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  • Weighted Generalized Hesitant Fuzzy Sets and Its Application in Ensemble Learning Open Access

    Haijun ZHOU  Weixiang LI  Ming CHENG  Yuan SUN  

     
    PAPER-Fundamentals of Information Systems

      Pubricized:
    2024/01/22
      Vol:
    E107-D No:5
      Page(s):
    694-703

    Traditional intuitionistic fuzzy sets and hesitant fuzzy sets will lose some information while representing vague information, to avoid this problem, this paper constructs weighted generalized hesitant fuzzy sets by remaining multiple intuitionistic fuzzy values and giving them corresponding weights. For weighted generalized hesitant fuzzy elements in weighted generalized hesitant fuzzy sets, the paper defines some basic operations and proves their operation properties. On this basis, the paper gives the comparison rules of weighted generalized hesitant fuzzy elements and presents two kinds of aggregation operators. As for weighted generalized hesitant fuzzy preference relation, this paper proposes its definition and computing method of its corresponding consistency index. Furthermore, the paper designs an ensemble learning algorithm based on weighted generalized hesitant fuzzy sets, carries out experiments on 6 datasets in UCI database and compares with various classification algorithms. The experiments show that the ensemble learning algorithm based on weighted generalized hesitant fuzzy sets has better performance in all indicators.

  • The Channel Modeling of Ultra-Massive MIMO Terahertz-Band Communications in the Presence of Mutual Coupling Open Access

    Shouqi LI  Aihuang GUO  

     
    LETTER-Communication Theory and Signals

      Pubricized:
    2023/08/23
      Vol:
    E107-A No:5
      Page(s):
    850-854

    The very high path loss caused by molecular absorption becomes the biggest problem in Terahertz (THz) wireless communications. Recently, the multi-band ultra-massive multi-input multi-output (UM-MIMO) system has been proposed to overcome the distance problem. In UM-MIMO systems, the impact of mutual coupling among antennas on the system performance is unable to be ignored because of the dense array. In this letter, a channel model of UM-MIMO communication system is developed which considers coupling effect. The effect of mutual coupling in the subarray on the functionality of the system has been investigated through simulation studies, and reliable results have been derived.

  • Dance-Conditioned Artistic Music Generation by Creative-GAN Open Access

    Jiang HUANG  Xianglin HUANG  Lifang YANG  Zhulin TAO  

     
    PAPER-Multimedia Environment Technology

      Pubricized:
    2023/08/23
      Vol:
    E107-A No:5
      Page(s):
    836-844

    We present a novel adversarial, end-to-end framework based on Creative-GAN to generate artistic music conditioned on dance videos. Our proposed framework takes the visual and motion posture data as input, and then adopts a quantized vector as the audio representation to generate complex music corresponding to input. However, the GAN algorithm just imitate and reproduce works what humans have created, instead of generating something new and creative. Therefore, we newly introduce Creative-GAN, which extends the original GAN framework to two discriminators, one is to determine whether it is real music, and the other is to classify music style. The paper shows that our proposed Creative-GAN can generate novel and interesting music which is not found in the training dataset. To evaluate our model, a comprehensive evaluation scheme is introduced to make subjective and objective evaluation. Compared with the advanced methods, our experimental results performs better in measureing the music rhythm, generation diversity, dance-music correlation and overall quality of generated music.

  • A Multiobjective Approach for Side-Channel Based Hardware Trojan Detection Using Power Traces Open Access

    Priyadharshini MOHANRAJ  Saravanan PARAMASIVAM  

     
    PAPER-Cryptography and Information Security

      Pubricized:
    2023/08/23
      Vol:
    E107-A No:5
      Page(s):
    825-835

    The detection of hardware trojans has been extensively studied in the past. In this article, we propose a side-channel analysis technique that uses a wrapper-based feature selection technique for hardware trojan detection. The whale optimization algorithm is modified to carefully extract the best feature subset. The aim of the proposed technique is multiobjective: improve the accuracy and minimize the number of features. The power consumption traces measured from AES-128 trojan circuits are used as features in this experiment. The stabilizing property of the feature selection method helps to bring a mutual trade-off between the precision and recall parameters thereby minimizing the number of false negatives. The proposed hardware trojan detection scheme produces a maximum of 10.3% improvement in accuracy and reduction up to a single feature by employing the modified whale optimization technique. Thus the evaluation results conducted on various trust-hub cryptographic benchmark circuits prove to be efficient from the existing state-of-art methods.

  • Distributed Event-Triggered Stochastic Gradient-Tracking for Nonconvex Optimization Open Access

    Daichi ISHIKAWA  Naoki HAYASHI  Shigemasa TAKAI  

     
    PAPER

      Pubricized:
    2024/01/18
      Vol:
    E107-A No:5
      Page(s):
    762-769

    In this paper, we consider a distributed stochastic nonconvex optimization problem for multiagent systems. We propose a distributed stochastic gradient-tracking method with event-triggered communication. A group of agents cooperatively finds a critical point of the sum of local cost functions, which are smooth but not necessarily convex. We show that the proposed algorithm achieves a sublinear convergence rate by appropriately tuning the step size and the trigger threshold. Moreover, we show that agents can effectively solve a nonconvex optimization problem by the proposed event-triggered algorithm with less communication than by the existing time-triggered gradient-tracking algorithm. We confirm the validity of the proposed method by numerical experiments.

  • Boosting Spectrum-Based Fault Localization via Multi-Correct Programs in Online Programming Open Access

    Wei ZHENG  Hao HU  Tengfei CHEN  Fengyu YANG  Xin FAN  Peng XIAO  

     
    PAPER-Software Engineering

      Pubricized:
    2023/12/11
      Vol:
    E107-D No:4
      Page(s):
    525-536

    Providing students with useful feedback on faulty programs can effectively help students fix programs. Spectrum-Based Fault Location (SBFL), which is a widely studied and lightweight technique, can automatically generate a suspicious value of statement ranking to help users find potential faults in a program. However, the performance of SBFL on student programs is not satisfactory, to improve the accuracy of SBFL in student programs, we propose a novel Multi-Correct Programs based Fault Localization (MCPFL) approach. Specifically, We first collected the correct programs submitted by students on the OJ system according to the programming problem numbers and removed the highly similar correct programs based on code similarity, and then stored them together with the faulty program to be located to construct a set of programs. Afterward, we analyzed the suspiciousness of the term in the faulty program through the Term Frequency-Inverse Document Frequency (TF-IDF). Finally, we designed a formula to calculate the weight of suspiciousness for program statements based on the number of input variables in the statement and weighted it to the spectrum-based fault localization formula. To evaluate the effectiveness of MCPFL, we conducted empirical studies on six student program datasets collected in our OJ system, and the results showed that MCPFL can effectively improve the traditional SBFL methods. In particular, on the EXAM metric, our approach improves by an average of 27.51% on the Dstar formula.

  • Coupling Analysis of Fiber-Type Polarization Splitter Open Access

    Taiki ARAKAWA  Kazuhiro YAMAGUCHI  Kazunori KAMEDA  Shinichi FURUKAWA  

     
    PAPER

      Pubricized:
    2023/10/27
      Vol:
    E107-C No:4
      Page(s):
    98-106

    We study the device length and/or band characteristics examined by two coupling analysis methods for our proposed fiber-type polarization splitter (FPS) composed of single mode fiber and polarization maintaining fiber. The first method is based on the power transition characteristics of the coupled-mode theory (CMT), and the second, a more accurate analysis method, is based on improved fundamental mode excitation (IFME). The CMT and IFME were evaluated and investigated with respect to the device length and bandwidth characteristics of the FPS. In addition, the influence of the excitation point shift of the fundamental mode, which has not been almost researched so far, is also analysed by using IFME.

  • Why the Controversy over Displacement Currents never Ends? Open Access

    Masao KITANO  

     
    PAPER

      Pubricized:
    2023/10/27
      Vol:
    E107-C No:4
      Page(s):
    82-90

    Displacement current is the last piece of the puzzle of electromagnetic theory. Its existence implies that electromagnetic disturbance can propagate at the speed of light and finally it led to the discovery of Hertzian waves. On the other hand, since magnetic fields can be calculated only with conduction currents using Biot-Savart's law, a popular belief that displacement current does not produce magnetic fields has started to circulate. But some people think if this is correct, what is the displacement current introduced for. The controversy over the meaning of displacement currents has been going on for more than hundred years. Such confusion is caused by forgetting the fact that in the case of non-stationary currents, neither magnetic fields created by conduction currents nor those created by displacement currents can be defined. It is also forgotten that the effect of displacement current is automatically incorporated in the magnetic field calculated by Biot-Savart's law. In this paper, mainly with the help of Helmholtz decomposition, we would like to clarify the confusion surrounding displacement currents and provide an opportunity to end the long standing controversy.

  • Overfitting Problem of ANN- and VSTF-Based Nonlinear Equalizers Trained on Repeated Random Bit Sequences Open Access

    Kai IKUTA  Jinya NAKAMURA  Moriya NAKAMURA  

     
    PAPER-Fiber-Optic Transmission for Communications

      Vol:
    E107-B No:4
      Page(s):
    349-356

    In this paper, we investigated the overfitting characteristics of nonlinear equalizers based on an artificial neural network (ANN) and the Volterra series transfer function (VSTF), which were designed to compensate for optical nonlinear waveform distortion in optical fiber communication systems. Linear waveform distortion caused by, e.g., chromatic dispersion (CD) is commonly compensated by linear equalizers using digital signal processing (DSP) in digital coherent receivers. However, mitigation of nonlinear waveform distortion is considered to be one of the next important issues. An ANN-based nonlinear equalizer is one possible candidate for solving this problem. However, the risk of overfitting of ANNs is one obstacle in using the technology in practical applications. We evaluated and compared the overfitting of ANN- and conventional VSTF-based nonlinear equalizers used to compensate for optical nonlinear distortion. The equalizers were trained on repeated random bit sequences (RRBSs), while varying the length of the bit sequences. When the number of hidden-layer units of the ANN was as large as 100 or 1000, the overfitting characteristics were comparable to those of the VSTF. However, when the number of hidden-layer units was 10, which is usually enough to compensate for optical nonlinear distortion, the overfitting was weaker than that of the VSTF. Furthermore, we confirmed that even commonly used finite impulse response (FIR) filters showed overfitting to the RRBS when the length of the RRBS was equal to or shorter than the length of the tapped delay line of the filters. Conversely, when the RRBS used for the training was sufficiently longer than the tapped delay line, the overfitting could be suppressed, even when using an ANN-based nonlinear equalizer with 10 hidden-layer units.

  • ILP Based Approaches for Optimizing Early Decompute in Two Level Adiabatic Logic Circuits

    Yuya USHIODA  Mineo KANEKO  

     
    PAPER-VLSI Design Technology and CAD

      Pubricized:
    2023/09/04
      Vol:
    E107-A No:3
      Page(s):
    600-609

    Adiabatic logic circuits are regarded as one of the most attractive solutions for low-power circuit design. This study is dedicated to optimizing the design of the Two-Level Adiabatic Logic (2LAL) circuit, which boasts a relatively simple structure and superior low-power performance among many asymptotically adiabatic or quasi-adiabatic logic families, but suffers from a large number of timing buffers for “decompute”. Our focus is on the “early decompute” technique for fully pipelined 2LAL, and we propose two ILP approaches for minimizing hardware cost through optimization of early decompute. In the first approach, the problem is formulated as a kind of scheduling problem, while it is reformulated as node selection problem (stable set problem). The performance of the proposed methods are evaluated using several benchmark circuits from ISCAS-85, and the maximum 70% hardware reduction is observed compared with an existing method.

  • Input Data Format for Sparse Matrix in Quantum Annealing Emulator

    Sohei SHIMOMAI  Kei UEDA  Shinji KIMURA  

     
    PAPER-Algorithms and Data Structures

      Pubricized:
    2023/09/25
      Vol:
    E107-A No:3
      Page(s):
    557-565

    Recently, Quantum Annealing (QA) has attracted attention as an efficient algorithm for combinatorial optimization problems. In QA, the input data size becomes large and its reduction is important for accelerating by the hardware emulation since the usable memory size and its bandwidth are limited. The paper proposes the compression method of input sparse matrices for QA emulator. The proposed method uses the sparseness of the coefficient matrix and the reappearance of the same values. An independent table is introduced and data are compressed by the search and registration method of two consecutive data in the value table. The proposed method is applied to Traveling Salesman Problem (TSP) with 32, 64 and 96 cities and Nurse Scheduling Problem (NSP). The proposed method could reduce the amount of data by 1/40 for 96 city TSP and could manage 96 city TSP on the hardware emulator. When applied to NSP, we confirmed the effectiveness of the proposed method by the compression ratio ranging from 1/4 to 1/11.8. The data reduction is also useful for the simulation/emulation performance when using the compressed data directly and 1.9 times faster speed can be found on 96 city TSP than the CSR-based method.

  • Performance Comparison of the Two Reconstruction Methods for Stabilizer-Based Quantum Secret Sharing

    Shogo CHIWAKI  Ryutaroh MATSUMOTO  

     
    LETTER-Quantum Information Theory

      Pubricized:
    2023/09/20
      Vol:
    E107-A No:3
      Page(s):
    526-529

    Stabilizer-based quantum secret sharing has two methods to reconstruct a quantum secret: The erasure correcting procedure and the unitary procedure. It is known that the unitary procedure has a smaller circuit width. On the other hand, it is unknown which method has smaller depth and fewer circuit gates. In this letter, it is shown that the unitary procedure has smaller depth and fewer circuit gates than the erasure correcting procedure which follows a standard framework performing measurements and unitary operators according to the measurements outcomes, when the circuits are designed for quantum secret sharing using the [[5, 1, 3]] binary stabilizer code. The evaluation can be reversed if one discovers a better circuit for the erasure correcting procedure which does not follow the standard framework.

  • Short DL-Based Blacklistable Ring Signatures from DualRing

    Toru NAKANISHI  Atsuki IRIBOSHI  Katsunobu IMAI  

     
    PAPER-Cryptography and Information Security

      Pubricized:
    2023/09/06
      Vol:
    E107-A No:3
      Page(s):
    464-475

    As one of privacy-enhancing authentications suitable for decentralized environments, ring signatures have intensively been researched. In ring signatures, each user can choose any ad-hoc set of users (specified by public keys) called a ring, and anonymously sign a message as one of the users. However, in applications of anonymous authentications, users may misbehave the service due to the anonymity, and thus a mechanism to exclude the anonymous misbehaving users is required. However, in the existing ring signature scheme, a trusted entity to open the identity of the user is needed, but it is not suitable for the decentralized environments. On the other hand, as another type of anonymous authentications, a decentralized blacklistable anonymous credential system is proposed, where anonymous misbehaving users can be detected and excluded by a blacklist. However, the DL-based instantiation needs O(N) proof size for the ring size N. In the research line of the DL-based ring signatures, an efficient scheme with O(log N) signature size, called DualRing, is proposed. In this paper, we propose a DL-based blacklistable ring signature scheme extended from DualRing, where in addition to the short O(log N) signature size for N, the blacklisting mechanism is realized to exclude misbehaving users. Since the blacklisting mechanism causes additional costs in our scheme, the signature size is O(log N+l), where l is the blacklist size.

  • Equivalences among Some Information Measures for Individual Sequences and Their Applications for Fixed-Length Coding Problems

    Tomohiko UYEMATSU  Tetsunao MATSUTA  

     
    PAPER-Source Coding and Data Compression

      Pubricized:
    2023/08/16
      Vol:
    E107-A No:3
      Page(s):
    393-403

    This paper proposes three new information measures for individual sequences and clarifies their properties. Our new information measures are called as the non-overlapping max-entropy, the overlapping smooth max-entropy, and the non-overlapping smooth max-entropy, respectively. These measures are related to the fixed-length coding of individual sequences. We investigate these measures, and show the following three properties: (1) The non-overlapping max-entropy coincides with the topological entropy. (2) The overlapping smooth max-entropy and the non-overlapping smooth max-entropy coincide with the Ziv-entropy. (3) When an individual sequence is drawn from an ergodic source, the overlapping smooth max-entropy and the non-overlapping smooth max-entropy coincide with the entropy rate of the source. Further, we apply these information measures to the fixed-length coding of individual sequences, and propose some new universal coding schemes which are asymptotically optimum.

  • Information-Theoretic Perspectives for Simulation-Based Security in Multi-Party Computation

    Mitsugu IWAMOTO  

     
    INVITED PAPER-Cryptography and Information Security

      Pubricized:
    2023/12/01
      Vol:
    E107-A No:3
      Page(s):
    360-372

    Information-theoretic security and computational security are fundamental paradigms of security in the theory of cryptography. The two paradigms interact with each other but have shown different progress, which motivates us to explore the intersection between them. In this paper, we focus on Multi-Party Computation (MPC) because the security of MPC is formulated by simulation-based security, which originates from computational security, even if it requires information-theoretic security. We provide several equivalent formalizations of the security of MPC under a semi-honest model from the viewpoints of information theory and statistics. The interpretations of these variants are so natural that they support the other aspects of simulation-based security. Specifically, the variants based on conditional mutual information and sufficient statistics are interesting because security proofs for those variants can be given by information measures and factorization theorem, respectively. To exemplify this, we show several security proofs of BGW (Ben-Or, Goldwasser, Wigderson) protocols, which are basically proved by constructing a simulator.

  • Hierarchical Latent Alignment for Non-Autoregressive Generation under High Compression Ratio

    Wang XU  Yongliang MA  Kehai CHEN  Ming ZHOU  Muyun YANG  Tiejun ZHAO  

     
    PAPER-Natural Language Processing

      Pubricized:
    2023/12/01
      Vol:
    E107-D No:3
      Page(s):
    411-419

    Non-autoregressive generation has attracted more and more attention due to its fast decoding speed. Latent alignment objectives, such as CTC, are designed to capture the monotonic alignments between the predicted and output tokens, which have been used for machine translation and sentence summarization. However, our preliminary experiments revealed that CTC performs poorly on document abstractive summarization, where a high compression ratio between the input and output is involved. To address this issue, we conduct a theoretical analysis and propose Hierarchical Latent Alignment (HLA). The basic idea is a two-step alignment process: we first align the sentences in the input and output, and subsequently derive token-level alignment using CTC based on aligned sentences. We evaluate the effectiveness of our proposed approach on two widely used datasets XSUM and CNNDM. The results indicate that our proposed method exhibits remarkable scalability even when dealing with high compression ratios.

  • CoVR+: Design of Visual Effects for Promoting Joint Attention During Shared VR Experiences via a Projection of HMD User's View

    Akiyoshi SHINDO  Shogo FUKUSHIMA  Ari HAUTASAARI  Takeshi NAEMURA  

     
    PAPER

      Pubricized:
    2023/12/14
      Vol:
    E107-D No:3
      Page(s):
    374-382

    A user wearing a Head-Mounted Display (HMD) is likely to feel isolated when sharing virtual reality (VR) experiences with Non-HMD users in the same physical space due to not being able to see the real space outside the virtual world. This research proposes a method for an HMD user to recognize the Non-HMD users' gaze and attention via a projector attached to the HMD. In the proposed approach, the projected HMD user's view is filtered darker than default, and when Non-HMD users point controllers towards the projected view, the filter is removed from a circular area for both HMD and Non-HMD users indicating which region the Non-HMD users are viewing. We conducted two user studies showing that the Non-HMD users' gaze can be recognized with the proposed method, and investigated the preferred range for the alpha value and the size of the area for removing the filter for the HMD user.

  • Chained Block is NP-Complete

    Chuzo IWAMOTO  Tatsuya IDE  

     
    LETTER

      Pubricized:
    2023/10/23
      Vol:
    E107-D No:3
      Page(s):
    320-324

    Chained Block is one of Nikoli's pencil puzzles. We study the computational complexity of Chained Block puzzles. It is shown that deciding whether a given instance of the Chained Block puzzle has a solution is NP-complete.

  • Non-Cooperative Rational Synthesis Problem on Stochastic Games for Positional Strategies

    So KOIDE  Yoshiaki TAKATA  Hiroyuki SEKI  

     
    PAPER

      Pubricized:
    2023/10/11
      Vol:
    E107-D No:3
      Page(s):
    301-311

    Synthesis problems on multiplayer non-zero-sum games (MG) with multiple environment players that behave rationally are the problems to find a good strategy of the system and have been extensively studied. This paper concerns the synthesis problems on stochastic MG (SMG), where a special controller other than players, called nature, which chooses a move in its turn randomly, may exist. Two types of synthesis problems on SMG exist: cooperative rational synthesis problem (CRSP) and non-cooperative rational synthesis problem (NCRSP). The rationality of environment players is modeled by Nash equilibria, and CRSP is the problem to decide whether there exists a Nash equilibrium that gives the system a payoff not less than a given threshold. Ummels et al. studied the complexity of CRSP for various classes of objectives and strategies of players. CRSP fits the situation where the system can make a suggestion of a strategy profile (a tuple of strategies of all players) to the environment players. However, in real applications, the system may rarely have an opportunity to make suggestions to the environment, and thus CRSP is optimistic. NCRSP is the problem to decide whether there exists a strategy σ0 of the system satisfying that for every strategy profile of the environment players that forms a 0-fixed Nash equilibrium (a Nash equilibrium where the system's strategy is fixed to σ0), the system obtains a payoff not less than a given threshold. In this paper, we investigate the complexity of NCRSP for positional (i.e. pure memoryless) strategies. We consider ω-regular objectives as the model of players' objectives, and show the complexity results of the problem for several subclasses of ω-regular objectives. In particular, the problem for terminal reachability (TR) objectives is shown to be Σp2-complete.

  • Uniaxially Symmetrical T-Junction OMT with 45° -Tilted Branch Waveguide Ports

    Hidenori YUKAWA  Yu USHIJIMA  Toru TAKAHASHI  Toru FUKASAWA  Yoshio INASAWA  Naofumi YONEDA  Moriyasu MIYAZAKI  

     
    PAPER-Electromagnetic Theory

      Pubricized:
    2023/10/13
      Vol:
    E107-C No:3
      Page(s):
    57-65

    A T-junction orthomode transducer (OMT) is a waveguide component that separates two orthogonal linear polarizations in the same frequency band. It has a common circular waveguide short-circuited at one end and two branch rectangular waveguides arranged in opposite directions near the short circuit. One of the advantages of a T-junction OMT is its short axial length. However, the two rectangular ports, which need to be orthogonal, have different levels of performance because of asymmetry. We therefore propose a uniaxially symmetrical T-junction OMT, which is configured such that the two branch waveguides are tilted 45° to the short circuit. The uniaxially symmetrical configuration enables same levels of performance for the two ports, and its impedance matching is easier compared to that for the conventional configuration. The polarization separation principle can be explained using the principles of orthomode junction (OMJ) and turnstile OMT. Based on calculations, the proposed configuration demonstrated a return loss of 25dB, XPD of 30dB, isolation of 21dB between the two branch ports, and loss of 0.25dB, with a bandwidth of 15% in the K band. The OMT was then fabricated as a single piece via 3D printing and evaluated against the calculated performance indices.

41-60hit(5900hit)