTER-Microwaves, Millimeter-Waves

      Vol:
    E88-C No:1
      Page(s):
    143-145

    The investigation presents a low cost and low insertion loss X-band dual mode bandpass filter (BPF) based on inexpensive commercial FR4 substrate. The proposed filter at a central frequency f0 of 11.3 GHz has high filter performance filter with a fractional bandwidth of 14%, the insertion loss of -2.7 dB, and two transmission zeros. The designed procedures are presented in this letter and the fabricated filter verifies the proposed designed concept.

  • An Optimal Satellite Selection Schema in Feeder Link Mapping for High-Capacity Scenario

    Rui CHEN  Wen-nai WANG  Wei WU  

     
    PAPER-Satellite Communications

      Pubricized:
    2023/07/24
      Vol:
    E106-B No:11
      Page(s):
    1237-1243

    Non-Terrestrial-Network (NTN) can provide seamless and ubiquitous connectivity of massive devices. Thus, the feeder links between satellites and gateways need to provide essentially high data transmission rates. In this paper, we focus on a typical high-capacity scenario, i.e., LEO-IoT, to find an optimal satellite selection schema to maximize the capacity of feeder links. The proposed schema is able to obtain the optimal mapping among all the satellites and gateways. By comparing with maximum service time algorithm, the proposed schema can construct a more balanced and reasonable connection pattern to improve the efficiency of the gateways. Such an advantage will become more significant as the number of satellites increases.

  • Image Quality Assessment by Quantifying Discrepancies of Multifractal Spectrums

    Hang ZHANG  Yong DING  Peng Wei WU  Xue Tong BAI  Kai HUANG  

     
    PAPER-Image Processing and Video Processing

      Vol:
    E97-D No:9
      Page(s):
    2453-2460

    Visual quality evaluation is crucially important for various video and image processing systems. Traditionally, subjective image quality assessment (IQA) given by the judgments of people can be perfectly consistent with human visual system (HVS). However, subjective IQA metrics are cumbersome and easily affected by experimental environment. These problems further limits its applications of evaluating massive pictures. Therefore, objective IQA metrics are desired which can be incorporated into machines and automatically evaluate image quality. Effective objective IQA methods should predict accurate quality in accord with the subjective evaluation. Motivated by observations that HVS is highly adapted to extract irregularity information of textures in a scene, we introduce multifractal formalism into an image quality assessment scheme in this paper. Based on multifractal analysis, statistical complexity features of nature images are extracted robustly. Then a novel framework for image quality assessment is further proposed by quantifying the discrepancies between multifractal spectrums of images. A total of 982 images are used to validate the proposed algorithm, including five type of distortions: JPEG2000 compression, JPEG compression, white noise, Gaussian blur, and Fast Fading. Experimental results demonstrate that the proposed metric is highly effective for evaluating perceived image quality and it outperforms many state-of-the-art methods.

  • Decoding the (23, 12, 7) Golay Code Using a Low-Complexity Scheme

    Ching-Lung CHR  Szu-Lin SU  Shao-Wei WU  

     
    LETTER-Coding Theory

      Vol:
    E89-A No:8
      Page(s):
    2235-2238

    Similar to algebraic decoding schemes, the (23, 12, 7) Golay code can be decoded by applying the step-by-step decoding algorithm. In this work, a modified step-by-step algorithm for decoding the Golay code is presented. Logical analysis yielded a simple rule for directly determining whether a bit in the received word is correct. The computational complexity can be reduced significantly using this scheme.

  • A Clustering K-Anonymity Scheme for Location Privacy Preservation

    Lin YAO  Guowei WU  Jia WANG  Feng XIA  Chi LIN  Guojun WANG  

     
    PAPER-Privacy

      Vol:
    E95-D No:1
      Page(s):
    134-142

    The continuous advances in sensing and positioning technologies have resulted in a dramatic increase in popularity of Location-Based Services (LBS). Nevertheless, the LBS can lead to user privacy breach due to sharing location information with potentially malicious services. A high degree of location privacy preservation for LBS is extremely required. In this paper, a clustering K-anonymity scheme for location privacy preservation (namely CK) is proposed. The CK scheme does not rely on a trusted third party to anonymize the location information of users. In CK scheme, the whole area that all the users reside is divided into clusters recursively in order to get cloaked area. The exact location information of the user is replaced by the cloaked spatial temporal boundary (STB) including K users. The user can adjust the resolution of location information with spatial or temporal constraints to meet his personalized privacy requirement. The experimental results show that CK can provide stringent privacy guarantees, strong robustness and high QoS (Quality of Service).

21-25hit(25hit)