Interoperability between different systems is becoming a more important issue for open distributed systems. In this paper, we investigate what kind of framework we need for constructing open distributed systems. Firstly, we enumerate the features and functions which the framework should have. We then evaluate a proposed multi-agent framework, Bee-gent, by using a typical example of open distributed systems. Lastly, we show clearly what is required for such a framework.

We report, in this paper, on a combined process of photo-oxidation and PECVD using TEOS and O2 gases to produce an SiO2 gate insulator for poly-Si TFTs. Light of 172 nm-wavelength from a Xe excimer lamp generates active oxygen radicals efficiently and selectively without producing ozone. These oxygen radicals efficiently oxidize silicon. In contrast to plasma oxidation, photo-oxidation offers the ability to produce gate oxides without ion bombardment. Oxide-silicon interfaces with interface trap densities of 2-3 1010 cm-2 eV-1 were obtained by photo-oxidation at 200-300. A stack structure was produced using 4.3-nm-thick photo-oxide topped with a 40-nm-thick PECVD oxide film deposited at 300. This stack structure without annealing exhibited excellent interface behavior and the same J-E characteristics as a 100-nm-thick PECVD film annealed at 600.

We describe in this paper our experience of developing a large-scale, highly distributed multi-agent system using wireless-networked sensors. We provide solutions to the problems of localization (position estimation) and dynamic, real-time mobile object tracking, which we call PET problems for short, using wireless sensor networks. We propose system architectures and a set of distributed algorithms for organizing and scheduling cooperative computation in distributed environments, as well as distributed algorithms for localization and real-time object tracking. Based on these distributed algorithms, we develop and implement a hardware system and software simulator for the PET problems. Finally, we present some experimental results on distance measurement accuracy using radio signal strengths of the wireless sensors and discuss future work.

Adaptive prediction iterative channel estimation is presented for combined antenna diversity and coherent rake reception of direct sequence spread spectrum (DSSS) signals. Its first stage uses pilot-aided adaptive prediction channel estimation, while the succeeding iteration stages use decision feedback and moving average filtering for channel re-estimation. The bit error rate (BER) performance of DSSS signal computer simulations evaluate transmission in a frequency selective Rayleigh fading channel. It is found that the adaptive prediction iterative channel estimation is superior to the non adaptive iterative channel estimation using the conventional weighted multi-slot averaging (WMSA) filtering at the first iteration stage, particularly in a fast fading channel.

This paper presents the basic characteristics of a forced resonant type EMI dipole antenna for frequencies below 80 MHz in which two reactance elements are used for the impedance matching at the feed point. The input impedance of the short dipole less than half-wavelength is controlled by the properly determined loading position and the value of loading reactance. The integral equation for unknown current distribution is solved by Galerkin's method of moments with piecewise sinusoidal functions. The numerical results show that the small-sized EMI dipole antenna with lower antenna factors for frequencies below 80 MHz can be realized by the reactance loading. In case the proposed center driven small-sized EMI dipole antenna with 0.3λ length is loaded c=0.133λ from the center, the input impedance is matched at feed line with 50 Ω, and hence the antenna has lower factors in the frequency range of 30 to 80 MHz. Also the normalized site attenuation characteristics are presented for the forced resonant type EMI dipole antenna.

A new iterative algorithm based on the Gauss-Seidel iteration method is proposed to solve the matrix equation in the MoM analysis of the array antennas. In the new algorithm, the impedance matrix is decomposed into a number of sub matrices, which describe the self and mutual impedance between the groups of the array, and each sub matrix is regarded as a basic iteration unit rather than the matrix element in the ordinary Gauss-Seidel iteration method. It is found that the convergence condition of the ordinary Gauss-Seidel iteration scheme is very strict for the practical use, while the convergence characteristics of the present algorithm are greatly improved. The new algorithm can be applied to the sub domain MoM with a fast convergence if the grouping technique is properly used. The computation time for solving the matrix equation is reduced to be almost proportional to the square of the number of the array elements. The present method is effective in MoM analysis of solving large-scale array antennas.

Performance evaluation criterion is one of the most important issues for design of network traffic control mechanisms and algorithms. Due to multiple performance objectives of network traffic control, performance evaluation criteria must include multiple performance metrics executed simultaneously, which is called integrated performance evaluation criteria. In this paper, we analyze various performance metrics of network traffic control, and propose three integrated performance evaluation criteria. One is the improvement on original Power formula; our new Power formula is based on the multi-service-class model. Another is about the fairness of user's QoS (Quality of Service) requirements (queuing delay and loss rate); especially the detailed discussion on Proportional Fairness Principle is given. And the third one is the integration of preceding two, in which the throughput, queuing delay, packet loss rate, and the fairness are considered simultaneously.

Fiber-optic access system integration is the key to providing various kinds of services to home users. The combination of ATM- and SCM-PON systems is essential to support a high-speed data service and analog/digital video distribution services. From this viewpoint, a frequency-division- multiplexing technique for digital baseband and subcarrier multiplexed signals is required to achieve system integration. However, system integration for these two access systems has not been fully investigated yet. The SCM-PON system, which uses a super wideband optical FM converter, will enable these two different kinds of access system (ATM and SCM) to be integrated. In this paper, we describe experimentally obtained results for frequency- division-multiplexed signals consisting of digital baseband and subcarrier- multiplexed signals. The experiments were carried out using a 622-Mb/s baseband signal and an FM-converted signal containing AM and 64QAM signals. The experimental results reveal that the inter-channel interference between the digital baseband and FM-converted signals restricts the number of subcarriers for AM and 64QAM. With an intermediate frequency of 3 GHz for the FM-converted signal, an FDM signal consisting of 622-Mb/s baseband, 30 carriers of 64QAM, and 11 carriers of AM was successfully transmitted.

Intelligent transport systems (ITS) are promising systems to give excellent solutions for many problems that we face in transport today. Not only road-to-vehicle communications but also inter-vehicle communications in ITS are expected to become popular in the future. On the other hand, an intra-vehicle communication network should be supported by multimedia information according to the explosive expansion of the Internet use and the like. An inexpensive transmission medium and transceiver becomes indispensable in such in-vehicle local area network (LAN) for multimedia information as these must handle full-motion video signals, without any electromagnetic interference. We have proposed on-board network architecture based on optical P1394b to realize effective inter-vehicle communications and enable all equipment which freely add and remove to the intra-vehicle network. And according to the proposed architecture, we have developed a 500-Mbit/s low-cost optical transceiver for the intra- and inter-vehicle communication network using a commercially available plastic clad fiber. An LD for the compact disk drive and a large area photodiode were adopted as low-cost and high-speed optical devices, and a logic direct driving type simple circuit having temperature compensation function was developed. Simple assembly technologies such as plastic molding and optical element press-fitting were also developed for mounting to reduce assembly cost. The total cost of the fabricated optical transceiver can be reduced less than 2/3, comparing with that of conventional one. We have performed transmission experiments and vibration tests using our optical transceivers that are mounted in on-board elements and connected to the on-board network, and have confirmed these stable operations. Experimental results show our proposed architecture and fabricated optical transceiver can play a key role in the intra- and inter-vehicle communication network.

We have successfully produced laterally-grown grains on large (300 350 mm) glass substrates by means of a newly developed excimer laser crystallization system that features a high-precision mask stage and an auto-focusing system. The original grains were produced with a steep beam edge and their lateral growth was extended by repeated irradiation and translation. TFTs fabricated with these extended grains were found to have mobilities that remained almost constant at 270 cm2/Vs (n-ch. TFTs) and 230 cm2/Vs (p-ch. TFTs) over a wide range of laser fluence (400-600 mJ/cm2).

The fields in the junctions between straight and curved rectangular waveguides are analyzed by using the method of separating variables. This method was succeeded because the authors developed the method of numerical calculation of the cylindrical functions of complex order. As a result, we numerically calculate the reflection and transmission coefficients in the junctions in various situations, and we compare these results with the results by the perturbation method and with the results by Jui-Pang et al.

We developed a new method to improve the efficiency of the PDP (plasma display panel) by the use of a novel protecting film or Gd doped MgO film. In the cells of the PDP, the VUV (vacuum ultraviolet ray) is generated by Xe discharge. The VUV is simply absorbed by the protecting film or MgO film. Therefore, normally the absorbed VUV doesn't contribute to the light conversion efficiency. However, the novel protecting film or MgO:Gd film radiates the ultraviolet ray of which 317 nm wavelength, by the irradiation of the shorter wavelength VUV, and it excites the blue phosphor. Consequently the efficiency of blue emission is improved.

To investigate the feasibility of a compact FEA image sensor with a large number of pixels, a 128 96 pixel FEA image sensor with a 4-µm-thick HARP target was fabricated and tested for the first time. The experimental results showed that the prototype could stably operate as a highly sensitive image sensor having both sufficient resolution corresponding to the number of pixels and a wide dynamic range, which demonstrated its potential as a next-generation image sensor.

In transmitter diversity, the received signal is the superposition of signals transmitted from transmitter antennas. Thus, the separation of channel characteristics corresponding to each transmitter antennas from these signals is very important. The conventional channel estimation scheme tends to show higher computational complexity for larger channel delay profile. To reduce this computational complexity, significant-tap-catching method has been proposed. However, there is still a burden of complexity for data transmission mode. Reference [14] has shown how to reduce the complexity for data transmission mode in system with constant modulus modulation. However, this method can't reduce the complexity required for multi-level signals such as QAM. In this paper, we propose an efficient channel estimation scheme for OFDM systems with transmitter diversity using space-time trellis coding. The computational complexity of the proposed scheme is independent of channel delay profile. Also, compared with the conventional scheme, the complexity of the proposed scheme is not related to modulation methods including multi-level signals such as QAM. The performance of the proposed scheme is evaluated by computer simulation in various multipath fading environments.

This paper describes the behavior of voids that were formed due to electromigration and diffusion in the interconnections of gold during a DC bias tests of GaAs ICs to current densities in the interconnections of 0.67 106 A/cm2 to 1.27 106 A/cm2 in the high temperature range of 230 to 260. We have found that the voids were formed at the centers in the cross sections of the interconnections and that gold is left around the voids, which means current still flows after the void formation. We have carefully observed the movement of the anode and cathode side edge of the voids during the tests and found that edges moved toward the cathode, in the direction opposite to the electron flow. This direction is constant. Also, the voids are extended, which means that the velocity of the cathode side edge is greater than that of the anode side edge. The velocity of the edges almost proportionally increased with the current density. The constant edge movement direction and the velocity of the edge dependence on the current density suggest that one of the causes of the edge movement is electromigration. The velocity of the edge depends on the distance between the anode side edge of the void and the through hole. The velocity increases in accordance with a decrease in the distance. This means that one of the causes of the edge movement is the diffusion of gold atoms by a concentration and pressure gradient. The GaAs IC failed at almost the same time as the voids appeared. It is important for reliability to prevent the formation of voids caused by electromigration and diffusion.

Model checking is a technique that can make a verification for finite state systems absolutely automatic. We propose a method for automatic verification of fault-tolerant concurrent systems using this technique. Unlike other related work, which is tailored to specific systems, we are aimed at providing an approach that can be used to verify various kinds of systems against fault tolerance. The main obstacle in model checking is state explosion. To avoid the problem, we design this method so that it can use a symbolic model checking tool called SMV (Symbolic Model Verifier). Symbolic model checking can overcome the problem by expressing the state space and the transition relation by Boolean functions. Assuming that a system to be verified is modeled as a guarded command program, we design a modeling language and propose a translation method from the modeling language to the input language of SMV. We show the results of applying the proposed method to various examples to demonstrate the feasibility of the method.

Finite-state vector quantization (FSVQ) is a well-known block encoding technique for digital image compression at low bit rate application. In this paper, an improved feature map finite-state vector quantization (IFMFSVQ) algorithm using three-sided side-match prediction is proposed for image coding. The new three-sided side-match improves the prediction quality of input blocks. Precoded blocks are used to alleviate the error propagation of side-match. An edge threshold is used to classify the blocks into nonedge or edge blocks to improve bit rate performance. Furthermore, an adaptive method is also obtained. Experimental results reveal that the new IFMFSVQ reduces bit rate significantly maintaining the same subjective quality, as compared to the basic FMFSVQ method.

In this letter, our proposed approach exploits the use of original and simplest Cellular Neural Network (CNN) for 2D Doubly Complementary (DC) Infinite Impulse Response (IIR) filter banks design. The properties of feedback and feedforward templates are studied for this purpose. Through some examples it is shown how generalizations of these templates can be used for DC IIR filter banks design. We modify Lagrangian function which is used for optimizing a low-pass filter design considering the constraint for stability of CNN. The brief conclusions with design examples that illustrate the proposed method and an image enhancement and restoration applications of designed filter banks are presented.

This letter presents a new approximation algorithm suitable for Taylor series expansion. The algorithm can effectively reduce the approximation error by using only a small number of terms in series expansion. The proposed algorithm can be more easily implemented and has better performance than the conventional Euler approximation algorithm. Also, the approximation performance of the proposed algorithm is compared with direct approaches, such as least-squares and Chebyshev approximation algorithm to show the relative advantages of the proposed algorithm. This letter also presents an application example of the proposed approximation algorithm in carrier recovery of OFDM (Orthogonal Frequency Division Multiplexing) modem.

The reception quality of terrestrial digital broadcasting when the directional pattern of a mobile terminal is controlled has been experimentally evaluated using test signal. It was found that the reception probabilities with a controlled directional pattern were significantly improved over the case when an omni-directional antenna was used.