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  • Conversational AI as a Facilitator Improves Participant Engagement and Problem-Solving in Online Discussion: Sharing Evidence from Five Cities in Afghanistan Open Access

    Sofia SAHAB  Jawad HAQBEEN  Takayuki ITO  

     
    PAPER

      Pubricized:
    2024/01/15
      Vol:
    E107-D No:4
      Page(s):
    434-442

    Despite the increasing use of conversational artificial intelligence (AI) in online discussion environments, few studies explore the application of AI as a facilitator in forming problem-solving debates and influencing opinions in cross-venue scenarios, particularly in diverse and war-ravaged countries. This study aims to investigate the impact of AI on enhancing participant engagement and collaborative problem-solving in online-mediated discussion environments, especially in diverse and heterogeneous discussion settings, such as the five cities in Afghanistan. We seek to assess the extent to which AI participation in online conversations succeeds by examining the depth of discussions and participants' contributions, comparing discussions facilitated by AI with those not facilitated by AI across different venues. The results are discussed with respect to forming and changing opinions with and without AI-mediated communication. The findings indicate that the number of opinions generated in AI-facilitated discussions significantly differs from discussions without AI support. Additionally, statistical analyses reveal quantitative disparities in online discourse sentiments when conversational AI is present compared to when it is absent. These findings contribute to a better understanding of the role of AI-mediated discussions and offer several practical and social implications, paving the way for future developments and improvements.

  • Fine Feature Analysis of Metal Plate Based on Two-Dimensional Imaging under Non-Ideal Scattering

    Xiaofan LI  Bin DENG  Qiang FU  Hongqiang WANG  

     
    PAPER-Electromagnetic Theory

      Pubricized:
    2023/05/29
      Vol:
    E106-C No:12
      Page(s):
    789-798

    The ideal point scattering model requires that each scattering center is isotropic, the position of the scattering center corresponding to the target remains unchanged, and the backscattering amplitude and phase of the target do not change with the incident frequency and incident azimuth. In fact, these conditions of the ideal point scattering model are difficult to meet, and the scattering models are not ideal in most cases. In order to understand the difference between non-ideal scattering center and ideal scattering center, this paper takes a metal plate as the research object, carries out two-dimensional imaging of the metal plate, compares the difference between the imaging position and the theoretical target position, and compares the shape of the scattering center obtained from two-dimensional imaging of the plate from different angles. From the experimental results, the offset between the scattering center position and the theoretical target position corresponding to the two-dimensional imaging of the plate under the non-ideal point scattering model is less than the range resolution and azimuth resolution. The deviation between the small angle two-dimensional imaging position and the theoretical target position using the ideal point scattering model is small, and the ideal point scattering model is still suitable for the two-dimensional imaging of the plate. In the imaging process, the ratio of range resolution and azimuth resolution affects the shape of the scattering center. The range resolution is equal to the azimuth resolution, the shape of the scattering center is circular; the range resolution is not equal to the azimuth resolution, and the shape of the scattering center is elliptic. In order to obtain more accurate two-dimensional image, the appropriate range resolution and azimuth resolution can be considered when using the ideal point scattering model for two-dimensional imaging. The two-dimensional imaging results of the plate at different azimuth and angle can be used as a reference for the study of non-ideal point scattering model.

  • Regressive Gaussian Process Latent Variable Model for Few-Frame Human Motion Prediction

    Xin JIN  Jia GUO  

     
    PAPER

      Pubricized:
    2023/05/23
      Vol:
    E106-D No:10
      Page(s):
    1621-1626

    Human motion prediction has always been an interesting research topic in computer vision and robotics. It means forecasting human movements in the future conditioning on historical 3-dimensional human skeleton sequences. Existing predicting algorithms usually rely on extensive annotated or non-annotated motion capture data and are non-adaptive. This paper addresses the problem of few-frame human motion prediction, in the spirit of the recent progress on manifold learning. More precisely, our approach is based on the insight that achieving an accurate prediction relies on a sufficiently linear expression in the latent space from a few training data in observation space. To accomplish this, we propose Regressive Gaussian Process Latent Variable Model (RGPLVM) that introduces a novel regressive kernel function for the model training. By doing so, our model produces a linear mapping from the training data space to the latent space, while effectively transforming the prediction of human motion in physical space to the linear regression analysis in the latent space equivalent. The comparison with two learning motion prediction approaches (the state-of-the-art meta learning and the classical LSTM-3LR) demonstrate that our GPLVM significantly improves the prediction performance on various of actions in the small-sample size regime.

  • Time-Resolved Observation of Organic Light Emitting Diode under Reverse Bias Voltage by Extended Time Domain Reflectometry

    Weisong LIAO  Akira KAINO  Tomoaki MASHIKO  Sou KUROMASA  Masatoshi SAKAI  Kazuhiro KUDO  

     
    BRIEF PAPER

      Pubricized:
    2022/10/26
      Vol:
    E106-C No:6
      Page(s):
    236-239

    We observed dynamical carrier motion in an OLED device under an external reverse bias application using ExTDR measurement. The rectangular wave pulses were used in our ExTDR to observe the transient impedance of the OLED sample. The falling edge of the transmission waveform reflects the transient impedance after applying pulse voltage during the pulse width. The observed pulse width variation at the falling edge waveform indicates that the frontline of the hole distribution in the hole transport layer was forced to move backward to the ITO electrode.

  • Exact Algorithm to Solve Continuous Similarity Search for Evolving Queries and Its Variant

    Tomohiro YAMAZAKI  Hisashi KOGA  

     
    PAPER

      Pubricized:
    2022/02/07
      Vol:
    E105-D No:5
      Page(s):
    898-908

    We study the continuous similarity search problem for evolving queries which has recently been formulated. Given a data stream and a database composed of n sets of items, the purpose of this problem is to maintain the top-k most similar sets to the query which evolves over time and consists of the latest W items in the data stream. For this problem, the previous exact algorithm adopts a pruning strategy which, at the present time T, decides the candidates of the top-k most similar sets from past similarity values and computes the similarity values only for them. This paper proposes a new exact algorithm which shortens the execution time by computing the similarity values only for sets whose similarity values at T can change from time T-1. We identify such sets very fast with frequency-based inverted lists (FIL). Moreover, we derive the similarity values at T in O(1) time by updating the previous values computed at time T-1. Experimentally, our exact algorithm runs faster than the previous exact algorithm by one order of magnitude and as fast as the previous approximation algorithm.

  • Single-Letter Characterizations for Information Erasure under Restriction on the Output Distribution

    Naruaki AMADA  Hideki YAGI  

     
    PAPER-Information Theory

      Pubricized:
    2020/11/09
      Vol:
    E104-A No:5
      Page(s):
    805-813

    In order to erase data including confidential information stored in storage devices, an unrelated and random sequence is usually overwritten, which prevents the data from being restored. The problem of minimizing the cost for information erasure when the amount of information leakage of the confidential information should be less than or equal to a constant asymptotically has been introduced by T. Matsuta and T. Uyematsu. Whereas the minimum cost for overwriting has been given for general sources, a single-letter characterization for stationary memoryless sources is not easily derived. In this paper, we give single-letter characterizations for stationary memoryless sources under two types of restrictions: one requires the output distribution of the encoder to be independent and identically distributed (i.i.d.) and the other requires it to be memoryless but not necessarily i.i.d. asymptotically. The characterizations indicate the relation among the amount of information leakage, the minimum cost for information erasure and the rate of the size of uniformly distributed sequences. The obtained results show that the minimum costs are different between these restrictions.

  • High Level Congestion Detection from C/C++ Source Code for High Level Synthesis Open Access

    Masato TATSUOKA  Mineo KANEKO  

     
    PAPER

      Vol:
    E103-A No:12
      Page(s):
    1437-1446

    High level synthesis (HLS) is a source-code-driven Register Transfer Level (RTL) design tool, and the performance, the power consumption, and the area of a generated RTL are limited partly by the description of a HLS input source code. In order to break through such kind of limitation and to get a further optimized RTL, the optimization of the input source code is indispensable. Routing congestion is one of such problems we need to consider the refinement of a HLS input source code. In this paper, we propose a novel HLS flow that performs code improvements by detecting congested parts directly from HLS input source code without using physical logic synthesis, and regenerating the input source code for HLS. In our approach, the origin of the wire congestion is detected from the HLS input source code by applying pattern matching on Program-Dependence Graph (PDG) constructed from the HLS input source code, the possibility of wire congestion is reported.

  • A Highly Reliable Compilation Optimization Passes Sequence Generation Framework

    Jiang WU  Jianjun XU  Xiankai MENG  Yan LEI  

     
    LETTER-Software System

      Pubricized:
    2020/06/22
      Vol:
    E103-D No:9
      Page(s):
    1998-2002

    We propose a new framework named ROICF based on reinforcement learning orienting reliable compilation optimization sequence generation. On the foundation of the LLVM standard compilation optimization passes, we can obtain specific effective phase ordering for different programs to improve program reliability.

  • Performance Prediction of Wireless Vital Data Collection System for Exercisers by a Network Simulator

    Takuma HAMAGAMI  Shinsuke HARA  Hiroyuki YOMO  Ryusuke MIYAMOTO  Yasutaka KAWAMOTO  Takunori SHIMAZAKI  Hiroyuki OKUHATA  

     
    PAPER

      Pubricized:
    2020/01/10
      Vol:
    E103-B No:6
      Page(s):
    653-661

    When we collect vital data from exercisers by putting wireless sensor nodes to them, the reliability of the wireless data collection is dependent on the position of node on the body of exerciser, therefore, in order to determine the suitable body position, it is essential to evaluate the data collection performances by changing the body positions of nodes in experiments involving human subjects. However, their fair comparison is problematic, because the experiments have no repeatability, that is, we cannot evaluate the performances for multiple body positions in an experiment at the same time. In this paper, we predict the performances by a software network simulator. Using two main functions such as a channel state function and a mobility function, the network simulator can repeatedly generate the same channel and mobility conditions for nodes. Numerical result obtained by the network simulator shows that when collecting vital data from twenty two footballers in a game, among three body position such as waist, forearm and calf, the forearm position gives the highest data collection rate and the predicted data collection rates agree well with the ones obtained by an experiment involving real subjects.

  • Symbolic Representation of Time Petri Nets for Efficient Bounded Model Checking

    Nao IGAWA  Tomoyuki YOKOGAWA  Sousuke AMASAKI  Masafumi KONDO  Yoichiro SATO  Kazutami ARIMOTO  

     
    LETTER-Software System

      Pubricized:
    2019/12/20
      Vol:
    E103-D No:3
      Page(s):
    702-705

    Safety critical systems are often modeled using Time Petri Nets (TPN) for analyzing their reliability with formal verification methods. This paper proposed an efficient verification method for TPN introducing bounded model checking based on satisfiability solving. The proposed method expresses time constraints of TPN by Difference Logic (DL) and uses SMT solvers for verification. Its effectiveness was also demonstrated with an experiment.

  • SCSE: Boosting Symbolic Execution via State Concretization

    Huibin WANG  Chunqiang LI  Jianyi MENG  Xiaoyan XIANG  

     
    PAPER-Software Engineering

      Pubricized:
    2019/04/26
      Vol:
    E102-D No:8
      Page(s):
    1506-1516

    Symbolic execution is capable of automatically generating tests that achieve high coverage. However, its practical use is limited by the scalability problem. To mitigate it, this paper proposes State Concretization based Symbolic Execution (SCSE). SCSE speeds up symbolic execution via state concretization. Specifically, by introducing a concrete store, our approach avoids invoking the constraint solver to check path feasibility at conditional instructions. Intuitively, there is no need to check the feasibility of a path along a concrete execution since it is always feasible. With state concretization, the number of solver queries greatly decreases, thus improving the efficiency of symbolic execution. Through experimental evaluation on real programs, we show that state concretization helps to speed up symbolic execution significantly.

  • A 3Gbps/Lane MIPI D-PHY Transmission Buffer Chip

    Pil-Ho LEE  Young-Chan JANG  

     
    LETTER

      Vol:
    E102-A No:6
      Page(s):
    783-787

    A 3Gbps/lane transmission buffer chip including a high-speed mode detector is proposed for a field-programmable gate array (FPGA)-based frame generator supporting the mobile industry processor interface (MIPI) D-PHY version 1.2. It performs 1-to-3 repeat while buffering low voltage differential signaling (LVDS) or scalable low voltage signaling (SLVS) to SLVS.

  • Modification of Velvet Noise for Speech Waveform Generation by Using Vocoder-Based Speech Synthesizer Open Access

    Masanori MORISE  

     
    LETTER-Speech and Hearing

      Pubricized:
    2018/12/05
      Vol:
    E102-D No:3
      Page(s):
    663-665

    This paper introduces a new noise generation algorithm for vocoder-based speech waveform generation. White noise is generally used for generating an aperiodic component. Since short-term white noise includes a zero-frequency component (ZFC) and inaudible components below 20 Hz, they are reduced in advance when synthesizing. We propose a new noise generation algorithm based on that for velvet noise to overcome the problem. The objective evaluation demonstrated that the proposed algorithm can reduce the unwanted components.

  • Automatic Generation of Train Timetables from Mesoscopic Railway Models by SMT-Solver Open Access

    Yoshinao ISOBE  Hisabumi HATSUGAI  Akira TANAKA  Yutaka OIWA  Takanori AMBE  Akimasa OKADA  Satoru KITAMURA  Yamato FUKUTA  Takashi KUNIFUJI  

     
    PAPER

      Vol:
    E102-A No:2
      Page(s):
    325-335

    This paper presents a formal approach for generating train timetables in a mesoscopic level that is more concrete than the macroscopic level, where each station is simply expressed in a black-box, and more abstract than the microscopic level, where the infrastructure in each station-area is expressed in detail. The accuracy of generated timetable and the computational effort for the generation is a trade-off. In this paper, we design a formal mesoscopic modeling language by analyzing real railways, for example Tazawako-line as the first step of this work. Then, we define the constraint formulae for generating train timetables with the help of SMT (Satisfiability Module Theories)-Solver, and explain our tool RW-Solver that is an implementation of the constraint formulae. Finally, we demonstrate how RW-Solver with the help of SMT-Solver can be used for generating timetables in a case study of Tazawako-line.

  • Convergence Comparison on the IDR(s)-Based IPNMs for Electromagnetic Multiple Scattering Simulations

    Norimasa NAKASHIMA  Seiji FUJINO  

     
    BRIEF PAPER

      Vol:
    E102-C No:1
      Page(s):
    51-55

    This paper presents various Iterative Progressive Numerical Methods (IPNMs) for the computation of electromagnetic (EM) wave scattering from many objects. We previously modified the original IPNM from the standpoint of the classical and the IDR-based linear iterative solvers. We demonstrate the performance of the IDR(s)-based IPNMs through some numerical examples of EM wave scattering from regularly placed 27 perfectly electric conducting spheres.

  • A Block-Permutation-Based Encryption Scheme with Independent Processing of RGB Components

    Shoko IMAIZUMI  Hitoshi KIYA  

     
    PAPER-Image Processing and Video Processing

      Pubricized:
    2018/09/07
      Vol:
    E101-D No:12
      Page(s):
    3150-3157

    This paper proposes a block-permutation-based encryption (BPBE) scheme for the encryption-then-compression (ETC) system that enhances the color scrambling. A BPBE image can be obtained through four processes, positional scrambling, block rotation/flip, negative-positive transformation, and color component shuffling, after dividing the original image into multiple blocks. The proposed scheme scrambles the R, G, and B components independently in positional scrambling, block rotation/flip, and negative-positive transformation, by assigning different keys to each color component. The conventional scheme considers the compression efficiency using JPEG and JPEG 2000, which need a color conversion before the compression process by default. Therefore, the conventional scheme scrambles the color components identically in each process. In contrast, the proposed scheme takes into account the RGB-based compression, such as JPEG-LS, and thus can increase the extent of the scrambling. The resilience against jigsaw puzzle solver (JPS) can consequently be increased owing to the wider color distribution of the BPBE image. Additionally, the key space for resilience against brute-force attacks has also been expanded exponentially. Furthermore, the proposed scheme can maintain the JPEG-LS compression efficiency compared to the conventional scheme. We confirm the effectiveness of the proposed scheme by experiments and analyses.

  • A Verification Framework for Assembly Programs Under Relaxed Memory Model Using SMT Solver

    Pattaravut MALEEHUAN  Yuki CHIBA  Toshiaki AOKI  

     
    PAPER-Software System

      Pubricized:
    2018/09/12
      Vol:
    E101-D No:12
      Page(s):
    3038-3058

    In multiprocessors, memory models are introduced to describe the executions of programs among processors. Relaxed memory models, which relax the order of executions, are used in the most of the modern processors, such as ARM and POWER. Due to a relaxed memory model could change the program semantics, the executions of the programs might not be the same as our expectation that should preserve the program correctness. In addition to relaxed memory models, the way to execute an instruction is described by an instruction semantics, which varies among processor architectures. Dealing with instruction semantics among a variety of assembly programs is a challenge for program verification. Thus, this paper proposes a way to verify a variety of assembly programs that are executed under a relaxed memory model. The variety of assembly programs can be abstracted as the way to execute the programs by introducing an operation structure. Besides, there are existing frameworks for modeling relaxed memory models, which can realize program executions to be verified with a program property. Our work adopts an SMT solver to automatically reveal the program executions under a memory model and verify whether the executions violate the program property or not. If there is any execution from the solver, the program correctness is not preserved under the relaxed memory model. To verify programs, an experimental tool was developed to encode the given programs for a memory model into a first-order formula that violates the program correctness. The tool adopts a modeling framework to encode the programs into a formula for the SMT solver. The solver then automatically finds a valuation that satisfies the formula. In our experiments, two encoding methods were implemented based on two modeling frameworks. The valuations resulted by the solver can be considered as the bugs occurring in the original programs.

  • Transistor Characteristics of Single Crystalline C8-BTBT Grown in Coated Liquid Crystal Solution on Photo-Alignment Films

    Risa TAKEDA  Yosei SHIBATA  Takahiro ISHINABE  Hideo FUJIKAKE  

     
    BRIEF PAPER

      Vol:
    E101-C No:11
      Page(s):
    884-887

    We examined single crystal growth of benzothienobenzothiophene-based organic semiconductors by solution coating method using liquid crystal and investigated its electrical characteristics. As the results, we revealed that the averaged mobility in the saturation region reached 2.08 cm2/Vs along crystalline b-axis, and 1.08 cm2/Vs along crystalline a-axis.

  • Applying an SMT Solver to Coverage-Driven Design Verification

    Kiyoharu HAMAGUCHI  

     
    LETTER

      Vol:
    E101-A No:7
      Page(s):
    1053-1056

    Simulation-based verification of hardware designs, in particular, register-transfer-level (RTL) designs, has been widely used, and has been one of the major bottlenecks in design processes. One of the approaches is coverage-driven verification, of its target is improvement of some metric called coverage. In a prior work of ours, we have proposed a coverage-driven verification using both randomly generated simulation patterns and patterns generated by a SAT (satisfiability) solver, and have shown its effectiveness. In this paper, we extend this approach with an SMT (satisfiability modulo theory) solver, which can handle arithmetic relations among integer, floating-point or bit-vector variables. Experimental results show that the more arithmetic modules are included, the more an SMT-based method gets superior to the method using only a SAT solver.

  • A General Low-Cost Fast Hybrid Reconfiguration Architecture for FPGA-Based Self-Adaptive System

    Rui YAO  Ping ZHU  Junjie DU  Meiqun WANG  Zhaihe ZHOU  

     
    PAPER-Computer System

      Pubricized:
    2017/12/18
      Vol:
    E101-D No:3
      Page(s):
    616-626

    Evolvable hardware (EHW) based on field-programmable gate arrays (FPGAs) opens up new possibilities towards building efficient adaptive system. State of the art EHW systems based on virtual reconfiguration and dynamic partial reconfiguration (DPR) both have their limitations. The former has a huge area overhead and circuit delay, and the later has slow configuration speed and low flexibility. Therefore a general low-cost fast hybrid reconfiguration architecture is proposed in this paper, which merges the high flexibility of virtual reconfiguration and the low resource cost of DPR. Moreover, the bitstream relocation technology is introduced to save the bitstream storage space, and the discrepancy configuration technology is adopted to reduce reconfiguration time. And an embedded RAM core is adopted to store bitstreams which accelerate the reconfiguration speed further. The proposed architecture is evaluated by the online evolution of digital image filter implemented on the Xilinx Virtex-6 FPGA development board ML605. And the experimental results show that our system has lower resource overhead, higher operating frequency, faster reconfiguration speed and less bitstream storage space in comparison with the previous works.

1-20hit(150hit)