Tsinghua Science and Technology


  • Developments and Applications of Tunneling Magnetoresistance Sensors

    Shaohua Yan;Zitong Zhou;Yaodi Yang;Qunwen Leng;Weisheng Zhao;

    Magnetic sensors based on tunneling magnetoresistance(TMR) effect exhibit high sensitivity, small size,and low power consumption. They have gained a lot of attention and have potential applications in various domains.This study first introduces the development history and basic principles of TMR sensors. Then, a comprehensive description of TMR sensors linearization and Wheatstone bridge configuration is presented. Two key performance parameters, the field sensitivity and noise mechanisms, are considered. Finally, the emerging applications of TMR sensors are discussed.

    2022年03期 v.27 443-454页 [查看摘要][在线阅读][下载 5259K]
    [下载次数:94 ] |[网刊下载次数:0 ] |[引用频次:1 ] |[阅读次数:1 ]
  • Memristor-Based Signal Processing for Edge Computing

    Han Zhao;Zhengwu Liu;Jianshi Tang;Bin Gao;Yufeng Zhang;He Qian;Huaqiang Wu;

    The rapid growth of the Internet of Things(IoTs) has resulted in an explosive increase in data, and thus has raised new challenges for data processing units. Edge computing, which settles signal processing and computing tasks at the edge of networks rather than uploading data to the cloud, can reduce the amount of data for transmission and is a promising solution to address the challenges. One of the potential candidates for edge computing is a memristor, an emerging nonvolatile memory device that has the capability of in-memory computing. In this article,from the perspective of edge computing, we review recent progress on memristor-based signal processing methods,especially on the aspects of signal preprocessing and feature extraction. Then, we describe memristor-based signal classification and regression, and end-to-end signal processing. In all these applications, memristors serve as critical accelerators to greatly improve the overall system performance, such as power efficiency and processing speed.Finally, we discuss existing challenges and future outlooks for memristor-based signal processing systems.

    2022年03期 v.27 455-471页 [查看摘要][在线阅读][下载 16895K]
    [下载次数:72 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:1 ]
  • A Survey of Voltage-Controlled-Oscillator-Based ?∑ ADCs

    Yi Zhong;Nan Sun;

    The benefits of technology scaling have fueled interest in realizing time-domain oversampling(?∑) of Analog-to-Digital Converters(ADCs). Voltage-Controlled Oscillators(VCO) are increasingly used to design ?∑ADCs because of their simplicity, high digitization, and low-voltage tolerance, making them a promising candidate to replace the classical Operational Transconductance Amplifier(OTA) in ?∑ ADC design. This work aims to provide a summary of the fully VCO-based ?∑ ADCs that are highly digital and scaling-friendly. This work presents a review of first-order and high-order VCO-based ?∑ ADCs with several techniques and architectures to mitigate the nonidealities introduced by VCO, achieving outstanding power efficiency. The contributions and drawbacks of these techniques and architectures are also discussed.

    2022年03期 v.27 472-480页 [查看摘要][在线阅读][下载 5802K]
    [下载次数:39 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:1 ]
  • Overview of Ultra-Wideband Transceivers——System Architectures and Applications

    Bowen Wang;Haixin Song;Woogeun Rhee;Zhihua Wang;

    The Ultra-WideBand(UWB) technique, which offers good energy efficiency, flexible data rate, and high ranging accuracy, has recently been recognized as a revived wireless technology for short distance communication.This paper presents a brief overview of two UWB techniques, covering Impulse-Radio UWB(IR-UWB) and FrequencyModulation UWB(FM-UWB) methods. The link margin enhancement technique, Very-WideBand(VWB), and power consumption reducing technique, chirp UWB, are also introduced. Then, several potential applications of IR-UWB with transceiver architectures are addressed, including high data rate proximity communication and secure wireless connectivity. With fine-ranging and energy-efficient communication features, the UWB wireless technology is highly promising for secure mobile Internet of Things(IoT) applications.

    2022年03期 v.27 481-494页 [查看摘要][在线阅读][下载 23833K]
    [下载次数:57 ] |[网刊下载次数:0 ] |[引用频次:3 ] |[阅读次数:1 ]
  • Review of Technologies for High-Voltage Integrated Circuits

    Bo Zhang;Wentong Zhang;Le Zhu;Jian Zu;Ming Qiao;Zhaoji Li;

    High-Voltage power Integrated Circuits(HVICs) are widely used to realize high-efficiency power conversions(e.g., AC/DC conversion), gate drivers for power devices and LED lighting, and so on. The Bipolar-CMOS-DMOS(BCD) process is proposed to fabricate devices with bipolar, CMOS, and DMOS modes, and thereby realize the single-chip integration of HVICs. The basic integrated technologies of HVICs include High-Voltage(HV) integrated device technology, HV interconnection technology, and isolation technology. The HV integrated device is the core of HVICs. The basic requirements of the HV integrated device are high breakdown voltage, low specific on-resistance,and process compatibility with low-voltage circuits. The REduced SURFace field(RESURF) technology and junction termination technology are developed to optimize the surface field of integration power devices and breakdown voltage. Furthermore, the ENhanced DIelectric layer Field(ENDIF) and REduced BULk Field(REBULF) technologies are proposed to optimize bulk fields. The double/triple RESURF technologies are further developed, and the superjunction concept is introduced to integrated power devices and to reduce the specific on-resistance. This work presents a comprehensive review of these technologies, including the innovation technologies of the authors' group,such as ENDIF and REBULF, substrate termination technology prospective integrated technologies and HVICs in wide band gap semiconductor materials are also discussed.

    2022年03期 v.27 495-511页 [查看摘要][在线阅读][下载 11785K]
    [下载次数:101 ] |[网刊下载次数:0 ] |[引用频次:4 ] |[阅读次数:1 ]
  • Building a Post-Layout Simulation Performance Model with Global Mapping Model Fusion Technique

    Zhikai Wang;Wenfei Hu;Sen Yin;Ruitao Wang;Jian Zhang;Yan Wang;Zuochang Ye;

    Building a post-layout simulation performance model is essential in closing the loop of analog circuits, but it is a challenging task because of the high-dimensional space and expensive simulation cost. To facilitate efficient modeling, this paper proposes a Global Mapping Model Fusion(GMMF) technique. The key idea of GMMF is to reuse the schematic-level model trained by the Artificial Neural Network(ANN) algorithm, and combine it with few mapping coefficients to build the post-simulation model. Furthermore, as an efficient global optimization algorithm,differential evolution is applied to determine the optimal mapping coefficients with few samples. In GMMF, only a small number of mapping coefficients are unknown, so the number of post-layout samples needed is significantly reduced. To enhance practical utility of the proposed GMMF technique, two specific mapping relations, i.e., linear or weakly no-linear and nonlinear, are carefully considered in this paper. We conduct experiments on two topologies of two-stage operational amplifier and comparator in different commercial processes. All the simulation data for modeling are obtained from a parametric design framework. A more than 5 runtime speedup is achieved over ANN without surrendering any accuracy.

    2022年03期 v.27 512-525页 [查看摘要][在线阅读][下载 6105K]
    [下载次数:20 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:1 ]
  • A Brief Review of Design and Simulation Methodology in Silicon Photonics

    Chonglei Sun;Liuge Du;Jia Zhao;

    Powerful electronic design automation tools have enabled the rapid development of electronic Integrated Circuits(ICs). Similar to electronic ICs, silicon photonics technology has sufficiently matured, and large-scale photonic circuits can now be implanted into a single chip. Design tools have also evolved from primary devices to complex photonic circuits. In this paper, we review the current state of photonic design automation in terms of device modeling methods and circuit simulation methodologies, and compare the photonics design flow with mature electronic design automation design flows. Key challenges and opportunities are also discussed.

    2022年03期 v.27 526-533页 [查看摘要][在线阅读][下载 3637K]
    [下载次数:27 ] |[网刊下载次数:0 ] |[引用频次:2 ] |[阅读次数:1 ]
  • Advanced Process and Electron Device Technology

    Dan Zhang;Xiaojing Su;Hao Chang;Hao Xu;Xiaolei Wang;Xiaobin He;Junjie Li;Fei Zhao;Qide Yao;Yanna Luo;Xueli Ma;Hong Yang;Yongliang Li;Zhenhua Wu;Yajuan Su;Tao Yang;Yayi Wei;Anyan Du;Huilong Zhu;Junfeng Li;Huaxiang Yin;Jun Luo;Tianchun Ye;Wenwu Wang;

    This article reviews advanced process and electron device technology of integrated circuits, including recent featuring progress and potential solutions for future development. In 5 years, for pushing the performance of fin field-effect transistors(FinFET) to its limitations, several processes and device boosters are provided. Then, the three-dimensional(3 D) integration schemes with alternative materials and device architectures will pave paths for future technology evolution. Finally, it could be concluded that Moore's law will undoubtedly continue in the next 15 years.

    2022年03期 v.27 534-558页 [查看摘要][在线阅读][下载 37043K]
    [下载次数:40 ] |[网刊下载次数:0 ] |[引用频次:1 ] |[阅读次数:1 ]
  • Investigation of Asynchronous Pipeline Circuits Based on Bundled-Data Encoding: Implementation Styles, Behavioral Modeling,and Timing Analysis

    Yu Zhou;

    As VLSI technology enters the post-Moore era, there has been an increasing interest in asynchronous design because of its potential advantages in power consumption, electromagnetic emission, and automatic speed scaling capacity under supply voltage variations. In most practical asynchronous circuits, a pipeline forms the micro-architecture backbone, and its characteristics play a vital role in determining the overall circuit performance.In this paper, we investigate a series of typical asynchronous pipeline circuits based on bundled-data encoding,spanning different handshake signaling protocols such as 2-phase(micropipeline, Mousetrap, and Click), 4-phase(simple, semi-decoupled, and fully-decoupled), and single-track(GasP). An in-depth review of each selected circuit is conducted regarding the handshaking and data latching mechanisms behind the circuit implementations, as well as the analysis of its performance and timing constraints based on formal behavior models. Overall, this paper aims at providing a survey of asynchronous bundled-data pipeline circuits, and it will be a reference for designers interested in experimenting with asynchronous circuits.

    2022年03期 v.27 559-580页 [查看摘要][在线阅读][下载 20596K]
    [下载次数:23 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:1 ]


  • Privacy-Aware Examination Results Ranking for the Balance Between Teachers and Mothers

    Qunying Yuan;Dongxing Wang;Yuanyuan Zhao;Yong Sang;Fan Wang;Yuwen Liu;Ying Miao;

    As the main parent and guardian, mothers are often concerned with the study performance of their children.More specifically, most mothers are eager to know the concrete examination scores of their children. However,with the continuous progress of modern education systems, most schools or teachers have now been forbidden to release sensitive student examination scores to the public due to privacy concerns, which has made it infeasible for mothers to know the real study level or examination performance of their children. Therefore, a conflict has come to exist between teachers and mothers, which harms the general growing up of students in their study. In view of this challenge, we propose a Privacy-aware Examination Results Ranking(PERR) method to attempt at balancing teachers' privacy disclosure concerns and the mothers' concerns over their children's examination performance.By drawing on a relevant case study, we prove the effectiveness of the proposed PERR method in evaluating and ranking students according to their examination scores while at the same time securing sensitive student information.

    2022年03期 v.27 581-588页 [查看摘要][在线阅读][下载 2024K]
    [下载次数:25 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:1 ]
  • CDCAT: A Multi-Language Cross-Document Entity and Event Coreference Annotation Tool

    Yang Xu;Boming Xia;Yueliang Wan;Fan Zhang;Jiabo Xu;Huansheng Ning;

    A tool for the manual annotation of cross-document entity and event coreferences that helps annotators to label mention coreference relations in text is essential for the annotation of coreference corpora. To the best of our knowledge, CROss-document Main Events and entities Recognition(CROMER) is the only open-source manual annotation tool available for cross-document entity and event coreferences. However, CROMER lacks multi-language support and extensibility. Moreover, to label cross-document mention coreference relations, CROMER requires the support of another intra-document coreference annotation tool known as Content Annotation Tool, which is now unavailable. To address these problems, we introduce Cross-Document Coreference Annotation Tool(CDCAT), a new multi-language open-source manual annotation tool for cross-document entity and event coreference, which can handle different input/output formats, preprocessing functions, languages, and annotation systems. Using this new tool, annotators can label a reference relation with only two mouse clicks. Best practice analyses reveal that annotators can reach an annotation speed of 0.025 coreference relations per second on a corpus with a coreference density of 0.076 coreference relations per word. As the first multi-language open-source cross-document entity and event coreference annotation tool, CDCAT can theoretically achieve higher annotation efficiency than CROMER.

    2022年03期 v.27 589-598页 [查看摘要][在线阅读][下载 3892K]
    [下载次数:19 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:1 ]
  • Spatial-Temporal ConvLSTM for Vehicle Driving Intention Prediction

    He Huang;Zheni Zeng;Danya Yao;Xin Pei;Yi Zhang;

    Driving intention prediction from a bird's-eye view has always been an active research area. However,existing research, on one hand, has only focused on predicting lane change intention in highway scenarios and, on the other hand, has not modeled the influence and spatiotemporal relationship of surrounding vehicles. This study extends the application scenarios to urban road scenarios. A spatial-temporal convolutional long short-term memory(ConvLSTM) model is proposed to predict the vehicle's lateral and longitudinal driving intentions simultaneously. This network includes two modules: the first module mines the information of the target vehicle using the long short-term memory(LSTM) network and the second module uses ConvLSTM to capture the spatial interactions and temporal evolution of surrounding vehicles simultaneously when modeling the influence of surrounding vehicles. The model is trained and verified on a real road dataset, and the results show that the spatial-temporal ConvLSTM model is superior to the traditional LSTM in terms of accuracy, precision, and recall, which helps improve the prediction accuracy at different time horizons.

    2022年03期 v.27 599-609页 [查看摘要][在线阅读][下载 3623K]
    [下载次数:141 ] |[网刊下载次数:0 ] |[引用频次:5 ] |[阅读次数:1 ]
  • Adversarial Training for Supervised Relation Extraction

    Yanhua Yu;Kanghao He;Jie Li;

    Most supervised methods for relation extraction(RE) involve time-consuming human annotation. Distant supervision for RE is an efficient method to obtain large corpora that contains thousands of instances and various relations. However, the existing approaches rely heavily on knowledge bases(e.g., Freebase), thereby introducing data noise. Various relations and noisy labeling instances make the issue difficult to solve. In this study, we propose a model based on a piecewise convolution neural network with adversarial training. Inspired by generative adversarial networks, we adopt a heuristic algorithm to identify noisy datasets and apply adversarial training to RE. Experiments on the extended dataset of SemEval-2010 Task 8 show that our model can obtain more accurate training data for RE and significantly outperforms several competitive baseline models. Our model has an F1 score of 89.61%.

    2022年03期 v.27 610-618页 [查看摘要][在线阅读][下载 1268K]
    [下载次数:34 ] |[网刊下载次数:0 ] |[引用频次:4 ] |[阅读次数:1 ]
  • Visual Information Based Social Force Model for Crowd Evacuation

    Wenhan Wu;Maoyin Chen;Jinghai Li;Binglu Liu;Xiaolu Wang;Xiaoping Zheng;

    With the increase in large-scale incidents in real life, crowd evacuation plays a pivotal role in ensuring the safety of human crowds during emergency situations. The behavior patterns of crowds are well rendered by existing crowd dynamics models. However, most related studies ignore the information perception of pedestrians.To overcome this issue, we develop a visual information based social force model to simulate the interpretable evacuation process from the perspective of visual perception. Numerical experiments indicate that the evacuation efficiency and decision-making ability promote rapidly within a small range with the increase in unbalanced prior knowledge. The propagation of acceleration behavior caused by emergencies is asymmetric due to the anisotropy of visual information. Therefore, this model effectively characterizes the effect of visual information on crowd evacuation and provides new insights into the information perception of individuals in complex scenarios.

    2022年03期 v.27 619-629页 [查看摘要][在线阅读][下载 6587K]
    [下载次数:36 ] |[网刊下载次数:0 ] |[引用频次:2 ] |[阅读次数:1 ]
  • Garbage Collection and Data Recovery for N2DB

    Shiyu Cai;Kang Chen;Mengxing Liu;Xuyang Liu;Yongwei Wu;Weimin Zheng;

    Non-Volatile Memory(NVM) offers byte-addressability and persistency. Because NVM can be plugged into memory and provide low latency, it offers a new opportunity to build new database systems with a single-layer storage design. A single-layer NVM-Native DataBase(N2 DB) provides zero copy and log freedom. Hence, all data are stored in NVM and there is no extra data duplication and logging during execution. N2 DB avoids complex data synchronization and logging overhead in the two-layer storage design of disk-oriented databases and in-memory databases. Garbage Collection(GC) is critical in such an NVM-based database because memory leaks on NVM are durable. Moreover, data recovery is equally essential to guarantee atomicity, consistency, isolation, and durability properties. Without logging, it is a great challenge for N2 DB to restore data to a consistent state after crashes and recoveries. This paper presents the GC and data recovery mechanisms for N2 DB. Evaluations show that the overall performance of N2 DB is up to 3:6 higher than that of InnoDB. Enabling GC reduces performance by up to 10%,but saves storage space by up to 67%. Moreover, our data recovery requires only 0:2% of the time and half of the storage space of InnoDB.

    2022年03期 v.27 630-641页 [查看摘要][在线阅读][下载 2043K]
    [下载次数:38 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:1 ]
  • Optimized Relinearization Algorithm of the Multikey Homomorphic Encryption Scheme

    Xiaoyuan Yang;Shangwen Zheng;Tanping Zhou;Yao Liu;Xiaoliang Che;

    Multikey homomorphic encryption(MKHE) supports arbitrary homomorphic evaluation on the ciphertext of different users and thus can be applied to scenarios involving multiusers(e.g., cloud computing and artificial intelligence) to protect user privacy. CDKS19 is the current most efficient MKHE scheme, and its relinearization process consumes most of the time of homomorphic evaluation. In this study, an optimized relinearization algorithm of CDKS19 is proposed. This algorithm reorganizes the evaluation key during the key generation process, decreases the complexity of relinearization, and reduces the error growth rate during homomorphic evaluation. First, we reduce the scale of the evaluation key by increasing its modulus instead of using a gadget vector to decompose the user's public key and extend the ciphertext of homomorphic multiplication. Second, we use rescaling technology to optimize the relinearization algorithm; thus, the error bound of the ciphertext is reduced, and the homomorphic operation efficiency is improved. Lastly, the average-case error estimation on the variances of polynomial coefficients and the upper bound of the canonical embedding map are provided. Results show that our scheme reduces the scale of the evaluation key, the error variance, and the computational cost of the relinearization process. Our scheme can effectively perform the homomorphic multiplication of ciphertexts.

    2022年03期 v.27 642-652页 [查看摘要][在线阅读][下载 761K]
    [下载次数:30 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:1 ]
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