Dhany ARIFIANTO Tomohiro TANAKA Takashi MASUKO Takao KOBAYASHI
Borrowing the notion of instantaneous frequency that was developed in the context of time-frequency signal analysis, an instantaneous frequency amplitude spectrum (IFAS) is introduced for estimating fundamental frequency of speech signal in both noiseless and adverse environments. We define harmonicity measure as a quantity that indicates degree of periodical regularity in the IFAS and that shows substantial difference between periodic signal and noise-like waveform. The harmonicity measure is applied to estimate the existence of fundamental frequency. We provide experimental examples to demonstrate the general applicability of the harmonicity measure and apply the proposed procedure to Japanese continuous speech signals. The results show that the proposed method outperforms the conventional methods with or without the presence of noise.
Kyung Tae DO Yang Hyo KIM Young Hwan KIM Jung Yun CHOI
We present a new approach to the power modeling of synthesizable soft macros, which uses the characteristics of individual input signals for high accuracy. We also present the parameterized power model, developed using the proposed approach, which can relieve us from the power characterization for all possible macro sizes. Extensive experiments illustrate that the proposed approaches exhibit the overall modeling errors below 4.24% and 4.71% for benchmark macros before and after parameterization, when compared with the results of gate-level analysis.
Seungwoo LEE Joohui AN Byung-Kwan KWAK Gary Geunbae LEE
An important issue in applying machine learning algorithms to Natural Language Processing areas such as Named Entity Recognition tasks is to overcome the lack of tagged corpora. Several bootstrapping methods such as co-training have been proposed as a solution. In this paper, we present a different approach using the Web resources. A Named Entity (NE) tagged corpus is generated from the Web using about 3,000 names as seeds. The generated corpus may have a lower quality than the manually tagged corpus but its size can be increased sufficiently. Several features are developed and the decision list is learned using the generated corpus. Our method is verified by comparing it to both the decision list learned on the manual corpus and the DL-CoTrain method. We also present a two-level classification by cascading highly precise lexical patterns and the decision list to improve the performance.
Ching-Ting HSU Hung-Ju LI Mei-Juan CHEN
The three main reasons why the new H.264 (MPEG-4 AVC) video coding standard has a significant performance better than the other standards are the adoption of variable block sizes, multiple reference frames, and the consideration of rate distortion optimization within the codec. However, these features incur a considerable increase in encoder complexity. As for the multiple reference frames motion estimation, the increased computation is in proportion to the number of searched reference frames. In this paper, a fast multi-frame selection method is proposed for H.264 video coding. The proposed scheme can efficiently determine the best reference frame from the allowed five reference frames. Simulation results show that the speed of the proposed method is over two times faster than that of the original scheme adopted in JVT reference software JM73 while keeping the similar video quality and bit-rate.
We develop an algorithm for a controller design method for Max-Plus Linear (MPL) systems with selective parameters. Since the conventional algorithm we proposed requires high computational load when the prediction horizon is large, two methods for reducing the calculation time are proposed. One is based upon the branch-and-bound method, and the other is to reuse the optimal solution. The effectiveness of these two methods is confirmed through numerical simulation.
This paper presents a multi-resolution optical flow estimation method that is robust against large variation in the estimation parameter. For each level solution of the multi-grid estimation, a nonlinear iteration is proposed differently from the existing method, where the incremental displacement from the coarser level optical flow is calculated by linear iteration. The experimental results show that the proposed scheme has better error-performance in a much wider range of regularization parameters.
Most traditional board and card games, such as Chess, Chinese Chess, Go, Chinese Mahjong, Hearts, Bridge, etc., share the same playing model: Players play around tables using physical objects such as cards and may hold objects in their own private areas, e.g., players hold cards in their own hands in Bridge. In this paper, this model is called the play-on-table (POT) game model and these games following the model are called POT games. The research of this paper is summarized as follows. First, formalize the definition of the POT game model. Second, present some game systems to allow players to design and play new POT games. Third, prove that these game systems are general for all POT games. Finally, in order to demonstrate the theory, practically implement one of the general game systems that allows players to design and play new POT games in a what-you-see-is-what-you-get (WYSIWYG) manner.
Hiroshi YOSHIDA Yoshitaka TAKASAKI
Application of multipled block codes (MBCs) for realizing new flexible and efficient transmission systems that feature in hunting-free reframing and asynchronous multiplexing is investigated. First, the principles of MBC are overviewed to show the capacities of filterless clock recovery. Then it is shown that modification of simple frame structure of MBC line code can be used for attaining hunting-free reframing for multiplexing systems. Two types of MBCs are developed to this end. While the one uses header blocks for hunting-free reframing, the other uses distributed frame patterns. Header design of multipled block codes (MBC) for hunting-free reframing (HFR) is investigated for frame patterns with and without violation compensation. The feasibility of hunting-free reframing is tested in an experimental system. Application of hunting-free reframing to asynchronous multiplexing is also investigated and tested in an experimental system. Finally, advantages of hunting-free multiplexing systems are discussed.
Estimating the parameters of a statistical distribution from measured sample values forms an essential part of many signal processing tasks. K-distribution has been proven to be an appropriate model for characterising the amplitude of sea clutter. In this paper, a new method for estimating the parameters of K-Distribution is proposed. The method greatly lowers the computational requirement and variance of parameter estimates when compared with the existing non-maximum likelihood methods.
There have been numerous studies on the enhancement of the noisy speech signal. In this paper, We propose a new speech enhancement method, that is, a DFF (Dissonant Frequency Filtering) scheme combined with NR (noise reduction) algorithm. The simulation results indicate that the proposed method provides a significant gain in perceptual quality compared with the conventional method. Therefore if the proposed enhancement scheme is used as a pre-filter, the output speech quality would be enhanced perceptually.
Kwee-Bo SIM Ji-Yoon KIM Dong-Wook LEE
When we try to solve Multiobjective Optimization Problems (MOPs) using an evolutionary algorithm, the Pareto Genetic Algorithm (Pareto GA) introduced by Goldberg in 1989 has now become a sort of standard. After the first introduction, this approach was further developed and lead to many applications. All of these approaches are based on Pareto ranking and use the fitness sharing function to maintain diversity. On the other hand in the early 50's another scheme was presented by Nash. This approach introduced the notion of Nash Equilibrium and aimed at solving optimization problems having multiobjective functions that are originated from Game Theory and Economics. Since the concept of Nash Equilibrium as a solution of these problems was introduced, game theorists have attempted to formalize aspects of the equilibrium solution. The Nash Genetic Algorithm (Nash GA), which is introduced by Sefrioui, is the idea to bring together genetic algorithms and Nash strategy. The aim of this algorithm is to find the Nash Equilibrium of MOPs through the genetic process. Another central achievement of evolutionary game theory is the introduction of a method by which agents can play optimal strategies in the absence of rationality. Not the rationality but through the process of Darwinian selection, a population of agents can evolve to an Evolutionary Stable Strategy (ESS) introduced by Maynard Smith in 1982. In this paper, we propose Game theory based Co-Evolutionary Algorithm (GCEA) and try to find the ESS as a solution of MOPs. By applying newly designed co-evolutionary algorithm to several MOPs, the first we will confirm that evolutionary game can be embodied by co-evolutionary algorithm and this co-evolutionary algorithm can find ESSs as a solutions of MOPs. The second, we show optimization performance of GCEA by applying this model to several test MOPs and comparing with the solutions of previously introduced evolutionary optimization algorithms.
Junya SHIMAKAWA Toshimichi SAITO
This letter considers relationship between cyclic digital-to-analog converters (DACs) and iterated function systems (IFSs). We introduce the cyclic DACs as inverse systems of analog-to-digital converters in terms of one-dimensional maps. We then compare the DACs with a typical example of existing applications of IFSs: chaos game representation for analysis of DNA structures. We also present a simple test circuit of a DAC for Gray decoding based on switched capacitors and confirm the basic operation experimentally.
Viet HUYNH QUANG HUY Michio MIWA Hidenori MARUTA Makoto SATO
In this paper, we propose a fixed monocular camera, which changes the focus cyclically to recognize completely the three-dimensional translational motion of a rigid object. The images captured in a half cycle of the focus change form a multi-focus image sequence. The motion in depth or the focus change of the camera causes defocused blur. We develop an in-focus frame tracking operator in order to automatically detect the in-focus frame in a multi-focus image sequence of a moving object. The in-focus frame gives a 3D position in the motion of the object at the time that the frame was captured. The reconstruction of the motion of an object is performed by utilizing non-uniform sampling theory for the 3D position samples, of which information were inferred from the in-focus frames in the multi-focus image sequences.
Jun YANG Kan SHA Woon-Seng GAN Jing TIAN
A directional audible sound can be generated by amplitude-modulated (AM) into ultrasound wave from a parametric array. To synthesize audio signals produced by the self-demodulation effect of the AM sound wave, a quasi-linear analytical solution, which describes the nonlinear wave propagation, is developed for fast numerical evaluation. The radiated sound field is expressed as the superposition of Gaussian Beams. Numerical results are presented for a rectangular parametric loudspeaker, which are in good agreement with the experimental data published previously.
Junho LEE Seungyoung AHN Woon-Seong KWON Kyung-Wook PAIK Joungho KIM
First we introduce the high-frequency equivalent circuit model of the Fine Pitched Ball Grid Array (FPBGA) bonding for frequencies up to 20 GHz. The lumped circuit model of the FPBGA bonding was extracted based on S-parameters measurement and subsequent fitting of the model parameters. The test packages, which contain probing pads, coplanar waveguides and FPBGA ball bonding, were fabricated and measured. The suggested π-model of the FPBGA bonding consists of self-inductor, self-capacitor, and self-resistor components. From the extracted model, a solder ball of 350 µm diameter and 800 µm ball pitch has less than 0.08 nH self-inductance, 0.40 pF self capacitance, and about 10 mΩ self-resistance. In addition, the mutual capacitance caused by the presence of the adjacent bonding balls is included in the model. The FPBGA solder ball bonding has less than 1.5 dB insertion loss up to 20 GHz, and it causes negligible delay time in digital signal transmission. The extracted circuit model of FPBGA bonding is useful in design and performance simulation of advanced packages, which use FPBGA bonding.
Huan-Bang LI Mitsugu OHKAWA Nobufumi SARUWATARI Noriyuki KARIYA
A prototype modem with unequal error protection (UEP) capability was developed using multiple block coded modulation (MBCM). Benefited from its unique structure, MBCM can be used to provide UEP straightforward. We propose a new method to increase the robustness of the carrier recovery process by taking advantage of the MBCM code structure. We also use a frame format to facilitate the synchronization operation. This modem was developed in preparation for the mobile satellite communication experiments using the Engineering Test Satellite of VIII-type (ETS-VIII). In addition of MBCM, some other types of modulation schemes have been implemented in the same modem to enable a range of communication experiments to be performed. The modem can operate at variable data rates. The results of laboratory measurements agreed well with computer simulation results. Typical link budgets based on the parameters of ETS-VIII are also presented.
In this proposed method, CRC coding is only applied to data unit, not to padded zeros that are to fill up the fixed length of data unit. So improved frame error rate and protocol efficiency are possible instead of increment of receiver complexity.
Junya SEKIKAWA Takayoshi KUBONO
Breaking arcs occurring between Ag or Cu electrical contact pairs in DC 56 V/7 A resistive circuit are observed with a high-speed camera (1000 frames/s). As a result, the increase of brightness of the arc-emitted light synchronizes with the increase of arc current in the latter half of arc duration. For the case of Ag contacts, the brightness increases in entire region of the breaking arc with sudden increase of the arc current. On the other hand, the increase of the intensity for Cu contacts occurs in not only entire discharge region but also anode spot region significantly.
Mehrdad PANAHPOUR TEHRANI Purim NA BANGCHANG Toshiaki FUJII Masayuki TANIMOTO
The Camera sensor network is a new advent of technology in which each sensor node can capture video signal, process and communicate with other nodes. We have investigated a dense node configuration. The requested processing task in this network is arbitrary view generation among nodes view. To avoid unnecessary communication between nodes in this network and to speed up the processing time, we propose a distributed processing architecture where the number of nodes sharing image data are optimized. Therefore, each sensor node processes part of the interpolation algorithm with local communication between sensor nodes. Two processing methods are used based on the image size shared. These two methods are F-DP (Fully image shared Distributed Processing) and P-DP (Partially image shared Distributed Processing). In this research, the network processing time has been theoretically analyzed for one user. The theoretical results are compatible with the experimental results. In addition, the performance of proposed DP methods were compared with Centralized Processing (CP). As a result, the best processing method for optimum number of nodes can be chosen based on (i) communication delay of the network, (ii) whether the network has one or more channels for communication among nodes and (iii) the processing ability of nodes.
This paper deals with a design problem of an adaptive robust control system for linear systems with structured uncertainties. The control law consists of a state feedback with a fixed gain designed by using the nominal system, a state feedback with an adaptive gain tuned by a parameter adjustment law and a compensation input. We show the parameter adjustment law and that sufficient conditions for the existence of the compensation input are given in terms of linear matrix inequalities (LMIs). Finally, a numerical example is included.