This paper describes IDDQ testability for bridging faults in a variety of flip-flops. The flip-flop is a basic element of the sequential circuit and there are various structures even for the same type. In this paper, we use five kinds of master-slave D-type flip-flops as the circuit under test. Target faults are two-line resistive bridging faults extracted from a circuit layout. A flip-flop with a deliberately introduced bridging fault is simulated by the SPICE simulator. Simulation results show that IDDQ testing cannot detect faults existing at specific points in some flip-flops, and this problem depends on the flip-flop structure. However, IDDQ testing has high fault coverage ( 98%) compared with traditional logic testing. We also examine performances of fully IDDQ testable flip-flops.

The Finite-Difference Time-Domain (FDTD) method is applied to the analysis of electromagnetic fields in a reverberation chamber. The chamber is used for radiated susceptibility/immunity measurement of electromagnetic compatibility (EMC) test and measurement of the radiated power of radio transmitters. The analytical results defined the distribution of the electric field in the reverberation chamber and clarified the effect on field uniformity of the size of the chamber and the number, size, and position of stirrers.

We discuss the security of the improved knapsack cryptosystem that Kobayashi and Kimura have proposed. Two attacking methods for their cryptosystem are proposed; one is the method for obtaining secret keys from public keys by using the continued fraction, and the other is for decrypting the ciphertext without knowing secret keys. We show that their cryptosystem is not secure against these attacks.

We investigate the basic properties of focused electron beam (FEB)-damaged Josephson junctions on silicon (Si) substrates for high-frequency device applications. YBa2Cu3O7-y (YBCO) Josephson junction arrays were also fabricated by FEB irradiation to confirm the junction uniformity and to investigate their applicability. The junctions exhibit resistively shunted junction (RSJ)-like current-voltage (I-V) curves and the microwave-induced Shapiro steps for all operation temperatures. Two-junction arrays show single-junction-like behavior with the Shapiro steps in an array up to 2 mV. Microwave-induced Shapiro steps correspond to the double voltages Vn=2nVJ, where VJ=f0h/2e in two-junction arrays. The microwave power dependence of I-V curves shows the steps corresponding to the RSJ model.

The small planar packaging (SPP) system described here can be combined with card-on-board (COB) packaging in high-speed asynchronous transfer mode (ATM) switching systems with throughput of over 40-Gb/s. The SPP system provides high I/O pin count density, high packaging density and high cooling capability. Prototype SPP system with air flow control structure for switching MCMs is constructed. Each MCM contained a 35 array of low thermal resistance butt-lead pin-grid-array on a glass ceramic substrate measuring 100170 mm with a plate fin heat-sink. This allows a power dissipation of more than 125 W per MCM, and 300 W per printed circuit board (PCB). Obtained board level heat flux density of the SPP system is 0. 37 W/cm2, which is six times that of conventional COB packaging. The SPP system combined with the COB packaging provides a small system foot-print and compact hardware for high-speed, large capacity ATM switching systems. This high-performance air cooling technology will be especially useful for future broadband ISDN high-speed switching systems.

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.

Many object-oriented database systems have used the notion of implicit authorization to avoid the overhead caused by explicitly storing all authorizations for each object. In implicit authorization, it is very important to detect efficiently conflicts between existing authorizations and new authorizations to be added. In this article we propose a conflict detection mechanism in the OODBMSs using implicit authorization with the notion of intention type authorization. When we grant an authorization on a node n in the database granularity hierarchy, the existing method is inefficient in determining the conflicts since it needs to examine all authorizations on the descendants of the node n. In contrast, our mechanism has the advantage of detecting the conflicts at the node n where an explicit authorization is to be granted without examining any authorizations below the node n. Thus, the proposed mechanism can detect a conflict with the average time complexity of O(d), which is smaller than O(md) of existing methods, where m is the number of children nodes at an arbitrary level and d is the difference of levels between the node with an existing explicit authorization and the higher node where an explicit authorization is to be granted. We also show that the additional storage overhead of storing all authorizations is negligible when compared with the total number of all explicit authorizations.

This paper introduces a probabilistic rebound automaton (pra), and investigates its accepting power and closure property. We show that (1) the class of languages recognized by pra's with error probability less than 1/2, PRA, is incomparable with the class of context-free languages, (2) there is a language accepted by a two-way nondeterministic one counter automaton, but not in PRA, and (3) there is a language accepted by a deterministic one-marker rebound automaton, but not in PRA. We also show that PRA is not closed under concatenation and Kleene + .

This paper addresses the problem of determining the 3-D pose of a curved rigid object from a single 2-D image. The surface of the object are assumed to be modeled with several patches, each of which be expressed by an implicit polynomial. Moreover, the sensed data are assumed to be the coordinates of those points that are on the image contours. Based on the idea of contour matching, the algorithm proposed computes the parameters defining the pose of the object, and achieves the segmentation of the sensed data and the recognition of the object.

In order to lessen overflow or underflow problem in numerical computation, several new floating-point arithmetics have been proposed. The significant advantage of these new arithmetics is that a number can be represented in a wider range since the fields of exponent and mantissa are changed depending on the magnitude of number. The main issues of these arithmetics are how to find the boundary between exponent and mantissa as well as to convert the formats between new floating-point arithmetic and fixed-point arithmetic quickly. In this paper, a CAM-based array converter based on the Universal Representation of Real number (URR) floating-point arithmetic is described. Using match retrieval device CAM, the detection of the boundary can be accomplished faster than conventional circuits. Arranging the basic cells into iterative array structure, the fast separation/connection operation is achieved. The speed, area and power consumption of the converter is estimated.

For the realization of the very high-speed data transmission over wide area network, the HIPPI-ATM conversion for connecting two remote HIPPI end systems is specified by ANSI. Since the credit scheme is adopted for the flow control on the ATM part in the specification, the propagation delay influences the remarkable transfer throughput degradation with the longer distance between end systems. In this paper, two priority types of HIPPI bursts are proposed, which include the flag indicating the priority, high priority or low priority. We propose the hybrid scheme that the credit scheme is adopted only for sending the high priority HIPPI bursts and the source can send low priority HIPPI bursts without reserving buffers in the receiver. In order to confirm the effectiveness of the proposed scheme, we show the characteristics of transfer performance and low priority bursts loss ratio v. s. transmission distance by simulation. Furthermore, we introduce the implemental example of the proposed scheme in the MPEG video transmission application, and show it's good performance.

An innovative small planar packaging(SPP)system is described that can be combined with card-on-board(COB)packaging in high-speed asynchronous transfer mode switching systems with throughput of over 40-Gb/s. The SPP system provides high I/O pin count density and high packaging density, combining the advantages of both planar packaging used in computer systems and COB packaging used in telecommunication systems. Using a newly developed quasi-coaxial zero-insertion-force connector, point-to-point 311 Mb/s of 8-bit parallel signal transmission is achieved in an arbitrary location on the SPP systems shelf. Also about 5400 I/O connections in the region of the planar packaging system are made, thus the SPP system effectively eliminates the I/O pin count limitation. Furthermore, the heat flux management capability of the SPP system is five times higher than of conventional COB packaging because of its air flow control structure. An SPP system can easily enlarge the switch throughput and it will be useful for future high-speed, high-throughput ATM switching systems.

In general, the performance of partial response maximum-likelihood (PRML) system is degraded by nonlinear distortion and high frequency noise in high-density digital magnetic recording. Conventional PRML system for single-track recording improves the performance when high order PRML systems and high rate codes are adopted. But, in general it is difficult to realize LSI circuits for high order PRML system and high rate code. In this paper, a trellis coded class four partial response maximum-likelihood (TC-PR4ML) system for high density two-track digital magnetic recording is proposed. Our two-track recording method can increase the coding rate over 1, which contributes to a decrease in both degradation effects from partial erasure, one of nonlinear distortions, and high frequency noise in high density recording. The error rate performance of the proposed system is obtained by computer simulation taking account of the partial erasure and it is compared with that of a conventional NRZ coded class four partial response maximum-likelihood (NRZ-PR4ML) system. The results show that the proposed system is hardly affected by partial erasure and keeps good performance in high density recording.

The complex conductivities of high Tc superconducting YBa2Cu3Ox thin films have been studied using the coplanar waveguide resonator technique. In order to evaluate the magnetic penetration depth precisely, we measured the temperature dependence of the resonant frequency and compared it with the numerical results self-consistently. The observed temperature dependence of the complex conductivities is shown to be able to distinguish the effects of the weaklink from the intrinsic property of the grain of an epitaxial thin film and demonstrate the weakly coupled grain model of YBa2Cu3Ox thin films.

We present a throughput analysis of a multi-address call extraction server in F-NET. The extraction server splits a multi-address call into individual calls. Since the actual operation mechanisms of the server are complicated, it is difficult to directly apply the standard Markov chain technique. Restricting ourselves to the case where the server is offered by a saturated input process, we propose a simple probabilistic method to investigate the departure process of the server and its asymptotic behavior. Numerical examples evaluated by the method are compared with simulations, which demonstrate the accuracy of our modeling approach.

Large-area high-temperature superconducting films and damage-free processing techniques have been developed to fabricate low insertion loss and sharp skirt filters for mobile telecommunication. An off-axis-type dc sputtering method was employed to deposit Y-Ba-Cu-O films on both sides of the substrate. The surface resistance of the films was about 0. 35 mΩ(at 70 K and 10 GHz). An 11-pole bandpass receiving filter for the IS-95 telecommunication system was designed and fabricated using 60 mm 50 mm YBCO films on a 0. 5-mm-thick MgO substrate. The passband insertion loss at 70 K was about 0. 1 dB with 0. 1 dB ripple. The third-order intercept point of the filter was 49. 5 dBm. We have assembled the filter and a low-noise amplifier in a dewar with a cryocooler. Ultralow-noise performance (noise figure: 0. 5 dB at 70 K) was presented by the cryogenic filter subsystem.

In this paper, we present a method for evaluating the minimum free Chernov distance of trellis-codes for a discrete memoryless channels (DMC). In order to design an efficient trellis-code for the DMC, we need to evaluate the minimum free Chernov distance of the target code. However, the lack of the additive property of the Chernov distance prevents a conventional branch-and-bound search for evaluating the minimum distance. To overcome the difficulty, we present a lower bound on the Chernov distance with an additive property. The lower bound plays a key role in the minimum distance evaluation algorithm presented here. By using the proposed algorithm, we have derived the minimum free Chernov distance of some binary linear convolutional codes over Z-channel.

We have studied an in situ edge preparation process and the effect of a substrate rotation during the edge preparation in order to improve the uniformity and electrical characteristics of high-Tc edge-type Josephson junctions. The improved YBa2Cu3Ox/PrBa2Cu3Ox/YBa2Cu3Ox edge junctions showed small 1σ-critical current spreads as low as 10% for 12 junctions. We have confirmed that the spreads do not increase significantly by adding groundplane over the junctions. In this paper, we will describe these processes developed for the fabrication of high-Tc superconducting integrated circuits.

The stability of slotted ALOHA systems with various types of capture phenomena and multiple packet reception capability is discussed in conjunction with the cusp catastrophe. The slotted ALOHA systems considered are classified into; 1) single packet reception with geometric capture, 2) independent multiple packet reception with geometric capture, 3) single packet reception with M-out-of-N capture (M N), 4) multiple packet reception with M-out-of-N capture, and 5) single packet reception with perfect capture. First, general expressions for the cusp points and the bifurcation sets are derived. Then, we present explicit formula for the stability of slotted ALOHA systems for the five types of capture and multi-packet reception capability and demonstrate how the bistable behavior is mitigated due to capture effect and multi-packet reception capability.

In this paper we present improved techniques for transmitting M-PSK signals in mobile radio environments. Conventionally an optimal linear combination of the observable fading at the pilot symbols has been used as estimations of all other fading. Recently, an improved technique was proposed by the authors which employs not only the pilot symbols but also the previously estimated fading values on data symbols to extract more information on fading channels. In this paper we present new methods by further improving the above method invented by the authors. The present methods utilize, instead of the estimated fading values on data symbols, the demodulator output normalized by the decided (decoded) data symbols to estimate the fading values in the current frame. We also show by computer simulations for BPSK system that the proposed estimation methods provide better performance than those of the conventional methods.