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1321-1340hit(42807hit)

  • A COM Based High Speed Serial Link Optimization Using Machine Learning Open Access

    Yan WANG  Qingsheng HU  

     
    PAPER

      Pubricized:
    2022/05/09
      Vol:
    E105-C No:11
      Page(s):
    684-691

    This paper presents a channel operating margin (COM) based high-speed serial link optimization using machine learning (ML). COM that is proposed for evaluating serial link is calculated at first and during the calculation several important equalization parameters corresponding to the best configuration are extracted which can be used for the ML modeling of serial link. Then a deep neural network containing hidden layers are investigated to model a whole serial link equalization including transmitter feed forward equalizer (FFE), receiver continuous time linear equalizer (CTLE) and decision feedback equalizer (DFE). By training, validating and testing a lot of samples that meet the COM specification of 400GAUI-8 C2C, an effective ML model is generated and the maximum relative error is only 0.1 compared with computation results. At last 3 link configurations are discussed from the view of tradeoff between the link performance and cost, illustrating that our COM based ML modeling method can be applied to advanced serial link design for NRZ, PAM4 or even other higher level pulse amplitude modulation signal.

  • Evaluation and Extraction of Equivalent Circuit Parameters for GSG-Type Bonding Wires Using Electromagnetic Simulator Open Access

    Takuichi HIRANO  

     
    BRIEF PAPER

      Pubricized:
    2022/05/17
      Vol:
    E105-C No:11
      Page(s):
    692-695

    In this paper, the author performed an electromagnetic field simulation of a typical bonding wire structure that connects a chip and a package, and evaluated the signal transmission characteristics (S-parameters). In addition, the inductance per unit length was extracted by comparing with the equivalent circuit of the distributed constant line. It turns out that the distributed constant line model is not sufficient because there are frequencies where chip-package resonance occurs. Below the resonance frequency, the conventional low-frequency approximation model was effective, and it was found that the inductance was about 1nH/mm.

  • Analysis of Instantaneous Acoustic Fields Using Fast Inverse Laplace Transform Open Access

    Seiya KISHIMOTO  Naoya ISHIKAWA  Shinichiro OHNUKI  

     
    BRIEF PAPER

      Pubricized:
    2022/03/14
      Vol:
    E105-C No:11
      Page(s):
    700-703

    In this study, a computational method is proposed for acoustic field analysis tasks that require lengthy observation times. The acoustic fields at a given observation time are obtained using a fast inverse Laplace transform with a finite-difference complex-frequency-domain. The transient acoustic field can be evaluated at arbitrary sampling intervals by obtaining the instantaneous acoustic field at the desired observation time using the proposed method.

  • A Low-Power High-Speed Sensing Scheme for Single-Ended SRAM

    Dashan SHI  Heng YOU  Jia YUAN  Yulian WANG  Shushan QIAO  

     
    PAPER-Integrated Electronics

      Pubricized:
    2022/05/06
      Vol:
    E105-C No:11
      Page(s):
    712-719

    In this paper, a reference-voltage self-selected pseudo-differential sensing scheme suitable for single-ended SRAM is proposed. The proposed sensing scheme can select different reference voltage according to the offset direction. With the employment of the new sensing scheme, the swing of the read bit-line in the read operation is reduced by 74.6% and 45.5% compared to the conventional domino and the pseudo-differential sense amplifier sensing scheme, respectively. Therefore, the delay and power consumption of the read operation are significantly improved. Simulation results based on a standard 55nm CMOS show that compared with the conventional domino and pseudo-differential sensing schemes, the sensing delay is improved by 66.4% and 47.7%, and the power consumption is improved by 31.4% and 22.5%, respectively. Although the area of the sensing scheme is increased by 50.8% compared with the pseudo-differential sense amplifier sensing scheme, it has little effect on the entire SRAM area.

  • Aggregate Signature Schemes with Traceability of Devices Dynamically Generating Invalid Signatures

    Ryu ISHII  Kyosuke YAMASHITA  Yusuke SAKAI  Tadanori TERUYA  Takahiro MATSUDA  Goichiro HANAOKA  Kanta MATSUURA  Tsutomu MATSUMOTO  

     
    PAPER

      Pubricized:
    2022/08/04
      Vol:
    E105-D No:11
      Page(s):
    1845-1856

    Aggregate signature schemes enable us to aggregate multiple signatures into a single short signature. One of its typical applications is sensor networks, where a large number of users and devices measure their environments, create signatures to ensure the integrity of the measurements, and transmit their signed data. However, if an invalid signature is mixed into aggregation, the aggregate signature becomes invalid, thus if an aggregate signature is invalid, it is necessary to identify the invalid signature. Furthermore, we need to deal with a situation where an invalid sensor generates invalid signatures probabilistically. In this paper, we introduce a model of aggregate signature schemes with interactive tracing functionality that captures such a situation, and define its functional and security requirements and propose aggregate signature schemes that can identify all rogue sensors. More concretely, based on the idea of Dynamic Traitor Tracing, we can trace rogue sensors dynamically and incrementally, and eventually identify all rogue sensors of generating invalid signatures even if the rogue sensors adaptively collude. In addition, the efficiency of our proposed method is also sufficiently practical.

  • Fully Dynamic Data Management in Cloud Storage Systems with Secure Proof of Retrievability

    Nam-Su JHO  Daesung MOON  Taek-Young YOUN  

     
    PAPER

      Pubricized:
    2022/07/19
      Vol:
    E105-D No:11
      Page(s):
    1872-1879

    For reliable storage services, we need a way not only to monitor the state of stored data but also to recover the original data when some data loss is discovered. To solve the problem, a novel technique called HAIL has been proposed. Unfortunately, HAIL cannot support dynamic data which is changed according to users' modification queries. There are many applications where dynamic data are used. So, we need a way to support dynamic data in cloud services to use cloud storage system for various applications. In this paper, we propose a new technique that can support the use of dynamic data in cloud storage systems. For dynamic data update, we design a new data chunk generation strategy which guarantee efficient data insertion, deletion, and modification. Our technique requires O(1) operations for each data update when existing techniques require O(n) operations where n is the size of data.

  • Priority Evasion Attack: An Adversarial Example That Considers the Priority of Attack on Each Classifier

    Hyun KWON  Changhyun CHO  Jun LEE  

     
    PAPER

      Pubricized:
    2022/08/23
      Vol:
    E105-D No:11
      Page(s):
    1880-1889

    Deep neural networks (DNNs) provide excellent services in machine learning tasks such as image recognition, speech recognition, pattern recognition, and intrusion detection. However, an adversarial example created by adding a little noise to the original data can result in misclassification by the DNN and the human eye cannot tell the difference from the original data. For example, if an attacker creates a modified right-turn traffic sign that is incorrectly categorized by a DNN, an autonomous vehicle with the DNN will incorrectly classify the modified right-turn traffic sign as a U-Turn sign, while a human will correctly classify that changed sign as right turn sign. Such an adversarial example is a serious threat to a DNN. Recently, an adversarial example with multiple targets was introduced that causes misclassification by multiple models within each target class using a single modified image. However, it has the weakness that as the number of target models increases, the overall attack success rate decreases. Therefore, if there are multiple models that the attacker wishes to attack, the attacker must control the attack success rate for each model by considering the attack priority for each model. In this paper, we propose a priority adversarial example that considers the attack priority for each model in cases targeting multiple models. The proposed method controls the attack success rate for each model by adjusting the weight of the attack function in the generation process while maintaining minimal distortion. We used MNIST and CIFAR10 as data sets and Tensorflow as machine learning library. Experimental results show that the proposed method can control the attack success rate for each model by considering each model's attack priority while maintaining minimal distortion (average 3.95 and 2.45 with MNIST for targeted and untargeted attacks, respectively, and average 51.95 and 44.45 with CIFAR10 for targeted and untargeted attacks, respectively).

  • Efficient Protection Mechanism for CPU Cache Flush Instruction Based Attacks

    Shuhei ENOMOTO  Hiroki KUZUNO  Hiroshi YAMADA  

     
    PAPER

      Pubricized:
    2022/07/19
      Vol:
    E105-D No:11
      Page(s):
    1890-1899

    CPU flush instruction-based cache side-channel attacks (cache instruction attacks) target a wide range of machines. For instance, Meltdown / Spectre combined with FLUSH+RELOAD gain read access to arbitrary data in operating system kernel and user processes, which work on cloud virtual machines, laptops, desktops, and mobile devices. Additionally, fault injection attacks use a CPU cache. For instance, Rowhammer, is a cache instruction attack that attempts to obtain write access to arbitrary data in physical memory, and affects machines that have DDR3. To protect against existing cache instruction attacks, various existing mechanisms have been proposed to modify hardware and software aspects; however, when latest cache instruction attacks are disclosed, these mechanisms cannot prevent these. Moreover, additional countermeasure requires long time for the designing and developing process. This paper proposes a novel mechanism termed FlushBlocker to protect against all types of cache instruction attacks and mitigate against cache instruction attacks employ latest side-channel vulnerability until the releasing of additional countermeasures. FlushBlocker employs an approach that restricts the issuing of cache flush instructions and the attacks that lead to failure by limiting control of the CPU cache. To demonstrate the effectiveness of this study, FlushBlocker was implemented in the latest Linux kernel, and its security and performance were evaluated. Results show that FlushBlocker successfully prevents existing cache instruction attacks (e.g., Meltdown, Spectre, and Rowhammer), the performance overhead was zero, and it was transparent in real-world applications.

  • SOME/IP Intrusion Detection System Using Machine Learning

    Jaewoong HEO  Hyunghoon KIM  Hyo Jin JO  

     
    LETTER

      Pubricized:
    2022/07/13
      Vol:
    E105-D No:11
      Page(s):
    1923-1924

    With the development of in-vehicle network technologies, Automotive Ethernet is being applied to modern vehicles. Scalable service-Oriented MiddlewarE over IP (SOME/IP) is an automotive middleware solution that is used for communications of the infotainment domain as well as that of other domains in the vehicle. However, since SOME/IP lacks security, it is vulnerable to a variety of network-based attacks. In this paper, we introduce a new type of intrusion detection system (IDS) leveraging on SOME/IP packet's header information and packet reception time to deal with SOME/IP related network attacks.

  • SDOF-Tracker: Fast and Accurate Multiple Human Tracking by Skipped-Detection and Optical-Flow

    Hitoshi NISHIMURA  Satoshi KOMORITA  Yasutomo KAWANISHI  Hiroshi MURASE  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2022/08/01
      Vol:
    E105-D No:11
      Page(s):
    1938-1946

    Multiple human tracking is a fundamental problem in understanding the context of a visual scene. Although both accuracy and speed are required in real-world applications, recent tracking methods based on deep learning focus on accuracy and require a substantial amount of running time. We aim to improve tracking running speeds by performing human detections at certain frame intervals because it accounts for most of the running time. The question is how to maintain accuracy while skipping human detection. In this paper, we propose a method that interpolates the detection results by using an optical flow, which is based on the fact that someone's appearance does not change much between adjacent frames. To maintain the tracking accuracy, we introduce robust interest point detection within the human regions and a tracking termination metric defined by the distribution of the interest points. On the MOT17 and MOT20 datasets in the MOTChallenge, the proposed SDOF-Tracker achieved the best performance in terms of total running time while maintaining the MOTA metric. Our code is available at https://github.com/hitottiez/sdof-tracker.

  • MP-BERT4REC: Recommending Multiple Positive Citations for Academic Manuscripts via Content-Dependent BERT and Multi-Positive Triplet

    Yang ZHANG  Qiang MA  

     
    PAPER-Natural Language Processing

      Pubricized:
    2022/08/08
      Vol:
    E105-D No:11
      Page(s):
    1957-1968

    Considering the rapidly increasing number of academic papers, searching for and citing appropriate references has become a nontrivial task during manuscript composition. Recommending a handful of candidate papers to a working draft could ease the burden of the authors. Conventional approaches to citation recommendation generally consider recommending one ground-truth citation from an input manuscript for a query context. However, it is common for a given context to be supported by two or more co-citation pairs. Here, we propose a novel scientific paper modelling for citation recommendations, namely Multi-Positive BERT Model for Citation Recommendation (MP-BERT4REC), complied with a series of Multi-Positive Triplet objectives to recommend multiple positive citations for a query context. The proposed approach has the following advantages: First, the proposed multi-positive objectives are effective in recommending multiple positive candidates. Second, we adopt noise distributions on the basis of historical co-citation frequencies; thus, MP-BERT4REC is not only effective in recommending high-frequency co-citation pairs, but it also significantly improves the performance of retrieving low-frequency ones. Third, the proposed dynamic context sampling strategy captures macroscopic citing intents from a manuscript and empowers the citation embeddings to be content-dependent, which allows the algorithm to further improve performance. Single and multiple positive recommendation experiments confirmed that MP-BERT4REC delivers significant improvements over current methods. It also effectively retrieves the full list of co-citations and historically low-frequency pairs better than prior works.

  • A Construction of Codebooks Asymptotically Meeting the Levenshtein Bound

    Zhangti YAN  Zhi GU  Wei GUO  Jianpeng WANG  

     
    LETTER-Coding Theory

      Pubricized:
    2022/05/16
      Vol:
    E105-A No:11
      Page(s):
    1513-1516

    Codebooks with small maximal cross-correlation amplitudes have important applications in code division multiple access (CDMA) communication, coding theory and compressed sensing. In this letter, we design a new codebook based on a construction of Ramanujan graphs over finite abelian groups. We prove that the new codebook with length K=q+1 and size N=q2+2q+2 is asymptotically optimal with nearly achieving the Levenshtein bound when n=3, where q is a prime power. The parameters of the new codebook are new.

  • Performance and Security Evaluation of Table-Based Access Control Applied to IoT Data Distribution Method Open Access

    Masaki YOSHII  Ryohei BANNO  Osamu MIZUNO  

     
    PAPER

      Pubricized:
    2022/05/27
      Vol:
    E105-B No:11
      Page(s):
    1390-1399

    New services can use fog nodes to distribute Internet of Things (IoT) data. To distribute IoT data, we apply the publish/subscribe messaging model to a fog computing system. A service provider assigns a unique identifier, called a Tag ID, to a player who owes data. A Tag ID matches multiple IDs and resolves the naming rule for data acquisition. However, when users configure their fog node and distribute IoT data to multiple players, the distributed data may contain private information. We propose a table-based access control list (ACL) to manage data transmission permissions to address this issue. It is possible to avoid unnecessary transmission of private data by using a table-based ACL. Furthermore, because there are fewer data transmissions, table-based ACL reduces traffic. Consequently, the overall system's average processing delay time can be reduced. The proposed method's performance was confirmed by simulation results. Table-based ACL, particularly, could reduce processing delay time by approximately 25% under certain conditions. We also concentrated on system security. The proposed method was used, and a qualitative evaluation was performed to demonstrate that security is guaranteed.

  • Online Probabilistic Activation Control of Base Stations Utilizing Temporal System Throughput and Activation States of Neighbor Cells for Heterogeneous Networks Open Access

    Junya TANI  Kenichi HIGUCHI  

     
    PAPER-Terrestrial Wireless Communication/Broadcasting Technologies

      Pubricized:
    2022/04/26
      Vol:
    E105-B No:11
      Page(s):
    1458-1466

    In this paper, we propose an online probabilistic activation/deactivation control method for base stations (BSs) in heterogeneous networks based on the temporal system throughput and activation states of neighbor BSs (cells). The conventional method iteratively updates the activation/deactivation states in a probabilistic manner at each BS based on the change in the observed system throughput and activation/deactivation states of that BS between past multiple consecutive discrete times. Since BS activation control increases the system throughput by improving the tradeoff between the reduction in inter-cell interference and the traffic off-loading effect, the activation of a BS whose neighbor BSs are deactivated is likely to result in improved system performance and vice versa. The proposed method newly introduces a metric, which represents the effective ratio of the activated neighbor BSs considering their transmission power and distance to the BS of interest, to the update control of the activation probability. This improves both the convergence rate of the iterative algorithm and throughput performance after convergence. Computer simulation results, in which the mobility of the user terminals is taken into account, show the effectiveness of the proposed method.

  • Blockchain-Based Optimization of Distributed Energy Management Systems with Real-Time Demand Response

    Daiki OGAWA  Koichi KOBAYASHI  Yuh YAMASHITA  

     
    PAPER-Systems and Control

      Pubricized:
    2022/05/12
      Vol:
    E105-A No:11
      Page(s):
    1478-1485

    Design of distributed energy management systems composed of several agents such as factories and buildings is important for realizing smart cities. In addition, demand response for saving the power consumption is also important. In this paper, we propose a design method of distributed energy management systems with real-time demand response, in which both electrical energy and thermal energy are considered. Here, we use ADMM (Alternating Direction Method of Multipliers), which is well known as one of the powerful methods in distributed optimization. In the proposed method, demand response is performed in real-time, based on the difference between the planned demand and the actual value. Furthermore, utilizing a blockchain is also discussed. The effectiveness of the proposed method is presented by a numerical example. The importance of introducing a blockchain is pointed out by presenting the adverse effect of tampering the actual value.

  • Hiding Data in the Padding Area of Android Applications without Re-Packaging

    Geochang JEON  Jeong Hyun YI  Haehyun CHO  

     
    LETTER

      Pubricized:
    2022/06/13
      Vol:
    E105-D No:11
      Page(s):
    1928-1929

    Anonymous attackers have been targeting the Android ecosystem for performing severe malicious activities. Despite the complement of various vulnerabilities by security researchers, new vulnerabilities are continuously emerging. In this paper, we introduce a new type of vulnerability that can be exploited to hide data in an application file, bypassing the Android's signing policy. Specifically, we exploit padding areas that can be created by using the alignment option when applications are packaged. We present a proof-of-concept implementation for exploiting the vulnerability. Finally, we demonstrate the effectiveness of VeileDroid by using a synthetic application that hides data in the padding area and updates the data without re-signing and updating the application on an Android device.

  • Opportunities, Challenges, and Solutions in the 5G Era Open Access

    Chien-Chi KAO  Hey-Chyi YOUNG  

     
    INVITED PAPER

      Pubricized:
    2022/05/27
      Vol:
    E105-B No:11
      Page(s):
    1291-1298

    For many countries in the world, 5G is of strategic significance. In the 5G era, telecom operators are expected to enable and provide multiple services with different communication characteristics like enhanced broadband, ultra-reliable and extreme real-time communications at the same time. To meet the requirements, the 5G network essentially will be more complex compared with traditional 3G/4G networks. The unique characteristics of 5G resulted from new technologies bring a lot of opportunities as well as significant challenges. In this paper we first introduce 5G vision and check the global status. And then we illustrate the 5G technical essentials and point out the new opportunities that 5G will bring to us. We also highlight the coming challenges and share our 5G experience and solutions toward 5G vision in many aspects, including network, management and business.

  • Convergence of the Hybrid Implicit-Explicit Single-Field FDTD Method Based on the Wave Equation of Electric Field

    Kazuhiro FUJITA  

     
    BRIEF PAPER

      Pubricized:
    2022/03/24
      Vol:
    E105-C No:11
      Page(s):
    696-699

    The hybrid implicit-explicit single-field finite-difference time-domain (HIE-SF-FDTD) method based on the wave equation of electric field is reformulated in a concise matrix-vector form. The global approximation error of the scheme is discussed theoretically. The second-order convergence of the HIE-SF-FDTD is numerically verified.

  • Multi-Target Position and Velocity Estimation Algorithm Based on Time Delay and Doppler Shift in Passive MIMO Radar

    Yao ZHOU  Hairui YU  Wenjie XU  Siyi YAO  Li WANG  Hongshu LIAO  Wanchun LI  

     
    PAPER-Digital Signal Processing

      Pubricized:
    2022/05/18
      Vol:
    E105-A No:11
      Page(s):
    1466-1477

    In this paper, a passive multiple-input multiple-output (MIMO) radar system with widely separated antennas that estimates the positions and velocities of multiple moving targets by utilizing time delay (TD) and doppler shift (DS) measurements is proposed. Passive radar systems can detect targets by using multiple uncoordinated and un-synchronized illuminators and we assume that all the measurements including TD and DS have been known by a preprocessing method. In this study, the algorithm can be divided into three stages. First, based on location information within a certain range and utilizing the DBSCAN cluster algorithm we can obtain the initial position of each target. In the second stage according to the correlation between the TD measurements of each target in a specific receiver and the DSs, we can find the set of DS measurements for each target. Therefore, the initial speed estimated values can be obtained employing the least squares (LS) method. Finally, maximum likelihood (ML) estimation of a first-order Taylor expansion joint TD and DS is applied for a better solution. Extensive simulations show that the proposed algorithm has a good estimation performance and can achieve the Cramér-Rao lower bound (CRLB) under the condition of moderate measurement errors.

  • Order Statistics Based Low-Power Flash ADC with On-Chip Comparator Selection

    Takehiro KITAMURA  Mahfuzul ISLAM  Takashi HISAKADO  Osami WADA  

     
    PAPER

      Pubricized:
    2022/05/13
      Vol:
    E105-A No:11
      Page(s):
    1450-1457

    High-speed flash ADCs are useful in high-speed applications such as communication receivers. Due to offset voltage variation in the sub-micron processes, the power consumption and the area increase significantly to suppress variation. As an alternative to suppressing the variation, we have developed a flash ADC architecture that selects the comparators based on offset voltage ranking for reference generation. Specifically, with the order statistics as a basis, our method selects the minimum number of comparators to obtain equally spaced reference values. Because the proposed ADC utilizes offset voltages as references, no resistor ladder is required. We also developed a time-domain sorting mechanism for the offset voltages to achieve on-chip comparator selection. We first perform a detailed analysis of the order statistics based selection method and then design a 4-bit ADC in a commercial 65-nm process and perform transistor-level simulation. When using 127 comparators, INLs of 20 virtual chips are in the range of -0.34LSB/+0.29LSB to -0.83LSB/+0.74LSB, and DNLs are in the range of -0.33LSB/+0.24LSB to -0.77LSB/+1.18LSB at 1-GS/s operation. Our ADC achieves the SNDR of 20.9dB at Nyquist-frequency input and the power consumption of 0.84mW.

1321-1340hit(42807hit)