The search functionality is under construction.
The search functionality is under construction.

Keyword Search Result

[Keyword] Y(22683hit)

201-220hit(22683hit)

  • Understanding File System Operations of a Secure Container Runtime Using System Call Tracing Technique

    Sunwoo JANG  Young-Kyoon SUH  Byungchul TAK  

     
    LETTER-Software System

      Pubricized:
    2023/11/01
      Vol:
    E107-D No:2
      Page(s):
    229-233

    This letter presents a technique that observes system call mapping behavior of the proxy kernel layer of secure container runtimes. We applied it to file system operations of a secure container runtime, gVisor. We found that gVisor's operations can become more expensive than the native by 48× more syscalls for open, and 6× for read and write.

  • BRsyn-Caps: Chinese Text Classification Using Capsule Network Based on Bert and Dependency Syntax

    Jie LUO  Chengwan HE  Hongwei LUO  

     
    PAPER-Natural Language Processing

      Pubricized:
    2023/11/06
      Vol:
    E107-D No:2
      Page(s):
    212-219

    Text classification is a fundamental task in natural language processing, which finds extensive applications in various domains, such as spam detection and sentiment analysis. Syntactic information can be effectively utilized to improve the performance of neural network models in understanding the semantics of text. The Chinese text exhibits a high degree of syntactic complexity, with individual words often possessing multiple parts of speech. In this paper, we propose BRsyn-caps, a capsule network-based Chinese text classification model that leverages both Bert and dependency syntax. Our proposed approach integrates semantic information through Bert pre-training model for obtaining word representations, extracts contextual information through Long Short-term memory neural network (LSTM), encodes syntactic dependency trees through graph attention neural network, and utilizes capsule network to effectively integrate features for text classification. Additionally, we propose a character-level syntactic dependency tree adjacency matrix construction algorithm, which can introduce syntactic information into character-level representation. Experiments on five datasets demonstrate that BRsyn-caps can effectively integrate semantic, sequential, and syntactic information in text, proving the effectiveness of our proposed method for Chinese text classification.

  • Development of a Coanda-Drone with Built-in Propellers

    Zejing ZHAO  Bin ZHANG  Hun-ok LIM  

     
    PAPER-Artificial Intelligence, Data Mining

      Pubricized:
    2023/11/10
      Vol:
    E107-D No:2
      Page(s):
    180-190

    In this study, a Coanda-drone with length, width, and height of 121.6, 121.6, and 191[mm] was designed, and its total mass was 1166.7[g]. Using four propulsion devices, it could produce a maximum of 5428[g] thrust. Its structure is very different from conventional drones because in this study it combines the design of the jet engine of a jet fixed-wing drone with the fuselage structure layout of a rotary-wing drone. The advantage of jet drone's high propulsion is kept so that it can output greater thrust under the same variation of PWM waveform output. In this study, the propulsion device performs high-speed jetting, and the airflow around the propulsion device will also be jetted downward along the direction of the airflow.

  • RR-Row: Redirect-on-Write Based Virtual Machine Disk for Record/Replay

    Ying ZHAO  Youquan XIAN  Yongnan LI  Peng LIU  Dongcheng LI  

     
    PAPER-Data Engineering, Web Information Systems

      Pubricized:
    2023/11/06
      Vol:
    E107-D No:2
      Page(s):
    169-179

    Record/replay is one essential tool in clouds to provide many capabilities such as fault tolerance, software debugging, and security analysis by recording the execution into a log and replaying it deterministically later on. However, in virtualized environments, the log file increases heavily due to saving a considerable amount of I/O data, finally introducing significant storage costs. To mitigate this problem, this paper proposes RR-Row, a redirect-on-write based virtual machine disk for record/replay scenarios. RR-Row appends the written data into new blocks rather than overwrites the original blocks during normal execution so that all written data are reserved in the disk. In this way, the record system only saves the block id instead of the full content, and the replay system can directly fetch the data from the disk rather than the log, thereby reducing the log size a lot. In addition, we propose several optimizations for improving I/O performance so that it is also suitable for normal execution. We implement RR-Row for QEMU and conduct a set of experiments. The results show that RR-Row reduces the log size by 68% compared to the currently used Raw/QCow2 disk without compromising I/O performance.

  • Capacitive Wireless Power Transfer System with Misalignment Tolerance in Flowing Freshwater Environments

    Yasumasa NAKA  Akihiko ISHIWATA  Masaya TAMURA  

     
    PAPER-Electromagnetic Theory

      Pubricized:
    2023/08/01
      Vol:
    E107-C No:2
      Page(s):
    47-56

    The misalignment of a coupler is a significant issue for capacitive wireless power transfer (WPT). This paper presents a capacitive WPT system specifically designed for underwater drones operating in flowing freshwater environments. The primary design features include a capacitive coupler with an opposite relative position between feeding and receiving points on the coupler electrode, two phase compensation circuits, and a load-independent inverter. A stable and energy-efficient power transmission is achieved by maintaining a 90° phase difference on the coupler electrode in dielectrics with a large unloaded quality factor (Q factor), such as in freshwater. Although a 622-mm coupler electrode is required at 13.56MHz, the phase compensation circuits can reduce to 250mm as one example, which is mountable to small underwater drones. Furthermore, the electricity waste is automatically reduced using the constant-current (CC) output inverter in the event of misalignment where efficiency drops occur. Finally, their functions are simulated and demonstrated at various receiver positions and transfer distances in tap water.

  • Electrically Controllable Light Scattering Properties of Nematic Liquid Crystal/Polyfluorene Gel Devices Open Access

    Asuka YAGI  Michinori HONMA  Ryota ITO  Toshiaki NOSE  

     
    INVITED PAPER

      Pubricized:
    2023/08/10
      Vol:
    E107-C No:2
      Page(s):
    29-33

    In recent years, demand for smart windows with dimming and other functions has been increasing, e.g., polymer dispersed liquid crystals. Liquid crystal (LC) gels also have the potential for smart glass applications owing to their light-scattering properties. In this study, LC gels were prepared by mixing nematic LC (E7) with poly(9,9-di-n-octylfluorenyl-2,7-diyl) (PFO) as a gelator. The LC gel formed a dense PFO network as the concentration increased. The PFO network structure changed in response to the change in the cooling rate. High contrast ratio of light scattering was obtained for the LC gel device that was fabricated via the 2-wt%-doping of PFO and natural cooling. Furthermore, the PFO concentration and cooling rate were found to affect the response time of the LC gel device.

  • Universal Angle Visibility Realized by a Volumetric 3D Display Using a Rotating Mirror-Image Helix Screen Open Access

    Karin WAKATSUKI  Chiemi FUJIKAWA  Makoto OMODANI  

     
    INVITED PAPER

      Pubricized:
    2023/08/03
      Vol:
    E107-C No:2
      Page(s):
    23-28

    Herein, we propose a volumetric 3D display in which cross-sectional images are projected onto a rotating helix screen. The method employed by this display can enable image observation from universal directions. A major challenge associated with this method is the presence of invisible regions that occur depending on the observation angle. This study aimed to fabricate a mirror-image helix screen with two helical surfaces coaxially arranged in a plane-symmetrical configuration. The visible region was actually measured to be larger than the visible region of the conventional helix screen. We confirmed that the improved visible region was almost independent of the observation angle and that the visible region was almost equally wide on both the left and right sides of the rotation axis.

  • Interdigital and Multi-Via Structures for Mushroom-Type Metasurface Reflectors

    Taisei URAKAMI  Tamami MARUYAMA  Shimpei NISHIYAMA  Manato KUSAMIZU  Akira ONO  Takahiro SHIOZAWA  

     
    PAPER-Antennas and Propagation

      Vol:
    E107-B No:2
      Page(s):
    309-320

    The novel patch element shapes with the interdigital and multi-via structures for mushroom-type metasurface reflectors are proposed for controlling the reflection phases. The interdigital structure provides a wide reflection phase range by changing the depth of the interdigital fingers. In addition, the multi-via structure provides the higher positive reflection phases such as near +180°. The sufficient reflection phase range of 360° and the low polarization dependent properties could be confirmed by the electromagnetic field simulation. The metasurface reflector for the normal incident plane wave was designed. The desired reflection angles and sharp far field patterns of the reflected beams could be confirmed in the simulation results. The prototype reflectors for the experiments should be designed in the same way as the primary reflector design of the reflector antenna. Specifically, the reflector design method based on the ray tracing method using the incident wave phase was proposed for the prototype. The experimental radiation pattern for the reflector antenna composed of the transmitting antenna (TX) and the prototype metasurface reflector was similar to the simulated radiation pattern. The effectiveness of the proposed structures and their design methods could be confirmed by these simulation and experiment results.

  • An Adaptive Energy-Efficient Uneven Clustering Routing Protocol for WSNs

    Mingyu LI  Jihang YIN  Yonggang XU  Gang HUA  Nian XU  

     
    PAPER-Network

      Vol:
    E107-B No:2
      Page(s):
    296-308

    Aiming at the problem of “energy hole” caused by random distribution of nodes in large-scale wireless sensor networks (WSNs), this paper proposes an adaptive energy-efficient balanced uneven clustering routing protocol (AEBUC) for WSNs. The competition radius is adaptively adjusted based on the node density and the distance from candidate cluster head (CH) to base station (BS) to achieve scale-controlled adaptive optimal clustering; in candidate CHs, the energy relative density and candidate CH relative density are comprehensively considered to achieve dynamic CH selection. In the inter-cluster communication, based on the principle of energy balance, the relay communication cost function is established and combined with the minimum spanning tree method to realize the optimized inter-cluster multi-hop routing, forming an efficient communication routing tree. The experimental results show that the protocol effectively saves network energy, significantly extends network lifetime, and better solves the “energy hole” problem.

  • A Recommendation-Based Auxiliary Caching for Mapping Record

    Zhaolin MA  Jiali YOU  Haojiang DENG  

     
    PAPER-Fundamental Theories for Communications

      Vol:
    E107-B No:2
      Page(s):
    286-295

    Due to the increase in the volume of data and intensified concurrent requests, distributed caching is commonly used to manage high-concurrency requests and alleviate pressure on databases. However, there is limited research on distributed record mapping caching, and traditional caching algorithms have suboptimal resolution performance for mapping records that typically follow a long-tail distribution. To address the aforementioned issue, in this paper, we propose a recommendation-based adaptive auxiliary caching method, AC-REC, which delivers the primary cache record along with a list of additional cache records. The method uses request correlations as a basis for recommendations, customizes the number of additional cache entries provided, and dynamically adjusts the time-to-live. We conducted evaluations to compare the performance of our method against various benchmark strategies. The results show that our proposed method, as compared to the conventional LCE method, increased the cache hit ratio by an average of 20%, Moreover, this improvement is achieved while effectively utilizing the cache space. We believe that our strategy will contribute an effective solution to the related studies in both traditional network architecture and caching in paradigms like ICN.

  • Parity-Check Polarization-Adjusted Convolutional Coding

    Qingping YU  You ZHANG  Renze LUO  Longye WANG  Xingwang LI  

     
    LETTER-Coding Theory

      Pubricized:
    2023/07/27
      Vol:
    E107-A No:2
      Page(s):
    187-191

    Polarization-adjusted convolutional (PAC) codes have better error-correcting performance than polar codes mostly because of the improved weight distribution brought by the convolutional pre-transformation. In this paper, we propose the parity check PAC (PC-PAC) codes to further improve error-correcting performance of PAC codes. The design principle is to establish parity check functions between bits with distinct row weights, such that information bits of lower reliability are re-protected by the PC relation. Moreover, an algorithm to select which bits to be involved in parity-check functions is also proposed to make sure that the constructed codes have fewer minimum-weight codewords. Simulation results show that the proposed PC-PAC codes can achieve nearly 0.2dB gain over PAC codes at frame error rate (FER) about 10-3 codes.

  • Development and Photoluminescence Properties of Dinuclear Eu(III)-β-Diketonates with a Branched Tetraphosphine Tetraoxide Ligand for Potential Use in LEDs as Red Phosphors Open Access

    Hiroki IWANAGA  Fumihiko AIGA  Shin-ichi SASAOKA  Takahiro WAZAKI  

     
    INVITED PAPER

      Pubricized:
    2023/08/03
      Vol:
    E107-C No:2
      Page(s):
    34-41

    In the field of micro-LED displays consisting of UV or Blue-LED arrays and phosphors, where the chips used are very small, particle size of phosphors must be small to suppress variation in hue for each pixel. Especially, there is a strong demand for a red phosphor with small particle sizes. However, quantum yields of inorganic phosphors decrease as particles size of phosphors get smaller. On the other hand, in the case of organic phosphors and complexes, quantum yields don't decrease when particle size gets smaller because each molecule has a function of absorbing and emitting light. We focus on Eu(III) complexes as candidates of red phosphors for micro-LED displays because their color purities of photoluminescence spectra are high, and have been tried to enhance photoluminescence intensity by coordinating non-ionic ligand, specifically, newly designed phosphine oxide ligands. Non-ionic ligands have generally less influential on properties of complexes compared with ionic ligands, but have a high degree of flexibility in molecular design. We found novel molecular design concept of phosphine oxide ligands to enhance photoluminescence properties of Eu(III) complexes. This time, novel dinuclear Eu(III)-β-diketonates with a branched tetraphosphine tetraoxide ligand, TDPBPO and TDPPPO, were developed. They are designed to have two different phosphine oxide portions; one has aromatic substituents and the other has no aromatic substituent. TDPBPO and TDPPPO ligands have functions of increasing absolute quantum yields of Eu(III)-β-diketonates. Eu(III)-β-diketonates with branched tetraphosphine tetraoxide ligands have sharp red emissions and excellent quantum yields, and are promising candidates for micro LED displays, security media, and sensing for their pure and strong photoluminescence intensity.

  • Re-Evaluating Syntax-Based Negation Scope Resolution

    Asahi YOSHIDA  Yoshihide KATO  Shigeki MATSUBARA  

     
    LETTER-Natural Language Processing

      Pubricized:
    2023/10/16
      Vol:
    E107-D No:1
      Page(s):
    165-168

    Negation scope resolution is the process of detecting the negated part of a sentence. Unlike the syntax-based approach employed in previous researches, state-of-the-art methods performed better without the explicit use of syntactic structure. This work revisits the syntax-based approach and re-evaluates the effectiveness of syntactic structure in negation scope resolution. We replace the parser utilized in the prior works with state-of-the-art parsers and modify the syntax-based heuristic rules. The experimental results demonstrate that the simple modifications enhance the performance of the prior syntax-based method to the same level as state-of-the-art end-to-end neural-based methods.

  • A CNN-Based Multi-Scale Pooling Strategy for Acoustic Scene Classification

    Rong HUANG  Yue XIE  

     
    LETTER-Speech and Hearing

      Pubricized:
    2023/10/17
      Vol:
    E107-D No:1
      Page(s):
    153-156

    Acoustic scene classification (ASC) is a fundamental domain within the realm of artificial intelligence classification tasks. ASC-based tasks commonly employ models based on convolutional neural networks (CNNs) that utilize log-Mel spectrograms as input for gathering acoustic features. In this paper, we designed a CNN-based multi-scale pooling (MSP) strategy for ASC. The log-Mel spectrograms are utilized as the input to CNN, which is partitioned into four frequency axis segments. Furthermore, we devised four CNN channels to acquire inputs from distinct frequency ranges. The high-level features extracted from outputs in various frequency bands are integrated through frequency pyramid average pooling layers at multiple levels. Subsequently, a softmax classifier is employed to classify different scenes. Our study demonstrates that the implementation of our designed model leads to a significant enhancement in the model's performance, as evidenced by the testing of two acoustic datasets.

  • Inference Discrepancy Based Curriculum Learning for Neural Machine Translation

    Lei ZHOU  Ryohei SASANO  Koichi TAKEDA  

     
    PAPER-Natural Language Processing

      Pubricized:
    2023/10/18
      Vol:
    E107-D No:1
      Page(s):
    135-143

    In practice, even a well-trained neural machine translation (NMT) model can still make biased inferences on the training set due to distribution shifts. For the human learning process, if we can not reproduce something correctly after learning it multiple times, we consider it to be more difficult. Likewise, a training example causing a large discrepancy between inference and reference implies higher learning difficulty for the MT model. Therefore, we propose to adopt the inference discrepancy of each training example as the difficulty criterion, and according to which rank training examples from easy to hard. In this way, a trained model can guide the curriculum learning process of an initial model identical to itself. We put forward an analogy to this training scheme as guiding the learning process of a curriculum NMT model by a pretrained vanilla model. In this paper, we assess the effectiveness of the proposed training scheme and take an insight into the influence of translation direction, evaluation metrics and different curriculum schedules. Experimental results on translation benchmarks WMT14 English ⇒ German, WMT17 Chinese ⇒ English and Multitarget TED Talks Task (MTTT) English ⇔ German, English ⇔ Chinese, English ⇔ Russian demonstrate that our proposed method consistently improves the translation performance against the advanced Transformer baseline.

  • Efficient Action Spotting Using Saliency Feature Weighting

    Yuzhi SHI  Takayoshi YAMASHITA  Tsubasa HIRAKAWA  Hironobu FUJIYOSHI  Mitsuru NAKAZAWA  Yeongnam CHAE  Björn STENGER  

     
    PAPER-Image Processing and Video Processing

      Pubricized:
    2023/10/17
      Vol:
    E107-D No:1
      Page(s):
    105-114

    Action spotting is a key component in high-level video understanding. The large number of similar frames poses a challenge for recognizing actions in videos. In this paper we use frame saliency to represent the importance of frames for guiding the model to focus on keyframes. We propose the frame saliency weighting module to improve frame saliency and video representation at the same time. Our proposed model contains two encoders, for pre-action and post-action time windows, to encode video context. We validate our design choices and the generality of proposed method in extensive experiments. On the public SoccerNet-v2 dataset, the method achieves an average mAP of 57.3%, improving over the state of the art. Using embedding features obtained from multiple feature extractors, the average mAP further increases to 75%. We show that reducing the model size by over 90% does not significantly impact performance. Additionally, we use ablation studies to prove the effective of saliency weighting module. Further, we show that our frame saliency weighting strategy is applicable to existing methods on more general action datasets, such as SoccerNet-v1, ActivityNet v1.3, and UCF101.

  • Speech Rhythm-Based Speaker Embeddings Extraction from Phonemes and Phoneme Duration for Multi-Speaker Speech Synthesis

    Kenichi FUJITA  Atsushi ANDO  Yusuke IJIMA  

     
    PAPER-Speech and Hearing

      Pubricized:
    2023/10/06
      Vol:
    E107-D No:1
      Page(s):
    93-104

    This paper proposes a speech rhythm-based method for speaker embeddings to model phoneme duration using a few utterances by the target speaker. Speech rhythm is one of the essential factors among speaker characteristics, along with acoustic features such as F0, for reproducing individual utterances in speech synthesis. A novel feature of the proposed method is the rhythm-based embeddings extracted from phonemes and their durations, which are known to be related to speaking rhythm. They are extracted with a speaker identification model similar to the conventional spectral feature-based one. We conducted three experiments, speaker embeddings generation, speech synthesis with generated embeddings, and embedding space analysis, to evaluate the performance. The proposed method demonstrated a moderate speaker identification performance (15.2% EER), even with only phonemes and their duration information. The objective and subjective evaluation results demonstrated that the proposed method can synthesize speech with speech rhythm closer to the target speaker than the conventional method. We also visualized the embeddings to evaluate the relationship between the distance of the embeddings and the perceptual similarity. The visualization of the embedding space and the relation analysis between the closeness indicated that the distribution of embeddings reflects the subjective and objective similarity.

  • A Novel Double-Tail Generative Adversarial Network for Fast Photo Animation

    Gang LIU  Xin CHEN  Zhixiang GAO  

     
    PAPER-Artificial Intelligence, Data Mining

      Pubricized:
    2023/09/28
      Vol:
    E107-D No:1
      Page(s):
    72-82

    Photo animation is to transform photos of real-world scenes into anime style images, which is a challenging task in AIGC (AI Generated Content). Although previous methods have achieved promising results, they often introduce noticeable artifacts or distortions. In this paper, we propose a novel double-tail generative adversarial network (DTGAN) for fast photo animation. DTGAN is the third version of the AnimeGAN series. Therefore, DTGAN is also called AnimeGANv3. The generator of DTGAN has two output tails, a support tail for outputting coarse-grained anime style images and a main tail for refining coarse-grained anime style images. In DTGAN, we propose a novel learnable normalization technique, termed as linearly adaptive denormalization (LADE), to prevent artifacts in the generated images. In order to improve the visual quality of the generated anime style images, two novel loss functions suitable for photo animation are proposed: 1) the region smoothing loss function, which is used to weaken the texture details of the generated images to achieve anime effects with abstract details; 2) the fine-grained revision loss function, which is used to eliminate artifacts and noise in the generated anime style image while preserving clear edges. Furthermore, the generator of DTGAN is a lightweight generator framework with only 1.02 million parameters in the inference phase. The proposed DTGAN can be easily end-to-end trained with unpaired training data. Extensive experiments have been conducted to qualitatively and quantitatively demonstrate that our method can produce high-quality anime style images from real-world photos and perform better than the state-of-the-art models.

  • Testing and Delay-Monitoring for the High Reliability of Memory-Based Programmable Logic Device

    Xihong ZHOU  Senling WANG  Yoshinobu HIGAMI  Hiroshi TAKAHASHI  

     
    PAPER-Dependable Computing

      Pubricized:
    2023/10/03
      Vol:
    E107-D No:1
      Page(s):
    60-71

    Memory-based Programmable Logic Device (MPLD) is a new type of reconfigurable device constructed using a general SRAM array in a unique interconnect configuration. This research aims to propose approaches to guarantee the long-term reliability of MPLDs, including a test method to identify interconnect defects in the SRAM array during the production phase and a delay monitoring technique to detect aging-caused failures. The proposed test method configures pre-generated test configuration data into SRAMs to create fault propagation paths, applies an external walking-zero/one vector to excite faults, and identifies faults at the external output ports. The proposed delay monitoring method configures a novel ring oscillator logic design into MPLD to measure delay variations when the device is in practical use. The logic simulation results with fault injection confirm the effectiveness of the proposed methods.

  • Node-to-Set Disjoint Paths Problem in Cross-Cubes

    Rikuya SASAKI  Hiroyuki ICHIDA  Htoo Htoo Sandi KYAW  Keiichi KANEKO  

     
    PAPER-Fundamentals of Information Systems

      Pubricized:
    2023/10/06
      Vol:
    E107-D No:1
      Page(s):
    53-59

    The increasing demand for high-performance computing in recent years has led to active research on massively parallel systems. The interconnection network in a massively parallel system interconnects hundreds of thousands of processing elements so that they can process large tasks while communicating among others. By regarding the processing elements as nodes and the links between processing elements as edges, respectively, we can discuss various problems of interconnection networks in the framework of the graph theory. Many topologies have been proposed for interconnection networks of massively parallel systems. The hypercube is a very popular topology and it has many variants. The cross-cube is such a topology, which can be obtained by adding one extra edge to each node of the hypercube. The cross-cube reduces the diameter of the hypercube, and allows cycles of odd lengths. Therefore, we focus on the cross-cube and propose an algorithm that constructs disjoint paths from a node to a set of nodes. We give a proof of correctness of the algorithm. Also, we show that the time complexity and the maximum path length of the algorithm are O(n3 log n) and 2n - 3, respectively. Moreover, we estimate that the average execution time of the algorithm is O(n2) based on a computer experiment.

201-220hit(22683hit)