Recently, information display equipment such as a navigation system has often come to be installed in a vehicle, and a variety of useful information has been offered to the driver by voice and images while driving. The necessity of improving safety when the driver receives such information has come to be stressed. As one of the means of solving this problem, we can develop a system that presents the driving and road conditions information such as a lane changing car to the driver by using a warning sound. The purpose of our study is to clarify the effectiveness of an auditory display that uses spatial sounds on such a system. An experiment for measuring the driver's reaction time and eye movements to LED lighting during actual driving has been carried out to investigate whether the spatial sound can quicken the driver's operation and decrease human error. We evaluated the effectiveness by two measures, average reaction time and the number of largely delayed reactions. We considered that the average reaction time corresponds to the quickness of the driver's operation, and the number of largely delayed reactions corresponds to the probability of human error. As a result of the experiment, the use of directional sound clearly showed better performance than the use of monaural sound and no sound in the number of largely delayed reactions. Moreover, we analyzed the factors involved in delay of the reaction by the results of eye movement measurements. Consequently, it has been found that directional sound can decrease the number of the largely delayed reactions, which lead to an accident during actual driving.

A new graphic and display processor, which is suitable for high-performance car navigation systems or next-generation ITS mobile terminals, has been developed. The performance bottleneck of conventional consumer graphic systems exists not only in the rendering performance of the graphic processor itself, but also in CPU-capability and CPU-bus bandwidth. To release this latter bottleneck, the new processor has Controller/DSP Unit and FPU for graphic-macro-command parsing and geometric operations, respectively, which used to be the CPU tasks and occupy some amount of CPU-bus bandwidth to transfer their results. The architecture of the new processor is organized so as to carry out macro-pipelined operations of graphic and display processing smoothly. One of the features of this processor is having special hardware, Polygon-Engine and Short-Vector-Accelerator, for the rapid rendering of 2D maps, where complex polygons and short line-segments are the dominant objects to be rendered. Another feature is the hardware support of multi-layer/window display with alpha-blend overlapping. This function and additional video processing capability, such as MPEG4 decoding, would be useful in the next generation intelligent terminals. The processor LSI has been successfully fabricated by using 0.18 µm standard CMOS technology. More than five million transistors are implemented on this chip. The peak rendering speed of this processor has been measured as 200 Mpixel/s at 133 MHz processor internal clock frequency. Other results of the graphic system evaluation have demonstrated that this new processor has appropriately high performance and useful functions for the next generation mobile terminals.

Using the great one-time password concept, the widely utilized one-way authentication scheme S/Key provides well protection against replay attacks. In this paper, S/key is enhanced to secure transactions in a critical environment. The proposed scheme is free from any of server spoofing attacks, preplay attacks, and off-line dictionary attacks. A session key here is also established to provide confidentiality. Moreover, simplicity and efficiency are taken into consideration from the user's point of view. A smart card is applied to simplify the user login process and only the hash function is used to keep its efficiency. Therefore, the scheme proposed hereinafter is able to build a safer shield for sensitive transactions like on-line banking or on-line trading in bonds and securities.

This paper presents a flexible learning algorithm for the binary neural network that can realize a desired Boolean function. The algorithm determines hidden layer parameters using a genetic algorithm. It can reduce the number of hidden neurons and can suppress parameters dispersion. These advantages are verified by basic numerical experiments.

We propose a novel three-dimensional (3-D) display using only two 2-D images displayed at different depths. It is based on a new perceptual phenomenon induced by the human binocular visual system and enables an observer using no extra equipment to perceive an apparent 3-D image of continuous depth when the luminance is divided between the 2-D images according to the 3-D image depth. Our prototype direct-vision 3-D display using this mechanism can easily produce moving 3-D color images by using conventional 2-D color displays.

We present the effects of N2O plasma treatment for hot carrier reliability and gate oxide stability in excimer-laser annealed poly-Si TFTs. N2O plasma treatment between SiO2 and poly-Si suppresses both the reduction in mobility caused by hot carrier stress and the Vth shift caused by gate bias stress. The results of XPS spectra and the energy distribution of the trap state density of stressed TFTs show that the introduction of Si-N bonds plays an important role in poly-Si TFT reliability.

Recently, Lin et al. addressed two weaknesses of a new strong-password authentication scheme, the SAS protocol, and then proposed an improved one called the OSPA (Optimal Strong-Password Authentication) protocol. However, we find that both the OSPA protocol and the SAS protocol are vulnerable to the stolen-verifier attack.

Electroluminescence (EL) under alternating-current (ac) operation is first reported for n+-polysilicon/SiO2/p-Si MOS capacitors with 50 nm Si-implanted SiO2. Visible EL can be observed with the naked eye in the dark. The ac operation by pulse-wave distinctly enhances the EL intensity and its lifetime. The pulse frequency affects the EL spectrum and thus the EL color. A model of EL mechanism is proposed for the Si-implanted MOS EL device, which has a possibility of visible light emitting device.

The plan of High Altitude Platform Station (HAPS) is considered as a revolutionary wireless system plan with several economic and technological advantages over both space- or ground-based counterparts. In this paper, we propose a joint system of terrestrial and HAPS cellular for Wideband-CDMA mobile communication. This system makes the conventional terrestrial W-CDMA cellular area smaller and the remainder area covered by HAPS to increase the total capacity. Furthermore in down link channel, we introduce the polarized wave and doughnut-like radiation. However, in the proposed system, the performance would be dependent on the terminal position especially near the boundary of doughnut-like cell zone. To overcome this, site diversity that uses both signals from terrestrial Base Station and HAPS Base Station is also introduced. To confirm the availability of the proposed system, we evaluate the system performance by computer simulation.

Low-profile inverter power supplies are increasingly required for backlight systems of liquid crystal displays (LCDs). A great deal of attention has been focused on the application of piezoelectric transformers (PTs) to such power supplies. To miniaturize PT inverters still further, PTs need to have sufficient high voltage-step-up-ratio, which can be achieved by a multilayered PT. First, this paper describes a method for simulating such performance using a distributed constant equivalent circuit model. The results of the simulation for a multilayered PT operated in the third order longitudinal vibration mode show that the resistance of internal electrodes causes the dominant loss factor. Next, a power inverter incorporating the multilayered PT was fabricated. This power inverter can be operated over a wide input DC voltage range from 7-20 V. Regarding a conventional inverter drive circuit, when input DC voltage range was extended, the inverter efficiency remarkably decreased. For the reason, we developed a new inverter circuit, which is equipped with an automatic drive voltage control circuit to maintain the drive voltage to the PT at a constant value. As a result, the fabricated power inverter exhibited more than 90% overall efficiency and 3.5 W output power, which is enough to light up a 12.1-inch color LCD. The maximum luminance efficiency on a light transmission plate of the backlight was as high as 30 cd/m2/W.

Unlike in existing mobile networks, a variety of services having different quality requirements will be provided in future mobile networks, where any single group of service users can not characterize the whole traffic distribution in the system. Beginning at the mobile network design, the population of service subscribers is estimated and then base stations are located. As the service market evolves, the volume of users might grow or the population of users distributed between the multiple services as well as the located cells might change. In this case, two questions are of interest: how much growth in user population and what change in user distribution can be accommodated in the current cell configuration. If such shifts could not be admitted, current frequency and base station allocations should be expanded or reallocated. In this paper, we provide a framework that can decide whether the present network configuration is able to admit the changes of interest. Admissibility decision rules are addressed with proofs.

Mobile terminals with Internet services such as i-mode are in wide use, and communication bandwidths are growing even further under 3G technology. However, displays of mobile terminals will remain small in view of their portable size and power consumption. In this paper, we propose a "ubiquitous display" that can be used in combination with mobile terminals. The user operates the mobile terminal and the ubiquitous display shows any content that requires a large screen space.

This paper proposes a test generation method using a compacted test table and a test generation method using a compacted test plan table for RTL data path circuits with DFT where hierarchical test generations are applicable. Moreover, a heuristic algorithm for a compacted test plan table generation is proposed. The proposed methods could shorten test lengths for some RTL data path circuits compared with the conventional hierarchical test generation method.

This paper describes a hybrid force-directed self-organizing neural network approach to printed circuit board (PCB) placement with consideration of electromagnetic compatibility (EMC). In most of the conventional PCB automatic placement algorithms, the only factor considered in the objective function is minimized total net length. However, for today's high speed and high density PCB, EMC compliance cannot be met by such single objective. To tackle this problem, the presented algorithm takes EMC into consideration, besides component overlap and minimized total net length. These factors are optimized by means of an adapted self-organizing map. Comparison of simulated placement results as well as actual measurements with commercial softwares confirms the effectiveness of the proposed method.

In this paper, we describe a novel technique to extract a polyhedral description from panoramic range data of a scene taken by a panoramic laser range finder. First, we introduce a reasonable noise model of the range data acquired with a laser radar range finder, and derive a simple and efficient approximate solution of the optimal fitting of a local plane in the range data under the assumed noise model. Then, we compute the local surface normals using the proposed method and extract stable planar regions from the range data by using both the distribution information of local surface normals and their spatial information in the range image. Finally, we describe a method which builds a polyhedral description of the scene using the extracted stable planar regions of the panoramic range data with 360 field of view in a polar coordinate system. Experimental results on complex real range data show the effectiveness of the proposed method.

Microstrip antennas with meshed ground planes are suitable for radiation elements of large satellite phased array antennas. Although they have some mechanical advantages such as the possibility of antenna weight reduction, they also cause electrical problems such as the resonant frequency shift and F/B ratio degradation. The first purpose of this paper is the analytical understanding of the resonant frequency shift, for which two perturbational methods are proposed. One has a closed form expression that provides some useful design data. The other is to solve the integral equations by using the periodicity of the meshed ground plane, which gives more accurate results. The second purpose of this paper is to investigate the backward radiation from the meshed ground plane analytically, for which we derive an analysis method from the calculated results of the resonant frequency shift. The proposed methods are verified with the measured ones.

Using less wavelengths to serve more communication channels is one of the primary goals in the design of WDM networks. By installing wavelength converters at some nodes in a network, the number of wavelengths needed can be reduced. It has been observed that the more converters installed in a network, the less number of wavelengths is needed, given the same network load. In this paper, we study the relationship between the number of converters and the number of wavelengths needed in a system, and propose a suite of theories and results on how to place the minimal number of converters in the system so that the number of wavelengths W is at most a constant α times the maximal link load L (i.e., W α L), where α = 3/2 or 5/3. The results show a significant saving of converters in networks of both special topologies and general topology.

Cellular Neural Networks (CNNs) have been developed as a high-speed parallel signal-processing platform. In this paper, a generalized two-layer cellular neural network model is proposed for image processing, in which two templates are introduced between the two layers. We found from the simulations that the two-layer CNNs efficiently behave compared to the single-layer CNNs for the many applications of image processing. For examples, simulation problems such as linearly non-separable task--logic XOR, center point detection and object separation, etc. can be efficiently solved with the two-layer CNNs. The stability problems of the two-layer CNNs with symmetric and/or special coupling templates are also discussed based on the Lyapunov function technique. Its equilibrium points are found from the trajectories in a phase plane, whose results agree with those from simulations.

A new type of triple-band antenna is introduced by combing a tab monopole antenna (TMA) and a planar inverted F antenna (PIFA). The antenna configuration is shown to operate at three discrete frequencies: GSM 900, GSM 1800 (DCS) and GSM 1900 (PCS). The performance of an antenna is presented as well as the results of the computer simulations with a software package based on the Finite Element Method. The simulated results with the real antenna's experimental results. The advantage of the design suggested in this paper is its simplicity of manufacturing and low cost.

Since the penetration of VSAT services is rapidly increasing, more earth stations will operate around airports than is currently true. This makes it essential to evaluate accurately and efficiently the impairment of received signals due to blockage by aircraft. This paper proposes developing an aircraft model using a thin, planar polygon to represent the aircraft projection and to apply GTD with corner diffraction terms. The effectiveness and applicability of the method is then examined numerically. It is demonstrated that the results measured in the Ku-band around two airports are a good match with the numerical simulations even when the distance between the aircraft and the stations is small.