Experiment is reported of enhanced backscattering of light in binary and ternary suspensions of rutile and/or alumina particles. With a conventional CCD camera system for observing the phenomena, the angular line shape and the enhancement factor were agreed with the theoretically predicted curve and value. Observation of the angular distribution scattered at the backscattered direction supported the hypothesis proposed by Pine et al. , in which the transport mean free path of the polydisperse mixture can be expressed in terms of summing its reciprocal values weighted over the particle sizes.

Recently, many on-line control methods of partially observed discrete event systems(DES's) have been proposed. This paper proposes an algorithm for on-line control based on a supervisor under complete observation. It is shown that DES's controlled by the proposed on-line controller generate maximally controllable and observable sublanguages which include the supremal normal sublanguages. Moreover, computational complexity of the proposed algorithm is polynomial with respect to the numbers of the unobservable events and the state of the supervisor under complete observation.

This paper presents a novel dead-beat synchronization scheme and applies it to communications in discrete-time chaotic systems. A well-known Henon system is considered as an illustrative example. In addition, a Henon-based image processing application effectively exploits the proposed scheme's effectiveness.

This paper proposes a new design method of nonlinear filtering and fixed-point smoothing algorithms in discrete-time stochastic systems. The observed value consists of nonlinearly modulated signal and additive white Gaussian observation noise. The filtering and fixed-point smoothing algorithms are designed based on the same idea as the extended Kalman filter derived based on the recursive least-squares Kalman filter in linear discrete-time stochastic systems. The proposed filter and fixed-point smoother necessitate the information of the autocovariance function of the signal, the variance of the observation noise, the nonlinear observation function and its differentiated one with respect to the signal. The estimation accuracy of the proposed extended filter is compared with the extended maximum a posteriori (MAP) filter theoretically. Also, the current estimators are compared in estimation accuracy with the extended MAP estimators, the extended Kalman estimators and the Kalman neuro computing method numerically.

A novel testing-pad placement method has been developed to greatly improve E-beam observability for multi-level wiring LSIs. In the method, testing pads connecting a lower-metal-layer wire with a top-metal-layer electrode are positioned in the design layout, making removal of the insulator unnecessary. The method features i) pad placement in unoccupied areas in mask patterns to avoid increases in chip size, ii) minimized pad size through the use of stacked vias so that the pads can be placed on as many wire nodes as possible, iii) placement as far as possible from the nearby wires to avoid local field effects, and iv) allocation of one testing pad to one circuit node to minimize the number of testing pads. These measures give us a practical pad-placement method, that has little influence on LSI design. It was shown that the proposed method yielded a dramatic improvement of observability from 13-33% to 88-99% in actual layouts of 0.25-µm ASICs with 20k, 120k, and 390k gates. It was also found that local field effects from nearby wires are negligible for almost all the testing pads. This approach will enable the use of E-beam testing on LSIs made with 0.25-µm technology and the even more sophisticated process technologies to come.

This paper proposes a new design method of a nonlinear filtering algorithm in continuous-time stochastic systems. The observed value consists of nonlinearly modulated signal and additive white Gaussian observation noise. The filtering algorithm is designed based on the same idea as the extended Kalman filter is obtained from the recursive least-squares Kalman filter in linear continuous-time stochastic systems. The proposed filter necessitates the information of the autocovariance function of the signal, the variance of the observation noise, the nonlinear observation function and its differentiated one with respect to the signal. The proposed filter is compared in estimation accuracy with the MAP filter both theoretically and numerically.

Using transmission electron microscopy (TEM), we studied structural defects in a Sr0. 7Bi2. 3Ta2O9 (SBT) thin film to be used for ferroelectric memory devices. We examined the effects of the substrate, crystal continuity, and dislocations in crystals as major causes of defects. For this study, we used an SBT thin film grown from an alkoxide solution. Since crystal growth was hardly influenced by the substrate, the substrate had little influence on the occurrence of defects resulted in misfit of lattice constant. Regions of partially low crystal continuity were observed in the SBT thin film. In these regions, the orientation was still uniform, but the continuity of the crystal grain was low because of the defects. In addition, variation in contrast was observed in the crystals, however, no obvious variation in chemical composition was found in this region of varying contrast. Therefore, the contrast variation is considered to be attributed to the dislocation. Such a dislocation was found to be occurred in the direction of the (2010) plane in many instances. The defects in the SBT film were also confirmed by the TEM observation.

We present here the Controlling Value Boolean Matching based on fault analysis. The problem is to match a Boolean function with don't cares on library cells under arbitrary input permutations and/or input-output phase assignments. Most of the library cells can be represented by tree structure circuits. The approach presented here is suitable for these structures and computes the Boolean matching better than the structural matching used in SIS. It can handle library cells with a general topology and reconvergent paths. The benchmark test shows that the Controlling Value Boolean Matching can be as facter as the structural matching used in SIS.

In this paper, a new trial for the signal processing is proposed along the same line as a previous study on the extended regression analysis based on the Bayes' theorem. This method enables us to estimate a response probability property of complicated systems in an actual case when observation values of the output response are roughly observed due to the quantization mechanism of measuring equipment. More concretely, the main purpose of this research is to find the statistics of the joint probability density function before a level quantization operation which reflects every proper correlation informations between the system input and the output fluctuations. Then, the output probability distribution for another kind of input is predicted by using the estimated regression relationship. Finally, the effectiveness of the proposed method is experimentally confirmed by applying it to the actually observed input-output data of the acoustic system.

We study state feedback control of discrete event systems described by the Golaszewski-Ramadge model. We derive a necessary and sufficient condition for the existence of a balanced state feedback controller under partial observations.

In the measurement of actual random phenomenon, the observed data often contain the fuzziness due to the existence of confidence limitation in measuring instruments, permissible error in experimental data, some practical simplification of evaluation procedure and a quantized error in digitized observation. In this study, by introducing the well-known fuzzy theory, a state estimation method based on the above fuzzy observations is theoretically proposed through an establishment of wide sense digital filter under the actual situation of existence of the background noise in close connection of the inverse problem. The validity and effectiveness of the proposed method are experimentally confirmed by applying it to the actual fuzzy data observed in an acoustic environment.

This paper describes a trial of evaluating the proper characteristics of multiple sound insulatain systems from their output responses contaminated by unknown background noises. The unknown parameters of sound insulation systems are first estimated on the basis of hte linear time series on an intensity scale, describing functionally the input-output relation of the systems. Then, their output probability distributions are predicted when an arbitrary input noise passes through these insulation systems.

This paper presents the concept of k-FR circuits. The controllability of such a circuit is high due to its special structure. It is shown that all stuck-at faults and stuck-open faults in a k-FR circuit can be detected and located by k(k1)1 test vectors under the highly observable condition which assumes the output of every gate to be observable. k is usually two or three. This paper also presents an algorithm for converting an arbitrary combinational circuit into a k-FR circuit. A k-FR circuit is easy to test when using technologies such as the electron-beam probing, the current measurement, or the CrossCheck testability solution.

We study robot navigation in unknown environment with rectangular obstacles aligned with the x and y axes. We propose a strategy called the modified-bian heuristic, and analyze its efficiency. Let n be the distance between the start point and the target of robot navigation, and let k be the maximum side length among the obstacles in a scene. We show that if k=(o(n) and if the summation of the widths of the obstacles on the line crossing the target and along the y axis is o(n), then ratio of the total distance walked by the robot to the shortest path length between the start point and the target is at most arbitrarily close to 1+k/2, as n grows. For the same restrictions as above on the sizes of the obstacles, the ratio is also at most arbitrarily close to 1+3/4n, as n grows, where is the summation of lengths of the obstacles in y axis direction.

When measuring the ejection fraction for the evaluation of the ventricular pumping function by means of the thermodilution technique, the slow response a conventional thermistor has caused it to be considered unsuitable, and fast thermistors have been proposed as an alternative. However, in this paper we propose improving the time-domain response of a conventional thermistor using a signal processing technique composed of a series of first-order high-pass filters which is known as the natural observation system. We considered the rise time of the thermistor in response to a step temperature change to effect correction for the measurement of the ejection fraction. The coefficients of the natural observation system were calculated by minimizing the square error between the step-response signal of the thermistor and the band-limited reference signal. In an experiment using a model ventricle, the thermodilution curve obtained from a conventional thermistor was improved using the proposed technique, thus enabling successful measurement of the ejection fraction of the ventricles.

We consider a class of unknown scenes Sk(n) with rectangular obstacles aligned with the axes such that Euclidean distance between the start point and the target is n, and any side length of each obstacle is at most k. We propose a strategy called the adaptive-bias heuristic for navigating a robot in such a scene, and analyze its efficiency. We show that a ratio of the total distance walked by a robot using the strategy to the shortest path distance between the start point and the target is at most 1+(3/5) k, if k=o(n) and if the start point and the target are at the same horizontal level. This ratio is better than a ratio obtained by any strategy previously known in the class of scenes, Sk(n), such that k=o(n).

The origin of and a method of enhancing the Optical Beam Induced Resistance Change (OBIRCH) signal for defect observation in VLSI metal interconnections is discussed based on a numerical analysis of three-dimensional thermal conduction and experimental results. The numerical analysis shows that the OBIRCH signal originates from a slight increase in the resistance of the metal line caused by laser beam heating and that its effect is influenced by the temperature of the metal layer. Both simulations and experimental results suggest that cooling the sample is preferable to detect the OBIRCH signal. The decrease in the total resistance of the metal line without any change in the amount of the resistance increase under laser illumination is found to be the main cause of the OBIRCH signal enhancement under low temperature measurement.

New focused ion beam (FIB) methods for microscopic cross-sectioning and observation, microscopic crosssectioning and elemental analysis, and aluminum film microstructure observation are presented. The new methods are compared to the conventional methods and the conventional FIB methods, from the four viewpoints such as easiness of analysis, analysis time, spatial resolution, and pinpointing precision. The new FIB methods, as a result, are shown to be the best ones totally judging from the viewpoints shown above.

In the future, it will be necessary that robot technology or environmental technology has an auditory function of recognizing sound expect for speech. In this letter, we propose a recognition system for the species of birds receiving birdcalls, based on network technology. We show the first step of a recognition system for the species of birds, as an application of a recognition system for environmental sound.

As in other fields, the automatization of railway maintenance work is a firm requirement. The authors have developed a system detecting obstacles around a railway for practical railway inspection. The system is based on an original laser-sectioning method and characterized by high accuracy with wide view and in-motion operation. It was confirmed that a static calibration was performed at an accuracy of within 5 mm. Furthermore, a theoretical estimation predicted that dynamic errors can be eliminated within a resolution of 4 mm by means of rail movement detection. In field tests on the Chuo Line, facilities were successfully inspected at speeds up to 40km/h.