We are developing a simple three-dimensional (3-D) display method that uses only two transparent images using luminance division displays without any extra equipment. This method can be applied to not only electronic displays but also the printed sheets. The method utilizes a 3-D visual illusion in which two ordinary images with many edges can be perceived as an apparent 3-D image with continuous depth between the two image planes, when two identical images are overlapped from the midpoint of the observer's eyes and their optical-density ratio is changed according to the desired image depths. We can use transparent printed sheets or transparent liquid crystal displays to display two overlapping transparent images using this 3-D display method. Subjective test results show that the perceived depths changed continuously as the optical-density ratio changed. Deviations of the perceived depths from the average for each observer were sufficiently small. The depths perceived by all six observers coincided well.

This paper proposes a channel allocation principle that prevents TCP throughput degradation in multihop transmissions in a mesh network based on the carrier sense multiple access with collision avoidance (CSMA/CA) MAC protocol. We first address the relationship between the network topology of wireless nodes and the TCP throughput degradation based on computer simulations. The channel allocation principle is discussed in terms of resolution into a coloring problem based on throughput degradation. The number of required channels for the proposed channel allocation principle is evaluated and it is shown that two channels are sufficient for more than 96% simulated multihop patterns. The proposed channel allocation principle is extendable to generic mesh networks. We also clarify the number of required channels for mesh networks. The simulation results show that three channels are sufficient for more than 98% patterns in the generic mesh networks when the number of nodes is less than 10.

Broadband fixed wireless access (BFWA) systems with multi-hop mesh topologies have attracted considerable attention as a promising technology for next generation, high quality, high capacity, and high density access infrastructures. The primary advantages of mesh network topologies are an improvement of availability in connectivity between pairs of nodes by means of diversity routes. This paper discusses wireless node architecture that enables the integrated control of route diversity and traffic engineering together with the control of wireless links whose quality and performance could be affected by radio propagation conditions. Taking into account the functional requirements for multi-hop mesh BFWA networks, such as adaptive link configuration with multiple channels, distributed network management, and traffic engineering in mesh networks, the entity called network control unit (NCU) is designed and developed on a common UNIX based server computer. Implemented functions and their performance are demonstrated using the experimental environments with wired networks.

Process-centered software engineering environments (PSEEs) facilitate controlling complicated software processes. Traditional PSEEs are generally centrally controlled, which may result in the following drawbacks: (1) the server may become a bottleneck and (2) when the server is down, processes need to be suspended. To overcome the drawbacks, we developed a decentralized process engine ADPE (agent-based decentralized process engine). ADPE can be embedded in any PSEE to decentralize the PSEE. This paper presents ADPE.

This paper describes continuous speech recognition incorporating the additional complement information, e.g., voice characteristics, speaking styles, linguistic information and noise environment, into HMM-based acoustic modeling. In speech recognition systems, context-dependent HMMs, i.e., triphone, and the tree-based context clustering have commonly been used. Several attempts to utilize not only phonetic contexts, but additional complement information based on context (factor) dependent HMMs have been made in recent years. However, when the additional factors for testing data are unobserved, methods for obtaining factor labels is required before decoding. In this paper, we propose a model integration technique based on general factor dependent HMMs for decoding. The integrated HMMs can be used by a conventional decoder as standard triphone HMMs with Gaussian mixture densities. Moreover, by using the results of context clustering, the proposed method can determine an optimal number of mixture components for each state dependently of the degree of influence from additional factors. Phoneme recognition experiments using voice characteristic labels show significant improvements with a small number of model parameters, and a 19.3% error reduction was obtained in noise environment experiments.

In this paper, a Web-based management system for the building network is described. We developed a multi-protocol converter based on SoC and embedded Linux. It requires an appropriate operating system for handling protocols and an advanced development environment very similar to embedded linux. The multi-protocol converter integrates control networks of RS-485 and LonWorks devices to BAS through TCP/IP protocol or a client with Java applet. The system consists of three-tier architecture, such as BAS or clients, a multi-protocol converter, and control devices. In order to compare the feasibility of system architecture, it was applied to a small BAS system. By using UML, we modeled a Web-based control system with a unified TCP/IP socket communication and the system architecture. The developed system includes the inverter motor control system with modbus protocol for the RS485 network. The experiment results show that the multi-protocol converter using embedded Linux is a flexible and effective way to build a Web-based monitoring and control system.

Communications in locally structured wireless networks, such as ad hoc networks, will play an important role for network services and applications in the ubiquitous networking environments of the future. Most of the time, however, mobile networks are used in much the same way as fixed networks: most of the time, mobile terminals merely access information which is stored in the backbone network. Applications based on the local exchange of information gathered or generated by mobile terminals will open up many novel possibilities. A new online storage system named CAOSS facilitates such exchange and constitutes a building block for various new applications. CAOSS is a server-less system that provides high availability of data in mobile and wireless network environments. We describe CAOSS and its application in a mobile video-information-sharing system named GT. Thanks to the good performance of CAOSS, the GT system gives users a convenient and easy way to share and accumulate video data in a wireless environment. We confirm that CAOSS has strong enough performance to deal with large volumes of video data.

The ring Fp + uFp + + uk-1Fp may be of interest in coding theory, which have already been used in the construction of optimal frequency-hopping sequence. In this work, cyclic codes over Fp + uFp + + uk-1Fp which is an open problem posed in [1] are considered. Namely, the structure of cyclic code over Fp + uFp + + uk-1Fp and that of their duals are derived.

We propose a novel approach based on wavelet decomposition for progressive full spectral rendering. In the fourth progressive stage, our method renders an image that is 95% similar to the final non-progressive approach but requires less than 70% of the execution time. The quality of the rendered image is visually plausible that is indistinguishable from that of the non-progressive method. Our approach is graceful, efficient, progressive, and flexible for full spectral rendering.

We propose a new diversity scheme for orthogonal frequency division multiplexing/multi-input multi-output (OFDM/MIMO) systems. The proposed scheme, named turbo layered space-frequency coded OFDM (TLSFC-OFDM), exploits the turbo principle with space hopping (SH). The TLSFC-OFDM system with SH provides a spatial coding so that we can obtain the transmit diversity. We also introduce a successive interference cancellation (SIC) algorithm that requires no ordering and fewer iterations to converge. As a result, this scheme reduces computational complexity. Computer simulation results show that the unordered SIC-based TLSFC-OFDM system outperforms the OFDM/H-BLAST system. It is also shown that the proposed system can operate even with fewer receive antennas than transmit antennas.

Process-centered software engineering environments (PSEEs) facilitate controlling software processes. Many issues related to PSEEs such as process evolution support have been addressed. We identify an unsolved issue, which is preventing information leakage when the process is being enacted. We developed a model called PsACL for the prevention. This paper proposes PsACL, which offers the following features: (a) controlling both read and write access of software products, (b) preventing indirect information leakage, (c) managing role associations, (d) managing role hierarchies, (e) enforcing static and simple dynamic separation-of-duty constraints, (f) allowing declassification of products, and (g) allowing access control information exchange among software processes.

This paper proposes a new robust adaptive processing algorithm that is based on the extended least squares (ELS) method with running spectrum filtering (RSF). By utilizing the different characteristics of running spectra between speech signals and noise signals, RSF can retain speech characteristics while noise is effectively reduced. Then, by using ELS, autoregressive moving average (ARMA) parameters can be estimated accurately. In experiments on real speech contaminated by white Gaussian noise and factory noise, we found that the method we propose offered spectrum estimates that were robust against additive noise.

The paper reports a compact and high performance dual-band bandpass filter (BPF) using two types of dual-mode resonators. The dual mode cross shaped resonator and the three dual mode ring resonators in the designed dual-band BPF are excited to control the first and second passband, respectively. It is shown that the designed and fabricated dual-band BPF has narrow bandwidths and very sharp attenuation rate due to the existence of the transmission zeros. The frequency response of the designed dual-band BPF shows good agreement between the simulations and experiments.

Fingerprinting is a technique to add identifying marks to each copy of digital contents in order to enhance traceability to a distribution system. Collusion attacks, in which the attackers collect two or more fingerprinted copies and try to generate an untraceable copy, are considered to be a threat for the fingerprinting system. With the aim of enhancing collusion security to the fingerprinting system, several collusion secure codes, such as c-frameproof code, c-secure frameproof code and c-identifiable parent property code, have been proposed. Here, c indicates the maximum number of colluding users. However, a practical construction of the above codes is still an issue because of the tight restrictions originated from their combinatorial properties. In this paper, we introduce an evaluation of frameproof, secure frameproof, and identifiable parent property by the probability that a code has the required property. Then, we focus on random codes. For frameproof and secure frameproof properties, we estimate the average probability that random codes have the required property where the probability is taken over the random construction of codes and random construction of coalitions. For the estimation, we assume the uniform distribution of symbols of random codes and the symbols that the coalitions hold. Therefore, we clarify the adequacy of the assumptions by comparison with numerical results. The estimates and numerical results resemble, which implies the adequacy of the assumption at least in the range of the experiment.

For fixed initial and destination states (i.e., markings), M0 and Md, there exist generally infinite firing count vectors in a Petri net. In this letter, it is shown that all fundamental particular solutions as well as all minimal T-invariants w.r.t. firing count vectors are needed to express an arbitrary firing count vector for the fixed M0 and Md. An algorithm for finding a special firing count vector which is expressed by using the only one specified fundamental particular solution is also given.

The investigation presents a low cost and low insertion loss X-band dual mode bandpass filter (BPF) based on inexpensive commercial FR4 substrate. The proposed filter at a central frequency f0 of 11.3 GHz has high filter performance filter with a fractional bandwidth of 14%, the insertion loss of -2.7 dB, and two transmission zeros. The designed procedures are presented in this letter and the fabricated filter verifies the proposed designed concept.

This letter presents an image rectification scheme that can be used by any image watermarking algorithms to provide robustness against rotation, scaling and translation (RST) transformations.

In this letter, we propose a fast modular reduction method over Euclidean rings, which is a generalization of Barrett's reduction algorithm over the ring of integers. As an application, we construct new universal hash function families whose operations are modular arithmetic over a Euclidean ring, which can be any of three rings, the ring of integers, the ring of Gauss integers and the ring of Eisenstein integers. The implementation of these families is efficient by using our method.

In this letter, a method to construct good binary and quaternary error correcting codes, called complex Hadamard codes, based on a complex Hadamard matrix is presented. The related properties of the codes are analyzed. In addition, through the operation in Z4 domain, a new simplex soft-decision decoding algorithm for the complex Hadamard codes is also proposed.

We propose efficient secret sharing schemes realizing general access structures. Our proposed schemes are perfect secret sharing schemes and include Shamir's (k, n)-threshold schemes as a special case. Furthermore, we show that a verifiable secret sharing scheme for general access structures is realized by one of the proposed schemes.