The relative permittivity and permeability are discontinuous at the grating profile, and the electric and magnetic flux densities are continuous. As for the method of analysis for scattering waves by surface relief gratings placed in conical mounting, the spatial harmonic expansion approach of the flux densities are formulated in detail and the validity of the approach is shown numerically. The present method is effective for uniform regions such as air and substrate in addition to grating layer. The matrix formulations are introduced by using numerical calculations of the matrix eigenvalue problem in the grating region and analytical solutions separated for TE and TM waves in the uniform region are described. Some numerical examples for linearly and circularly polarized incidence show the usefulness of the flux densities expansion approach.

A design of a linearly-polarized non-resonant waveguide broad-wall transverse slot linear array with suppressed grating lobes is presented. Each unit element in the array consists of a transverse slot, an inductive post and a parasitic dipole-pair at a height of half of the free space wavelength. It is designed as an isolated unit without considering mutual coupling by using the Method of Moments (MoM) for radiation suppression in grating beam direction and reflection cancellation at the input. The elements thus designed are used in a travelling wave array environment. It is predicted that the reflection is less than -20 dB at 11.95 GHz while the grating lobes are suppressed by more than 15 dB. The design and the characteristics of the array are confirmed by measurements.

This paper introduces τk notation to be used to assess test generation complexity of classes of sequential circuits. Using τk notation, we reconsider and restate the time complexity of test generation for existing classes of acyclic sequential circuits. We also introduce a new DFT method called feedback shift register (FSR) scan design technique, which is extended from the scan design technique. Therefore, for a given sequential circuit, the corresponding FSR scan designed circuit has always equal or lower area overhead and test application time than the corresponding scan designed circuit. Furthermore, we identify some new classes of sequential circuits that contain some cyclic sequential circuits, which are τ-equivalent and τ2-bounded. These classes are the l-length-bounded testable circuits, l-length-bounded validity-identifiable circuits, t-time-bounded testable circuits and t-time-bounded validity-identifiable circuits. In addition, we provide two examples of circuits belonging to these classes, namely counter-cycle finite state machine realizations and state-shiftable finite state machine realizations. Instead of using a DFT method, a given sequential circuit described at the finite state machine (FSM) level can be synthesized using another test methodology called synthesis for testability (SFT) into a circuit that belongs to one of the easily testable classes of cyclic sequential circuits.

A new dual-slope ramp (DSR) reset waveform is proposed to improve the dark room contrast ratio in AC-PDPs. The proposed reset waveform has two different voltage slopes during a ramp-up period. The first voltage slope lower than the conventional ramp voltage slope plays a role in producing the priming particles under the low background luminance, which is considered to be a kind of pre-reset discharge. On the other hand, the second voltage slope higher than the conventional ramp voltage slope produces a stable reset discharge due to the presence of the priming particles, but gives rise to a slight increase in the background luminance. Thus, a bias voltage is also applied during a part of the second voltage-slope period to adjust the background luminance and address discharge characteristics. As a result, the proposed dual-slope reset waveform can lower the background luminance without causing the discharge instability, thereby improving the high dark room contrast ratio of an AC-PDP without reducing the address voltage margin.

In this paper, we propose an efficient rate and power allocation scheme for multiuser OFDM systems to minimize the total transmit power under the given QoS requirements. We deduce the optimal solution of transmit power minimization problem and develop a suboptimal algorithm with low complexity based on the theoretical analysis. Because of the avoidance of iterative procedure, it is less complex than the existing schemes. The simulation results show that our proposal outperforms the existing schemes and it is very close to the optimal solution.

A multi-user space-time block coding (STBCa) system is a multi-access system where co-channel users employ space-time block codes (STBC). In this paper, we aimed at the design of efficient zero-forcing (ZF) receivers, especially ZF iterative interference cancellation (IC) receivers, for multi-user {G2, G3, G4} STBC systems with an arbitrary number of users, based on the identification of algebraic properties existing in the systems. First, we identify some algebraic properties for {G2, G3, G4} STBC systems. Then, utilizing these algebraic properties, we further expose two significative properties, called "ZF output uncorrelated property" and "ZF output equal Post-detection SNR property" respectively, for least-squares (LS) ZF receivers in multi-user {G2, G3, G4} STBC systems by detailed proofs. Based on the two properties, a novel LS ZF user-ordered successive interference cancellation (ZF UOSIC) detection algorithm is proposed subsequently. Finally, simulation results show that ZF UOSIC is superior to the conventional ZF IC and maximum-likelihood (ML) algorithms and the non-ordered ZF user-based SIC (ZF USIC) algorithm due to adopting iterative IC and optimal ordering among users, and has very close performance to the ZF symbol-ordered SIC but with lower complexity due to the fewer iterative times.

Coupling between resonators are analyzed theoretically on basis of the coupled mode theory. New and basic equations for the coupling coefficient are derived and compared with those of waveguides. They should be useful for understanding the physical background of coupling and designing a new coupling scheme.

This paper investigates intermodultation distortion in ferroelectric phase shifters depending on bias voltage. Two analog phase shifters based on barium-strontium-titantate (BST) coated sapphire substrates have been fabricated with interdigital capacitors (IDCs) which have 2 and 4 µm spacing between adjacent fingers. In case of the phase shifter with 4 µm-spaced IDCs, a phase shift of more than 121was obtained with a maximum insertion loss of 1.8 dB from 2.4 to 2.5 GHz over a bias voltage range of 0-140 V. The phase shifter with 2 µm-spaced IDCs exhibited a phase shift of more than 135with a maximum insertion loss of 2.37 dB in the same frequency range. In this case, a bias voltage of 80 V was used. Using 2 and 4 µm-spaced phase shifters, a third-order intermodulation (IM3) measurement was carried out with a two-tone cancellation setup to investigate nonlinearity, resulting in an input third-order intercept point (IIP3) of about 30.5 dBm and 38.5 dBm, respectively.

We propose utilizing subband-based blind source separation (BSS) for convolutive mixtures of speech. This is motivated by the drawback of frequency-domain BSS, i.e., when a long frame with a fixed long frame-shift is used to cover reverberation, the number of samples in each frequency decreases and the separation performance is degraded. In subband BSS, (1) by using a moderate number of subbands, a sufficient number of samples can be held in each subband, and (2) by using FIR filters in each subband, we can manage long reverberation. We confirm that subband BSS achieves better performance than frequency-domain BSS. Moreover, subband BSS allows us to select a separation method suited to each subband. Using this advantage, we propose efficient separation procedures that consider the frequency characteristics of room reverberation and speech signals (3) by using longer unmixing filters in low frequency bands and (4) by adopting an overlap-blockshift in BSS's batch adaptation in low frequency bands. Consequently, frequency-dependent subband processing is successfully realized with the proposed subband BSS.

This paper discusses clock skew due to manufacturing variability and environmental change. In clock tree design, transition time constraint is an important design parameter that controls clock skew and power dissipation. In this paper, we evaluate clock skew under several variability models, and demonstrate relationship among clock skew, transition time constraint and power dissipation. Experimental results show that constraint of small transition time reduces clock skew under manufacturing and supply voltage variabilities, whereas there is an optimum constraint value for temperature gradient. Our experiments in a 0.18 µm technology indicate that clock skew is minimized when clock buffer is sized such that the ratio of output and input capacitance is four.

In this Letter, linear least squares (LLS) techniques for phase estimation of real sinusoidal signals with known or unknown amplitudes are studied. It is proved that the asymptotic performance of the LLS approach attains Cramér-Rao lower bound. For the case of a single tone, a novel LLS algorithm with unit-norm constraint is derived. Simulation results are also included for algorithm evaluation.

The blind separation problem of analog modulated radio signals and their DOA (Direction Of Arrival) estimation problem are considered. These problems are very important in radio surveillance. Based on the idea of Carlos and Takada [1], the following two methods are proposed for an Independent Component Analysis (ICA) based radio surveillance system. The first method is concerned with the improvement of DOA estimation accuracy after signal separation by ICA. Another method treats separation and DOA estimation in multipath environment. The effectiveness of the proposed methods is proved by computer simulation.

Petri nets are a well-known graphical and modeling tool for concurrent and distributed systems, and there have been many results on the theory, and also on practical applications. In the last decade, various Object-Oriented Petri nets (OO-nets) are proposed. As object orientation was adopted for programming languages, extension to OO-nets inspired from object-oriented programming is a natural flow. This article presents state-of-the-art on OO-nets.

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.

We are developing a helper robot that carries out tasks ordered by the user through speech. The robot needs a vision system to recognize the objects appearing in the orders. It is, however, difficult to realize vision systems that can work in various conditions. Thus, we have proposed to use the human user's assistance through speech. When the vision system cannot achieve a task, the robot makes a speech to the user so that the natural response by the user can give helpful information for its vision system. Our previous system assumes that it can segment images without failure. However, if there are occluded objects and/or objects composed of multicolor parts, segmentation failures cannot be avoided. This paper presents an extended system that tries to recover from segmentation failures using photometric invariance. If the system is not sure about segmentation results, the system asks the user by appropriate expressions depending on the invariant values. Experimental results show the usefulness of the system.

This letter describes a permutation attack (PA) to the subsampling-based watermarking scheme where the high correlations between subimages obtained by subsampling the original image are used for watermark embedding. We show that the correlations can also be easily used to attack the watermarking scheme through a simple permutation procedure, while the quality degradation of attacked watermarked image is visually acceptable. Experimental results show the efficiency of the proposed attack algorithm.

The minimum initial marking problem MIM of Petri nets is described as follows: "Given a Petri net and a firing count vector X, find an initial marking M0, with the minimum total token number, for which there is a sequence δ of transitions such that each transition t appears exactly X(t) times in δ, the first transition is enabled at M0 and the rest can be fired one by one subsequently." This paper proposes two heuristic algorithms AAD and AMIM + and shows the following (1) and (2) through experimental results: (1) AAD is more capable than any other known algorithm; (2) AMIM + can produce M0, with a small number of tokens, even if other algorithms are too slow to compute M0 as the size of an input instance gets very large.

Access selection in future multiple radio access environments is considered in this paper from a new perspective, that of the consumer. A model is proposed for the automatic acquisition of user preferences to assist in access selection decision making. The proposed approach uses a two-level Bayesian C-Metanetwork that models individual user preferences in terms of affordable cost, acceptable level of quality of service and reputation of the access networks. User preferences under different contexts, such as leisure and business, are also considered. The model also adapts to the change of user preferences over time. A simulator has been developed to evaluate the proposed model and the simulation results are promising in terms of the proportion of correct preference predictions after a small number of training samples.

The problem of multi-body motion segmentation is important in many computer vision applications. In this paper, we propose a novel algorithm called fuzzy k-subspace clustering for robust segmentation. The proposed method exploits the property that under orthographic camera model the tracked feature points of moving objects reside in multiple subspaces. We compute a partition of feature points into corresponding subspace clusters. First, we find a "soft partition" of feature points based on fuzzy k-subspace algorithm. The proposed fuzzy k-subspace algorithm iteratively minimizes the objective function using Weighted Singular Value Decomposition. Then the points with high partition confidence are gathered to form the subspace bases and the remaining points are classified using their distance to the bases. The proposed method can handle the case of missing data naturally, meaning that the feature points do not have to be visible throughout the sequence. The method is robust to noise and insensitive to initialization. Extensive experiments on synthetic and real data show the effectiveness of the proposed fuzzy k-subspace clustering algorithm.

Authors have developed a wide color gamut and high brightness WUXGA LCD monitor with color calibrators. This monitor has the world's highest performance level for color gamut and brightness for a UXGA rating or greater (number of pixels). This monitor provides the necessary performance in fields requiring advanced color control, such as DTP, prepress operations, printing and moving images. This paper describes the background of the development, technical problems and the results of evaluation.