A new method using new test structure, which is connected 15.4 million MOS transistor, for evaluating extrinsic oxide breakdown is proposed. The active gate area which is needed to predict reliability will be shown. And by using this new method, activation energy not only for the intrinsic breakdown but also for the extrinsic breakdown are obtained.

This paper describes low-power architecture-methodologies for programmable multimedia processors, which will become major functional units in System-On-a-Chip. After brief review on multimedia processing and low-power considerations, recent programmable chips, including MPUs and DSPs, are investigated in terms of low-power implementation. In order to show the difference of the low-power approaches between programmable processors and ASIC processors, a single-chip MPEG-2 encoder is also included as an example of ASIC design.

The equivalence between Aperture Field Integration Method (AFIM) and Physical Optical (PO) is discussed for polyhedron surfaces in this paper. The necessary conditions for the equivalence are summarized which demand complete equivalent surface currents and complete apertures. The importance of the exact expressions for both incident and reflected fields in constructing equivalent surface currents is emphasized and demonstrated numerically. The fields from reflected components on additional surface which lies on the Geometrical Optics (GO) reflection boundary are evaluated asymptotically. The analytical expression enhances the computational efficiency of the complete AFIM. The equivalent edge currents (EECs) for AFIM (AFIMEECs) are used to extract the mechanism of this equivalence between AFIM and PO.

A novel cumulant based MUSIC like DOA estimation algorithm for multicarrier modulation has been proposed in this paper. While the conventional MUSIC algorithm is not applicable to a correlation matrix calculated from received signals transmitted over the different carriers, the proposed algorithm can estimate the DOA of the signals with multicarrier modulation. The proposed algorithm does not require the sensor array responses for the frequency range of the interest and the initial phases of the carriers. With the proposed algorithm the number of signals whose DOA are estimated can be increased and the accuracy of the DOA estimation can be improved by employing larger number of carriers.

This paper describes a new Artificial Neural Network (ANN), UNItary Decomposition ANN (UNIDANN), which can perform the unitary eigendecomposition of the synaptic weight matrix. It is shown both analytically and quantitatively that if the synaptic weight matrix is Hermitian positive definite, the neural output, based on the proposed dynamic equation, will converge to the principal eigenvectors of the synaptic weight matrix. Compared with previous works, the UNIDANN possesses several advantageous features such as low computation time and no synchronization problem due to the underlying analog circuit structure, faster convergence speed, accurate final results, and numerical stability. Some simulations with a particular emphasis on the applications to high resolution bearing estimation problems are also furnished to justify the proposed ANN.

A correction of the physical optics approximation by accounting for the presence of specific currents concentrated near shadow boundaries on the surface of a convex non-metallic scatterer is analysed by considering a canonical problem of diffraction of a plane electromagnetic wave incident normally to the axis of an infinite circular cylinder with impedance boundary conditions. The analysis focuses on the development of Fock-type asymptotic representations for magnetic field tangent components on the surface of the scatterer. The Fock-type representation of the surface field is uniformly valid within the penumbra region, providing a continuous transition from the geometrical optics formulas on the lit portion of the surface to the creeping waves approximation in the deep shadow region. A new numerical procedure for evaluating Fock-type integrals is proposed that extracts rapidly varying factors and approximates the rest, slowly varying coefficients via interpolation. This allows us to obtain accurate and simple representations for the shadow boundary currents that can be directly inserted into the radiation integral and effectively integrated. We show that accounting for the shadow boundary currents considerably improves the traditional PO analysis of the high-frequency electromagnetic fields scattered from smooth and convex non-metallic obstacles, particularly near the forward scattering direction.

An efficient hybrid scheme has been developed for optimizing register allocation applicable to CISC and RISC processors, which is crucial for maximizing their execution speed. Graph-coloring at the function level is combined with a powerful local register assigner. This assigner uses accurate program flows and access patterns of variables, and optimizes a wider local range, called an extended basic-block (EBB), than other optimizing compilers. The EBB is a set of basic-blocks that constitute a tree-shaped control flow, which is suitable for the large nested branches that frequently appear in embedded system-control programs, such as those for telephone call processing. The coloring at the function level involves only the live-ranges of program variables that span EBBs. The interference graph is therefore very small even for large functions, so it can be constructed quickly. Instead of iterative live-range splitting or spilling, the unallocated live-ranges are optimized by the EBB-based register assigner, so neither load/store insertion nor code motion is needed. This facilitates generating reliable code and debug symbols. The information provided for the EBB-based assigner facilitates the priority-based heuristics, fine-grained interference checking, and deferred coloring, all of which increase the colorability. Using a thread-support package for CHILL as a sample program, performance measurement showed that local variables are successfully located in registers, and the reduction of static cycles is about 20-30%. Further improvements include using double registers and improving debuggability.

We describe several properties of very thin stacks of 10 to 20 intrinsic Josephson junctions fabricated on the surface of Bi2Sr2CaCu2O8+δ single crystals. We show that the Joule heating is significantly reduced in these stacks and that the gap structure is clearly observable in the quasiparticle current-voltage (I-V) characteristics. The I-V curves are characterized by a large subgap conductance and a significant gap suppression due to the injection of quasiparticle current. It is found that the IcRn product of these intrinsic Josephson junction stacks is significantly small compared with that expected from the BCS theory. It is also found that there is a tendency that IcRn decreases with increasing c-axis resistivity. Both Ic and the gap voltage exhibit unsaturated temperature dependence at low temperatures. The behavior presents a sharp contrast to that of Josephson junctions made of conventional superconductors. The characteristics are discussed in relation to the d-wave symmetry of the order parameter.

In order to improve microprocessor performance, we propose to utilize histories of dynamic instruction sequences. A lot of special purpose memories integrated in a processor chip hold the histories. In this paper, we describe the usefulness of using two special purpose memories: Non-Consecutive basic block Buffer (NCB) and Reference Prediction Table (RPT). The NCB improves instruction fetching efficiency in order to relieve control dependences. The RPT predicts data addresses in order to speculate data dependences. From the simulation study, it has been found that the proposed mechanisms improve processor performance by up to 49. 2%.

This paper describes a new architecture-based DSP processor, which consists of n n mesh multiprocessor for digital signal processing. A prototype chip, RCDSP9701 has been designed and implemented using a CMOS 0. 6 µm process. This architecture has better performance compare to the traditional microprocessor solution to Digital Signal Processing. The proposed method poses remarkable flexibility compare to ASIC (Application Specified Integrated Circuits) approach for Digital Signal Processing applications. In addition, the proposed architecture is fault tolerant and suitable for parallel computing applications. In this paper, an implementation into a silicon chip of the new architecture is presented to give a better understanding of our work.

This paper proposes a new approach to recover the sign of local surface curvature of object from three shading images using neural network. The RBF (Radial Basis Function) neural network is used to learn the mapping of three image irradiances to the position on a sphere. Then, the learned neural network maps the image irradiances at the neighbor pixels of the test object taken from three illuminating directions of light sources onto the sphere images taken under the same illuminating condition. Using the property that basic six kinds of surface curvature has the different relative locations of the local five points mapped on the sphere, not only the Gaussian curvature but also the kind of curvature is directly recovered locally from the relation of the locations on the mapped points on the sphere without knowing the values of surface gradient for each point. Further, two step neural networks which combines the forward mapping and its inverse mapping one can be used to get the local confidence estimate for the obtained results. The entire approach is non-parametric, empirical in that no explicit assumptions are made about light source directions or surface reflectance. Results are demonstrated by the experiments for real images.

An efficient algorithm is proposed to identify the active users and extracting their respective timing information in asynchronous direct sequence CDMA (DS-CDMA) communication system over Rayleigh fading channel. The joint identification and timing estimation algorithm is derived by performing discrete Fourier transform (DFT) on the observation vector and exploiting the uniqueness and nullity characteristics of the root-MUSIC test polynomial. The root-MUSIC based algorithm is shown to be asymptotically near-far resistant. Compared to the maximum a posteriori (MAP) or maximum likelihood (ML) based multiuser timing estimator, the complexity is greatly reduced by separating the multi-dimensional optimization problem into several polynomial rooting problems. Moreover, we characterize the dependence of system performance with respect to signature sequence length, number of active users, window size, desired user's signal-to-noise ratio (SNR) and crosscorrelation property of the code structure. The analytical results reveal that under the uncorrelated Rayleigh fading model, the root-MUSIC timing estimator tends to achieve the Cramer-Rao lower bound (CRLB) at interesting signature sequence length and desired user's SNR.

The H-polarized diffraction by a wedge consisting of perfect conductor and lossless dielectric is investigated by employing the dual integral equations. Its physical optics diffraction coefficients are expressed in a finite series of cotangent functions weighted by the Fresnel reflection coefficients. A correction rule is extracted from the difference between the diffraction coefficients of the physical optics field and those of the exact solution to a perfectly conducting wedge. The angular period of the cotangent functions is changed to satisfy the edge condition at the tip of the wedge, and the poles of the cotangent functions are relocated to cancel out the incident field in the artificially complementary region. Numerical results assure that the presented correction is highly effective for reducing the error posed in the physical optics solution.

This paper deals with two different quantitative inversion algorithms for reconstructing the complex permittivity profile of bounded inhomogeneous objects from measured scattered field data. The first algorithm involves an imaging method with single frequency excitation and multiincidence illumination and the second algorithm involves a method with synthetic pulse (multifrequency mode) excitation for objects surrounded by freespace or buried in stratified half-space media. Transmission or reflection imaging protocols are considered depending on aimed applications: microwave imaging in free-space from far-field data for target identification, microwave imaging from near-field data for nondestructive testing (NDT), microwave tomography of buried objects for mine detection and localization, civil engineering and geophysical applications. And Edge-Preserving regularization scheme leading to a significant enhancement in the image reconstructions is also proposed. The methods are illustrated with synthetic and experimental data.

Equivalence of physical optics (PO) and aperture field integration method (AFIM) in the full 360 observation angle is discussed for polyhedron approximate reflectors; the necessary conditions of integration surface in AFIM for the equivalence to PO are presented. In addition to the condition that complete equivalent currents consisting of both geometrical optics (GO) reflected fields from the reflector and direct incident fields from the feed source are used, the integration surface should cap the reflector perfectly and should be in the illuminated region of the GO reflected field. Validity of the conditions is numerically confirmed for a two-dimensional (2-D) strip reflector, 3-D corner reflectors and a 2-D polyhedron approximate reflector.

In this paper we propose a comprehensive approach to physical design based on the constraint paradigm. Bounds on the most critical circuit parasitics are automatically generated to help designers and/or physical design tools meet a set of high-level specifications. The constraint generation engine is based on constrained optimization, where various parasitic effects on interconnect and devices are accounted for and dealt with in different manners according to their statistical behavior and their effect on performance.

Service interaction resolution is an important study subject to realize a network supporting various advanced communication services. This paper proposes service interaction resolution by service node connected with the communication network via the user-network interface. By executing various advanced services on the service node, service interactions can be efficiently resolved without adding new functions to the existing network. In other words, the service node enables a unified execution control of all the services including those for the originating side and those for the terminating side. This prevents the signalling system and the signalling procedure from being expanded to resolve service interactions. Moreover, the interactions between the services initiated at the conversation active state can be resolved by the service node equipped with function of receiving plural types of in-band signals. This avoids functional expansion of the switching systems in the network. In this paper, feasibility of the proposed resolution scheme is proved by showing a structure of the service node and a detailed procedure to resolve interactions on that service node. In the proposed service node, the application part is divided into basic call processing part and service processing part, and the basic call processing part is represented by three kinds of basic call processing state models. The proposed method for resolving service interactions can control services execution with high flexibility by using feature interaction table.

We successfully observed curent-voltage (I-V) curves which showed the behavior of intrinsic Josephson junctions using Tl2Ba2CaCu2Ox (Tl-2212) thin films on MgO substrates by structuring mesas and measuring the electrical transport properties along the c-axis. For a 55 µm2 mesa, a hysteretic I-V curve was observed up to 80 K, which showed that series-connected SIS-type junctions are formed. Compared with the critical current density (Jc) of more than 106 A/cm2 parallel to the ab-plane, an anisotropic Jc of 1.4102 A/cm2 along the c-axis was observed at 4.9 K. By focusing on the I-V curve at lower bias current, the constant voltage jumps measured at the first seven branches were estimated to be 26 mV. The normal resistance (Rnk) of a unit SIS junction was estimated to be 580 Ω by substituting the measured voltage jump in the Ambegaokar and Baratoff relation. Using the calculation for McCumber parameter (βc), the capacitance (Ck) of the unit SIS junction was estimated to be 3.610-10 F/cm2 at 77 K. The IckRnk product was estimated to be 6.4 mV and the cut-off frequency (fc1/2πRnkCk) was calculated to be 3.1 THz at 77 K. The Jc and the hysteresis decreased with an increase in the mesa area, and finally, for a 300300µm2 mesa, a resistively shunted junction (RSI) like curve without hysteresis was observed up to 98 K. A Jc of 5.6101 A/cm2 along the c-axis was observed at 6.4 K. This may be explained by the higher content of conductive grain boundaries for a larger mesa area.

The key concept of Physical Optics (PO), originally developed for a perfectly electric conductor (PEC), consists in that the high frequency fields on the scatterer surface are approximated by those which would exist on the infinite flat surface tangent to the scatterer. The scattered fields at arbitrary observation points are then calculated by integrating these fields on the scatterer. This general concept can be extended to arbitrary impedance surfaces. The asymptotic evaluation of this surface integration in terms of diffraction coefficients gives us the fields in analytical forms. In this paper, uniform PO diffraction coefficients for the impedance surfaces are presented and their high accuracy is verified numerically. These coefficients are providing us with the tool for the mechanism extraction of various high frequency methods such as aperture field integration method and Kirchhoff's method.

A large scale simulation for polymer chains in good solvent is performed. The implementation technique for efficient parallel execution, optimization, and load-balancing are discussed on this practical application. Finally, a simple performance model is proposed.