With the growing demand for mobile communications, multicarrier (MC) schemes are receiving an increasing amount of attention, primarily because they handle frequency selective channels better than ordinary single-carrier schemes. However, despite offering several advantages, MC systems have certain weak points. One is their high sensitivity to interchannel interference (ICI). The influence of Doppler shift and ICI are the focus of this paper. Newly proposed B3G/4G systems are developed for data transmission rates higher than those of the IEEE 801.11. It is then necessary that the bandwidth of the subcarrier be small. Moreover, for a higher carrier frequency and mobile speed, the influence of the Doppler shift will be large; therefore, the influence of ICI becomes severer. Using a Markov chain approach, we synthesized a turbo equalizer (TE) that minimizes ICI when interference affects the arbitrary number M of adjacent subchannels. This approach shows the complexity of the proposed algorithm exhibits linear growth with respect to M and independence with respect to the total number of subchannels in the multicarrier system. The proposed ICI cancellation scheme can also be effective in the case of multiple Doppler frequency offsets. This makes the proposed approach attractive for practical implementations.

As digital television transmission is becoming ubiquitous, a method that can remotely monitor the quality of the final and intermediate pictures is urgently needed. In particular, the case where standards conversion is included in the transmission chain is a serious issue as the input and output cannot simply be compared. This letter proposes a novel method to solve this issue. The combination of skipping fields/pixels and the previously proposed SSSWHT-RR method, using the information of correlation coefficients and variance of the picture, achieves accurate detection of picture failure.

In this paper, a revised method is proposed in order to determine the parameters of an F0 generation model from the observed F0 contour automatically. Compared with the previous method, there are two points revised in the proposed method. Firstly, we relax the endpoint constraint in the dynamic programming method, especially we allow the timing of the first phrase command to be earlier than the beginning point of the actual F0 pattern. Secondly, the z-transform method is introduced to convert the equation of the F0 model in order to simplify the calculation and save the computation time. An experiment with 100 sentences spoken by two males and two females selected from the speech database "ATR 503 sentences" has shown that the proposed method is effective as we expected.

Digital watermarks on pictures are more useful when they are better able to survive image processing operations and when they cause less degradation of picture quality. Random geometric distortion is one of the most difficult kinds of image processing for watermarks to survive because of the difficulty of synchronizing the expected watermark patterns to the watermarks embedded in pictures. This paper proposes three methods to improve a previous method that is not affected by this difficulty but that is insufficient in maintaining picture quality and treating other problems in surviving image processing. The first method determines the watermark strength in L*u*v* space, where human-perceived degradation of picture quality can be measured in terms of Euclidian distance, but embeds and detects watermarks in YUV space, where the detection is more reliable. The second method, based on the knowledge of image quantization, uses the messiness of color planes to hide watermarks. The third method reduces detection noises by preprocessing the watermarked image with orientation-sensitive image filtering, which is especially effective in picture portions where pixel values change drastically. Subjective evaluations have shown that these methods improved the picture quality of the previous method by 0.5 point of the mean evaluation score at the representative example case. On the other hand, the watermark strength of the previous method could be increased by 30% through 60% while keeping the same picture quality. Robustness to image processing has been evaluated for random geometric distortion, JPEG compression, Gaussian noise addition, and median filtering and it was clarified that these methods reduced the detection error ratio to 1/10 through 1/4. These methods can be applied not only to the previous method but also to other types of pixel-domain watermarking such as the Patchwork watermarking method and, with modification, to frequency-domain watermarking.

In this paper, we demonstrate an immersive and interactive broadcasting production system with a new haptically enhanced multimedia broadcasting chain. The system adapts Augmented Reality (AR) techniques, which merges captured videos and virtual 3D media seamlessly through multimedia streaming technology, and haptic interaction technology in near real-time. In this system, viewers at the haptic multimedia client can interact with AR broadcasting production transmitted via communication network. We demonstrate two test applications, which show that the addition of AR- and haptic-interaction to the conventional audio-visual contents can improve immersiveness and interactivity of viewers with rich contents service.

This paper investigates the 10 m semi anechoic chamber using a new type hybrid EM wave absorber consisted of the grid-ferrite and the open-top hollow pyramidal EM wave absorber. We designed a new type hybrid EM wave absorber, which length could be slightly realized 65 cm. The 10 m semi anechoic chamber was constructed in the size of L21.5 mW13.5 mH8.9 m as the result of the ray-tracing simulation using this absorber. Then, the site attenuation in the constructed anechoic chamber was measured by using the broadband calculable dipole antennas. As the result, the maximum deviations between the measured site attenuation and theoretical calculated one were obtained within 3.6 dB in the frequency range of 30 MHz to 300 MHz. It was confirmed the validity of a new type hybrid EM wave absorber. Moreover, it was confirmed that the measured results agree with the ray-tracing simulation results, in which the differences are about 1.5 dB.

The Gallant-Lambert-Vanstone method [14](GLV method for short) is a scalar multiplication method for elliptic curve cryptography (ECC). In WAP WTLS [49], SEC 2 [44], ANSI X9.62 [1] and X9.63 [2], several domain parameters for applications of the GLV method are described. Curves with those parameters have efficiently-computable endomorphisms. Recently the GLV method for Jacobians of hyperelliptic curve (HEC) has also been studied. In this paper, we discuss applications of the GLV method to curves with real multiplication (RM). It is the first time to use RM for efficient scalar multiplication as far as we know. We describe the general algorithm for using such RM, and we show that some genus 2 curves with RM have enough effciency to be used in the GLV method as in the previous CM case. Moreover, we will see that such RM curves can be obtained abundantly unlike the previously proposed CM curves of genus 2.

Phonetic string search of written text is an important topic in Information Retrieval. While most of the previous methods convert a string into intermediate codes with phonetic transformation rules, this paper proposes a novel algorithm to segment two phonetic strings into syllables and find the optimal pairing of the corresponding syllables to calculate their similarity score. The experiment shows that this method is very effective and flexible. It can be easily adapted to different datasets and achieves optimal performance on average.

Recently, the direct conversion scheme has been actively investigated for the purpose of cost miniaturization and low power consumption of wireless receivers. IQ imbalance is one of the problems for the direct conversion receiver. In the case of OFCDM modulations, this IQ imbalance causes intercarrier interference (ICI) in the demodulated signals. In this paper, the decision directed scheme for IQ imbalance compensation is proposed. In the proposed scheme, the combination of received symbols which satisfies orthogonality conditions is used for compensation of IQ imbalance. Therefore, in addition to the pilot symbols, the received symbols can be used in order to improve the accuracy of the compensation matrix and BER can be reduced.

In this paper, a novel projection-based method is presented to register partial 3D point clouds, acquired from a multi-view camera, for 3D reconstruction of an indoor scene. In general, conventional registration methods for partial 3D point clouds require a high computational complexity and much time for registration. Moreover, these methods are not robust for 3D point cloud which has a low precision. To overcome these drawbacks, a projection-based registration method is proposed. Firstly, depth images are refined based on both temporal and spatial properties. The former involves excluding 3D points with large variation, and the latter fills up holes referring to four neighboring 3D points, respectively. Secondly, 3D point clouds acquired from two views are projected onto the same image plane, and two-step integer mapping is applied to search for correspondences through the modified KLT. Then, fine registration is carried out by minimizing distance errors based on adaptive search range. Finally, we calculate a final color referring to the colors of corresponding points and reconstruct an indoor scene by applying the above procedure to consecutive scenes. The proposed method not only reduces computational complexity by searching for correspondences on a 2D image plane, but also enables effective registration even for 3D points which have a low precision. Furthermore, only a few color and depth images are needed to reconstruct an indoor scene. The generated model can be adopted for interaction with as well as navigation in a virtual environment.

In this paper, we discuss the efficiency of tunneling techniques which are expected to accelerate multicast deployment. Our motivation is that, despite the proposal of many tunneling techniques, no paper has studied their impact on multicast efficiency. Through detailed computer experiments, we find that there is a critical size of multicast island, above which the loads imposed on tunneling endpoints are suddenly diminished. In addition, multicast islands equaling or exceeding the critical size reduce the overhead of forwarding states on routers. We also find a scaling law between the critical size and group size. Based on these findings, we present simple guidelines on using tunneling when deploying multicast systems. A possible explanation for our findings is uncovered by a simple analysis. Our work is the first to evaluate the impact of tunneling and clarify conditions in which multicast deployment is well supported by tunneling.

This paper presents the design of low-power low-noise 10 GHz CMOS monolithic integrated LC VCOs suitable for data clock recovery architectures in optical receivers of SDH (STM-64) and SONET (OC-192). Optimizations of device parameters and passive components are given in detail. For passive components, differential and single-ended inductor structures as well as MOS varactors with and without lightly doped drain/source (LDD) implantation have been investigated. The VCOs implemented in a 0.18 µm process demonstrate the single-side-band phase noise of as low as -107 dBc/Hz at 1 MHz offset and 21% tuning range while consuming only 7 mW under 1.8 V supply.

This paper presents a new type of wearable teleoperation system that can be applied to the control of a humanoid robot. The proposed system has self-contained computing hardware with a stereo head-mounted display, a microphone, a set of headphones, and a wireless LAN. It also has a mechanism that tracks arm and head motion by using several types of sensors that detect the motion data of an operator, along with a simple force reflection mechanism that uses vibration motors at appropriate joints. For remote tasks, we use intelligent self-sensory feedback and autonomous behavior, such as automatic grasping and obstacle avoidance in a slave robot, and we feed the information back to an operator through a multimodal communication channel. Through this teleoperation system, we successfully demonstrate several teleoperative tasks, including object manipulation and mobile platform control of a humanoid robot.

In this paper, we propose a method to solve the distributed optimal power flow problem and discuss the associated implementation. We have combined this method with a projected Jacobi (PJ) method and a modified parallel block scaled gradient (MPBSG) method possessing decomposition effects. With the decomposition, our method can be parallel processed and is computationally efficient. We have tested our method for distributed OPF problems on numerous power systems. As seen from the simulation results, our method achieved a dramatic speed-up ratio compared with the commercial IMSL subroutines.

This paper examines polarimetric scattering characteristics caused by a dihedral corner reflector of finite size. The dihedral corner reflector is a basic model of double-bounce structure in urban area. The detailed scattering information serves the interpretation of Polarimetric Synthetic Aperture Radar (POLSAR) data analysis. The Finite-Difference Time-Domain (FDTD) method is utilized for the scattering calculation because of its simplicity and flexibility in the target shape modeling. This paper points out that there exists a stable double-bounce squint angle region both for perfect electric conductor (PEC) and dielectric corner reflectors. Beyond this stable squint angular region, the scattering characteristics become completely different from the assumed response. A criterion on the double-bounce scattering is proposed based on the physical optics (PO) approximation. The detailed analyses on the polarimetric index (co-polarization ratio) with respect to squint angle and an experimental result measured in an anechoic chamber are shown.

This paper presents an approach that uses the Viterbi algorithm in a stereo correspondence problem. We propose a matching process which is visualized as a trellis diagram to find the maximum a posterior result. The matching process is divided into two parts: matching the left scene to the right scene and matching the right scene to the left scene. The last result of stereo problem is selected based on the minimum error for uniqueness by a comparison between the results of the two parts of matching process. This makes the stereo matching possible without explicitly detecting occlusions. Moreover, this stereo matching algorithm can improve the accuracy of the disparity image, and it has an acceptable running time for practical applications since it uses a trellis diagram iteratively and bi-directionally. The complexity of our proposed method is shown approximately as O(N2P), in which N is the number of disparity, and P is the length of the epipolar line in both the left and right images. Our proposed method has been proved to be robust when applied to well-known samples of stereo images such as random dot, Pentagon, Tsukuba image, etc. It provides a 95.7 percent of accuracy in radius 1 (differing by 1) for the Tsukuba images.

Syntax and prosody are closely related to each other. This paper is concerned with the problem of exploiting pause information for recovering dependency structures of read Japanese sentences. Our parser can handle both symbolic information such as dependency rule and numerical information such as the probability of dependency distance of a phrase in a unified way as linguistic information. In our past work, post-phrase pause that immediately succeeds a phrase in question was employed as prosodic information. In this paper, we employed two kinds of pauses in addition to the post-phrase pause: post-post-phrase pause that immediately succeeds the phrase that follows a phrase in question, and pre-phrase pause that immediately precedes a phrase in question. By combining the three kinds of pause information linearly with the optimal combination weights that were determined experimentally, the parsing accuracy was improved compared to the case where only the post-phrase pause was used as in our previous work. Linear combination of pause and fundamental frequency information yielded further improvement of parsing accuracy.

Extending the domain of the vector potential in the so-called Hallen's equation, four unknown constants are determined to satisfy the boundary conditions in the same way as the circuit theory, where the vector potential plays the leading role, from which the current density and the current itself are derived. Vanishing of the current density just outside the ends of the antenna is required. For a tube-shaped antenna with walls of infinitesimal thickness, further the current just inside the ends of the antenna should vanish, as a result, the current distribution becomes sinusoidal. Adoption of either the surface current distribution or axial current distribution incurs a crucial effect on the value of the currents calculated from the vector potential. The numerical results of the radiation impedance of a hslf-wave antenna show a tendency of consistency with that relatively newly obtained by employing the exact kernel. The problem on the nonsolvability of Hallen's equation is cleared up. Comments are given on the moment method in relation to the boundary value problems to recommend to add two more undecided constants to Hallen's equation.

Finding intracranial aneurysms plays a key role in preventing serious cerebral diseases such as subarachnoid hemorrhage. For detection of aneurysms, magnetic resonance angiography (MRA) can provide detailed images of arteries non-invasively. However, because over 100 MRA images per subject are required to cover the entire cerebrum, image diagnosis using MRA is very time-consuming and labor-intensive. This article presents a computer-aided diagnosis (CAD) system for finding aneurysms with MRA images. The principal components are identification of aneurysm candidates (= ROIs; regions of interest) from MRA images and estimation of a fuzzy degree for each aneurysm candidate based on a case-based reasoning (CBR). The fuzzy degree indicates whether a candidate is true aneurysm. Our system presents users with a limited number of ROIs that have been sorted in order of fuzzy degree. Thus, this system can decrease the time and the labor required for detecting aneurysms. Experimental results using phantoms indicate that the system can detect all aneurysms at branches of arteries and all saccular aneurysms produced by dilation of a straight artery in 1 direction perpendicular to the principal axis. In a clinical evaluation, performance in finding aneurysms and estimating the fuzzy degree was examined by applying the system to 16 subjects with a total of 19 aneurysms. The experimental results indicate that this CAD system detected all aneurysms except a fusiform aneurysm, and gave high fuzzy degrees and high priorities for the detected aneurysms.

Security protocols flaws represent a substantial portion of security exposures of data networks. In order to evaluate security protocols against any attack, formal methods are equipped with a number of techniques. Unfortunately, formal methods are applicable for static state only, and don't guarantee detecting all possible flaws. Therefore, formal methods should be complemented with dynamic protection. Anomaly detection systems are very suitable for security protocols environments as dynamic activities protectors. This paper presents an intrusion detection system that uses a number of different anomaly detection techniques to detect attacks against security protocols.