As wireless communication is penetrating every corner of the globe, the optimum design and accurate analysis of RF, power semiconductor devices become one of the biggest challenges in EDA and TCAD (Technology CAD) tool development. The performance gauge for these devices is quite different from that for either digital or analog devices aimed at small-signal applications in that the power gain, efficiency, and distortion (or the range of linearity) are the utmost design concerns. In this article, the methodology and mathematical foundation for numerical analysis of large signal distortion at the device simulation level are discussed. Although the harmonic balance (HB) method has long been used in circuit simulation for large signal distortion analysis, the implementation of the same method in device simulation faces daunting challenges, among which are the tremendous computational cost and memory storage management. But the benefits from conducting such a device level simulation are also obvious--for the first time, the impact of technology and structural variation of device on large signal performance can directly be assessed. The necessary steps to make the HB analysis feasible in device simulation are outlined and algorithmic improvement to ease the computation/storage burden is discussed. The applications of the device simulator for various RF power devices, including GaAs MESFETs and silicon LDMOS (lateral diffusion MOS) are presented, and the insight gained from such an analysis is provided.

A complex modular process flow was developed for PRISM technology to permit increased system integration. In order to combine the required functions--submicron CMOS Logic, Nonvolatile Memories, Precision Linear, and Power Drivers--on a monolithic silicon chip, a highly structured, systematic approach to process synthesis was developed. TCAD tools were used extensively for process design and verification. The 60 V LDMOS power transistor and the Flash memory cell built in the technology will be described to illustrate the process synthesis methodology.

Equipment simulation can provide valuable support in reactor design and process optimization. This article describes the physical and chemical models used in this technique and the current state of the art of the available software tools is reviewed. Moreover, the potential of equipment simulation will be highlighted by means of three recent examples from advanced quarter micron silicon process development. These include a vertical batch reactor for LPCVD of arsenic doped silicon oxide, a multi station tungsten CVD reactor, and a plasma reactor for silicon etching.

This paper discusses the implementation and cost- and performance- evaluations of a distributed processing network, called DONA-α, which is one of the possible physical networks mainly implementing connection-oriented public switched network functions corresponding to OSI layers 1 to 3. The first feature of the DONA-α network is that it separates a switching subsystem and a control subsystem of a conventional switching system and independently allocates them over distributed nodes as a switching node and a control node. Each DONA-α switching node is given a much smaller switching capacity than the switching subsystem of the conventional switching system and is located near subscribers. In contrast, each DONA-α control node has much higher performance than the control subsystem of the conventional switching system. This allows a large number of switching nodes to share the same control node, which controls their connection setups. This separation provides the network with greater flexibility and allows more effective utilization of network resources, such as control processors, switching fabrics, and transmission links, than ever before. The second feature of DONA-α is that it provides a network with network-wide distribution transparency. This allows network resources including software such as databases and application programs to be shared and therefore to be utilized in the network more easily and more efficiently. The results of a network performance simulation and cost calculation confirm the viability of the DONA-α network.

Recent years have seen great advances in our understanding and modeling of the coupled diffusion of dopants and defects in silicon during integrated circuit fabrication processes. However, the ever-progressing shrinkage of device dimensions and tolerances leads to new problems and a need for even better models. In this review, we address some of the advances in the understanding of defect-mediated diffusion, focusing on the equations and parameters appropriate for modeling of dopant diffusion in submicron structures.

This paper presents a method of calculating an interval including a bifurcation point. Turning points, simple bifurcation points, symmetry breaking bifurcation points and hysteresis points are calculated with guaranteed accuracy by the extended systems for them and by the Krawczyk-based interval validation method. Taking several examples, the results of validation are also presented.

Homogeneous but distinct visual objects having low-contrast boundaries are usually merged in most of the segmentation algorithms. To alleviate this problem, an efficient image segmentation algorithm based on a bottom-up approach is proposed by using spatial domain information only. For initial image segmentation, we adopt a new marker extraction algorithm conforming to the human visual system. It generates dense markers in visually complex areas and sparse markers in visually homogeneous areas. Then, two region-merging algorithms are successively applied so that homogeneous visual objects can be represented as simple as possible without destroying low-contrast real boundaries among them. The first one is to remove insignificant regions in a proper merging order. And the second one merges only homogeneous regions, based on ternary region classification. The resultant segmentation describes homogeneous visual objects with few regions while preserving semantic object shapes well. Finally, a size-based region decision procedure may be applied to represent complex visual objects simpler, if their precise semantic contents are not necessary. Experimental results show that the proposed image segmentation algorithm represents homogeneous visual objects with a few regions and describes complex visual objects with a marginal number of regions with well-preserved semantic object shapes.

A new concept of "an imperfect singular solution" is defined as an approximate solution which becomes a singular solution by adding a suitable small perturbation to the original equations. A numerical method is presented for proving the existence of imperfect singular solutions of nonlinear equations with guaranteed accuracy. A few numerical examples are also presented for illustration.

The characteristics of the decision feedback carrier recovery loop (DFL) for conventional QPSK signaling is evaluated experimentally through measurements of the carrier-to-noise ratio of the regenerated carrier, lock range, acquisition waveforms and bit error rates. The results show that the DFL hardly exhibits inferiority to the ideal synchronization by designing the loop natural frequency adequately small. The DFL is shown superb in carrier tracking.

Since ATM network is a connection-oriented network, the operation for connectionless service is required for data service in it. There are many ways to support connectionless service in ATM network. They are ATM LAN Emulation, Classical IP and ARP over ATM, Indirect approach, Direct approach, and IP switch. It is known that Direct approach is suited for public network. The connectionless server supports connectionless service in Direct approach. There have been presented two kinds of methods, that is, streaming forwarding method and reassembly forwarding method, to forward the frames in the connectionless server. Reassembly forwarding method can work well with AAL5 which has better efficient characteristics than AAL3/4 in terms of easy use and fewer overheads. This paper proposes an algorithm that can decrease the loss of frame by a proposed buffer management working with AAL5. This paper also investigates the structure of the proposed connectionless server and its performance with the one of the conventional connectionless server through simulations. The proposed connectionless server shows a less frame loss and transfer delay than that of the conventional connectionless server.

An on-chip high voltage generator applicable to low voltage flash memory is introduced. Bootstrapped gate transfer switches of two parallel paths suppress the voltage loss due to threshold voltage drop of transfer transistors. The simulated results demonstrate that proposed circuit designed with NMOS transistors having 0.8 volt threshold voltage works like an ideal charge pump circuit near 1.0 volt range with enough current driving capability.

This paper reports computational results of a new approach of analyzing network reliability against probabilistic link failures. This problem is hard to solve exactly when it is large-scale, which is shown from complexity theory, but the approach enables us to analyze networks of moderate size, as demonstrated by our experimental results. Furthermore, this approach yields a polynomial-time algorithm for complete graphs, whose reliability provides a natural upper bound for simple networks, and also leads to an efficient algorithm for computing the dominant part of the reliability function when the failure probability is sufficiently small. Computational results for these cases are also reported. This approach thus establishes a fundamental technology of analyzing network reliability in practice.

We show that the permanent of an m n rectangular matrix can be computed with O(n 2m 3m) multiplications and additions. Asymptotically, this is better than straightforward extensions of the best known algorithms for the permanent of a square matrix when m/n log3 2 and n .

IP multicast is very useful mechanism to deliver data to a large number of receivers such as interactive multimedia sessions. It can not accommodate the heterogeneity of the receivers including network heterogeneity. We propose a multicast traffic controller(s) in a router to solve such situation. A traffic controller has a filter to moderate the output data rate to a link. It makes use of Time-to-Live (TTL) threshold to specify the minimum requirement of a packet. Multimedia data are encoded into multiple layers; basic layer and enhanced layers. By associating TTLs of data layers and the threshold of the filter, we can moderate the traffic by dropping the data of less significant layer. The threshold is dynamically modified according to the local network traffic and link traffic. Our scheme also helps a network and a link(s) avoid from congestion and accommodate other types of traffic at the same time.

In this paper, a new multicast routing method for layered streams is proposed. This method is an extension of the weighted greedy algorithm (WGA) and uses two kinds of weight values to refine the link distance. It can cope with dynamic change in the group members without multicast tree re-construction. The method is compatible with the RSVP and can be utilized in existing shared tree type routing protocols such as CBT and PIM sparse mode. The network resources can be utilized efficiently; furthermore, the loss rate of member's requests to receive more layers can be reduced by this routing method when a sufficient number of nodes have the packet filtering function and a sufficient number of hops is permitted.

This letter proposes improvement to the previously presented watermarking method which spreads an ID pattern with a random sequence and embeds it throughout the spatial domain of an image. The proposed method can extract embedded watermarks without an original image even from images converted by brightness/contrast conversion, edge-enhancement, posterization and JPEG compression.

In this paper we study n-input m-output Boolean functions (abbr. (n,m)-functions) with high nonlinearity. First, we present a basic construction method for a balanced (n,m)-function based on a primitive element in GF(2m). With an iterative procedure, we improve some lower bounds of the maximum nonlinearity of balanced (n,m)-functions. The resulting bounds are larger than the maximum nonlinearity achieved by any previous construction method for (n,m)-functions. Finally, our basic method is developed to construct an (n,m)-bent function and discuss its maximum algebraic degree.

Regular ternary logic functions are one of the most useful special classes of Kleenean functions, and a lot of research has been done on them. However, there has been little work done on incompletely specified regular ternary logic functions. This paper describes the following points: (1) Minimization of incompletely specified regular ternary logic functions. (2) A new definition of incompletely specified fuzzy switching functions and their minimization. (Concretely speaking, minimal disjunctive forms of incompletely specified fuzzy switching functions are represented in formulas of regular ternary logic functions. ) (3) Their application to fuzzy logic circuits such as fuzzy PLAs of AND-OR type.

This paper shows the best operators for sum-of-products expressions. We first describe conditions of functions for product and sum operations. We examine all two-variable functions and select those that meet the conditions and then evaluate the number of product terms needed in the minimum sum-of-products expressions when each combination of selected product and sum functions is used. As a result of this, we obtain three product functions and nine sum functions on three-valued logic. We show that each of three product functions can express the same functions and MODSUM function is the most suitable for reduction of product terms. Moreover, we show that similar results are obtained on four-valued logic.

When the degree of intersections A B of events A, B is unknown arises a problem: how to evaluate the probability P(A B) and P(A B) from P(A) and P(B). To treat related problems two models of valuation: interval and paired probabilities are proposed. It is shown that the valuation corresponding to the set operations (intersection), (union) and (complement) can be described by the truth functional (AND), (OR) and (negation) operations in both models. The probabilistic AND and OR operations are represented by combinations of Kleene and Lukasiewicz operations, and satisfy the axioms of MV (multiple-valued logic)-Algebra except the complementary laws.