Chen ZHONG Chegnyu WU Xiangyang LI Ao ZHAN Zhengqiang WANG
A novel temporal convolution network-gated recurrent unit (NTCN-GRU) algorithm is proposed for the greatest of constant false alarm rate (GO-CFAR) frequency hopping (FH) prediction, integrating GRU and Bayesian optimization (BO). GRU efficiently captures the semantic associations among long FH sequences, and mitigates the phenomenon of gradient vanishing or explosion. BO improves extracting data features by optimizing hyperparameters besides. Simulations demonstrate that the proposed algorithm effectively reduces the loss in the training process, greatly improves the FH prediction effect, and outperforms the existing FH sequence prediction model. The model runtime is also reduced by three-quarters compared with others FH sequence prediction models.
Feng WEN Haixin HUANG Xiangyang YIN Junguang MA Xiaojie HU
Multi-object tracking (MOT) algorithms are typically classified as one-shot or two-step algorithms. The one-shot MOT algorithm is widely studied and applied due to its fast inference speed. However, one-shot algorithms include two sub-tasks of detection and re-ID, which have conflicting directions for model optimization, thus limiting tracking performance. Additionally, MOT algorithms often suffer from serious ID switching issues, which can negatively affect the tracking effect. To address these challenges, this study proposes the DETrack algorithm, which consists of feature decomposition and feature enhancement modules. The feature decomposition module can effectively exploit the differences and correlations of different tasks to solve the conflict problem. Moreover, it can effectively mitigate the competition between the detection and re-ID tasks, while simultaneously enhancing their cooperation. The feature enhancement module can improve feature quality and alleviate the problem of target ID switching. Experimental results demonstrate that DETrack has achieved improvements in multi-object tracking performance, while reducing the number of ID switching. The designed method of feature decomposition and feature enhancement can significantly enhance target tracking effectiveness.
Shuto HASEGAWA Koichiro ENOMOTO Taeko MIZUTANI Yuri OKANO Takenori TANAKA Osamu SAKAI
Melanin, which is responsible for the appearance of spots and freckles, is an important indicator in evaluating skin condition. To assess the efficacy of cosmetics, skin condition scoring is performed by analyzing the distribution and amount of melanin from microscopic images of the stratum corneum cells. However, the current practice of diagnosing skin condition using stratum corneum cells images relies heavily on visual evaluation by experts. The goal of this study is to develop a quantitative evaluation system for skin condition based on melanin within unstained stratum corneum cells images. The proposed system utilizes principal component regression to perform five-level scoring, which is then compared with visual evaluation scores to assess the system’s usefulness. Additionally, we evaluated the impact of indicators related to melanin obtained from images on the scores, and verified which indicators are effective for evaluation. In conclusion, we confirmed that scoring is possible with an accuracy of more than 60% on a combination of several indicators, which is comparable to the accuracy of visual assessment.
Shinobu NAGAYAMA Tsutomu SASAO Jon T. BUTLER
This paper proposes a decomposition method for symmetric multiple-valued functions. It decomposes a given symmetric multiple-valued function into three parts. By using suitable decision diagrams for the three parts, we can represent symmetric multiple-valued functions compactly. By deriving theorems on sizes of the decision diagrams, this paper shows that space complexity of the proposed representation is low. This paper also presents algorithms to construct the decision diagrams for symmetric multiple-valued functions with low time complexity. Experimental results show that the proposed method represents randomly generated symmetric multiple-valued functions more compactly than the conventional representation method using standard multiple-valued decision diagrams. Symmetric multiple-valued functions are a basic class of functions, and thus, their compact representation benefits many applications where they appear.
Hongbo LI Aijun LIU Qiang YANG Zhe LYU Di YAO
To improve the direction-of-arrival estimation performance of the small-aperture array, we propose a source localization method inspired by the Ormia fly’s coupled ears and MUSIC-like algorithm. The Ormia can local its host cricket’s sound precisely despite the tremendous incompatibility between the spacing of its ear and the sound wavelength. In this paper, we first implement a biologically inspired coupled system based on the coupled model of the Ormia’s ears and solve its responses by the modal decomposition method. Then, we analyze the effect of the system on the received signals of the array. Research shows that the system amplifies the amplitude ratio and phase difference between the signals, equivalent to creating a virtual array with a larger aperture. Finally, we apply the MUSIC-like algorithm for DOA estimation to suppress the colored noise caused by the system. Numerical results demonstrate that the proposed method can improve the localization precision and resolution of the array.
Yang XIAO Zhongyuan ZHOU Mingjie SHENG Qi ZHOU
The method of extracting impedance parameters of surface mounted (SMD) electronic components by test is suitable for components with unknown model or material information, but requires consideration of errors caused by non-coaxial and measurement fixtures. In this paper, a fixture for impedance measurement is designed according to the characteristics of passive devices, and the fixture de-embedding method is used to eliminate errors and improve the test accuracy. The method of obtaining S parameters of fixture based on full wave simulation proposed in this paper can provide a thought for obtaining S parameters in de-embedding. Taking a certain patch capacitor as an example, the S parameters for de-embedding were obtained using methods based on full wave simulation, 2×Thru, and ADS simulation, and de-embedding tests were conducted. The results indicate that obtaining the S parameter of the testing fixture based on full wave simulation and conducting de-embedding testing compared to ADS simulation can accurately extract the impedance parameters of SMD electronic components, which provides a reference for the study of electromagnetic interference (EMI) coupling mechanism.
Shion UTSUMI Kosei SAKAMOTO Takanori ISOBE
Lightweight block ciphers have gained attention in recent years due to the increasing demand for sensor nodes, RFID tags, and various applications. In such a situation, lightweight block ciphers Piccolo and TWINE have been proposed. Both Piccolo and TWINE are designed based on the Generalized Feistel Structure. However, it is crucial to address the potential vulnerability of these structures to the impossible differential attack. Therefore, detailed security evaluations against this attack are essential. This paper focuses on conducting bit-level evaluations of Piccolo and TWINE against related-key impossible differential attacks by leveraging SAT-aided approaches. We search for the longest distinguishers under the condition that the Hamming weight of the active bits of the input, which includes plaintext and master key differences, and output differences is set to 1, respectively. Additionally, for Tweakable TWINE, we search for the longest distinguishers under the related-tweak and related-tweak-key settings. The result for Piccolo with a 128-bit key, we identify the longest 16-round distinguishers for the first time. In addition, we also demonstrate the ability to extend these distinguishers to 17 rounds by taking into account the cancellation of the round key and plaintext difference. Regarding evaluations of TWINE with a 128-bit key, we search for the first time and reveal the distinguishers up to 19 rounds. For the search for Tweakable TWINE, we evaluate under the related-tweak-key setting for the first time and reveal the distinguishers up to 18 rounds for 80-bit key and 19 rounds for 128-bit key.
Nawras KHUDHUR Aryo PINANDITO Yusuke HAYASHI Tsukasa HIRASHIMA
This study investigates the efficacy of a partial decomposition approach in concept map recomposition tasks to reduce cognitive load while maintaining the benefits of traditional recomposition approaches. Prior research has demonstrated that concept map recomposition, involving the rearrangement of unconnected concepts and links, can enhance reading comprehension. However, this task often imposes a significant burden on learners’ working memory. To address this challenge, this study proposes a partial recomposition approach where learners are tasked with recomposing only a portion of the concept map, thereby reducing the problem space. The proposed approach aims at lowering the cognitive load while maintaining the benefits of traditional recomposition task, that is, learning effect and motivation. To investigate the differences in cognitive load, learning effect, and motivation between the full decomposition (the traditional approach) and partial decomposition (the proposed approach), we have conducted an experiment (N=78) where the participants were divided into two groups of “full decomposition” and “partial decomposition”. The full decomposition group was assigned the task of recomposing a concept map from a set of unconnected concept nodes and links, while the partial decomposition group worked with partially connected nodes and links. The experimental results show a significant reduction in the embedded cognitive load of concept map recomposition across different dimensions while learning effect and motivation remained similar between the conditions. On the basis of these findings, educators are recommended to incorporate partially disconnected concept maps in recomposition tasks to optimize time management and sustain learner motivation. By implementing this approach, instructors can conserve cognitive resources and allocate saved energy and time to other activities that enhance the overall learning process.
We address a path planning problem for heterogeneous multi-robot systems under specifications consisting of temporal constraints and routing tasks such as package delivery services. The robots are partitioned into several groups based on their dynamics and specifications. We introduce a concise description of such tasks, called a work, and extend counting LTL to represent such specifications. We convert the problem into an ILP problem. We show that the number of variables in the ILP problem is fewer than that of the existing method using cLTL+. By simulation, we show that the computation time of the proposed method is faster than that of the existing method.
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.
This letter deals with the joint direction of arrival and direction of departure estimation problem for overloaded target in bistatic multiple-input multiple-output radar system. In order to achieve the purpose of effective estimation, the presented Khatri-Rao (KR) MUSIC estimator with the ability to handle overloaded targets mainly combines the subspace characteristics of the target reflected wave signal and the KR product based on the array response. This letter also presents a computationally efficient KR noise subspace projection matrix estimation technique to reduce the computational load due to perform high-dimensional singular value decomposition. Finally, the effectiveness of the proposed method is verified by computer simulation.
Jiaxuan LU Yutaka MASUDA Tohru ISHIHARA
Approximate computing (AC) saves energy and improves performance by introducing approximation into computation in error-torrent applications. This work focuses on an AC strategy that accurately performs important computations and approximates others. In order to make AC circuits practical, we need to determine which computation is how important carefully, and thus need to appropriately approximate the redundant computation for maintaining the required computational quality. In this paper, we focus on the importance of computations at the flip-flop (FF) level and propose a novel importance evaluation methodology. The key idea of the proposed methodology is a two-step fault injection algorithm to extract the near-optimal set of redundant FFs in the circuit. In the first step, the proposed methodology performs the FI simulation for each FF and extracts the candidates of redundant FFs. Then, in the second step, the proposed methodology extracts the set of redundant FFs in a binary search manner. Thanks to the two-step strategy, the proposed algorithm reduces the complexity of architecture exploration from an exponential order to a linear order without understanding the functionality and behavior of the target application program. Experimental results show that the proposed methodology identifies the candidates of redundant FFs depending on the given constraints. In a case study of an image processing accelerator, the truncation for identified redundant FFs reduces the circuit area by 29.6% and saves power dissipation by 44.8% under the ASIC implementation while satisfying the PSNR constraint. Similarly, the dynamic power dissipation is saved by 47.2% under the FPGA implementation.
Wang XU Yongliang MA Kehai CHEN Ming ZHOU Muyun YANG Tiejun ZHAO
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.
Shuhei TSUCHIDA Satoru FUKAYAMA Jun KATO Hiromu YAKURA Masataka GOTO
Composing choreography is challenging because it involves numerous iterative refinements. According to our video analysis and interviews, choreographers typically need to imagine dancers' movements to revise drafts on paper since testing new movements and formations with actual dancers takes time. To address this difficulty, we present an interactive group-dance simulation interface, DanceUnisoner, that assists choreographers in composing a group dance in a simulated environment. With DanceUnisoner, choreographers can arrange excerpts from solo-dance videos of dancers throughout a three-dimensional space. They can adjust various parameters related to the dancers in real time, such as each dancer's position and size and each movement's timing. To evaluate the effectiveness of the system's parametric, visual, and interactive interface, we asked seven choreographers to use it and compose group dances. Our observations, interviews, and quantitative analysis revealed their successful usage in iterative refinements and visual checking of choreography, providing insights to facilitate further computational creativity support for choreographers.
Linhan LI Qianying ZHANG Zekun XU Shijun ZHAO Zhiping SHI Yong GUAN
The Linux kernel has been applied in various security-sensitive fields, so ensuring its security is crucial. Vulnerabilities in the Linux kernel are usually caused by undefined behaviors of the C programming language, the most threatening of which are memory safety vulnerabilities. Both the software-based and hardware approaches to memory safety have disadvantages of poor performance, false positives, and poor compatibility. This paper explores the feasibility of using the safe programming language Rust to reconstruct a Linux kernel component and open-source the component's code. We leverage the Rust FFI mechanism to design a safe foreign interface layer to enable the reconstructed component to invoke other Linux functionalities, and then use Rust to reconstruct the component, during which we leverage Rust's type-safety and ownership mechanisms to improve its security, and finally export the C interface of the component to enable the invocation by the Linux kernel. The performance and memory overhead of the reconstructed component, referred to as “rOOM”, were evaluated, revealing a performance overhead of 8.9% in kernel mode, 5% in user mode, 3% in real time, and a memory overhead of 0.06%. These results suggest that it is possible to develop key components of the Linux kernel using Rust in terms of functionality, performance, and memory overhead.
Hidenori YUKAWA Yu USHIJIMA Toru TAKAHASHI Toru FUKASAWA Yoshio INASAWA Naofumi YONEDA Moriyasu MIYAZAKI
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.
Keita TERASHIMA Koichi KOBAYASHI Yuh YAMASHITA
In a multi-agent system, it is important to consider a design method of cooperative actions in order to achieve a common goal. In this paper, we propose two novel multi-agent reinforcement learning methods, where the control specification is described by linear temporal logic formulas, which represent a common goal. First, we propose a simple solution method, which is directly extended from the single-agent case. In this method, there are some technical issues caused by the increase in the number of agents. Next, to overcome these technical issues, we propose a new method in which an aggregator is introduced. Finally, these two methods are compared by numerical simulations, with a surveillance problem as an example.
Aorui GOU Jingjing LIU Xiaoxiang CHEN Xiaoyang ZENG Yibo FAN
Convolutional Neural Networks (CNNs) and Transformers have achieved remarkable performance in detection and classification tasks. Nevertheless, their feature extraction cannot consider both local and global information, so the detection and classification performance can be further improved. In addition, more and more deep learning networks are designed as more and more complex, and the amount of computation and storage space required is also significantly increased. This paper proposes a combination of CNN and transformer, and designs a local feature enhancement module and global context modeling module to enhance the cascade network. While the local feature enhancement module increases the range of feature extraction, the global context modeling is used to capture the feature maps' global information. To decrease the model complexity, a shared sublayer is designed to realize the sharing of weight parameters between the adjacent convolutional layers or cross convolutional layers, thereby reducing the number of convolutional weight parameters. Moreover, to effectively improve the detection performance of neural networks without increasing network parameters, the optimal transport assignment approach is proposed to resolve the problem of label assignment. The classification loss and regression loss are the summations of the cost between the demander and supplier. The experiment results demonstrate that the proposed Combination of CNN and Transformer with Shared Sublayer (CCTSS) performs better than the state-of-the-art methods in various datasets and applications.
Canonical decomposition for bipartite graphs, which was introduced by Fouquet, Giakoumakis, and Vanherpe (1999), is a decomposition scheme for bipartite graphs associated with modular decomposition. Weak-bisplit graphs are bipartite graphs totally decomposable (i.e., reducible to single vertices) by canonical decomposition. Canonical decomposition comprises series, parallel, and K+S decomposition. This paper studies a decomposition scheme comprising only parallel and K+S decomposition. We show that bipartite graphs totally decomposable by this decomposition are precisely P6-free chordal bipartite graphs. This characterization indicates that P6-free chordal bipartite graphs can be recognized in linear time using the recognition algorithm for weak-bisplit graphs presented by Giakoumakis and Vanherpe (2003).
Satoshi SHINADA Yuta GOTO Hideaki FURUKAWA
We propose a novel mode-multiplexed light source using angularly-multiplexed volume holograms. Mode division multiplexing beams can be generated from a simple transmitter that is made of a laser array, single lens, and volume holograms. Hologram media has low recording sensitivity; hence, using holograms in the communication band is difficult. However, a dual wavelength method that uses different wavelengths for recording and reading holograms can realize the volume holograms for the infrared region. The volume holograms for three spatial mode multiplexing are formed using a compact Michelson interferometer type recording setup; simultaneous generations of three modes were demonstrated using a fiber array or vertical cavity surface emitting laser array with the volume holograms. A low loss coupling of three modes to few-mode-fiber can be achieved through the precise design and recording of volume holograms. The simple and low-cost mode-multiplexed light source using the volume holograms has the potential to broaden the application of MDM.