Recently, efficient algorithms that exploit the separability of nonlinear mappings have been proposed for finding all solutions of piecewise-linear resistive circuits. In this letter, it is shown that these algorithms can be extended to circuits containing piecewise-linear resistors that are neither voltage nor current controlled. Using the parametric representation for these resistors, the circuits can be described by systems of nonlinear equations with separable mappings. This separability is effectively exploited in finding all solutions. A numerical example is given, and it is demonstrated that all solutions are computed very rapidly by the new algorithm.

This paper proposes a datagram delivery (class D service) architecture in an ATM-Internet, which is the network interconnecting ATM-LANs through the IWUs, Inter-Working Unit. We can provide a fast datagram delivery system through the following techniques. The datagram delivery to the destination terminal is performed by the datagram delivery server, so called CLS, which is located in the ATM-LAN where the destination terminal belongs to. Each CLS only manages the addresses for the terminals belonging to the corresponding ATM-LAN. The cells belonging to a certain datagram are transferred through a single (seamless) ATM connection from the source terminal to the CLS in the ATM-LAN where the destination terminal belongs to. The source terminal only resolves the access point address corresponding to the ATM-LAN where the destination terminal belongs to, when it submits the cells to the network to transfer the datagram to the corresponding destination terminal. The proposed datagram delivery architecture can be applied to the ATM-LAN system based on VPI routing architecture, easily. The number of the required ATM connections so as to provide datagram delivery through the proposed architecture is less than 1.0% of the ATM connections that the ATM-Internet can provide. Also, the required address space at UNI to provide datagram delivery are less than 1.0% of the UNI address space which is available to be used as an ATM connection identifier.

We have investigated the relationship between particle removal efficiency and etched depth in SC-1 solution (the mixture composed of ammonium hydroxide, hydrogen peroxide and DI water) for Si wafers. The Si etching rate increases with increasing NH4OH (ammonium hydroxide) concentration. The particle removal efficiency depends on the etched Si depth, and is independent of NH4OH concentration. The minimum required Si etching depth to get over 95% particle removal efficiency is 4 nm. Particles on the Si wafers exponentially decrease with increasing the etched Si depth. However the particle removal efficiency is not affected by particle size ranging from 0.2 to 0.5 µm. The particle removal mechanism on the Si wafers in SC-1 solution is dominated by the lift-off of particles due to Si undercutting and redeposition of the removed particle.

A modified illumination technique recently developed is known to improve the resolution and DOF (depth of focus) dramatically. But, it requires substantial modification in optical projection system and has some problems such as low throughput caused by low intensity and poor uniformity. And it is very difficult to adjust illumination source according to pattern changes. To solve these problems, we developed a new illumination technique, named ATOM (Advanced Tilted illumination On Mask) which applies the same concept as quadrupole illumination technique but gives many advantages over conventional techniques. This newly inserted mask gives drastic improvements in many areas such as DOF, resolution, low illumination intensity loss, and uniformity. In our experiments, we obtained best resolution of 0.28µm and 2.0µm DOF for 0.36µm feature sizes with i-line stepper, which is two times as wide as that of conventional illumination technique. We also obtained 0.22µm resolution and 2.0µm DOF for 0.28µm with 0.45NA KrF excimer laser stepper. For complex device patterns, more than 1.5 times wider DOF could be obtained compared to conventional illumination technique. From these results, we can conclude that 2nd generation of 64M DRAM with 0.3µm design rule can be printed with this technology combined with high NA (0.5) i-line steppers. With KrF excimer laser stepper, 256M DRAM can be printed with wide DOF.

An eye-contact technique using a blazed half-transparent mirror (BHM) is developed. This half-transparent mirror (HM) consists of an in-line array of many slanting micro-HMs. We fabricated a prototype system and confirmed the principle of this technique. The resolution of an image reflected by a BHM was simulated to determine how to improve the image quality and the factors degrading the resolution were clarified.

It has been 15 years since we started producing the electric double-layer capacitors (also known as Super Capacitor) in 1978. Over the years we have introduced improvements that increased reliability and increased life. For example, after subjecting capacitors manufactured in 1984 and 1990 to load life tests (70, 5.5 V) for 2,000 hours, we discovered that the rate of change in capacitance (ΔC/C) of capacitors manufactured in 1990 was less than one-half that of capacitors manufactured in 1984. This shows that we have successfully increased the life of our electric double-layer capacitors. We conducted investigations regarding factors that contribute to volume of the electrolyte solution and better sealing properties. In the load life test, we observed that when the ratio of the weights of the electrolyte solution and the powdered activated carbon (hereinafter referred to as LB) was increased, the time it took before ΔC/C reached -30% was lengthened. This means that increasing LB also increases life. Furthermore, we also observed that when the gas permeability rate of the collector's rubber material was decreased in the load life test (70, 5.5 V), the time it took befor (ΔC/C) reached -30% was longer. Therefore life is dependent on the gas permeability rate (sealing property) of the collector rubber.

An efficient algorithm is presented for finding all solutions of piecewise-linear resistive circuits. In this algorithm, a simple sign test is performed to eliminate many linear regions that do not contain a solution. This makes the number of simultaneous linear equations to be solved much smaller. This test, in its original form, is applied to each linear region; but this is time-consuming because the number of linear regions is generally very large. In this paper, it is shown that the sign test can be applied to super-regions consisting of adjacent linear regions. Therefore, many linear regions are discarded at the same time, and the computational efficiency of the algorithm is substantially improved. The branch-and-bound method is used in applying the sign test to super-regions. Some numerical examples are given, and it is shown that all solutions are computed very rapidly. The proposed algorithm is simple, efficient, and can be easily programmed.

MultiWave data compression algorithm is based on the multiresolution wavelet techniqu for decomposing Electrocardiogram (ECG) signals into their coarse and successively more detailed components. At each successive resolution, or scale, the data are convolved with appropriate filters and then the alternate samples are discarded. This procedure results in a data compression rate that increased on a dyadic scale with successive wavelet resolutions. ECG signals recorded from patients with normal sinus rhythm, supraventricular tachycardia, and ventriular tachycardia are analyzed. The data compression rates and the percentage distortion levels at each resolution are obtained. The performance of the MultiWave data compression algorithm is shown to be superior to another algorithm (the Turning Point algorithm) that also carries out data reduction on a dyadic scale.

The size and weight of marine pulse radar systems must be limited in order to mount them on board boats. However, the azimuthal resolution of a marine radar with a small antenna is degraded by the antenna beam width. It is desirable to use signal processing techniques to increase both the azimuthal resolution and the range resolution of such systems without changing their external configuration. This paper introduces a resolution enhancement method based on deconvolution, which is a kind of inversion. The frequency domain deconvolution method is described first. The effectiveness of the proposed method is shown by simulation. Then, an example of resolution enhancement processing is applied to a pulse radar. The results of practical experiments show that this method is a promising way of upgrading radars by simply processing the received signals.

An efficient algorithm is presented for finding all solutions of piecewise-linear resistive circuits. In this algorithm, a simple sign test is performed to eliminate many linear regions that do not contain a solution. Therefore, the number of simultaneous linear equations to be solved is substantially decreased. This test, in its original form, requires O(Ln2) additions and comparisons in the worst case, where n is the number of variables and L is the number of linear regions. In this paper, an effective technique is proposed that reduces the computational complexity of the sign test to O(Ln). Some numerical examples are given, and it is shown that all solutions can be computed very efficiently. The proposed algorithm is simple and can be easily programmed by using recursive functions.

Many simulators in several fields use the finite difference method and they must solve the large sparse linear equations related. Particularly, if we use the direct solution method because of the convergency problem, it is necessary to adopt a method that can reduce the CPU time greatly. The Multi-Step Diakoptics (MSD) method is proposed as a parallel computation method with a direct solution which is based on Diakoptics, that is, a tearing-based parallel computation method for the sparse linear equations. We have applied the MSD algorithm for one, two and three dimensional finite difference methods. We require a parallel schedule that automatically partitions the desired object's region for study, assigns the processor elements to the partitioned regions according to the MSD method, and controls communications among the processor elements. This paper describes a parallel scheduling that was extended from a one dimensional case to a three dimensional case for the MSD method, and the evaluation of the algorithm using a massively parallel computer with distribuled memory(AP1000).

A new method by which images are coded with predictable and controllable subjective picture quality in the minimum cost of bit rate is developed. By using wavelet transform, the original image is decomposed into a set of subimages with different frequency channels and resolutions. By utilizing human contrast sensitivity, each decomposed subimage is treated according to its contribution to the total visual quality and to the bit rate. A relationship between physical errors (mainly quantization errors) incurred in the orthonormal wavelet image coding system and the subjective picture quality quantified as the mean opinion score (MOS) is established. Instred of using the traditional optimum bit allocation scheme which minimizes a distortion cost function under the constraint of a given bit rate, we develop an "optimum visually weighted noise power allocation" (OVNA) scheme which emphasizes the satisfying of a desired subjective picture quality in the minumum cost of bit rate. The proposed method enables us to predict and control the picture quality before the reconstruction and to compress images with desired subjective picture quality in the minimum bit rate.

It is known that the resolution conversion based on orthogonal transform has a problem that is difference of luminance between the converted image and the original. In this paper, the scale factor of the system employing various orthogonal transforms is generally formulated by considering the DC gain, and the condition of alias free for DC component is indicated. If the condition is satisfied, then the scale factor is determined by only the basis functions.

An estimation method of region is presented, in which a solution path of the so-called Newton type homotopy equation in guaranteed to exist, it is applied to a certain class of uniquely solvable nonlinear equations. The region can be estimated a posteriori, and its upper bound also can be estimated a priori.

This paper deals with the uniqueness of a solution of the basic equation obtained from the analysis of resistive circuits including ideal diodes. The equation in consideration is of the type of (A-)X=b, where A is a constant matrix, b a constant vector, X an unknown vector satisfying X 0, and a diagonal matrix whose diagonal elements take the value 0 or 1 arbitrarily. The necessary and sufficient conditions for the equation to have a unique solution X 0 for an arbitrary vector b are shown. Some numerical examples are given for the illustration of the result.

This paper describes a monolithic 10-b A/D converter that realized a maximum conversion frequency of 300 MHz. Through the development of the interpolated-parallel scheme, the severe requirement for the transistor Vbe matching can be alleviated drastically, which improves differential nonlinearity (DNL) significantly to within 0.4 LSB. Furthermore, an extremely small input capacitance of 8 pF can be attained, which translates into better dynamic performance such as SNR of 56 dB and THD of 59 dB for an input frequency of 10 MHz. Additionally, the folded differential logic circuit has been developed to reduce the number of elements, power dissipation, and die area drastically. Consequently, the A/D converter has been implemented as a 9.0 4.2-mm2 chip integrating 36K elements, which consumes 4.0 W using a 1.0-µm-rule, 25-GHz ft, double-polysilicon self-aligned bipolar technology.

The properties of the Haar Transform (HT) are discussed based on the Wavelet Transform theory. A system with two channels at resolution 2-1 and 2-2 for detecting paroxysm-spike in human's EEG is presented according to the multiresolution properties of the HT. The system adopts a coarse-to-fine strategy. First, it performs the coarse recognition on the 2-2 channel for selecting the candidate of spike in terms of rather relaxed criterion. Then, if the candidate appears, the fine recognition on the 2-1 channel is carried out for detecting spike in terms of stricter criterion. Three features of spike are extracted by investigating its intrinsic properties based on the HT. In the case of having no knowledge of prior probability of the presence of spike, the Neyman-Pearson criteria is applied to determining thresholds on the basis of the probability distribution of background and spike obtained by the results of statistical analysis to minimize error probability. The HT coefficients at resolution 2-2 and 2-1 can be computed individually and the data are compressed with 4:1 and 2:1 respectively. A half wave is regarded as the basic recognition unit so as to be capable of detecting negative and positive spikes simultaneously. The system provides a means of pattern recognition for non-stationary signal including sharp variation points in the transform domain. It is specially suitable and efficient to recognize the transient wave with small probability of occurrence in non-stationary signal. The practical examples show the performance of the system.

This paper discusses the conversion of spatial resolution (pixel density) and amplitude resolution (levels of brightness) for multilevel images. A source image is sampled by an image scanner or a video camera, and a converted image is printed by a printer with the capability of higher spatial but lower amplitude resolution than the image input device. In the proposed method, the impulse response of the scanner sensor is modeled to obtain pixel values from the convolution of the impulse and the image signal. Discontinuous areas (edge) of the original image are detected locally according to the impulse model and neighbouring pixel values. The edge route is estimated which gives the pixel values for the output resolutions. Comparison of the proposed method with two conventional methods, reciprocal distance weight interpolation and pixel replication, shows higher edge quality for the proposed method.

Fabrication of 0.2 to 0.3 µm features is vital for future ultralarge scale integration devices. An area of particular concern is whether optical lithography can delineate such feature sizes, i.e., less than the exposure wavelength. The use of a phase shift mask is one of the most effective means of improving resolution in optical lithography. This technology basically makes use of the interference between light transmitting through adjacent apertures of the mask. Various types of phase shift masks and their imaging characteristics are discussed and compared with conventional normal transmission masks. To apply these masks effectively to practical patterns, a phase shifter pattern design tool and mask repair method must be established. The phase shifting technology offers a potential to fabricate 0.3 µm features by using the current i-line stepper, and 0.2 µm features by using excimer laser stepper.

New illumination principle for photolithography is investigated. As the optical microlithography approaches its own limit, it becomes apparent that the simple extrapolation of the present technology is not sufficient for the future demands. This paper introduces the new imaging technology that overcomes such a boundary. First, the basic imaging formulae are analyzed and the illumination light is classified into 4 cases. 3-beam case and 2-beam case carry the object information, and the comparison of these 2 cases is carried out theoretically. It can be shown that the 2-beam case has greater depth of focus than that of the 3-beam case, though it has inferior contrast at the best focus. Since this degradation, however, has little effect, the enlargement of the depth of focus can be achieved. In reality, 2-dimensional imaging must be considered. Quadrupole effect can be deduced by the results of the analysis. It shows great improvement in the depth of focus near resolution limit. As it can be applied to the conventional masks, it can be a promising candidate for fhe future lithography. Experimental results are also shown to demonstrate the analysis.