This paper proposes a non-destructive dielectric measurement method for a solid lossy dielectric material with sufficiently large dimensions compared to the wavelength. The proposed non-destructive measurement method employs an open-ended waveguide infilled with a low-loss dielectric material at the end of the waveguide. A numerical model of the open-ended waveguide attached to the surface of a solid dielectric material is simulated using the FDTD method. The reflection coefficient is calculated while the complex permittivity of the solid lossy dielectric material is varied. A permittivity estimation chart representing the relationship between the complex permittivity and the reflection coefficient is derived at 2 GHz. The measured reflection coefficient is plotted on the permittivity estimation chart. The chart indicates that the reflection coefficient varies drastically according to the variation in the complex permittivity of the solid dielectric material if a low-loss dielectric material is used. As a result, it became possible to estimate the complex permittivity of the solid lossy dielectric material by measuring the reflective coefficient. The estimated complex permittivity using the proposed method is comparable to the measured complex permittivity using the S-parameter method employing a coaxial line.

MT19937 is a kind of Mersenne Twister, which is a pseudo-random number generator. This study presents new designs for a MT19937 circuit suitable for custom computing machinery for high-performance scientific simulations. Our designs can generate multiple random numbers per cycle (multi-port design). The estimated throughput of a 52-port design was 262 Gbps, which is 115 times higher than the software on a Pentium 4 (2.53 GHz) processor. Multi-port designs were proven to be more cost-effective than using multiple single-port designs. The initialization circuit can be included without performance loss in exchange for a slight increase of logic scale.

In the letter, properties of m-sequence are derived, based on these properties, a family of binary nonlinear constant weight codes is presented, these binary nonlinear constant weight codes can apply to automatic repeat request (ARQ) communication system, as detecting-error codes.

We can model embedded systems as hybrid systems. Moreover, they are distributed and real-time systems. Therefore, it is important to specify and verify randomness and soft real-time properties. For the purpose of system verification, we formally define probabilistic linear hybrid automaton and its symbolic reachability analysis method. It can describe uncertainties and soft real-time characteristics.

In this paper, we propose a parametric model checking algorithm for a subclass of Timed Automata called Parametric Time-Interval Automata (PTIA). In a PTIA, we can specify upper- and lower-bounds of the execution time (time-interval) of each transition using parameter variables. The proposed algorithm takes two inputs, a model described in a PTIA and a property described in a PTIA accepting all invalid infinite/finite runs (called a never claim), or valid finite runs of the model. In the proposed algorithm, firstly we determinize and complement the given property PTIA if it accepts valid finite runs. Secondly, we accelerate the given model, that is, we regard all the actions that are not appeared in the given property PTIA as invisible actions and eliminate them from the model while preserving the set of visible traces and their timings. Thirdly, we construct a parallel composition of the model and the property PTIAs which is accepting all invalid runs that are accepted by the model. Finally, we perform the extension of Double Depth First Search (DDFS), which is used in the automata-theoretic approach to Linear-time Temporal Logic (LTL) model checking, to derive the weakest parameter condition in order that the given model never executes the invalid runs specified by the given property.

Recent advances in 77-GHz MMIC module design techniques for automotive radar applications are reviewed in this paper. The target of R&D activities is moving from high performance to low cost, mass production, high-yield manufacturing and testing. To meet the stringent requirements, millimeter-wave module design techniques have made significant progress especially in packaging, bonding, and making interface with other modules. In addition, millimeter-wave semiconductor devices and MMICs have made remarkable improvements for low cost and mass production. In this paper, the topics focusing on millimeter-wave semiconductor devices and 77-GHz MMICs are reviewed first. Then the recent R&D results on 77-GHz MMIC module design techniques are introduced, showing the technical trend of packaging, bonding, and making interface with other modules for millimeter-wave, highly-integrated, low-cost MMIC modules. Finally, the existing and future module design issues for automotive radar applications are discussed.

This paper presents a novel method of structure selection and identification for Hammerstein type nonlinear systems. An unknown nonlinear static part to be estimated is approximately represented by an automatic choosing function (ACF) model. The connection coefficients of the ACF and the system parameters of the linear dynamic part are estimated by the linear least-squares method. The adjusting parameters for the ACF model structure, i.e. the number and widths of the subdomains and the shape of the ACF are properly selected by using a genetic algorithm, in which the Akaike information criterion is utilized as the fitness value function. The effectiveness of the proposed method is confirmed through numerical experiments.

In this paper, the electrical constants of a biological tissue-equivalent agar-based solid phantom from 3.0 to 6.0 GHz are described. The developed phantom can reproduce the electrical constants of biological tissues from 3.0 to 6.0 GHz, and it is not necessary to change the phantom for each frequency band in the range of 3.0 to 6.0 GHz during the measurements. Moreover, adjustments to the dielectric constants of the phantom at 3.0, 3.8, 5.2, and 5.8 GHz are presented. The constants of this phantom can be adjusted mainly by using polyethylene powder and sodium chloride. The phantom can be used to evaluate the Specific Absorption Rate (SAR) as well as the antenna characteristics in the range of 3.0 to 6.0 GHz. Furthermore, the effect of the electrical constants of the phantom on the SAR is investigated. The investigation of SAR measurements is performed on the phantom at 5.2 GHz using the thermographic method. Calculations using the FD-TD method and the finite difference method based on the heat conduction equation are carried out in order to evaluate the thermal diffusion in the measurements using the thermographic method. The measured and calculated results are in good agreement. There is evidence that the thermal diffusion influences the SAR estimation at 5.2 GHz more than in a lower frequency range even though this method basically does not depend on the frequency.

In this paper, we introduce and describe the computational environment that we have developed for cellular automata (CA). CA are powerful methods to understand and simulate the behavior of complex systems such as traffic jams, fluid crosscurrents, and natural disasters. In CA method, modeling of such a system or a phenomenon is to define a transition function, which determines local interactions, so-called "CA rules." However, no systematic method for design of CA rules has been established. We require a CA simulator for "trial and error" in study of modeling based on CA. Furthermore, the CA simulation environment that does not require special knowledge of a user for parallel processing is desired. The purpose of this study is to develop a comprehensive system that enables us to expedite the design of local rules and to accelerate simulations. We have implemented two kinds of simulators differing in their characteristics to improve both design efficiency and execution speed. The major difference between the two simulators is whether a source code is compiled or not. The source code is described in DORA language the authors have designed for the system. DORA language is designed for describing CA rules simply.

An Insertion-Deletion system, first introduced in [1], is a theoretical computing model in the DNA computing framework based on insertion and deletion operations. When insertion and deletion operations work together, as expected, they are very powerful. In fact, it has been shown that even the very restricted Insertion-Deletion systems can characterize the class of recursively enumerable languages [1]-[4]. In this paper, we investigate the computational power of Insertion-Deletion systems and show that they preserve the computational universality without using contexts.

This paper proposes the test phantom for the cochlear implant to estimate electromagnetic interference (EMI) from a cellular phone. This test phantom is constructed from a square tank filled with saline solution. The use of a flat phantom provides a level of consistency in duplicating the exposure conditions in the EMI tests. The measurement and calculation results show that there is no difference in the E-field strength near the surface of the phantom when comparing flat and head-shaped phantoms and that the flat phantom is sufficiently thick to disregard the influence of reflective waves near the surface of the phantom. The calculation results also indicate the appropriateness of using physiological saline (0.18 g/l) up to 3 GHz when comparing the E-field strength inside a phantom comprising physiological saline and in a 2/3 muscle model. The results of actual EMI testing of a cochlear implant show that there is no difference in the maximum interference distance when using either the flat or head-shaped phantom. Based on these results, this paper presents the validity of using the flat phantom in EMI tests from cellular phone for the cochlear implant.

A speech signal captured by a distant microphone is generally smeared by reverberation, which severely degrades both the speech intelligibility and Automatic Speech Recognition (ASR) performance. Previously, we proposed a single-microphone dereverberation method, named "Harmonicity based dEReverBeration (HERB)." HERB estimates the inverse filter for an unknown room transfer function by utilizing an essential feature of speech, namely harmonic structure. In previous studies, improvements in speech intelligibility was shown solely with spectrograms, and improvements in ASR performance were simply confirmed by matched condition acoustic model. In this paper, we undertook a further investigation of HERB's potential as regards to the above two factors. First, we examined speech intelligibility by means of objective indices. As a result, we found that HERB is capable of improving the speech intelligibility to approximately that of clean speech. Second, since HERB alone could not improve the ASR performance sufficiently, we further analyzed the HERB mechanism with a view to achieving further improvements. Taking the analysis results into account, we proposed an appropriate ASR configuration and conducted experiments. Experimental results confirmed that, if HERB is used with an ASR adaptation scheme such as MLLR and a multicondition acoustic model, it is very effective for improving ASR performance even in unknown severely reverberant environments.

In this study, we have proposed an efficient automatic multilevel thresholding method for image segmentation. An effective criterion for measuring the separability of the homogenous objects in the image, based on discriminant analysis, has been introduced to automatically determine the number of thresholding levels to be performed. Then, by applying this discriminant criterion, the object regions with homogeneous illuminations in the image can be recursively and automatically thresholded into separate segmented images. The proposed method is fast and effective in analyzing and thresholding the histogram of the image. In order to conduct an equitable comparative performance evaluation of the proposed method with other thresholding methods, a combinatorial scheme is also introduced to properly reduce the computational complexity of performing multilevel thresholding. The experimental results demonstrated that the proposed method is feasible and computationally efficient in automatic multilevel thresholding for image segmentation.

This paper addresses the variation of the attenuation characteristics of the Specific Absorption Rate (SAR) in a lossy medium as a function of the distance between an antenna and the medium with different EM-source sizes. Analysis and measurements were performed using a dipole antenna at 900 MHz and a COST244 cubic phantom. From this, an empirical equation has been derived, representing the attenuation characteristics of the SAR. The equation takes into consideration an energy loss due to the spatial spread of electromagnetic waves. In the case where an antenna is placed more than λ/2π away from the medium, the attenuation characteristics of the SAR are those obtained from plane waves in the lossy medium. In the case where a half-wavelength dipole antenna is located close to the medium, at a distance of less than λ/2π, the attenuation characteristics of the SAR are calculated from an equation that includes a loss caused by the spread of energy as a cylindrical wave. Moreover, when the length of antenna is short, it is found that a spatial attenuation factor appropriate to a spherical wave should be taken into account.

It is not always possible to find a global parse for an input sentence owing to problems such as errors of a sentence, incompleteness of lexicon and grammar. Partial parsing is an alternative approach to respond to these problems. Partial parsing techniques try to recover syntactic information efficiently and reliably by sacrificing completeness and depth of analysis. One of the difficulties in partial parsing is how the grammar might be automatically extracted. In this paper we present a method of automatically extracting partial parsing rules from a tree-annotated corpus using the decision tree method. Our goal is deterministic global parsing using partial parsing rules, in other words, to extract partial parsing rules with higher accuracy and broader expansion. First, we define a rule template that enables to learn a subtree for a given substring, so that the resultant rules can be more specific and stricter to apply. Second, rule candidates extracted from a training corpus are enriched with contextual and lexical information using the decision tree method and verified through cross-validation. Last, we underspecify non-deterministic rules by merging substructures with ambiguity in those rules. The learned grammar is similar to phrase structure grammar with contextual and lexical information, but allows building structures of depth one or more. Thanks to automatic learning, the partial parsing rules can be consistent and domain-independent. Partial parsing with this grammar processes an input sentence deterministically using longest-match heuristics, and recursively applies rules to an input sentence. The experiments showed that the partial parser using automatically extracted rules is not only accurate and efficient but also achieves reasonable coverage for Korean.

There have been many arguments that the underlying structure of natural languages is beyond the descriptive capacity of context-free languages. A well-known example is tree adjoining grammars; less common are spine grammars, linear indexed grammars, head grammars, and combinatory categorial grammars. It is known that these models of grammars have the same generative power of string languages and fall into the class of mildly context-sensitive grammars. For an automaton, it is known that the class of languages accepted by transfer pushdown automata is exactly the class of linear indexed languages. In this paper, deterministic transfer pushdown automata is introduced. We will show that the language accepted by a deterministic transfer pushdown automaton is generated by an unambiguous spine grammar. Moreover, we will show that there exists an inherently ambiguous language.

We have proposed a recognition method for pulmonary nodules based on experimentally selected feature values (such as contrast, circularity, etc.) of pathologic candidate regions detected by our Variable N-Quoit (VNQ) filter. In this paper, we propose a new recognition method for pulmonary nodules by use of not experimentally selected feature values, but each CT value itself in a region of interest (ROI) as a feature value. The proposed method has 2 phases: learning and recognition. In the learning phase, first, the pathologic candidate regions are classified into several clusters based on a principal component score. This score is calculated from a set of CT values in the ROI that are regarded as a feature vector, and then eigen vectors and eigen values are calculated for each cluster by application of principal component analysis to the cluster. The eigen vectors (we call them "eigen-images") corresponding to the S-th largest eigen values are utilized as base vectors for subspaces of the clusters in a feature space. In the recognition phase, correlations are measured between the feature vector derived from testing data and the subspace which is spanned by the eigen-images. If the correlation with the nodule subspace is large, the pathologic candidate region is determined to be a nodule, otherwise, it is determined to be a normal organ. In the experiment, first, we decide on the optimal number of subspace dimensions. Then, we demonstrated the robustness of our algorithm by using simulated nodule images.

Recently, wearable devices which use the human body as a transmission channel have been developed. However, there has been a lack of information related the transmission mechanism of such devices in the physical layer. Electro-magnetic communication trials using human body as transmission media have more than a decade's history. However, most of the researches have been conducted by researchers who just want to utilize the fact and practically no physical mechanisms have been researched until recently. Hence, in previous study, the authors proposed calculation models of the wearable transmitter and the receiver attached to the arm using the FDTD method. Moreover, the authors compared the calculated received signal levels to the measured ones by using a biological tissue-equivalent phantom. However, there was little analysis on each component of the propagated signal. In this paper, the authors clarified the transmission mechanism of the wearable device using the human body as a transmission channel from the view point of the interaction between electromagnetic wave and the human body. First, the authors focused their attention on measuring the each component of the propagated signal using a shielded loop antenna. From these results, the favorable direction of electrodes of the transmitter was proposed to use the human body as a transmission channel. As a result, longitudinal direction is effective for sending the signal to the receiver, compared to the transversal direction. Next, the authors investigated the dominant signal transmission channel, because the question of whether the dominant signal channel is in or around the arm had remained unsettled. To clear this question, the authors proposed the calculation model of an arm wearing the transmitter and receiver placed into a hole of a conductor plate. The electric field distribution and received signal voltage was investigated as a function of the gap between the hole of the conductor plate and the surface of the arm. The result indicated that the dominant signal transmission channel is not inside but the surface of the arm because signal seems to be distributed as a surface wave.

In this study, a cascade open-short-thru (COST) de-embedding procedure is proposed for the first time for on-wafer device characterization in the RF/microwave frequency regime. This technique utilizes the "open" and "short" dummy structures to de-embed the probe-pad parasitics of a device-under-test (DUT). Furthermore, to accurately estimate the input/output interconnect parasitics, including the resistive, inductive, capacitive, and conductive components, the "thru" dummy device has been characterized after probe-pad de-embedding. With the combination of transmission-line theory and cascade-configuration concept, this method can efficiently generate the scalable and repeatable interconnect parameters to completely eliminate the redundant parasitics of the active/passive DUTs of various device sizes and interconnect dimensions. Consequently, this method is very suitable for the on-wafer automatic measurement.

This paper investigates a relationship between inkdot and one-pebble for two-dimensional finite automata (2-fa's). Especially we show that (1) alternating inkdot 2-fa's are more powerful than nondeterministic one-pebble 2-fa's, and (2) there is a set accepted by an alternating inkdot 2-fa, but not accepted by any alternating one-pebble 2-fa with only universal states.