Many network protocols for routing messages have been proposed for mobile computing environments. In this paper, we consider the query processing strategy which operates over these network protocols. To begin with, we introduce five fundamental location update methods based on ideas extracted from the representative network protocols. They are the single broadcast notification (SBN), the double broadcast notification (WBN), the single default notification (SDN), the double default notification (WDN), and the no notification (NN). As a network protocol, each method is strong in performance in some system enrivonment, but weak in others. In practical situations, where various kinds of applications are used for various purposes, however, it is required to use a single method. We therefore propose an adaptive query processing strategy where these five location update methods can be dynamically selected. Moreover, we analyze the performance of this adaptive query processing strategy via the Markov chain. We also use the statistical approach to estimate the traffic of individual hosts. Finally, we show the efficiency of our proposed strategy over a wide area of system environments.

A low voltage dual VT self-timed CMOS logic in which the subthreshold leakage current path is blocked by a large high-VT MOS is proposed. An active signal at each node of the self-timed circuit resets its own voltage to its standby state after 4 inverter delays. This pulsed nature speeds up the signal propagation and enables the synchronous DRAM to adopt a fast pipelining scheme.

In this letter, the absolute exponential stability result of neural networks with asymmetric connection matrices is obtained, which generalizes the existing one about absolute stability of neural networks, by a new proof approach. It is demonstrated that the network time constant is inversely proportional to the global exponential convergence rate of the network trajectories to the unique equilibrium. A numerical simulation example is also given to illustrate the obtained analysis results.

The cell structure of surface discharge ACPDPs with a long gap between the sustaining electrodes achieves high luminous efficiency. However, the long gap cell structure causes high firing voltage and thus makes driving more difficult than with the conventional gap cell structure. The rise in firing voltage in the long gap cell structure could not be explained by Paschen's scaling law. We derived a new governing equation for firing voltage, involving the influence of a non-uniform electric field, to investigate this deviation from Paschen's law. From the calculated results we found that changing the gap length corresponds to the change in the degree of distortion of the electric field between the sustaining electrodes.

This paper compares three cell transfer quality control schemes, namely HPS, DAS and ORS, which integrate a preventive congestion control and a reactive congestion control in ATM switch. Simulation results showed that ORS achieves the largest network utilization, and HPS provides enough large throughput compared with DAS only when many VBR connections are multiplexed.

This paper describes a method to distinguish phase noise and amplitude noise from total oscillator noise in circuit simulation, and derives general relationships between periodic time-varying transfer functions for oscillators and phase and amplitude noises.

Introducing a mathematical model of noise in stereo images, we propose a new criterion for intelligent statistical inference about the scene we are viewing by using the geometric information criterion (geometric AIC). Using synthetic and real-image experiments, we demonstrate that a robot can test whether or not the object is located very far away or the object is a planar surface without using any knowledge about the noise magnitude or any empirically adjustable thresholds.

Recently, the number of users utilizing mobile communication services has increased greatly in many information and communication fields. In the future, the number of mobile communication system users will increase even faster, until the rate of diffusion ultimately reaches that of telephones. The day that each person has his own portable mobile terminal is not so far off. Moreover, the systems will not only be used as telephones but also as mobile computing for multimedia information. Digitalization technologies of mobile communication systems needed to realize such mobile computing will be introduced in this paper.

In this paper, a new trial for the signal processing is proposed along the same line as a previous study on the extended regression analysis based on the Bayes' theorem. This method enables us to estimate a response probability property of complicated systems in an actual case when observation values of the output response are roughly observed due to the quantization mechanism of measuring equipment. More concretely, the main purpose of this research is to find the statistics of the joint probability density function before a level quantization operation which reflects every proper correlation informations between the system input and the output fluctuations. Then, the output probability distribution for another kind of input is predicted by using the estimated regression relationship. Finally, the effectiveness of the proposed method is experimentally confirmed by applying it to the actually observed input-output data of the acoustic system.

The CROMACLEAR color display tube has been developed as a display that offers attractive icon quality and highly legible characters. The color display tube is composed of a striped superfine pitch phosphor screen with slot-type shadow mask. We explain the character legibility by Fourier transform. Moreover, the electron beam shape is improved. As a result, the CROMACLEAR color display tube has achieved higher legibility and lower moire phenomenon. This CROMACLEAR color display tube is already mounted in new monitor series.

We give an explicit formula for the number of n-variable clique function in terms of the parameters based upon the numbers of intersecting antichains of the lower half of the n-cube. We present the numbers of clique functions with up to seven variables through computer evaluation of the parameters.

In the field of speech recognition, many researchers have proposed speech recognition methods using auditory information like acoustic signal or visual information like shape and motion of lips. Auditory information has valid features for speech recognition, but it is difficult to accomplish speech recognition in noisy environment. On the other side, visual information has advantage to accomplish speech recognition in noisy environment, but it is difficult to extract effective features for speech recognition. Thus, in case of using either auditory information or visual information, it is difficult to accomplish speech recognition perfectly. In this paper, we propose a method to fuse auditory information and visual information in order to realize more accurate speech recognition. The proposed method consists of two processes: (1) two probabilities for auditory information and visual information are calculated by HMM, (2) these probabilities are fused by using linear combination. We have performed speech recognition experiments of isolated words, whose auditory information (22.05kHz sampling, 8-bit quantization) and visual information (30-frame/s sampling, 24-bit quantization) are captured with multi-media personal computer, and have confirmed the validity of the proposed method.

In this paper, a systematic method which synthesizes the datapath of Application Specific Instruction Processor (ASIP) is proposed. The behavioral description of application is written in instruction code defined on abstract machine. We introduce register transfer graph (RTG) to represent instructions and synthesis constraint tree to select the combinations of synthesis constraints to explore design space along area and performance axis. The high performance is achieved by scheduling micro-operations of instruction in out-of-order. The practical datapath is synthesized by considering connection geometry as well as the maximum utilization of hardware resources. To reduce connection cost, data transfer paths are minimized by replacing an inefficient data transfer path with its bypass route. The feasibility of the proposed synthesis method is verified with several experimental instruction sequences.

A new compression algorithm for fingerprint images is introduced. A modified wavelet packet scheme which uses a fixed decomposition structure, matched to the statistics of fingerprint images, is used. Based on statistical studies of the subbands, different compression techniques are chosen for different subbands. The decision is based on the effect of each subband on reconstructed image, taking into account the characteristics of the Human Visual System (HVS). A noise shaping bit allocation procedure which considers the HVS, is then used to assign the bit rate among subbands. Using Lattice Vector Quantization (LVQ), a new technique for determining the largest radius of the Lattice and its scaling factor is presented. The design is based on obtaining the smallest possible Expected Total Distortion (ETD) measure, using the given bit budget. At low bit rates, for the coefficients with high-frequency content, we propose the Positive-Negative Mean (PNM) algorithm to improve the resolution of the reconstructed image. Furthermore, for the coefficients with low-frequency content, a lossless predictive compression scheme is developed. The proposed algorithm results in a high compression ratio and a high reconstructed image quality with a low computational load compared to other available algorithms.

This paper describes a design technique of perfect reconstruction (PR) two-channel IIR filter bank. M.J.T. Smith et al., gave two types of PR IIR filter bank systems. One is the system such that the analysis and synthesis filters with nonlinear phase are implemented with all-pass polyphase filters and satisfy the power complementary condition approximately. The other is the system such that all the analysis and synthesis filters have liner phase responses and do not satisfy the power complementary condition. To improve coding performance, we propose a filter bank system such that all the analysis and synthesis filters have linear phase and satisfy the power complementary condition approximately.

This paper presents a generating method of LSP parameter sequences for speech synthesis by rule. In our method, neural networks are schemed to generate LSP parameter sequences of Vowel-Consonant-Vowel (VCV) units. The quality of synthesized speech by concatenation way of VCV units through table-look-up technique can not be improved so much owing to the distortion appearing on VCV units junction. In our method, the neural networks concatenate VCV units step by step with less distortion on VCV units junction, which synthesizes good quality speech.

This paper presents a new method for constructing orthonormal wavelet bases with vanishing moments based on general IIR filters. It is well-known that orthonormal wavelet bases can be generated by paraunitary filter banks. Then, synthesis of orthonormal wavelet bases can be reduced to design of paraunitary filter banks. From the orthonormality and regularity of wavelets, we derive some constraints to IIR filter banks, and investigate relations between the constrained filter coefficients and its zeros and poles. According to these relations, we can apply Remez exchange algorithm in stopband directly, and formulate the design problem in the form of an eigenvalue problem. Therefore, a set of filter coefficients can be easily computed by solving the eigenvalue problem, and the optimal filter coefficients with an equiripple response can be obtained after applying an iteration procedure. The proposed procedure is computationally efficient, and the number of vanishing moments can be arbitrarily specified.

This paper proposes a protocol to support mobile hosts in IPv6 by introducing a new addressing architecture and a new hop-by-hop option. This protocol also allows a mobile host to communicate with another host via a firewall machine which drops packets from untrustworthy hosts. The new addressing scheme is based on the separation of the identifier and the location of a mobile host. This is a straightforward implementation of the basic concept of VIP, a protocol providing seamless mobility in IPv4. The new hop-by-hop option of IPv6 allows a firewall machine to authenticate the source host of the forwarded packet with negligible overhead. The author plans to implement this protocol on several operating systems in the near future.

Overview of Cell Switch Router (CSR) and the CSR prototype system are described. CSR can simultaneously support both connection oriented IP flows and connectionless IP flows. CSR contains cell switch fabric and IP packet switch fabric to achieve high throughput IP forwarding. IP packets are forwarded either through a cut-thru packet transmission, in which packet are forwarded without reassembling IP packet nor IP header processing, or through a conventional hop-by-hop IP packet forwarding. This paper describes and proposes the mechanism to forward the connectionless IP packet flows at the CSR. A CSR prototype system has been developed. The CSR prototype system uses PVC connections to transfer the IP packets. With the CSR prototype system, we can make sure that CSR system can achieve a high throughput, i.e., 2.4 Gbps aggregated throughput. For end-to-end TCP/IP packet transmission, more than 90 Mbps can be achieved and realtime video transmission (30 Mbps video) can be achieved.

In this paper,a protocol-based modeling and simulation method of performance evaluation for heavy traffic and transient LAN is proposed. In the method a node on a LAN is modeled as a set of detailed communication protocol models. By parallel and event driven processing of the models, high accuracy and high time-resolution of evaluation of LAN behaviors can be obtained at multi-layer protocols. The LANs at computer education sites have highly loaded peaks, and it is very hard to design large scale educational LANs. Proposed method can be used to evaluate such cases of heavy traffic and transient LAN.