This paper discusses the design of an ITS to realize a load-oriented tutoring to enhance the student's explanation understanding. In the explanation understanding, it is to be hoped that a student not only memorizes the new information from an explanation, but also relates the acquired information with his/her own knowledge to recognize what it means. This relating process can be viewed as the one in which the student structures his/her knowledge with the explanation. In our ITS, we regard the knowledge-structuring activities as the explanation understanding. In this paper, we propose an explanation, called a load-oriented explanation, with the intention of applying a load to the student's knowledge-structuring activities purposefully. If the proper load is applied, the explanation can induce the student to think by himself/herself. Therefore he/she will have a chance of gaining the deeper understanding. The important point toward the load-oriented explanation generation is to control the load heaviness appropriately, which a student will bear in understanding the explanation. This requires to estimate how an explanation promotes the understanding activities and how much the load is applied to the activities. In order to provide ITS with the estimation, we have built an Explanation Effect Model, EEM for short. Our ITS consists of an explanation planner and a self-explanation environment. The planner generates the load-oriented explanation based on EEM. The system also makes a student explain the explanation understanding process to himself/herself. Such self-explanation is useful to let the student be conscious of the necessity of structuring his/her knowledge with the explanation. The self-explanation environment supports the student's self-explanation. Furthermore, if the student reaches an impasse in self-explaining, the planner can generate the supporting explanation for the impasse.

It was more than 10 years ago that the first map navigation system, as an example of invehicle information system, has appeared in the market in Japan. Today's navigation system has been improved to the level that the latest system has 10 micro-processors, 7 MBytes of memories, and 4 GBytes of external data storage for map database. From the viewpoint of the automobile driver, there are still some problems with the system. Major problems in general are a lack of traffic information, better human interface, and a need for cost-reduction. The introduction of application specific ICs (ASICs) is expected to make systems smaller, costless, and give higher speed response. Today's in-vehicle information systems are reviewed function by function to discover what functions need to be implemented into ASICs for future systems, what ASICs will be required, and what technology has to be developed. It is concluded that more integration technology is expected including high parformance CPUs, large capacity memories, interface circuits, and some analog circuits such as DA converter. To develop this technology, some, major problems such as power consumption, number of input/output signals, as well as design aid and process technology are pointed out.

An electrocardiogram (ECG) data compression algorithm using a polygonal approximation and the template beat variation method (TBV) has been evaluated by reconstruction error and automatic interpretation. The algorithm combining SAPA3 with TBV (SAPA3/TBV) has superior compression performance in PRD and compression ratio. The reconstruction errors, defined as the difference of the amplitude and the time duration between the original ECG and the reconstructed one, are large at waves with small amplitude and/or gradual slopes such as the P wave. Tracing rebuilt from the compressed ECG has been analysed using the automatic interpretative program, and the diagnostic answers with the realated measurements have been compared with the results obtained on the original ECG. The data compression algorithms (SAPA3 and SAPA3/TBV) have been tested on 100 cases in the data base produced by CSE. The reconstruction errors are related to the diagnostic errors. The TBV method suppresses these errors and more than 90% of diagnostic agreements at the error limit of 15µV can be obtained.

Electromagnetic plane wave scattering by a wide trough on the ground has been analyzed by high frequency asymptotic techniques based on Geometrical Theory of Diffraction. Field in the trough region has been formulated in terms of parallel plane waveguide modes, whose excitation (coupling) coefficients are obtained by ray-mode conversion techniques. Numerical calculation has been done extensively and thus obtained results are then compared with those by other methods. Good agreements have been observed except for oblique incidence case. It is found that first and secondary modal re-radiation fields from the indented trough region play an important role for scattering far field, and primary edge diffracted field contributes mainly to reflection boundary direction.

This letter proposes a microstrip band elimination filter having an optically controlled small gap on a resonant section for the shift of the eliminated frequency range using the semiconductor plasma. The basic characteristics of this filter are analized theoretically utilizing the (FD)2TD method.

This paper proposed a new algorithm of data compression for ambulatory ECG, where no distortion was included in the reconstructed signal, templates were constructed selectively from detected beats, and categorized ECG morphologies (templates) could be displayed in decoding the compressed data. This algorithm consisted of subtracting a best-fit template from the detected beat with an aid of multi-template matching, first differencing of the resulting residuals and modified Huffman coding. This algorithm was evaluated by applying it to ECG signals of the American Heart Association (AHA) data base in terms of bit rates. Following features were indicated. (1) Decompressed signal coincided completely with the original sampled ECG data. (2) Bit rate was approximately 800 bps at the appropriate threshold 50-60 units (1 unit2.4µVolt) for the template matching. This bit rate was almost the same as that of the direct compression (encoding the first differenced signal of original signal). (3) The decompressed templates could make it easy to classify the templates into the normal and abnormal beats; this could be executed without fully decompressing the ECG signal.

For the effective control of microwaves in the frequency domain, we propose a new method utilizing current distributions of standing waves on the terminated microstrip line. We analized a short ended microstrip line using the (FD)2TD method to indicate the effectiveness of our proposal. Further we proposed an optically controlled microstrip filter as an application of this method.

Field distributions and energy flows of the surface waves excited in singlelayer-overcoated gratings are evaluated in order to investigate the behavior of the resonance absorption in the grating.

The scattering of electromagnetic waves by a dielectric grating with planar slanted-fringe is analyzed using the improved Fourier series expansion method. In the analysis, the slanted grating region is divided into layers to make an assembly of stratified thin modulated index layers. This method can be applied to a wide range of periodic structures and is especially effective in the case of planar slanted grating, because the electromagnetic fields in the each layer can easily be obtained by shifting the solution in the first layer. In this paper, the numerical results are given for grating with rectangular and sinusoidal dielectric profiles, and for TM and TE cases of arbitrary incident angle. The diffraction efficiencies obtained by the presented method are compared with the results by the coupled-wave approach; the influences of the slant angle on the diffraction efficiencies at the Wood's anomaly and at the coupling resonance frequency are also discussed.

This letter presents a new method for adaptive control of nonminimum phase discrete-time systems with disturbances based on the technique of pole-zero placement. The long division method is used to decompose apolynomial into a stable polynomial and an unstable one. Finally, the results of computer simulation are presented to illustrate the effectiveness of the proposed method.

A method to measure the displacement from the phase rotation of the Doppler signal including the displacement information of the moving body is proposed, where the displacement resolution can be improved 4 times by making the phase rotation faster. Furthermore, this test system is applied in clinical use. The test system is built up by using a two-phase microwave Doppler sensor covering a 10GHz band, where the Doppler frequency is multiplied 4 times by signal processing. Thus, the resolution is improved from a conventional 12.6mm (in case of 11.9GHz) to 3.15mm, and practical utilization has been attained. The microwave Doppler radar system described in this paper is adequate for the displacement measurement for a relatively fast moving body. As a medical sensor for clinical use, measurement examples of head movement in a vestibule examination (vestibule oculomotor reflexive inspection) and finger movement in a cerebellum function test are given. Furthermore by using two sets of this Doppler radar system, a 2-dimensional measurement of head movement is possible.

The transient scattering of a half sine pulse wave by a conducting rectangular cylinder with an open sidewall is rigorously analyzed by using the point matching method (taking into account the edge condition exactly) combined with the fast inversion of Laplace transform. Numerical results are presented for back scattered and forward scattered responses of the far fields when a half sine pulse is incident on the open side and the closed side of the cylinder. The physical meaning of the transient responses is discussed in detail. The comparison of the responses with those by a perfect conducting rectangular cylinder is presented.

The physical system is considered more suitable for measurement purposes the greater is its linearity. However, in nature and engineering there are no purely linear physical transducing systems for convertion a primary onformation. The use of the linear features of the system in the measurement process finally causes the drawbacks: systematic error due to nonlinear distortions, low ratio informative signal/ noise, the necessity to evaluate a great number of the a priori parameters of the transducer in order to receive an absolute result, low thermostability because every a priori parameter itself has a temperature dependence. To exclude these drawbacks a method has been developed using nonlinear physical systems in the base of the displacements measurement. In this work is presented the realization of the method using electretic and electrostatic transducer as a converting physical system. A contactless transducer is placed parallelly to the surface of the object which displacements are measured. The transducer is driven to harmonic oscillations. Typical time intervals between even and odd extremums of the transducer output signal are measured. The object displacements are determined according to the changes of the typical time intervals. The method itself has no errors because approximations were not made while deriving the relations. The source of the errors is inaccurate registration of the start and the end of the typical time intervals. In the work are analysed the errors related to the concrete realization devices: analogue differentiator, peak detector and analog digital transducer. It is shown that the measurement is possible only if the physical system is nonlinear. The method is generalized to that case if the function of transformation of ths system has the form f(x) and monotonous character. The results of experimental investigations confirm the theoretical conclusions.

A strictly nonblocking 88 matrix switch was designed and fabricated using silica-based planar lightwave circuits (PLC) on a silicon substrate. The average insertion loss was 11 dB in the TE mode and 11.3 dB in the TM mode. The average switch element extinction ratio was 16.7 dB in the TE mode and 17.7 dB in the TM mode. The accumulated crosstalk was estimated to be 7.4 dB in the TE mode and 7.6 dB in the TM mode. The driving power of the phase shifter required for switching was about 0.5 W and the polarization dependence of the switching power was 4%. The switching response time was 1.3 msec. The wavelength range with a switch extinction ratio of over 15 dB was 1.31 µm30 nm.

A radial line slot antenna (RLSA) is a high gain and high efficiency planar array. A single-layered RLSA is much simple in structure but the slot length must be varied to synthesize uniform aperture illumination. These are now commercialized for 12GHz band DBS reception. In RLSAs, considerable power is dissipated in the termination as is common to other traveling wave antennas; the uniform aperture illumination is not the optimum condition for high gain in RLSAs. Authors proposed a theoretical method reducing the termination loss for further efficiency enhancement. This paper presents the measured performances of the SL-RLSAs of this design with non-uniform aperture illumination. The efficiency enhancement of about 10% is observed; the measured gain of 36.7dBi (87%) and 32.9dBi (81%) for a 0.6mφ and 0.4mφ antennas respectively verify this technique.

Toward the age of ultra-high-density digital ULSI systems, the development of new integrated circuits suitable for an ultimately fine geometry feature size will be an important issue. Resonant-tunneling (RT) diodes and transistors based on quantum effects in deep submicron geometry are such kinds of key devices in the next-generation ULSI systems. From this point of view, there has been considerable interests in RT diodes and transistors as functional devices for circuit applications. Especially, it has been recognized that RT functional devices with multiple peaks in the current-voltage (I-V) characteristic are inherently suitable for implementing multiple-valued circuits such as a multiple-state memory cell. However, very few types of the other multiple-valued logic circuits have been reported so far using RT devices. In this paper, a new multiple-valued programmable logic array (MVPLA) based on RT devices is proposed for the next-generation ULSI-oriented hardware implementation. The proposed MVPLA consists of 3 basic building blocks: a universal literal circuit, an AND circuit and a linear summation circuit. The universal literal circuit can be directly designed by the combination of the RT diodes with one peak in the I-V characteristic, which is programmable by adjusting the width of quantum well in each RT device. The other basic building blocks can be also designed easily using the wired logic or current-mode wired summation. As a result, a highdensity RT-diode-based MVPLA superior to the corresponding binary implementation can be realized. The device-model-based design method proposed in this paper is discussed using static characteristics of typical RT diode models.

In this letter, the effectiveness of the quasi-TEM approximation is studied for the microstrip line including optically induced semiconductor plasma region. This approximation is considered to be efficient under several restrictions such as the upper limit of the microwave frequency and the plasma density.

This paper discusses the development of a monolithic image-rejection mixer with very wide-band (about 60% of the center frequency) image rejection characteristics for 16-QAM digital microwave radio communication receivers. The mixer can be commonly used in 4-, 5-, and 6-GHz bands, which reduces the cost. The mixer consists of a wide-band 90splitter, in-phase divider and drain LO injection mixers. They are designed on a single 2.81.8 mm2 GaAs chip based on a uniplanar MMIC lumped-constant element technique. The mixer achieved an image rejection ratio of greater than 25 dB and a conversion loss of less than 2 dB at a wide LO frequency range from 3.5 to 6.5 GHz, without consuming any DC power.

This paper presents a general form and a set of basic gates to implement (K+1)-valued PLA structure logic circuits. A complete fault analysis on the proposed circuit has been done and it is shown that all fanout stem faults can be collapsed to branch faults. A procedure for fault collapsing is derived. For any function implemented in the (K+1)-valued circuit, the number of remaining faults is smaller than that of the 2-valued circuit after the collapsing, where the value of K is dependent on the number of outputs and the assignment of the OR plane of the 2-valued logic circuit.

A systematic method is proposed to generate a random image with a known correlation function and the modified Laplace distribution; the modified Laplace distribution includes the one-side exponential distribution and the Laplace distribution as a special case. Several random images with an isotropic correlation and the modified Laplace distribution are generated and displayed in figures.