A speedup of Lenstra's Elliptic Curve Method of factorization is presented. The speedup works for integers of the form N = PQ2, where P is a prime sufficiently smaller than Q. The result is of interest to cryptographers, since integers with secret factorization of this form are being used in digital signatures. The algorithm makes use of what we call Jacobi signatures. We believe these to be of independent interest.

A new superresolution technique is proposed for high-resolution estimation of the scattering analysis. For complicated multipath propagation environment, it is not enough to estimate only the delay-times of the signals. Some other information should be required to identify the signal path. The proposed method can estimate the frequency characteristic of each signal in addition to its delay-time. One method called modified (Root) MUSIC algorithm is known as a technique that can treat both of the parameters (frequency characteristic and delay-time). However, the method is based on some approximations in the signal decorrelation, that sometimes make problems. Therefore, further modification should be needed to apply the method to the complicated scattering analysis. In this paper, we propose to apply a time-domain null filtering scheme to reduce some of the dominant signal components. It can be shown by a simple experiment that the new technique can enhance estimation accuracy of the frequency characteristic in the Root-MUSIC algorithm.

A new yield prediction model has been developed, which can successfully describe the actual chip fabrication yield. It basically consists of modeling of particles deposited on wafer surface, considering the change in their size and spatial distribution due to the subsequent processing steps and a new concept of virtual line width in pattern layouts. It is confirmed that this yield prediction model serves as an effective navigator for improvement/optimization of fabrication lines such as pointing out the process step/equipments to be modified for yield improvements.

A new line simulator, SEMALIS has been developed. This simulator can handle complicated lot processings to maintain processing quality and efficient line operations to improve line performance. The current manufacturing line consists of five resource models: lot, process sequence, equipment, lot processing, and line operations. The parameters of these models are defined so as to accurately reflect the state of the line operations. From our simulation results, we confirmed that SEMALIS accurately identifies bottlenecks or starvations where equipment can be added or reduced to optimize equipment utilization through resource planning, and that SEMALIS can also be used to evaluate the long-term effects of line operating methods on the line performance of ASIC manufacturing lines.

In this paper, we show a collusion attack on the novel and sophisticated ID-based non-interactive key sharing scheme proposed by Tanaka [2], [3]. It is based on a linear algebraic approach [4]. We discuss its complexity and provide numerical simulation results of the success probability in forging the shared keys.

This paper compares two techniques in recovering the capacity degradation caused by sectorization in a cellular system. They are the Directed Retry and Load Sharing in sector cells. Since both techniques requires an overlapping area between adjacent sectors, the values of the overlapping area are chosen such that the Carrier to Interference Ratio (CIR) is satisfied.

An efficient full-wave approach for the accurate characterization of a H-plane waveguide π-junction with an inductive post and a waveguide cross-junction is proposed. By employing the port reflection coefficient method (PRCM), the analysis and solution procedures of these complex waveguide junctions are greatly simplified and only the calculation of field reflections caused by the simplest waveguide step-junction discontinuities are required. The reflections are easily determined by the mode-matching technique. Scattering parameters of these junctions are provided and discussed in terms of the working frequency and the geometrical dimensions of the junctions. Calculated results are compared with those of other papers and measurements, all show good agreement.

The scaling laws between the design rules and the smallest sizes and numbers of particles capable of causing pattern defects and scrapping dies in semiconductor device manufacturing are described. Simulation with electromagnetic waveguide model indicates the possibility that particles, the sizes of which are of comparable order or even smaller than the wavelength of the lithography irradiation sources, are capable of causing pattern defects. For example, in the future 0.25 µm-design-rule era, the critical sizes of Si, Al, and SiO2 particles are simulated as 120 nm 120 nm, 120 nm 120 nm, and 560 nm 560 nm, respectively, in the case of 0.7 µm-thick chemically-amplified positive photoresist with 47 nm-thick top anti-reflective coating films. Future giga-scale integration era is also predicted.

Several papers have been shown equalization in the reception side. However, equalization in transmission side that is partial response signaling (PRS) or precoding is also possible in a two-way interactive communication such as time or frequency division duplex (TDD of FDD). This paper proposes and investigates a system which includes a transmission equalization and reception equalization based on an array antenna. This system is the extension in spatial and temporal domains. The channel capacity can be improved in the super channel which includes the transmitter and receiver array antenna.

The problem of TM-mode scattering from the finite number of rectangular notches in a parallel plate waveguide is considered. The Fourier-transform is employed to obtain simultaneous equations and the simultaneous equations are solved to obtain an analytic solution in rapidly-convergent series. Numerical computations are performed to investigate the scattering behavior in terms of frequency and notch sizes. The presented theory is applicable to the analysis of scattering from the E-plane stubs in the rectangular waveguide.

Throughout the paper, the proper operating of the self-routing principle in 2-D shuffle multistage interconnection networks (MINs) is analysed. (The notation 1-D MIN and 2-D MIN is applied for a MIN which interconnects 1-D and 2-D data, respectively.) Two different methods for self-routing in 2-D shuffle MINs are presented: (1) The application of self-routing in 1-D MINs by a switch-pattern preserving transformation of 1-D shuffle stages into 2-D shuffle stages (and vice versa) and (2) the general concept of self-routing in 2-D shuffle MINs based on self-routing with regard to each coordinate which is the original contribution of the paper. Several examples are provided which make the various problems transparent.

A performance estimation method has been developed that combines conventional performance evaluation with Bayesian regression analysis. The conventional method is used to estimate performance a priori; this a priori estimate is then updated through Bayesian regression analysis using monitored performance. This method compensates for modeling errors in the conventional technique without recreating complex performance models; it does not require additional traffic measurement or system behavior models. Numerical examples and applications of traffic management in ATM PVC networks have demonstrated its effectiveness.

Access control has been an important security issue in information systems. Multilevel hierarchical information access widely exists in present-day government, military, and business applications. Extending access control design to work in a hierarchical environment is natural and necessary but rarely addressed so far in the literature. In this paper, a dynamic group-oriented cryptographic scheme to access a multilevel data hierarchy is proposed. In the proposed scheme, a trusted central authority is in charge of the administrative activities among the organization hierarchy. At the beginning, each user class submits its associated information and a cryptographic key of its preference to the central authority. Next the central authority generates a public information for each class according to their location in the organization hierarchy. The cryptographic key held by each class can be used directly as an encryption key to encipher data. These keys need not be modified when adding/deleting a class to/from the system. Compare with other existing schemes, ours has the advantages of flexibility in choosing user preferred cryptographic keys, cryptographic keys not exceeding a fixed length, reduced storage space in publishing pubic information, and protection from conspiracy attack.

In this paper it is pointed out that although an elegant differential-like approach is developed, Coppersmith' attacking method on NIKS-TAS cannot succeed to forge a shared key of legitimate entities especially when p-1 contains highly composite divisors, as well as decomposibility-hard divisors. This is mainly due to a severe reduction of modulo size. Computer simulation results confirm this assertion. The ambiguity in the solutions to the collusion equations in the first phase can be analyzed by the elementary divisor theory. Moreover, two basis vectors, qi,ri in the second phase, are found to be inadequate to represent the space spanned by xi-yi and ui-vi(i=1,...,N), because qi,ri exist frequently over the space with small modulo size. Then, the erroneous values of αi,βi,...,εi(i=1,...,N) are derived from the inadequate basis vectors, qi,ri. Also, when the degeneracy in modulo size happens, the solutions to αi,βi,...,εi(i=1,...,N) cannot be solved even by means of the exhaustive search over the small prime divisors of p-1.

An optoelectronic beam forming network (BFN) is presented for a single beam, 3-element phased array antenna that utilizes electrically controllable birefringence mode nematic liquid-crystal cells (ECB mode NLC cells) for phase shifting and amplitude control. In the circuit, a microwave signal is carried by a pair of orthogonal linearly polarized lightwaves (signal and reference lightwaves) using the optical heterodyning technique. Birefringence of liquid-crystals is utilized to selectively control the phase of the signal and reference lightwaves. Because an interferometer is formed on a single signal path, the complexity of the optical circuit is much reduced, compared to the BFNs based on arrays of Mach-Zender interferometers. A prototype circuit is built using laser sources of 1.3 µm, and its performance experimentally examined. With small deviations among the three cells, phase shifts of up to 240 degrees are achived for MW signals from 0.9 GHz to 20 GHz with good stability; attenuation of more than 18dB is achieved. An optoelectronic technique for parallel control of amplitude and phase of MW signals was developed.

The Bidirectional Reflectance Distribution Function (BRDF) is an intrinsic measurement of directional properties of the earth's surface. However, the estimation of the BRDF requires many remote sensing measurements of a given surface target from different viewing angles. In addition, a good atmospheric correction scheme is a prerequisite for such an attempt. The airborne POLDER sensor measures successively reflected radiation by terrestrial surfaces in a framed image form at different viewing angles during a single airplane pass, like taking snap-shot pictures. A specially improved atmospheric correction algorithm which is applicable to a framed image data by POLDER sensor is presented. The observed reflectance images taken successively by the airborne POLDER at slightly different viewing angles are converted to a series of surface albedo images by applying our atmospheric correction algorithm. Then, the BRDFs for three surface covers, namely, "River Water," "Forest," and "Rice Field," are estimated by using successive albedo images. It is found that the BRDF for "River Water" follows Lambert law at both 550nm and 850nm. It is also found that the BRDFs for "Forest" and "Rice Field" follow Lambert's law at 550nm, but they follow an anisotropic reflection law at 850nm and fitting parameters for their BRDFs are presented.

Physical and optical parameters within the atmosphere-ocean system have been retrieved by a multiple scattering analysis of the reflectance and degree of linear polarization data measured by the airborne POLDER sensor in Medimar campaign in 1991. Assuming an atmosphere-ocean system with a Cox-Munk type rough sea surface model, the theoretical reflectance and -degree of linear polarization were computed by the doubling and adding method for several different models. In this study the retrieval was made by assuming a fixed refractive index of the aerosol particles, i.e., Nr=1.33-0.0i. We obtained several important results in this study as follows: 1) By comparing computed results with the observed data at 0.85m, we rejected the oceanic type aerosol model and found Junge type aerosol model with its index range of 4.0v4.5 as an appropriate model for aerosols at the observation time. 2) The reflectance data analysis in the perpendicular plane rejected an isotropic Cox-Munk model, but it indicated that an anisotropic Cox-Munk model should be used in the sea surface wind field retrieval. 3) The surface wind speed was estimated to be 10.0m/secV15.0m/sec with an best estimate of V=12.5m/sec, which agrees with the observed wind speed of V=14.4m/sec. The range of the water column reflectance was also estimated to be 0.025rwc0.045 from Medimar reflectance data at 0.45m. 4) Further study should be made for other refractive indices of the aerosol particles. More refinement of the present multiple scattering code to include upwelling polarization components from below the sea surface is also necessary.

There have been many developments on neural network research, and ability of a multi-layered network for classification of multi-spectral image data has been studied. We can classify non-Gaussian distributed data using the neural network trained by a back-propagation method (BPM) because it is independent of noise conditions. The BPM is a supervised classifier, so that we can get a high classification accuracy by using the method, so long as we can choose the good training data set. However, the multi-spectral data have many kinds of category information in a pixel because of its pixel resolution of the sensor. The data should be separated in many clusters even if they belong to a same class. Therefore, it is difficult to choose the good training data set which extract the characteristics of the class. Up to now, the researchers have chosen the training data set by random sampling from the input data. To overcome the problem, a hybrid pattern classification system using BPM and Kohonens feature mapping (KFM) has been proposed recently. The system performed choosing the training data set from the result of rough classification using KFM. However, how the remotely sensed data had been influenced by the KFM has not been demonstrated quantitatively. In this paper, we propose a new approach using the competitive weight vectors as the training data set, because we consider that a competitive unit represents a small cluster of the input patterns. The approach makes the training data set choice work easier than the usual one, because the KFM can automatically self-organize a topological relation among the target image patterns on a competitive plane. We demonstrate that the representative of the competitive units by principal component analysis (PCA). We also illustrate that the approach improves the classification accuracy by applying it on the classification of the real remotely sensed data.

This paper presents Ternary Decision Diagrams which represent sets of products. This paper also presents manipulating methods for sum-of-products forms and ringsum-of-products forms using Ternary Decision Diagrams, and gives comparison results between Ternary Decision Diagrams and Binary Decision Diagrams.

This paper proposes an efficient clustering algorithm for region merging. To speed up the search of the best pair of regions which is merged into one region, dissimilarity values of all possible pairs of regions are stored in a heap. Then the best pair can be found as the element of the root node of the binary tree corresponding to the heap. Since only adjacent pairs of regions are possible to be merged in image segmentation, this constraints of neighboring relations are represented by sorted linked lists. Then we can reduce the computation for updating the dissimilarity values and neighboring relations which are influenced by the merging of the best pair. The proposed algorithm is applied to the segmentations of a monochrome image and range images.