Two computational-geometric approaches to linear programming are surveyed. One is based on the prune-and-search paradigm and the other utilizes randomization. These two techniques are quite useful to solve geometric problems efficiently, and have many other applications, some of which are also mentioned.

This paper describes operating characteristics of a new device named multi-step function MOS transistor (MSF MOSFET) which has stair-shaped I-V curve caused by a stairshaped gap between drain and gate. A quantizing inverter is obtained by using only a single MSF MOSFET as a coupling element of an emitter common amplifier. A pair of the quantizing inverters whose input and output are cross-coupled to each other has multi-stable states. This multiple-valued (MV) flip-flop is available for MV registers and MV memories whose states are changeable by an analog input voltage.

In this paper we propose a new timing optimization technique for multi-level networks by restructuring multiple nodes simultaneously. Multi-output subcircuits on critical paths are extracted and resynthesized so that the delays of the paths are reduced. The complete design space of the subcircuits is captured by Boolean relations, which allow us to perform more powerful resynthesis than previous approaches using don't cares. Experimental results are reported to show the effectiveness of the proposed technique.

We apply Fahlman and Lebiere's (FL) algorithm to network synthesis and incremental learning by making use of already-trained networks, each performing a specified task, to design a system that performs a global or extended task without destroying the information gained by the previously trained nets. Investigation shows that the synthesized or expanded FL networks have generalization ability superior to Back propagation (BP) networks in which the number of newly added hidden units must be pre-specified.

A Decision Feedback Equalizer (DFE) structure with a varying number of tap lengths was used with a recursive least squares (RLS) algorithm to determine tradeoffs between equalizer size and performance in mobile and portable digital radio systems. A mobile channel simulator, SMRCIM, was used to demonstrate how much an equalizer can improve the BER in real world urban channels. The results show that at 850MHz, the DFE is unable to improve the BER when the mobile terminal exceeds speeds of 115km/h for U.S. Digital Cellular systems. The performance of adaptive equalization for indoor high data rate systems was evaluated using the indoor channel simulator SIRCIM, and we found that DFEs have excellent performance for indoor radio channels. For simple structures, the BER is less than 10-3 at 15dB Eb/NO using coherent QPSK modulation. Finally, an equalizer structure for non-coherent π/4 DQPSK modulation was developed and simulation results are presented.

This paper proposes and investigates an adaptive equalizer with diversity-combining over a multipath fading channel. It consists of two space-diversity antennas and a Ts/2-spaced decision-feedback-equalizer (DFE). Received signals from the two antennas are alternatively switched and fed into the feed forward-filter of DFE. We call this structure a Switched Input Combining Equalizer with diversity-combining (SICE). By using an SICE, the receiver structure for combining diversity equalization can be simplified, because it needs only two receiver sections up to IF BPF. The bit error rate (BER) performance of SICE was evaluated by both computer simulation and experiment over a multipath fading channel. We experimentally confirmed the excellent BER performance, around 1% of BER over a multipath fading channel at 160Hz of maximum doppler fading frequency. Therefore, the proposed SICE is applicable to highly reliable transmission in the 1.5-GHz-band mobile radio.

High Tc superconducting (SC) active antennas made from thin films were produced by the magnetron sputtering method. The SC active antennas are found to be good for detecting 50GHz electromagnetic waves. Furthermore, the improvement of the sensitivity of the SC active antennas is demonstrated with the use of a corner reflector.

The research for rational quadratic Bézier curve and its applications for generating conics and curve-fitting have been reported in some papers. But rational cubic Bézier curves, for the complexity of computation of the weight parameters and the difficulty of the shape control, have very rarely been applied up to the present. In this letter, we proposed a new method to generate a rational cubic Bézier curve. For a given point S (assuming the curve pass it) and a given value of the intermediate variable t in the point, we can compute the weight parameters of the rational cubic Bézier curve according to the relation of the control polygon and the given point, and can generate the curve. Then we explained the relation among shape of curve, given point S and intermediate varisble t. As the samples of using the method, we showed the generation of the gear-shape curve, symmetrical curve and spindle-shape curve, etc.. Finally, we discuss the application of this method for curve-fitting.

This letter describes the concepts that the learnability of multilayer neural networks exists in a constrained hypersurface in learning space which is formed by input and output subspace of multilayer neural networks, and that a priori information, providing constraints on the learning space, is required for generalization.

The robust finite settling time stabilization problem is considered for a multivariable discrete time plant with structured uncertainties. Finite settling time (FST) stability of a feedback system is a notion introduced recently for discrete time systems as a generalization of the dead-beat response. The uncertain plant treated in this paper is described by (E0+ΣKi=1qiEi)x(t+1)(A0+ΣKi=1qiAi)x(t)+(B0+ΣKi=1qiBi)u(t), and y(t)=(C0+ΣKi=1qiCi)x(t) where Ei, Ai, Bi and Ci (0iK) are prescribed real matrices and qi (1iK) are uncertain parameters restricted to prescribed intervals [qi, i]. It is shown in this paper that a controller robustly FST stabilizes such an uncertain plant, if, the uncertain plant satisfies some conditions, and the controller simultaneously FST stabilizes a finite set of plants. The result leads to a testable necessary and sufficient condition of the existence of a solution to the robust FST stabilization problem, and a systematic method of designing a robust FST stable feedback system, in the case where the plant contains only one uncertain parameter.

In this paper, we investigate the round complexity of zero-knowledge interactive proof systems of possession of knowledge, and mainly show that if a relation R has a three move blackbox simulation zero-knowledge interactive proof system of possession of knowledge, then there exists a probabilistic polynomial time algorithm that on input x{0,1}*, outputs y such that (x,y)R with overwhelming probability if xdom R, and outputs "" with probability 1 if x dom R. The result above can not be generalized to zero-knowledge interactive proof systems of possession of knowledge with more than four moves, because it is known that there exists a "four" move blackbox simulation perfect zero-knowledge interactive proof system of possession of knowledge for a nontrivial relation R.

We show that, if NP language L has an invulnerable generator and if L has an honest verifier standard statistical ZKIP, then L has a 5 move statistical ZKIP. Our class of languages involves random self reducible languages because they have standard perfect ZKIPs. We show another class of languages (class K) which have standard perfect ZKIPs. Blum numbers and a set of graphs with odd automorphism belong to this class. Therefore, languages in class K have 5 move statistical ZKIPs if they have invulnerable generators.

This paper presents two methods for securely realizing caller-authenticated and callee-specified calls over telecommunication networks with terminals that accept IC cards having KPS-based cryptographic functions. In the proposed protocols, users can verify that the partner is the proper owner of a certain ID or a certain pen name. Users' privacy is protected even if they do the caller-authenticated and callee-specified calls and do not pay their telephone charge in advance.

We define the communication complexity of a perfect zero-knowledge interactive proof (ZKIP) as the expected number of bits communicated to achieve the given error probabilities (of both the completeness and the soundness). While the round complexity of ZKIPs has been studied greatly, no progress has been made for the communication complexity of those. This paper shows a perfect ZKIP whose communication complexity is 11/12 of that of the standard perfect ZKIP for a specific class of Quadratic Residuosity.

Given an integer N, it is easy to determine whether or not N is prime, because a set of primes is in LPP. Then given a composite number N, is it easy to determine whether or not N is of a specified form? In this paper, we consider a subset of odd composite numbers +1MOD4 (resp. +3MOD4), which is a subset of odd composite numbers consisting of prime factors congruent to 1 (resp. 3) modulo 4, and show that (1) there exists a four move (blackbox simulation) perfect ZKIP for the complement of +1MOD4 without any unproven assumption; (2) there exists a five move (blackbox simulation) perfect ZKIP for +1MOD4 without any unproven assumption; (3) there exists a four move (blackbox simulation) perfect ZKIP for +3MOD4 without any unproven assumption; and (4) there exists a five move (blackbox simulation) statistical ZKIP for the complement of +3MOD4 without any unproven assumption. To the best of our knowledge, these are the first results for a language L that seems to be not random self-reducible but has a constant move blackbox simulation perfect or statistical ZKIP for L and without any unproven assumption.

Formation of thin insulating SiO2 films by anodic oxidation of silicon was studied as a part of investigating an alternative method of fabricating low-cost silicon MIS solar cells. Anodization in the constant-voltage mode was carried out in nonaqueous ethylene glycol solution. The film thickness was carefully measured using an ellipsometer of wavelength 6238 . MIS cell performance was evaluated by comparing the open circuit voltage VOC and the short circuit current density ISC with those of the bare Schottky cell (without anodization) under illumination by a tungsten lamp. It was found that anodization in the constant-voltage mode can increase VOC without reducing ISC, and that anodization in the constant-voltage mode is more controllable and reproducible. The optimun formation voltage which gives the maximum VOC of the MIS cell depends on the forming voltage of oxide. A brief discussion on the mechanism for VOC increase is given.

In this paper, we investigate the discrepancy between a serial version and a parallel version of zero-knowledge protocols, and clarify the information "leaked" in the parallel version, which is not zero-knowledge unlike the case of the serial version. We consider two sides: one negative and the other positive in the parallel version of zero-knowledge protocols, especially of the Fiat-Shamir scheme.

An adaptive fuzzy network (AFN) is described that can be used to implement most of fuzzy logic functions. We introduce a learning algorithm largely borrowed from backpropagation algorithm and train the AFN system for several typical fuzzy problems. Simulations show that an adaptive fuzzy network can be implemented with the proposed network and algorithm, which would be impractical for a conventional fuzzy system.

The interface between laser-recrystallized Si and SiO2 is investigated by means of capacitance-voltage curve measurements. The recrystallization is performed by scanning cw Ar+ laser. The change in the C-V curves shows that the laser-recrystallization generates positive charge and the fast interface states at the Si-SiO2 interface, and creates n-type defects in recrystallized bulk silicon. Nominal interface charge increases linearly with a laser power. The increase in the charge is enhanced by fast laser-beam scanning velocity. The change in the C-V curve is suppressed, if a substrate is heated up to 450 during recrystallization. Complete recovery of the induced change in the C-V curves requires a subsequent furnace annealing at a temperature as high as 1100. These phenomena are explained by the generation of oxygen vacancy at the Si-SiO2 interface and quenched-in point defects in the recrystallized Si. The oxygen vacancy is produced by a reaction between the melted Si and SiO2. The quenched-in defects are produced during fast cooling of the melted Si.

Thin- and ultra-thin-film SOI MOSFET's are promising candidates to overcome the constraints for future miniaturized devices. This paper presents simulation results for a 0.1 µm gate length SOI MOSFET structure using a two-dimensional/two-carrier device simulator with a nonlocal model for the avalanche induced carrier generation. For the suppression of punchthrough effect in devices with a channel doping of 1 1016 cm-3 and 5 nm thick gate oxide it is found that the SOI layer thickness has to be reduced to at least 20 nm. The thickness of the buried oxide should not be smaller than 50 nm in order to avoid the degradation of thin SOI performance advantages. Investigating ways to suppress the degradation of the sub-threshold slope factor at these device dimensions it was found in contrast to the common expectation that the S-factor can be improved by increasing the body doping concentration. This phenomenon, which is a unique feature of thin-film depleted SOI MOSFET's, is explained by an analytical mode. At lower doping the area of the current flow is reduced by a decreasing effective channel thickness resulting in a slope factor degradation. Other approaches for S-factor improvement are the reduction of the channel edge capacitances by source/drain engineering or the decrease of SOI thickness or gate oxide thickness. For the latter approach a higher permittivity gate insulating material should be used in order to prevent tunnelling. The low breakdown voltage can be increased by utilizing an LDD structure to be suitable for a 1.5 V power supply. However, this is at the expense of reduced current drive. An alternative could be the supply voltage reduction to 1.0 V for single drain structure use. A dual-gated SOI MOSFET has an improved performance due to the parallel combination of two MOSFET's in this device. A slightly reduced breakdown voltage indicates a larger drain electric field present in this structure.