Miao ZHANG Jiro HIROKAWA Makoto ANDO
In this paper, a three-way divider is proposed for a partially-corporate feed in an alternating phase-fed single-layer slotted waveguide array. The divider is placed at the middle of the feed waveguide and reduces the long line effects; the frequency bandwidth is doubled. It is a kind of cross junction with one input port and three output ports; most of the power is equally divided into the right and left halves of the feed waveguide while the rest of power goes straight into the center radiating waveguide. Based upon the moment method design of the three-way divider, an inductive post is introduced for wide band power dividing control to the radiating waveguide. Reflection is below -20 dB over a wide bandwidth of 24.3-26.3 GHz, and the range of power dividing ratio ranges from 1/43 to 1/4. The amplitude and the phase from the two output ports to the feed waveguide are well balanced, and the differences are less than 0.1 dB and 5.0 degrees, respectively. The MoM analysis and the wide band design are verified experimentally in the 4 GHz band.
Makoto TACHIBANA Junichi YAMAGISHI Takashi MASUKO Takao KOBAYASHI
This paper describes an approach to generating speech with emotional expressivity and speaking style variability. The approach is based on a speaking style and emotional expression modeling technique for HMM-based speech synthesis. We first model several representative styles, each of which is a speaking style and/or an emotional expression, in an HMM-based speech synthesis framework. Then, to generate synthetic speech with an intermediate style from representative ones, we synthesize speech from a model obtained by interpolating representative style models using a model interpolation technique. We assess the style interpolation technique with subjective evaluation tests using four representative styles, i.e., neutral, joyful, sad, and rough in read speech and synthesized speech from models obtained by interpolating models for all combinations of two styles. The results show that speech synthesized from the interpolated model has a style in between the two representative ones. Moreover, we can control the degree of expressivity for speaking styles or emotions in synthesized speech by changing the interpolation ratio in interpolation between neutral and other representative styles. We also show that we can achieve style morphing in speech synthesis, namely, changing style smoothly from one representative style to another by gradually changing the interpolation ratio.
Tatsuo YOTSUKURA Shigeo MORISHIMA Satoshi NAKAMURA
An accurate audio-visual speech corpus is inevitable for talking-heads research. This paper presents our audio-visual speech corpus collection and proposes a head-movement normalization method and a facial motion generation method. The audio-visual corpus contains speech data, movie data on faces, and positions and movements of facial organs. The corpus consists of Japanese phoneme-balanced sentences uttered by a female native speaker. An accurate facial capture is realized by using an optical motion-capture system. We captured high-resolution 3D data by arranging many markers on the speaker's face. In addition, we propose a method of acquiring the facial movements and removing head movements by using affine transformation for computing displacements of pure facial organs. Finally, in order to easily create facial animation from this motion data, we propose a technique assigning the captured data to the facial polygon model. Evaluation results demonstrate the effectiveness of the proposed facial motion generation method and show the relationship between the number of markers and errors.
Tomohiko OHTSUKA Akiyoshi KONDO
A new detection methodology for both of the core and the delta of the fingerprint using the extended relational graph is presented. This paper shows the way to detect both of the core loop and the delta loop from the extended relational graph, which we proposed in order to summarize the global feature of the fingerprint ridge pattern distribution. The experimental results for 180 fingerprint samples show that the processing time is ranging from 0.34 [sec] to 0.44 [sec] for each fingerprint image by using Pentium 4 1.8 GHz Processor. In our experiments, the core and the delta were successfully extracted in 94.4% of the 180 samples.
JaeGwi CHOI Goichiro HANAOKA KyungHyune RHEE Hideki IMAI
Digital fingerprinting schemes are cryptographic methods deterring buyers from illegally redistributing digital contents. It enables sellers to identify the traitor by providing each buyer with a slight different version. What is important in designing fingerprinting scheme is to make it more practical and efficient. Recently, two oblivious transfer protocol-based schemes to consider practicality were proposed. These are significant in the sense that they are completely specified from a computation point of view and are thus readily implementable. But these schemes cannot offer the security of sellers and buyers. In this paper, we show how to break the existing oblivious transfer-based fingerprinting schemes and then suggest how to make secure fingerprinting schemes against the dishonesty of sellers and buyers. We use oblivious transfer protocol with two-lock cryptosystem to make it practical and secure. All computations are performed efficiently and the security degree is strengthened in our proposal.
Tomohiko OHTSUKA Takeshi TAKAHASHI
This paper describes a new approach to detect a fingerprint core location using the extended relational graph, which is generated by the segmentation of the ridge directional image. The extended relational graph presents the adjacency between segments of the directional image and the boundary information between segments of the directional image. The boundary curves generated by the boundary information in the extended relational graph is approximated to the straight lines. The fingerprint core location is calculated as center of the gravity in the points of intersection of these approximated lines. Experimental results show that 90.8% of the 130 fingerprint samples are succeeded to detect the core location.
Hisashi AOMORI Kohei KAWAKAMI Tsuyoshi OTAKE Nobuaki TAKAHASHI Masayuki YAMAUCHI Mamoru TANAKA
The lifting scheme is an efficient and flexible method for the construction of linear and nonlinear wavelet transforms. In this paper, a novel lossless image coding technique based on the lifting scheme using discrete-time cellular neural networks (DT-CNNs) is proposed. In our proposed method, the image is interpolated by using the nonlinear interpolative dynamics of DT-CNN, and since the output function of DT-CNN works as a multi-level quantization function, our method composes the integer lifting scheme for lossless image coding. Moreover, the nonlinear interpolative dynamics by A-template is used effectively compared with conventional CNN image coding methods using only B-template. The experimental results show a better coding performance compared with the conventional lifting methods using linear filters.
Hua-Yi LIN Yueh-Min HUANG Tzone-I WANG
Unlike traditional networks, the characteristics of mobile wireless devices that can dynamically form a network without any infrastructure and wired line mean that mobile ad hoc networks frequently display partition owing to node mobility or link failures. Consequently, an ad hoc network is difficult to provide on-line access to trusted authorities or centralized servers. Despite the existence of well-known security mechanisms, the absence of a stationary central authorization facility in an open and distributed communication environment is a major challenge. Consequently, applying traditional Public Key Infrastructure (PKI) security architecture to mobile ad hoc networks will create secure blind sides. Based on this perspective, this study proposes a novel scalable and robust cluster-organized key management scheme. Distribution of trust to an aggregation of cluster heads using a threshold scheme faculty provides mobile ad hoc networks with robust key management. Furthermore, the proposed approach provides Certificate Authority (CA) with a fault tolerance mechanism to prevent a single point of compromise or failure, and saves CA large repositories from maintaining member certificates, making the proposed approach more suitable for numerous mobile devices. Additionally, this study proposes a Cluster Secure Based Routing Protocol (CSBRP) to integrate into the key management to enhance non-repudiation of routing information and routing performances. Finally, this study introduces a mathematical model to demonstrate that the proposed cluster-based communication outperforms the node-based approach.
Yoshihisa TAKAHASHI Hisakazu KIKUCHI Shogo MURAMATSU Yoshito ABE Naoki MIZUTANI
This paper presents a color demosaicing method by introducing iterative asymmetric average interpolation. Missing primary colors on a Bayer pattern color filter array (CFA) are estimated by an asymmetric average interpolation where less intensity variation is assumed to be of stronger significance, before sharpness of an initial estimate is further improved by an iterative procedure. The iteration is implemented by an observation process followed by a restoration process. The former is modeled by blurring followed by CFA sampling and the latter is completely as same as the color demosaicing method initially applied. Experimental results have shown a favorable performance in terms of PSNR and visual appearance, in particular, in sharpness recovery.
Freddy PERRAUD Christian VIARD-GAUDIN Emmanuel MORIN Pierre-Michel LALLICAN
This paper incorporates statistical language models into an on-line handwriting recognition system for devices with limited memory and computational resources. The objective is to minimize the error recognition rate by taking into account the sentence context to disambiguate poorly written texts. Probabilistic word n-grams have been first investigated, then to fight the curse of dimensionality problem induced by such an approach and to decrease significantly the size of the language model an extension to class-based n-grams has been achieved. In the latter case, the classes result either from a syntactic criterion or a contextual criteria. Finally, a composite model is proposed; it combines both previous kinds of classes and exhibits superior performances compared with the word n-grams model. We report on many experiments involving different European languages (English, French, and Italian), they are related either to language model evaluation based on the classical perplexity measurement on test text corpora but also on the evolution of the word error rate on test handwritten databases. These experiments show that the proposed approach significantly improves on state-of-the-art n-gram models, and that its integration into an on-line handwriting recognition system demonstrates a substantial performance improvement.
Hyeon-Ho KIM Sung-Hwan HAN Hyeon-Deok BAE
Recently, DOAS (differential optical absorption spectroscopy) has been used for nondestructive air monitoring, in which the LS (least squares) method is used to calculate trace gas concentrations due to its computational simplicity. This paper applies the ICA (independent component analysis) method to the DOAS system of air monitoring, since the LS method is insufficient to recover the desired spectra perfectly due to sparsity characteristic. If the sparsity of reference spectra in the DOAS system imposes the assumption of independence, the ICA algorithm can be used. The proposed method is used to regress the observed spectrum on the estimates of the reference spectra. The ICA algorithm can be seen as a preprocessing method where the ICs of the references are used as the input in the regression. The performance of the proposed method is evaluated in simulation studies using synthetic data.
Chikaaki KODAMA Kunihiro FUJIYOSHI
This paper discusses how to minimize the number of dissection lines regarded as wiring channels on a floorplan corresponding to a placement of n modules. In a floorplan (rectangular dissection), the number of dissection lines exceeds the number of rooms exactly by three. Since a floorplan obtained from a given module placement may have many empty rooms where no module is assigned, redundant wiring channels and wire bends may also be generated. Hence, in order to reduce redundant channels and wire bends, removal of empty rooms is required. For this purpose, we formulate a problem of obtaining a floorplan with the minimum possible empty rooms based on a given module placement. Then, we propose a method of removing as many redundant empty rooms as possible by merging dissection lines on a floorplan in O(n) time. The number of empty rooms in the resultant floorplan is reduced to n- or less.
Jun MIYAZU Toru SEGAWA Shinji MATSUO Tetsuyoshi ISHII Hiroyuki SUZUKI Yuzo YOSHIKUNI
Apodised chirped gratings based on InGaAsP/InP deep-ridge waveguides with vertical-groove surface gratings were fabricated. Reflectivity ripple and group delay ripple were reduced from around 4 dB to 1 dB and from around 5 ps to 2 ps, respectively, by apodisation over a wavelength range of around 20 nm.
Liansheng TAN Yan YANG Chuang LIN Naixue XIONG
Resilient Packet Ring (RPR) is a new technology currently being standardized in the IEEE 802.17 working group. The existed bandwidth allocation algorithms for RPR networks are not able to provide satisfactory solutions to meet the performance requirements. In this paper we propose one fair bandwidth allocation algorithm, termed PID-RPR, which satisfies the performance goals of RPR networks, such as fairness, high utilization and maximal spatial reuse. The algorithm is operated at each RPR node in a distributive way; the proportional, integral and differential (PID) controller is used to allocate bandwidth on the outgoing link of the node for the flows over the link in a weighted manner. To achieve the global coordination, one control packet containing every node's message runs around the ring in order to update the relevant message for all nodes on the ring. When the packet reaches one node, this node adjusts its own rate according to its own message in the control packet; in the meantime it updates other nodes' control message in the control packet. As the control packet propagates around the ring, each node can eventually adjust its sending rate to reach its fair share according to the fairness criterion, and the buffer occupancy at each node is kept within the target value. Our algorithm is of distributed nature in the sense that upstream ring nodes inject traffic at a rate according to congestion and fairness criteria downstream. The simulation results demonstrate that satisfactory performance of RPR networks can be achieved under the proposed bandwidth allocation scheme.
Gordana Jovanovic DOLECEK Sanjit K. MITRA
This paper presents a new multistage comb-rotated sinc (RS) decimator with a sharpened magnitude response. Novelty of this paper is that the multistage structure has more design parameters that provides additional flexibility to the design procedure. It uses different sharpening polynomials and different cascaded comb filters at different stages. As the comb filters at the latter stages are of lower order than that of the original comb filter, the use of more complex sharpening polynomials at latter stages is possible. This leads to an improvement of the frequency characteristic without a significant increase in the complexity of the overall filter. The comb filter of the first stage is realized in a non-recursive form and can be implemented in a computationally efficient form by making use of the polyphase decomposition of the transfer function in which the subfilters operate at a lower rate that depends on the down-sampling factor employed in the first stage. In addition, both multipliers of the rotated sinc (RS) filter of the second stage work at a lower rate.
Shinsuke TAKAOKA Fumiyuki ADACHI
In this paper, a pilot-assisted channel estimation using adaptive interpolation (in which, different interpolation filter tap weights is used for different symbol position) is proposed. Each set of tap weights is updated using the normalized least mean square (NLMS) algorithm, the reference signal for which is obtained by decision feedback and reverse modulation of the received data symbol. In order to reduce the number of tap weight sets and to achieve fast convergence, the conjugate centrosymmetry property of the tap weight set is used. The average bit error rate (BER) performance in a frequency-selective Rayleigh fading channel is evaluated by computer simulation. Also evaluated is the robustness against the frequency offset between a transmitter and a receiver.
Kumiko NOMURA Satoshi TAYU Shuichi UENO
In this paper we show that an outerplanar graph G with maximum degree at most 3 has a 2-D orthogonal drawing with no bends if and only if G contains no triangles. We also show that an outerplanar graph G with maximum degree at most 6 has a 3-D orthogonal drawing with no bends if and only if G contains no triangles.
In order to boost the translation quality of corpus-based MT systems for speech translation, the technique of splitting an input utterance appears promising. In previous research, many methods used word-sequence characteristics like N-gram clues among splitting positions. In this paper, to supplement splitting methods based on word-sequence characteristics, we introduce another clue using similarity based on edit-distance. In our splitting method, we generate candidates for utterance splitting based on N-grams, and select the best one by measuring the utterance similarity against a corpus. This selection is founded on the assumption that a corpus-based MT system can correctly translate an utterance that is similar to an utterance in its training corpus. We conducted experiments using three MT systems: two EBMT systems, one of which uses a phrase as a translation unit and the other of which uses an utterance, and an SMT system. The translation results under various conditions were evaluated by objective measures and a subjective measure. The experimental results demonstrate that the proposed method is valuable for the three systems. Using utterance similarity can improve the translation quality.
Takefumi YOSHIKAWA Tsuyoshi EBUCHI Yukio ARIMA Toru IWATA
A Spread Spectrum Clock Generator (SSCG) using Digital Tracking scheme (DT-SSCG) is described. Using digital tracking control outside a PLL, DT-SSCG can realize stable modulation characteristic independent of the PLL constants. Moreover, DT-SSCG can apply to various modulation profiles easily by brief change of the digital tracking parameters. A test chip has realized the fitting of 5000 ppm downspread with 6.02 dB and 8.02 dB spectrum peak reduction for triangle and Non-Linear modulation.
Sineenard PINYAPONG Toshikazu KATO
Nowadays more people have started using their mobile phone to access information they need from anywhere at anytime. In advanced mobile technology, Location Service allows users to quickly pinpoint their location as well as makes a recommendation to fascinating events. However, users desire more appropriate recommendation services. In other words, the message service should push a message at a proper place in time. In consequence, customers obtain a higher level of satisfaction. In this paper, we propose a framework of time, place, purpose and personal profile based recommendation service. We illustrate scenarios in "push", "pull" and "don't disturb" services, where our DB queries can recommend the relevant message to users. The three factors: time, place and purpose are mutually dependent and the basic rules to analyze the essential data are summarized. We also create algorithms for DB query. We are filtering messages by one important factor: personal profile such as user's preference and degree of preference. Furthermore, we discuss an implementation of the prototype system, including results of experimental evaluation.