Graph parameters such as connectivity and diameter have been studied extensively due to their intrinsic importance in graph theory, combinatorics and their relations to (and applications in) fault tolerance and transmission delay in communications networks. The advent of VLSI technology and fiber optics material science has enabled us to design massively parallel processing computer systems and fast and complicated communications networks. All these systems increase their reliability by studying (among other) the existence of two (or more) disjoint paths connecting any two nodes. This paper addresses these issues by studying the width and length of containers in graphs and networks. In particular, the notions of w-distance and w-diameter on a graph are defined and studied which generalize both concepts of connectivity and diameter. Thses notions are also considered in finite groups. Other closely related parameters will be explored in the contexts of fault tolerance and routing. Known results are surveyed and open problems are offered for further investigation.

Results of a DC motor driving test with a power sent by a microwave and extracted with a rectenna array are reported. No significant difference has been observed in the output DC power from the rectenna array between a motor load and a resistive load. Mechanical output could be extracted from the received microwave power with an efficiency of 26%.

Thin (Ba0.75Sr0.25)TiO3 (BST) films to be used as dielectric materials in 256 Mbit DRAM capacitors were investigated. These films were deposited by an rf-sputtering method at substrate temperatures of 480 to 750. As substrate temperature increases, the dielectric constant to the films also increases, from 230 to 550. BST films prepared at temperatures higher than 700 show larger current leaks than films prepared at lower temperatures. A dielectric constant of 250, corresponding to a silicon oxide equivalent thickness (teq) of 0.47 nm, and a leak current density about 110-8 A/cm2 were obtained in 30-nm-thick film deposited at 660. Both of these values are sufficient for use in a 256 Mbit DRAM capacitor.

This paper describes a future private network service and the system configurations for providing it. Technologies and service trends in local area and wide area networks are shown. As network services become more diversified and integrated, it becomes more difficult for users to use the networks effectively. This paper shows how this problem can be solved by using virtual network technology to attain seamless networking. It also presents the concept of group networking among many parties, which can be used as the basis for a virtual private network.

The dielectric breakdown strength of thermally grown silicon dioxide films was studied for MOS capacitors fabricated on silicon wafers that were intentionally contaminated with magnesium and zinc. Most of magnesium was detected in the oxide film after oxidation. Zinc, some of which evaporated from the surface of wafers, was detected only in the oxide film. The mechanism of the dielectric degradation is dominated by formation of metal silicates, such as Mg2SiO4 (Forsterite) and Zn2SiO4 (Wilemite). The formation of metal silicates has no influence on the generation lifetime of minority carriers, however, it provides the flat-band voltage shift less than 0.3 eV, and forces to increase the density of deep surface states with the zinc contamination.

Although the perception of gloss is based on human visual perception, some methods for extracting glossiness, in contrast to human ability, have been proposed involving curved surfaces. Glossiness defined in these methods, however, does not correspond with psychological glossiness perceived by the human eye over the wide range from relatively low gloss to high gloss. In addition, the obtained glossiness in these methods changes remarkably when the curvature radius of the high-gloss object becomes larger than 10mm. In reality, psychological glossiness does not change. These methods, furthermore, are available only for spherical objects. A new method for extracting glossiness is proposed in this study. For the new definition of glossiness, a spatial filter which simulates human retina function is utilized. The light intensity distribution of the curved object is convoluted with the spatial filter. The maximum value Hmax of the convoluted distribution has a high correlation with psychological glossiness Gph. From the relationship between Gph and Hmax, new glossiness Gf is defined. The gloss-extraction equipment consists of a light source, TV camera, an image processor and a personal computer. Cylinders with the curvature radii of 3-30 mm are used as the specimens in addition to spherical balls. In all specimens, a strong correlation, with a correlation coefficient of more than 0.97, has been observed between Gf and Gph over a wide range. New glossiness Gf conforms to Gph even if the curvature radius in more than 10 mm. Based on these findings, it is found that this method for extracting glossiness is useful for the extraction of glossiness of spherical and cylindrical objects over a wide range from relatively low gloss to high gloss.

In this paper, an efficient and robust circuit parameter determination method suitable for analog circuit synthesis is presented. The method uses block diagram representation of circuits as implicit design knowledge. Circuit parameter determination is carried out by propagating known values along signal flow in the block diagram. The circuit parameter determination using signal propagation performs successfully when unknown circuit parameters can be solved in one way. However, when the block diagram involves implicit calculation, the propagation stops before all unknown parameters are determined. In order to cope with this problem, we introduced a method that employs a symbolic analysis technique combined with a numerical method. When the propagation of known values stops, one of unknown signals is selected, a unique symbol is assigned to the selected signal, and the signal propagation is restarted. This operation is repeated until there is no unknown signal. When the symbol propagation reaches the signal where the signal value is already set, one nonlinear equation for the signal is obtained by equating both signal values. It can be solved by a numerical method, such as Newton's method. The parameter determination method using procedural description is superior to the optimization based method because it is straightforward to incorporate design knowhow in the description. However, it is burdensome for designers to develop design procedures for each circuit to be synthesized. Because the block diagram based calculation method can be used as subroutine calls during the design procedure development, it simplifies the design procedural description and lowers the burden of designers. The method was applied to the element value determination of bias circuits to demonstrate its effectiveness.

This paper deals with the size of switching functions in Exclusive-OR sum-of-products expressions (ESOPs). The size is the number of products in ESOP. There are no good algorithms to find an exact minimum ESOP. Since the exact minimization algorithms take a time in double exponential order, it is almost impossible to minimize ESOPs for an arbitrary n-variable functions with n5. Then,it is necessary to study the size of some concrete functions. These concrete functions are useful for testing heuristic minimization algorithms. In this paper we present the lower bounds on size of periodic functions in ESOPs. A symmetric function is said to be periodic when the vector of weights of inputs X such that f(X)1 is periodic. We show that the size of a 2t+1-periodic function with rank r is proportional to n2t+r, where t0 and 0r2t, i.e., in polynomial order,and thet the size of a (2s+1)2t-periodic function with s0 and t0 is greater than or equal to (3/2)n-(2s+1)2t, i.e., in exponential order. The concrete function the size of which is greater than or equal to 32(3/2)n-8 is presented. This function requires the largest size among the concrete functions the sizes of which are known. Some results for non-periodic symmetric functions are also given.

In order to construct a high-capacity and high-reliable indoor wireless communications system, it is essential to design the modulation/demodulation, coding and access schemes with high and variable data rate transmission capabilities, which meet the technical requirements inherent to wireless communications, i.e., high frequency utilization efficiency and robustness for fading. In this paper, we propose the frequency and time division multiple access with demand-assignment (FTDMA/DA) using multicarrier modulation as a frequency and time synchronous answer to meet the requirements, and analyze the performance of the FTDMA/DA system, taking account of teletraffic characteristics of multimedia information sources.

This paper studies the problem of embedding a graph into a book with nodes on a line along the spine of the book and edges on the pages in such a way that no edge crosses another. Atneosen as well as Bernhart and Kainen has shown that every graph can be embedded into a 3-page book when each edge can be embedded in more than one page. The time complexity of Bernhart and Kainen's method is Ω(ν(G)), where ν(G) is the crossing number of a graph G. A new 0(mn) algorithm is derived in this paper for embedding a graph G=(V, E), where m=│E│ and n= │V│ . The number of points at which edges cross over the spine in embedding a complete graph into a 3-page book is also investigated.

This paper describes a color segmentation method which is essential for automatic diagnosis of stained images. This method is applicable to the variance of input images using a three-layered neural network model. In this network, a back-propagation algorithm was used for learning, and the training data sets of RGB values were selected between the dark and bright images of normal mammary glands. Features of both normal mammary glands and breast cancer tissues stained with hematoxylin-eosin (HE) staining were segmented into three colors. Segmented results indicate that this network model can successfully extract features at various brightness levels and magnifications as long as HE staining is used. Thus, this color segmentation method can accommodate change in brightness levels as well as hue values of input images. Moreover, this method is effective to the variance of scaling and rotation of extracting targets.

The Minimum Covering Run (MCR) expression used for representing binary images has been proposed [1]-[3]. The MCR expression is an adaptation from horizontal and vertical run expression. In the expression, some horizontal and vertical runs are used together for representing binary images in which total number of them is minimized. It was shown that, sets of horizontal and vertical runs representing any binary image could be viewed as partite sets of a bipartite graph, then the MCR expression of binary images was found analogously by constructing a maximum matching as well as a minimum covering in the corresponding graph. In the original algorithm, the most efficient algorithm, proposed by Hopcroft, solving the graph-theoretical problems mentioned above, associated with the Rectangular Segment Analysis (RSA) was used for finding the MCR expression. However, the original algorithm still suffers from a long processing time. In this paper, we propose two new efficient MCR algorithms that are beneficial to a practical implementation. The new algorithms are composed of two main procedures; i.e., Partial Segment Analysis (PSA) and construction of a maximum matching. It is shown in this paper that the first procedure which is directly an improvement to the RSA, appoints well a lot of representative runs of the MCR expression in regions of text and line drawing. Due to the PSA, the new algorithms reduce the number of runs used in the technique of solving the matching problem in corresponding graphs so that satisfactory processing time can be obtained. To clarify the validity of new algorithms proposed in this paper, the experimental results show the comparative performance of the original and new algorithms in terms of processing time.

A new evaluation technique of hot carrier degradation is proposed and applied to practical evaluation of p-channel polycrystalline silicon thin film transistors (TFT). The proposed technique introduces emission microscopy which is particularly effective for evaluating TFT devices. We have developed an automatic measurement system in which measurement of the electrical characteristics and monitoring the photo emission are done simultaneously. Using this system, we have identified the dominant mechanism of hot carrier degradation in TFTs, and evaluated the effect of plasma hydrogenation on hot carrier degradation.

This paper proposes new algorithms for adaptive FIR filters. The proposed algorithms provide both fast convergence and small final misadjustment with an adaptive step size even under an interference to the error. The basic algorithm pays special attention to the interference which contaminates the error. To enhance robustness to the interference, it imposes a special limit on the increment/decrement of the step-size. The limit itself is also varied according to the step-size. The basic algorithm is extended for application to nonstationary signals. Simulation results with white signals show that the final misadjustment is reduced by up to 22 dB under severe observation noise at a negligible expense of the convergence speed. An echo canceler simulation with a real speech signal exhibits its potential for a nonstationary signal.

Today, defect sources of LSI device mainly lie in the process equipments. The particles generating in these equipments are introduced onto the wafer, and form the defects resulting in functional failures of LSI device. Thus, reducing these particles is acquired for increasing production yield and higher productivity, and it is important to identify the particle source in the equipment. In this study, we discussed new two methods to identify this source in the equipment used in the production line. The important point of identifing is to estimate the particle generation with short time and high accuracy, and to minimize long time stop of the equipment requiring disassembly. First, we illustrated "particle distribution analysis method." In this method, we showed the procedure to express the particle distribution mathematically. We applied this method to our etching equipment, and could identify the particle source without stopping this etching equipment. Secondly, we illustrated the method of "in-situ particle monitoring method," and applied this method to our AP-CVD equipment. As a result, it was clear the main particle source of this equipment and the procedure for decreasing these particles. By using this method, we could estimate the particle generation at real time in process without stopping this equipment. Thus, both methods shown in this study could estimate the particle generation and identify the particle source with short time and high accuracy. Furthermore, they do not require long time stop of the process equipment and interrupting the production line. Therefore, these methods are concluded to be very useful and effective in LSI manufacturing process.

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.

Optical parameters of KrF excimer laser stepper are optimized for 0.25 µm level patterning by means of a light intensity simulation method. The light intensity simulation method is applied conventional and two modified illuminations (annular and 4-point) to improve the depth of focus (DOF) at 0.25 µm periodic lines and spaces pattern (L&S). Simulation results obtained are; (1) the DOF of conventional illumination is not sufficient even in the optimum condition (NA=0.5, σ=0.8), (2) more than 1.5 µm DOF could be achieved with an annular illumination, if present resist performance is improved slightly, and (3) wider DOF is obtained in the case of with 4-point illumination. However, the DOF is rather degraded in the specific sized (near double/triple sized) region and oblique pattern, therefore the application of this illumination is restricted into some specific mask layout pattern.

Optical and electrical measurements of thin film n-channel SOI-MOSFETs reveal that the exponential tail in photon emission spectra originates from electron-hole recombination. Bremsstrahlung radiation model as a physical mechanism of photon emission was experimentally negated. Negative threshold voltage shift at the initial stage of high field stress is found to be caused by hole trapping in buried oxide. Subsequent turnover characteristics is explained by a competing process between electron trapping in the front gate oxide and hole trapping in the buried oxide. As to the degradation of transconductance, generated surface state as well as trapped holes in the buried oxide which reduce vertical electric field in SOI film are involved in the complicate degradation of transconductance.

A new approach to the problem of optimal software testing time is described. Most models implicitly assume the testing is terminated at the end of a prescribed period of time without user's approval. It means the release time and the in-service reliability are determined unilaterally by the developer. If software developer uses and maintains it, the assumption is appropriate. But, it may be inappropriate, if a software requiring more stringent reliability is developed by second party on a contract basis. In this case, the time of release is usually determined with the user's approval. To overcome the weaknesses of the assumption, a two stage testing with failure-free release policy is proposed. A software, after being tested by the developer for some time (in-house testing), is transferred to acceptance testing performed jointly with the user. During the acceptance testing, it is released when τ units of time specified by user is observed to be failure-free for the first time. The policy may be attractive to a user because he can determine the time of release, and extend the testing time by increasing τ. A software cost model for the policy is developed. For the software developer, an optimal in-house testing time minimizing software cost, and various quantities of interests, such as expected periods of acceptance testing, are derived based on the Jelinski-Moranda software reliability model. Finally, numerical examples are shown to illustrate the results.

A local area network (LAN) can now provide high-speed data communications in a local area environment to establish distributed processing among personal computers and workstations, and the need for interconnecting LANs, which are geographically distributed, is naturally arising. Asynchronous Transfer Mode (ATM) technology has been widely recognized as a promising way to provide the high-speed wide area networks (WAN) for Broadband Integrated Services Digital Network (B-ISDN), and the commercial service offerings are expected in the near future. The ATM network seems to have a capability as a backbone network for interconnecting LANs, and the LAN interconnection is expected to be the first service in ATM networks. However, there remain some technical challenges for this purpose; one of the main difficulties in LAN interconnection is the support of connectionless traffic by the ATM network, which is basically a connection-oriented network. Another one is the way of achieving the very high-speed data transmission over the ATM network. In this paper, we first discuss a LAN internetworking methodology based on the current technology. Then, the recent deployments of LAN interconnection methods through B-ISDN are reviewed.