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[Author] Tong LIU(7hit)

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  • Highly Integrated DBC-Based IPM with Ultra-Compact Size for Low Power Motor Drive Applications

    Huanyu WANG  Lina HUANG  Yutong LIU  Zhenyuan XU  Lu ZHANG  Tuming ZHANG  Yuxiang FENG  Qing HUA  

     
    BRIEF PAPER-Electronic Circuits

      Pubricized:
    2023/02/20
      Vol:
    E106-C No:8
      Page(s):
    442-445

    This paper proposes the new series highly integrated intelligent power module (IPM), which is developed to provide a ultra-compact, high performance and reliable motor drive system. Details of the key design technologies of the IPM is given and practical application issues such as electrical characteristics, system operation performance and power dissipation are discussed. Layout placement and routing have been optimized in order to reduce and balance the parasitic impedances. By implementing an innovative direct bonding copper (DBC) ceramic substrate, which can effectively dissipate heat, the IPM delivers a fully integrated power stages including two three-phase inverters, power factor correction (PFC) and rectifier in an ultra-compact 75.5mm × 30mm package, offering up to a 17.3 percent smaller space than traditional motor drive scheme.

  • A Structured Walking-1 Approach for the Diagnosis of Interconnects and FPICs*

    Tong LIU  Fabrizio LOMBARDI  Susumu HORIGUCHI  Jung Hwan KIM  

     
    PAPER-Fault Tolerant Computing

      Vol:
    E79-D No:1
      Page(s):
    29-40

    This paper presents a generalized new approach for testing interconnects (for boundary scan architectures) as well as field programmable interconnect chips (FPICs). This approach relies on a structured walking-1 test set in the sense that a structural analysis based on the layout of the interconnect system, is carried out. The proposed structural test method differs from previous approaches as it explicitly avoids aliasing and confounding and is applicable to dense as well as sparse layouts and in the presence of faults in the programmable devices of a FPIC. The proposed method is applicable to both one-step and two-step test generation and diagnosis. Two algorithms with an execution complexity of O(n2), where n is the number of nets in the interconnect, are given. New criteria for test vector compaction are proposed; a greedy condition is exploited to compact test vectors for one-step and two-step diagnosis. For a given interconnect, the two-step diagnosis algorithm requires a number of tests as a function of the number of faults present, while the one-step algorithm requires a fixed number of tests. Simulation results for benchmark and randomly generated layouts show a substantial reduction in the number of tests using the proposed approaches compared with previous approaches. The applicability of the proposed approach to FPICs as manufactured by [1] is discussed and evaluated by simulation.

  • Exploring Hypotactic Structure for Chinese-English Machine Translation with a Structure-Aware Encoder-Decoder Neural Model

    Guoyi MIAO  Yufeng CHEN  Mingtong LIU  Jinan XU  Yujie ZHANG  Wenhe FENG  

     
    PAPER-Natural Language Processing

      Pubricized:
    2022/01/11
      Vol:
    E105-D No:4
      Page(s):
    797-806

    Translation of long and complex sentence has always been a challenge for machine translation. In recent years, neural machine translation (NMT) has achieved substantial progress in modeling the semantic connection between words in a sentence, but it is still insufficient in capturing discourse structure information between clauses within complex sentences, which often leads to poor discourse coherence when translating long and complex sentences. On the other hand, the hypotactic structure, a main component of the discourse structure, plays an important role in the coherence of discourse translation, but it is not specifically studied. To tackle this problem, we propose a novel Chinese-English NMT approach that incorporates the hypotactic structure knowledge of complex sentences. Specifically, we first annotate and build a hypotactic structure aligned parallel corpus to provide explicit hypotactic structure knowledge of complex sentences for NMT. Then we propose three hypotactic structure-aware NMT models with three different fusion strategies, including source-side fusion, target-side fusion, and both-side fusion, to integrate the annotated structure knowledge into NMT. Experimental results on WMT17, WMT18 and WMT19 Chinese-English translation tasks demonstrate that the proposed method can significantly improve the translation performance and enhance the discourse coherence of machine translation.

  • A Novel Structure of HTTP Adaptive Streaming Based on Unequal Error Protection Rateless Code

    Yun SHEN  Yitong LIU  Jing LIU  Hongwen YANG  Dacheng YANG  

     
    PAPER-Image Processing and Video Processing

      Vol:
    E97-D No:11
      Page(s):
    2903-2911

    In this paper, we design an Unequal Error Protection (UEP) rateless code with special coding graph and apply it to propose a novel HTTP adaptive streaming based on UEP rateless code (HASUR). Our designed UEP rateless code provides high diversity on decoding probability and priority for data in different important level with overhead smaller than 0.27. By adopting this UEP rateless channel coding and scalable video source coding, our HASUR ensures symbols with basic quality to be decoded first to guarantee fluent playback experience. Besides, it also provides multiple layers to ensure the most suitable quality for fluctuant bandwidth and packet loss rate (PLR) without estimating them in advance. We evaluate our HASUR against the alternative solutions. Simulation results show that HASUR provides higher video quality and more adapts to bandwidth and PLR than other two commercial schemes under End-to-End transmission.

  • Quality of Experience Study on Dynamic Adaptive Streaming Based on HTTP

    Yun SHEN  Yitong LIU  Hongwen YANG  Dacheng YANG  

     
    PAPER

      Vol:
    E98-B No:1
      Page(s):
    62-70

    In this paper, the Quality of Experience (QoE) on Dynamic Adaptive Streaming based on HTTP (DASH) is researched. To study users' experience on DASH, extensive subjective tests are firstly designed and conducted, based on which, we research QoE enhancement in DASH and find that DASH ensures more fluent playback (less stall) than constant bitrate (CBR) streaming to promote users' satisfaction especially in mobile networks. Then we adopt two-way analysis of variance (ANOVA) tests in statistics to identify the effect of specific factors (segment bitrate, bitrate fluctuation pattern, and bitrate switching) that impair users' experience on DASH. The impairment functions are then derived for these influence factors based on the Primacy and Recency Effect, a psychological phenomenon that has been proved to exist in users' experience on DASH in this paper. And the final QoE evaluation model is proposed to provide high correlation assessment for QoE of DASH. The good performance of our QoE model is validated by the subjective tests. In addition, our QoE study on DASH is also applied for QoE management to propose a QoE-based bitrate adaptation strategy, which promotes users' experience on DASH more strongly than the strategy based on QoS.

  • Fast CU Termination Algorithm with AdaBoost Classifier in HEVC Encoder

    Yitong LIU  Wang TIAN  Yuchen LI  Hongwen YANG  

     
    LETTER

      Pubricized:
    2018/06/20
      Vol:
    E101-D No:9
      Page(s):
    2220-2223

    High Efficiency Video Coding (HEVC) has a better coding efficiency comparing with H.264/AVC. However, performance enhancement results in increased computational complexity which is mainly brought by the quadtree based coding tree unit (CTU). In this paper, an early termination algorithm based on AdaBoost classifier for coding unit (CU) is proposed to accelerate the process of searching the best partition for CTU. Experiment results indicate that our method can save 39% computational complexity on average at the cost of increasing Bjontegaard-Delta rate (BD-rate) by 0.18.

  • Formal Method for Security Analysis of Electronic Payment Protocols

    Yi LIU  Qingkun MENG  Xingtong LIU  Jian WANG  Lei ZHANG  Chaojing TANG  

     
    PAPER-Information Network

      Pubricized:
    2018/06/19
      Vol:
    E101-D No:9
      Page(s):
    2291-2297

    Electronic payment protocols provide secure service for electronic commerce transactions and protect private information from malicious entities in a network. Formal methods have been introduced to verify the security of electronic payment protocols; however, these methods concentrate on the accountability and fairness of the protocols, without considering the impact caused by timeliness. To make up for this deficiency, we present a formal method to analyze the security properties of electronic payment protocols, namely, accountability, fairness and timeliness. We add a concise time expression to an existing logical reasoning method to represent the event time and extend the time characteristics of the logical inference rules. Then, the Netbill protocol is analyzed with our formal method, and we find that the fairness of the protocol is not satisfied due to the timeliness problem. The results illustrate that our formal method can analyze the key properties of electronic payment protocols. Furthermore, it can be used to verify the time properties of other security protocols.