Jiaxin WU Bing LI Li ZHAO Xinzhou XU
Maaki SAKAI Kanon HOKAZONO Yoshiko HANADA
Xuecheng SUN Zheming LU
Yuanhe WANG Chao ZHANG
Jinfeng CHONG Niu JIANG Zepeng ZHUO Weiyu ZHANG
Xiangrun LI Qiyu SHENG Guangda ZHOU Jialong WEI Yanmin SHI Zhen ZHAO Yongwei LI Xingfeng LI Yang LIU
Meiting XUE Wenqi WU Jinfeng LUO Yixuan ZHANG Bei ZHAO
Rong WANG Changjun YU Zhe LYU Aijun LIU
Huijuan ZHOU Zepeng ZHUO Guolong CHEN
Feifei YAN Pinhui KE Zuling CHANG
Manabu HAGIWARA
Ziqin FENG Hong WAN Guan GUI
Sungryul LEE
Feng WANG Xiangyu WEN Lisheng LI Yan WEN Shidong ZHANG Yang LIU
Yanjun LI Jinjie GAO Haibin KAN Jie PENG Lijing ZHENG Changhui CHEN
Ho-Lim CHOI
Feng WEN Haixin HUANG Xiangyang YIN Junguang MA Xiaojie HU
Shi BAO Xiaoyan SONG Xufei ZHUANG Min LU Gao LE
Chen ZHONG Chegnyu WU Xiangyang LI Ao ZHAN Zhengqiang WANG
Izumi TSUNOKUNI Gen SATO Yusuke IKEDA Yasuhiro OIKAWA
Feng LIU Helin WANG Conggai LI Yanli XU
Hongtian ZHAO Hua YANG Shibao ZHENG
Kento TSUJI Tetsu IWATA
Yueying LOU Qichun WANG
Menglong WU Jianwen ZHANG Yongfa XIE Yongchao SHI Tianao YAO
Jiao DU Ziwei ZHAO Shaojing FU Longjiang QU Chao LI
Yun JIANG Huiyang LIU Xiaopeng JIAO Ji WANG Qiaoqiao XIA
Qi QI Liuyi MENG Ming XU Bing BAI
Nihad A. A. ELHAG Liang LIU Ping WEI Hongshu LIAO Lin GAO
Dong Jae LEE Deukjo HONG Jaechul SUNG Seokhie HONG
Tetsuya ARAKI Shin-ichi NAKANO
Shoichi HIROSE Hidenori KUWAKADO
Yumeng ZHANG
Jun-Feng Liu Yuan Feng Zeng-Hui Li Jing-Wei Tang
Keita EMURA Kaisei KAJITA Go OHTAKE
Xiuping PENG Yinna LIU Hongbin LIN
Yang XIAO Zhongyuan ZHOU Mingjie SHENG Qi ZHOU
Kazuyuki MIURA
Yusaku HIRAI Toshimasa MATSUOKA Takatsugu KAMATA Sadahiro TANI Takao ONOYE
Ryuta TAMURA Yuichi TAKANO Ryuhei MIYASHIRO
Nobuyuki TAKEUCHI Kosei SAKAMOTO Takuro SHIRAYA Takanori ISOBE
Shion UTSUMI Kosei SAKAMOTO Takanori ISOBE
You GAO Ming-Yue XIE Gang WANG Lin-Zhi SHEN
Zhimin SHAO Chunxiu LIU Cong WANG Longtan LI Yimin LIU Zaiyan ZHOU
Xiaolong ZHENG Bangjie LI Daqiao ZHANG Di YAO Xuguang YANG
Takahiro IINUMA Yudai EBATO Sou NOBUKAWA Nobuhiko WAGATSUMA Keiichiro INAGAKI Hirotaka DOHO Teruya YAMANISHI Haruhiko NISHIMURA
Takeru INOUE Norihito YASUDA Hidetomo NABESHIMA Masaaki NISHINO Shuhei DENZUMI Shin-ichi MINATO
Zhan SHI
Hakan BERCAG Osman KUKRER Aykut HOCANIN
Ryoto Koizumi Xiaoyan Wang Masahiro Umehira Ran Sun Shigeki Takeda
Hiroya Hachiyama Takamichi Nakamoto
Chuzo IWAMOTO Takeru TOKUNAGA
Changhui CHEN Haibin KAN Jie PENG Li WANG
Pingping JI Lingge JIANG Chen HE Di HE Zhuxian LIAN
Ho-Lim CHOI
Akira KITAYAMA Goichi ONO Hiroaki ITO
Koji NUIDA Tomoko ADACHI
Yingcai WAN Lijin FANG
Yuta MINAMIKAWA Kazumasa SHINAGAWA
Sota MORIYAMA Koichi ICHIGE Yuichi HORI Masayuki TACHI
Sendren Sheng-Dong XU Albertus Andrie CHRISTIAN Chien-Peng HO Shun-Long WENG
Zhikui DUAN Xinmei YU Yi DING
Hongbo LI Aijun LIU Qiang YANG Zhe LYU Di YAO
Yi XIONG Senanayake THILAK Yu YONEZAWA Jun IMAOKA Masayoshi YAMAMOTO
Feng LIU Qian XI Yanli XU
Yuling LI Aihuang GUO
Mamoru SHIBATA Ryutaroh MATSUMOTO
Haiyang LIU Xiaopeng JIAO Lianrong MA
Ruixiao LI Hayato YAMANA
Riaz-ul-haque MIAN Tomoki NAKAMURA Masuo KAJIYAMA Makoto EIKI Michihiro SHINTANI
Kundan LAL DAS Munehisa SEKIKAWA Tadashi TSUBONE Naohiko INABA Hideaki OKAZAKI
Kensaku FUJII Kenji KASHIHARA Mitsuji MUNEYASU Masakazu MORIMOTO
In this paper, we propose a method capable of shortening the distance from a noise detection microphone to a loudspeaker, which is one of important issues in the field of active noise control (ANC). In the ANC system, the secondary noise provided by the loudspeaker is required arriving at an error microphone simultaneously with the primary noise to be cancelled. However, the reverberation involved in the secondary path from the loudspeaker to the error microphone increases the secondary noise components arriving later than the primary noise. The late components are not only invalid for canceling the primary noise but also impede the cancellation. To reduce the late components, the distance between the noise detection microphone and the loud speaker is generally extended. The proposed method differently reduces the late components by forming the noise control filter, which produces the secondary noise, with the cascade connection of a non-recursive and a recursive filters. The distance can be thus shortened. On the other hand, the recursive filter is required to work stably. The proposed method guarantees the stable work by forming the recursive filter with the lattice filter whose coefficients are restricted to less than unity.
Toshio ITO Masanori SUGIMOTO Hiromichi HASHIZUME
This paper presents and evaluates a new acoustic imaging system that uses multicarrier signals for correlation division in synthetic transmit aperture (CD-STA). CD-STA is a method that transmits uncorrelated signals from different transducers simultaneously to achieve high-speed and high-resolution acoustic imaging. In CD-STA, autocorrelations and cross-correlations in transmitted signals must be suppressed because they cause artifacts in the resulting images, which narrow the dynamic range as a consequence. To suppress the correlation noise, we had proposed to use multicarrier signals optimized by a genetic algorithm. Because the evaluation of our proposed method was very limited in the previous reports, we analyzed it more deeply in this paper. We optimized three pairs of multicarrier waveforms of various lengths, which correspond to 5th-, 6th- and 7th-order M-sequence signals, respectively. We built a CD-STA imaging system that operates in air. Using the system, we conducted imaging experiments to evaluate the image quality and resolution of the multicarrier signals. We also investigated the ability of the proposed method to resolve both positions and velocities of target scatterers. For that purpose, we carried out an experiment, in which both moving and fixed targets were visualized by our system. As a result of the experiments, we confirmed that the multicarrier signals have lower artifact levels, better axial resolution, and greater tolerance to velocity mismatch than M-sequence signals, particularly for short signals.
Taichi YOSHIDA Taizo SUZUKI Seisuke KYOCHI Masaaki IKEHARA
In this paper, we propose a two dimensional (2D) non-separable adaptive directional lifting (ADL) structure for discrete wavelet transform (DWT) and its image coding application. Although a 2D non-separable lifting structure of 9/7 DWT has been proposed by interchanging some lifting, we generalize a polyphase representation of 2D non-separable lifting structure of DWT. Furthermore, by introducing the adaptive directional filteringingto the generalized structure, the 2D non-separable ADL structure is realized and applied into image coding. Our proposed method is simpler than the 1D ADL, and can select the different transforming direction with 1D ADL. Through the simulations, the proposed method is shown to be efficient for the lossy and lossless image coding performance.
Masahiro IWAHASHI Hitoshi KIYA
This paper proposes a reversible two dimensional (2D) discrete wavelet transform (DWT) for lossless coding which is compatible with the irreversible 2D 9-7 DWT for lossy coding in the JPEG 2000. Since all the filters and scalings are factorized into a product of lifting steps, and signal values are rounded into integers, the proposed DWT is reversible and applicable to lossless coding of 2D signals. We replace a part of the separable 2D transfer function of the 2D DWT by a non separable 2D lifting structure, so that the number of rounding operations is decreased. We also investigate performance of the DWT under octave decomposition case and theoretically endorse it. As a result, reduction of the rounding errors due to the replacement was confirmed. It means that compatibility of the reversible DWT to the irreversible 2D 9-7 DWT is improved.
Kuo-Hsiung TSENG Tuo-Wen CHANG Ming-Fu HUNG
This study focused on three simplified models, namely (1) one set of single-phase DC-DC converter, (2) two sets of parallel connection single-phase DC-DC converter, and (3) two sets of series connection single-phase DC-DC converter. The purposes are: (1) to propose the simplification conditions and procedures for the three-phase AC-DC converter; (2) propose a set of new simplification steps for modeling, and present the examples of different three-phase AC-DC circuit topologies, detailed discussion on the simplification steps for modeling of a three-phase AC-DC converter is offered, to help people simplify and analyze the simplified model easily; (3) according to three types of simplified modeling in the three-phase AC-DC converter, this study established a useful reference for the design and analysis of the control systems of the three-phase AC-DC converter simply; (4) to acquire PWM control strategy beforehand based on PFC-Controlled property; (5) to reduce the switching loss for the PWM control strategy of the simplified model; (6) to maintain the original circuit topology and verify that the theory can extensively apply the knowledge of single-phase DC-DC converter to the simplified modeling of three-phase AC-DC converter.
Takaaki OKUMURA Masanori HASHIMOTO
This paper discusses how to cope with dynamic power supply noise in FF timing estimation. We first review the dependence of setup and hold times on supply voltage, and point out that setup time is more sensitive to supply voltage than hold time, and hold time at nominal voltage is reasonably pessimistic. We thus propose a procedure to estimate setup time and clock-to-Q delay taking into account given voltage drop waveforms using an equivalent DC voltage approach. Experimental results show that the proposed procedure estimates setup time and clock-to-Q delay fluctuations well with 5% and 3% errors on average.
Hideki TAKASE Hiroyuki TOMIYAMA Hiroaki TAKADA
Energy minimization has become one of the primary goals in the embedded real-time domains. Consequently, scratch-pad memory has been employed as partial or entire replacement for cache memory due to its better energy efficiency. However, most previous approaches were not applicable to a preemptive multi-task environment. We propose three methods of partitioning and allocation of scratch-pad memory for fixed-priority-based preemptive multi-task systems. The three methods, i.e., spatial, temporal, and hybrid methods, achieve energy reduction in the instruction memory subsystems. With the spatial method, each task occupies its exclusive space in scratch-pad memory. With the temporal method, the running task uses entire scratch-pad space. The content of scratch-pad memory is swapped out as a task executes or gets preempted. The hybrid method is based on the spatial one but a higher priority task can temporarily use the space of lower priority task. The amount of space is prioritized for higher priority tasks. We formulate each method as an integer programming problem that simultaneously determines (1) partitioning of scratch-pad memory space for the tasks, and (2) allocation of program code to scratch-pad memory space for each task. Our methods not only support the real-time task scheduling but also consider aggressively the periods and priorities of tasks for the energy minimization. Additionally, we implement an RTOS-hardware cooperative support mechanism for runtime code allocation to the scratch-pad memory space. We have made the experiments with the fully functional real-time operating system. The experimental results have demonstrated the effectiveness of our techniques. Up to 73% energy reduction compared to a conventional method was achieved.
Andry SETIAWAN Shin-ichi NAKANO
In this paper we give a simple algorithm to generate all st-orientations of a given biconnected plane graph G with a designated edge (s,t) on the outer face of G. Our algorithm generates all st-orientations of G in O(n) time for each without duplications, where n is the number of vertices.
Takeshi SUGAWARA Naofumi HOMMA Takafumi AOKI Akashi SATOH
This paper proposes an efficient scheme for concurrent error detection for hardware implementations of the block cipher AES. In the proposed scheme, the circuit component for the round function is divided into two stages, which are used alternately for encryption (or decryption) and error checking in a pipeline. The proposed scheme has a limited overhead with respect to size and speed for the following reasons. Firstly, the need for a double number of clock cycles is eliminated by virtue of the reduced critical path. Secondly, the scheme only requires minimal additional circuitry for error detection since the detection is performed by the remaining encryption (or decryption) components within the pipeline. AES hardware with the proposed scheme was designed and synthesized by using 90-nm CMOS standard cell library with various constraints. As a result, the proposed circuit achieved 1.66 Gbps @ 12.9 Kgates for the compact version and 4.22 Gbps @ 30.7 Kgates for the high-speed version. These performance characteristics are comparable to those of a basic AES circuit without error detection, where the overhead of the proposed scheme is estimated to be 14.5% at maximum. The proposed circuit was fabricated in the form of a chip, and its error detection performance was evaluated through experiments. The chip was tested with respect to fault injection by using clock glitch, and the proposed scheme successfully detected and reacted to all introduced errors.
Sung-Ming YEN Wei-Chih LIEN Chien-Ning CHEN
Power analysis can be used to attack many implementations of cryptosystems, e.g., RSA and ECC, and the doubling attack is a collision based power analysis performed on two chosen ciphertexts. In this paper, we introduced a modified doubling attack to threaten RSA and ECC implementations by exploiting only one chosen ciphertext of small order. To attack the RSA implementations we selected an input of order two while to attack the ECC implementations we exploited one chosen invalid point of small order on a cryptographically weak curve rather than on the original curve. We showed that several existing power analysis countermeasures for RSA and ECC implementations are still vulnerable to the proposed attack. To prevent the proposed attack, we suggested countermeasures for RSA as well as for ECC.
In network coding, for the case that the network topology is unknown completely, random linear network coding has been proposed as an acceptable coding technique. In this paper, we define average failure probability of random linear network coding in order to characterize the performance of random network coding, and then analyze this failure probability for different known topological information of network. We obtain several upper bounds on the failure probabilities, and further show that, for some networks, these upper bounds are tight or asymptotically tight. Moreover, if the more topological information of the network is utilized, the better upper bounds are acquired.
Marzieh DASHTI Mir GHORAISHI Katsuyuki HANEDA Jun-ichi TAKADA Kenichi TAKIZAWA
This paper proposes a method for setting the threshold for ultra-wide-band (UWB) threshold-based ranging in indoor scenarios. The optimum threshold is derived based on the full analysis of the ranging error, which is equivalent to the probability of correct detection of first arriving signal in time-based ranging techniques. It is shown that the probability of correct detection is a function of first arriving signal, which has variations with two independent distributions. On the one hand, the first arriving signal varies in different positions with the same range due to multipath interference and on the other, it is a function of distance due to free space path-loss. These two distributions are considered in the derivation of the ranging error, based on which the optimum threshold is obtained. A practical method to derive this threshold is introduced based on the standard channel model. Extensive Monte Carlo simulations, ray-tracing simulations and ranging measurements confirm the analysis and the superior performance of the proposed threshold scheme.
Jia SU Yiqing HUANG Lei SUN Shinichi SAKAIDA Takeshi IKENAGA
With the increasing demand of high video quality and large image size, adaptive interpolation filter (AIF) addresses these issues and conquers the time varying effects resulting in increased coding efficiency, comparing with recent H.264 standard. However, currently most AIF algorithms are based on either frame level or macroblock (MB) level, which are not flexible enough for different video contents in a real codec system, and most of them are facing a severe time consuming problem. This paper proposes a content based coarse to fine AIF algorithm, which can adapt to video contents by adding different filters and conditions from coarse to fine. The overall algorithm has been mainly made up by 3 schemes: frequency analysis based frame level skip interpolation, motion vector modeling based region level interpolation, and edge detection based macroblock level interpolation. According to the experiments, AIF are discovered to be more effective in the high frequency frames, therefore, the condition to skip low frequency frames for generating AIF coefficients has been set. Moreover, by utilizing the motion vector information of previous frames the region level based interpolation has been designed, and Laplacian of Gaussian based macroblock level interpolation has been proposed to drive the interpolation process from coarse to fine. Six 720p and six 1080p video sequences which cover most typical video types have been tested for evaluating the proposed algorithm. The experimental results show that the proposed algorithm reduce total encoding time about 41% for 720p and 25% for 1080p sequences averagely, comparing with Key Technology Areas (KTA) Enhanced AIF algorithm, while obtains a BDPSNR gain up to 0.004 and 3.122 BDBR reduction.
Seokjin LEE Sang Ha PARK Koeng-Mo SUNG
In this paper, an on-line nonnegative matrix factorization (NMF) algorithm for acoustic signal processing systems is developed based on the recursive least squares (RLS) method. In order to develop the on-line NMF algorithm, we reformulate the NMF problem into multiple least squares (LS) normal equations, and solve the reformulated problems using RLS methods. In addition, we eliminate the irrelevant calculations based on the NMF model. The proposed algorithm has been evaluated with a well-known dataset used for NMF performance evaluation and with real acoustic signals; the results show that the proposed algorithm performs better than the conventional algorithm in on-line applications.
To reduce the error of channel estimation caused by noise, a novel noise suppression method based on the degree of confidence is proposed in this paper. The false alarm and false dismissal probabilities, corresponding to noise being taken as part of channel impulse response (CIR) and part of the CIR being mis-detected as noise, respectively, are also investigated. A false alarm reduction method is therefore presented to reduce the false alarms in the estimated CIR while the mis-detection ratio still remains low. Simulation results show the effectiveness of the proposed method.
Jae-Hun CHOI Joon-Hyuk CHANG Dong Kook KIM Suhyun KIM
In this paper, we propose a spectral difference approach for noise power estimation in speech enhancement. The noise power estimate is given by recursively averaging past spectral power values using a smoothing parameter based on the current observation. The smoothing parameter in time and frequency is adjusted by the spectral difference between consecutive frames that can efficiently characterize noise variation. Specifically, we propose an effective technique based on a sigmoid-type function in order to adaptively determine the smoothing parameter based on the spectral difference. Compared to a conventional method, the proposed noise estimate is computationally efficient and able to effectively follow noise changes under various noise conditions.
Hui CHEN Qun WAN Hongyang CHEN Tomoaki OHTSUKI
A new direction of arrival (DOA) estimation method is introduced with arbitrary array geometry when uncorrelated and coherent signals coexist. The DOAs of uncorrelated signals are first estimated via subspace-based high resolution DOA estimation technique. Then a matrix that only contains the information of coherent signals can be formulated by eliminating the contribution of uncorrelated signals. Finally a subspace block sparse reconstruction approach is taken for DOA estimations of the coherent signals.
This paper deals with underwater target classification using synthesized active sonar signals. Firstly, we synthesized active sonar returns from a 3D highlight model of underwater targets using the ray tracing algorithm. Then, we applied a multiaspect target classification scheme based on a hidden Markov model to classify them. For feature extraction from the synthesized sonar signals, a matching pursuit algorithm was used. The experimental results depending on the number of observations and signal-to-noise ratios are presented with our discussions.
Although unavailability and failure frequency are important reliability measures for designing telecommunications networks, having two different reliability measures causes difficulties when their evaluation results contradict each other. To overcome this difficulty, for determining a single reliability measure is proposed. Market share, which is an important management index, was used and the effect of each reliability measure on this index was studied. If we the effect of one of the reliability measures is small enough to be ignored, then the other one is chosen as the single reliability measure. The procedure of the proposed statistical analysis method and test results suggesting that failure frequency is promising as a single reliability measure are discussed.
Leida LI Jianying ZHANG Ajith ABRAHAM
This letter presents a new image watermarking scheme using Polar Sine Transform (PST), a new kind of orthogonal moment defined on a circular domain. The PSTs are easy to compute and have no numerical stability problem, thus are more suitable for watermarking. In the proposed method, the PSTs are modified according to the binary watermark bits, producing a compensation image. The watermarked image is obtained by adding the compensation image to the original image directly. Simulation results show the advantages of the proposed scheme in terms of both watermark capacity and watermark robustness.
Saeed SADEGHIAN Babak SADEGHIYAN
In this paper, we study how exploiting multiple differential characteristics with a common initial difference and different output differences improves the complexity of differential cryptanalysis attack. We call such an approach Multiple Differential Cryptanalysis. We describe such an attack rigorously by studying the probability distribution of multiple differential characteristics and giving an attack algorithm based on LLR statistic. We also present a statistical analysis on the attack complexity based on LLR probabilistic technique. Our analysis shows that the data complexity of the proposed attack decreases as the number of characteristics increases. We do an experiment with the described method to show its improvements through cryptanalyzing a reduced round PRESENT block cipher with 5 rounds.
Xiaoyan ZHANG Qichun WANG Bin WANG Haibin KAN
In algebraic attack on stream ciphers based on LFSRs, the secret key is found by solving an overdefined system of multivariate equations. There are many known algorithms from different point of view to solve the problem, such as linearization, relinearization, XL and Grobner Basis. The simplest method, linearization, treats each monomial of different degrees as a new variable, and consists of
In this letter, dynamic decode-and-forward (DDF) protocol and static decode-and-forward (SDF) protocol are considered in a two-way half-duplex fading system, where two sources are equipped with multiple antennas and a relay is equipped with a single antenna. Their closed-form expressions of diversity multiplexing tradeoff (DMT) are derived, respectively. From the results, DDF always outperforms SDF in terms of DMT, achieves DMT gain over nonorthogonal amplify-and-forward (NAF) in low spectral efficiency scenarios, but is inferior to NAF in high spectral efficiency scenarios.