In learning of feed-forward neural networks, so-called 'training error' is often minimized. This is, however, not related to the generalization capability which is one of the major goals in the learning. It can be interpreted as a substitute for another learning which considers the generalization capability. Admissibility is a concept to discuss whether a learning can be a substitute for another learning. In this paper, we discuss the case where the learning which minimizes a training error is used as a substitute for the projection learning, which considers the generalization capability, in the presence of noise. Moreover, we give a method for choosing a training set which satisfies the admissibility.

We discuss optimal estimation of the current location of a mobile robot by matching an image of the scene taken by the robot with the model of the environment. We first present a theoretical accuracy bound and then give a method that attains that bound, which can be viewed as describing the probability distribution of the current location. Using real images, we demonstrate that our method is superior to the naive least-squares method. We also confirm the theoretical predictions of our theory by applying the bootstrap procedure.

In this letter, a new scheme of designing two-level minimum mean square error quantizer for image coding is proposed. Genetic algorithm is applied to achieve this goal. Comparisons of results with various methods have verified, the proposed method can reach nearly optimal quantization with only less iterations.

Speech signals transmitted over telephone network often suffer from interference due to ambient noise and channel distortion. In this paper, a novel frame-dependent fuzzy channel compensation (FD-FCC) method employing two-stage bias subtraction is proposed to minimize the channel effect. First, through maximum likelihood (ML) estimation over the set of all word models, we choose the word model which is best matched with the input utterance. Then, based upon this word model, a set of mixture biases can be derived by averaging the cepstral differences between the input utterance and the chosen model. In the second stage, instead of using a single bias, a frame-dependent bias is calculated for each input frame to equalize the channel variations in the input utterance. This frame-dependent bias is achieved by the convex combination of those mixture biases which are weighted by a fuzzy membership function. Experimental results show that the channel effect can be effectively canceled even though the additive background noise is involved in a telephone speech recognition system.

We propose a real-time low-rate video compression algorithm using fixed-rate multi-stage hierarchical vector quantization. Vector quantization is suitable for mobile computing, since it demands small computation on decoding. The proposed algorithm enables transmission of 10 QCIF frames per second over a low-rate 29.2 kbps mobile channel. A frame is hierarchically divided by sub-blocks. A frame of images is compressed in a fixed rate at any video activity. For active frames, large sub-blocks for low resolution are mainly transmitted. For inactive frames, smaller sub-blocks for high resolution can be transmitted successively after a motion-compensated frame. We develop a compression system which consists of a host computer and a memory-based processor for the nearest neighbor search on VQ. Our algorithm guarantees real-time decoding on a poor CPU.

This letter examines outline measures of strength against the differential and linear cryptanalysis. These measures are useful to estimate the number of rounds giving an immune iterated cipher. This letter reports that the outline measures of strength are useful to relatively estimate the strength of generalized feistel ciphers.

Connector contact resistance may become unstable if fretting occurs. Such motions result in the formation of insulating oxides on the surface of base metal contacts or organic polymers on contacts made of platinum group metals. These degradations are termed fretting corrosion and frictional polymerization, respectively. Motion may be caused by external vibration or fluctuating temperature. The lower the frequency of movement, the fewer the number of cycles to contact failure. Increasing the contact normal load or reducing the amplitude of movement may stabilize the connection. Tin and palladium and many of their alloys are especially prone to fretting failure. Tin mated to gold is worse than all-tin contacts. Gold and high gold-silver alloys that are softer when mated to palladium stabilize contact resistance since these metals transfer to the palladium during fretting; but flash gold coatings on palladium and palladium nickel offer marginal improvement for the gold often quickly wears out. Dissimilar metal contact pairs show behaviors like that of the metal which predominates on the surface by transfer. Contact lubricants can often prevent fretting failures and may even restore unlubricated failed contacts to satisfactory service.

In 1992 Burmester studied how to adapt the Guillou-Quisquater identification scheme to a proven zero-knowledge proof without significantly increasing the communication complexity and computational overhead. He proposed an almost constant round version of Guillou-Quisquater. Di Crescenzo and Persiano presented a 4-move constant round zero-knowledge interactive proof of membership for the corresponding language. A straightforward adaptation of the ideas of Bellare-Micali-Ostrovsky will also give a constant round protocol. However, these protocols significantly increase the communication and computational complexity of the scheme. In this paper we present constant round variants of the protocols of Guillou-Quisquater and Schnorr with the same (order-wise) communication and computational complexity as the original schemes. Note that in our schemes the probability that a dishonest prover will fool a honest verifier may be exponentially small, while it can only be one over a superpolynomial in Burmester's scheme. Our protocols are perfect zero-knowledge under no cryptographic assumptions.

High-speed and low-power techniques are described for megabit-class size-configurable CMOS SRAM macrocells. To shorten the design turn-around-time, the methodology of abutting nine kinds of leaf cells is employed; two-level via-hole programming and the array-address decoder embedded in each control leaf cell present a divided-memory-array structure. A new squashed-memory-cell architecture using trench isolation and stacked-via-holes is proposed to reduce access times and power dissipation. To shorten the time for writing data, per-bitline architecture is proposed, in which every bitline has a personal writing driver. Also, read-out circuitry using a current-sense-type two-stage sense amplifier is designed. The effect of the non-multiplexed bitline scheme for fast read-out is shown in a simulation result. To reduce the noise from the second- to first-stage amplifier due to a feedback loop, current paths are separated so as not to cause common impedance. To confirm the techniques described in this paper, a 1-Mb SRAM test chip was fabricated with an advanced 0.35-µm CMOS/bulk process. The SRAM has demonstrated 250-MHz operation with a 2.5-V typical power supply. Also, 100-mW power dissipation was obtained at a practical operating frequency of 150-MHz.

The Web is a collection of multimedia documents in the form of HTML pages connected through hyperlinks. Unlike most search engines, which focus on information retrieval based on keywords, WebDB aims at supporting database-like comprehensive query functionalities as well navigation, and document generation functionalities with customizability. To support hypermedia database functionalities, we augment the traditional concepts of tables in relational databases and classes in object-oriented databases with notions of document formats and navigation. We design WQL (Web Query Language) as an HTML document manipulation language. WQL language statements contain two parts: SELECT. . . FROM. . . WHERE clauses for specifying retrieval of data contents from hypermedia databases and CREATE. . . AS. . . clauses for specifying the output HTML format and navigation of the query results. This paper presents the architecture of WebDB and its functionalities. The extension to SQL for hypermedia document manipulation, query, and navigation and implementation on NEC PERCIO OODBMS are described in detail.

We present a receiver structure with joint blind equalization, carrier recovery, and timing recovery. The blind equalizer employs a decomposition transversal filtering technique which can reduce the complexity of convolution to about a half. We analyze the performance surface of the equalizer cost function and show that the global minima correspond to perfect equalization. We also derive proper initial tap settings of the equalizer for convergence to the global minima. We describe the timing recovery and the carrier recovery methods employed. And we describe a startup sequence to bring the receiver into full operation. The adaptation algorithms for equalization, carrier recovery, and timing recovery are relatively independent, resulting in good operational stability of the overall receiver. Some simulation results for cable-modem type of transmission are presented.

This paper proposes two numerical methods to solve the optimal problem of contrast enhancement in the cross-pol and co-pol channels. For the cross-pol channel case, the contrast (power ratio) is expressed in a homogeneous form, which leads the polarimetric contrast optimization to a distinctive eigenvalue problem. For the co-pol channel case, this paper proposes a cross iterative method for optimization, based on the formula used in the matched-pol channel. Both these numerical methods can be proved as convergent algorithms, and they are effective for obtaining the optimum polarization state. Besides, one of the proposed methods is applied to solve the optimal problem of contrast enhancement for the time-independent targets case. To verify the proposed methods, this paper provides two numerical examples. The results of calculation are completely identical with other authors', showing the validity of the proposed methods.

This paper proposes the first provably secure multi-signature schemes under the random oracle model. The security of our schemes can be proven in the sense of concrete security in Ref. [13]. The proposed schemes are efficient if the random oracle is replaced by practical hash functions. The essential techniques in our proof of security are the optimal reduction from breaking the corresponding identification to breaking signatures (ID Reduction Technique), and the hierarchical heavy row lemmas used in the concrete reduction from solving the primitive problem to breaking the identification scheme.

This paper focuses on the problems how to organize and retrieve video data in an effective manner. First we identify several issues to be solved for the problems. Next, we overview our current research results together with a brief survey in the research area of video databases. We especially describe the following research results obtained by the the Japanese Ministry of Education under Grant-in-Aid for Scientific Research on Priority Area: "Advanced Databases" concerned with organization and retrieval of video data: Instance-Based Video Annotation Models, Self-Organization of Video Data, and A Query Model for Fragmentally Indexed Video.

Detecting security flaws is important in order to keep the database secure. A security flaw in object-oriented databases means that a user can infer the result of an unpermitted method only from permitted methods. Although a database management system enforces access control by an authorization, security flaws can occur under the authorization. The main aim of this paper is to show an efficient decision algorithm for detecting a security flaw under a given authorization. This problem is solvable in polynomial time in practical cases by reducing it to the congruence closure problem. This paper also mentions the problem of finding a maximal subset of a given authorization under which no security flaw exists.

This paper presents results of subjective assessment of the media synchronization quality in the virtual-time rendering (VTR) media synchronization algorithm. For the assessment, stored voice and video streams were transmitted as two separate transport streams from a source to a destination on various traffic conditions in an experimental system. At the destination, they were output after synchronization control. We subjectively assessed the quality of media synchronization in a systematic way. This paper examines the effects of the difference between methods of recovery from asynchrony on the media synchronization quality. The paper also clarifies the relationships between the subjective and objective performance measures. Furthermore, it examines the effect of the difference in scene between media streams and that of the modification of the target output time on the media synchronization quality.

We propose and experimentally confirm two approaches to improve the sensitivity of the H-type piezoelectric crystal gyroscope of LiTaO3. One is to adjust the resonant frequencies of the fz mode through additional mass control; the other is to change the driving mode from fx mode to fz mode, while the driving frequency is the resonant frequency of the fx mode. The sensitivity of the unit driving voltage is almost the same, but the threshold driving voltage level may increase more than 1,000 times, because it is far from the mechanical resonance. The high sensitivity of 0.11 pC (deg/sec) was obtained at a driving voltage of 30 Vpp.

Epsilon serializability (ESR) was proposed to relax serializability constraints by allowing transactions to execute with a limited amount of inconsistency (ε-spec). Divergence control algorithms, viewed as extensions of concurrency control algorithms, enable read-only transactions to complete if their inconsistencies do not exceed ε-spec. This paper studies the performance of two-phase locking divergence control (2PLDC) and optimistic divergence control (ODC) algorithms. We develop a central part of the ESR transaction processing system that runs with 2PLDC and ODC. We applied a comprehensive centralized database simulation model to measure the performance. Evaluations are conducted with multi-class workloads where on-line update transactions and long-duration queries progress under various ε-spec. Our results demonstrate that significant performance enhancements are achieved with a non-zero tolerable inconsistency. With sufficient ε-spec and limited system resources, both algorithms result in comparable performance. However, with low resource contention, ODC performs significantly better than 2PLDC. Furthermore, in the range of small ε-spec, the queries committed by ODC have more accurate results than those committed by 2PLDC.

This paper proposes a bit-commitment scheme, BC(), and an efficient statistical zero-knowledge (in short, SZK) protocol in which, for any given multi-variable polynomial, f(X1,,Xt), and any given modulus, n, a prover, P, gives (I1,,It) to a verifier,ν, and can convince ν that P knows (x1,,xt) which satisfies f(x1,,xt) 0 (mod n) and Ii = BC(xi), (i = 1,,t). The proposed protocol is O(|n|) times more efficient than the corresponding previous ones. The (knowledge) soundness of our protocol holds under a computational assumption, the intractability of a modified RSA problem (see Def. 3.2), while the (statistical) zero-knowledgeness of the protocol needs no computational assumption. The protocol can be employed to construct various practical cryptographic protocols, such as fair exchange, untraceable electronic cash and verifiable secret sharing protocols.

This paper proposes two types of acceleration parameters for the Durand-Kerner method and its variant, where the values of parameters are determined at each iteration step. Numerical examples are also shown.