Liquid-crystal devices with in-plane switching electrodes (IPS-LCD) are superior to twisted nematic ones in their wider range of viewing angle, but show serious color shift with viewing angle. The color shift is a phenomenon governed by the three-dimensional orientation of liquid-crystal molecules. In order to evaluate such effects numerically, light wave propagation in the IPS-LCD is studied using a two-dimensional finite-difference time-domain method, where all six components of electromagnetic field are analysed and the three-dimensional properties of liquid-crystal materials are taken into account through the dielectric tensor. The computational space termination is provided by a combination of the uniaxial perfectly matched layer and periodic boundary conditions. It is found for the first time numerically that the color shift effects strongly depend on the asymmetrical profile of liquid-crystal orientation, which is originated from the small pretilt angle.

In this paper, a test architecture optimization for system-on-a-chip under floorplanning constraints is proposed. The models of previous test architecture optimizations were too ideal to be applied to industrial SOCs. To make matters worse, they couldn't treat topological locality of cores, that is, floorplanning constraints. The optimization proposed in this paper can avoid long wires for TAMs in consideration of floorplanning constraints and finish optimizing test architectures within reasonable computation time.

This paper introduces an efficient affine projection algorithm (APA) using iterative hyperplane projection. The inherent effectiveness against the rank deficient problem has led APA to be the preferred algorithm to be employed for various applications over other variety of fast converging adaptation algorithms. However, the amount of complexity of the conventional APA could not be negligible because of the accomplishment of sample matrix inversion (SMI). Another issue is that the "shifting invariance property," which is typically exploited for single channel case, does not hold ground for space-time decision-directed equalizer (STDE) application deployed in single-input-multi-output (SIMO) systems. Therefore, fast adaptation schemes, such as fast traversal filter based APA (FTF-APA), becomes impossible to utilize. The motivation of this paper deliberates on finding an effective algorithm on the basis of APA, which yields low complexity while sustaining fast convergence as well as excellent tracking ability. The performance of the proposed method is evaluated under wireless SIMO channel in respect to bit error rate (BER) behavior and computational complexity, and upon completion, the validity is confirmed. The performance of the proposed method is evaluated under wireless SIMO channel in respect to bit error rate (BER) behavior and computational complexity, and upon completion, the validity is confirmed.

In this letter, we propose an approach to incorporate a statistical model for the voiced/unvoiced (V/UV) speech decision under background noise environments. Our approach consists of splitting the input noisy speech into two separate bands and applying a statistical model for each band. We compute and compare the likelihood ratio (LR) for each band based on the statistical model and estimated noise statistics for the V/UV decision. According to the simulation test, the proposed V/UV decision shows a better performance compared with the selectable mode vocoder (SMV) V/UV decision algorithm, particularly in clean and white noise environments.

A challenge to an automated layout of analog ICs starts with the insight into high quality placements crafted by experts. We observe first that matched devices or elemental functions such as input, output, amplifiers, etc are clustered. Second, devices in the same cluster are located faithfully to the drawn schema. Third, these two features are simultaneously fulfilled in a well-compacted placement. This paper proposes a novel device-level placement that simulates the above features based on Sequence-Pair. A slight modification of the meaning, say, of relation "A is left-of B" to relation "A is not right-of B" enlarges the freedom and allows a neater compaction of clusters allowing zigzag border curves. As the consequence, clusters are placed faithfully to relative position in the schema. We tested our algorithm for industrial instances and compared results with those by manual design. The results showed better features in performance figures than the those of manual designs by, on average, 13.5% and 21.2% with respect to the area and total net-length.

In this letter, we present a new triple-band planar antenna, a non-uniform meandered and fork-type grounded antenna (NMFGA), for mobile communication systems. The antenna is designed for triple-band operations at 900 MHz, 1800 MHz, and 2450 MHz bands. A prototype of the NMFGA was constructed and studied. Measured and simulated return loss and measured radiation patterns were obtained. The experimental results demonstrate the attractive bandwidth and radiation performance of the newly developed antenna for all the three bands.

A large memory is typically designed with multiple identical memory blocks for reducing delay and power. The circuit verification of individual memory blocks can be effectively handled by the Symbolic Trajectory Evaluation (STE) approach. However, if multiple memory blocks are integrated into a single system, the STE approach cannot verify it economically. This paper introduces algorithms for verifying block-level connectivity of memories. The verification time of a large memory can be reduced drastically by using bottom-up verification scheme. That is, a memory block is first verified thoroughly, and then only the interconnection between memory blocks of the large memory needs to be verified. The proposed verification algorithms require (3n+2(log2n+1)+3log2m) Read/Write operations for a 2nm-bit memory, where n and m are the address width and data width, respectively. Also, the algorithms can verify 100% of the inter-port and intra-port signal misplaced faults of the address, data input, and data output ports.

Some plants have air purification ability. This purification ability of plants is considered a promising method for indoor air purification because of the low cost and high purification performance. Therefore, several studies have been carried out to investigate the relationship between the air purification ability of plants and environmental conditions. Nevertheless, the purification mechanism and process have not been clarified yet. In this paper, we investigated the air purification process in plants by bioelectrical potential analysis using linear and nonlinear analysis methods. First, we showed that two types of plants have a high air purification ability; Schefflera and Boston fern. Next, we measured AC bioelectrical potential during the purifying process of plants for pollutant gas. Then, we evaluated the power spectra of time series data of the bioelectrical potential. We found that the power spectra shifted to a lower level after gas injection over all frequencies. Thus, the higher power spectrum came from possible higher physiological activities of the plant. Finally, we introduced a nonlinear analysis method from the dynamical system theory. We transformed the time series data of the potential to a higher dimensional state space using a delay coordinate, which is often used in the field of nonlinear time series analysis. The results show that the orbits in the reconstructed state space have a large variation in gas injection. These experimental results suggest that the measurement of bioelectrical potential could become a useful method for evaluating the air purification ability of plants.

In wide-area wireless access systems such as satellite communications systems and stratospheric platform systems, electric power supplies for radio communications are realized using solar photovoltaic cells and/or fuel cells. However, the on-board weight limits restrict the number of cells that can be equipped. In addition, the transmission power of such systems is limited taking account of issues and regulations on sharing the same frequency band with other systems. Hence, both the frequency band and electric power is limited, which are crucial radio resources for those systems. Although radio channel allocation methods taking account of the frequency constraint only or the power constraint only have been proposed, radio channel allocation methods taking account of both constraints simultaneously have been insufficiently studied. This paper proposes a radio channel allocation method that provides global optimum allocation results by utilizing the linear programming method. The proposed method has features such that the method first allocates radio channels in proportion to the traffic demand distributed over the service coverage area and then maximizes the total radio channels allocated to systems. Numerical results are presented for a stratospheric platform system that covers an area of Japan, as an example, to demonstrate that the proposed method optimally allocates radio channels taking account of both constraints while efficiently allocating excess resources. In addition, whether a system reaches either the frequency or power limit can be estimated, by investigating the radio channel allocation results. Furthermore, enhanced linear programming models based on a method aiming at practical use of the radio channel allocation results in operation are also introduced. The enhanced model is demonstrated to work effectively to avoid unbalanced radio channel allocations over geographical areas. The proposed method and linear programming models are useful not only for making pre-plans but also for determining the amount of necessary frequency and power resources in designing systems.

The success in topdown design of recent huge system LSIs is in a seamless transfer of the information resulted from the high level design to the lower level of floorplanning. For the purpose, we introduce a new concept abstract floorplan which is included in the output of high level design. From the abstract floorplan, the pillar blocks are derived which are critical sets of blocks that are expected to determine the width and height of the chip, named the frame. Since the frame and pillar blocks are obtained in the high level stage, they are useful to keep the consistency in the low level physical design if we apply optimization regarding them as constraints. Experiments to MCNC benchmarks showed that abstract floorplanning by pillar blocks output a placement faithful to the one physically optimized block placement with respect to the chip area and the wire-length.

A floorplan specifies the layout of modules in very large scale integration (VLSI) design, and a new code, called the EQ-sequence, for representing a floorplan is presented in this paper. The EQ-sequence is based on a Q-sequence. The EQ-sequence can preserve the adjacent relationships of rooms on a floorplan, but the Q-sequence cannot. The algorithms for encoding, moving and decoding of an EQ-sequence are introduced. With the EQ-sequence, we can check whether two modules abut each other on a floorplan. It has been proved that any floorplan of n rooms is uniquely encoded by an EQ-sequence and any EQ-sequence is uniquely decoded to a floorplan, both in O(n) time.

In recent years the size of transformer in a DC-DC converter becomes smaller and thinner for power module type application. It results in the increase of the leakage inductances because the number of turns of the secondary winding becomes smaller. This paper presents the analysis of static and dynamic characteristics of the novel flyback converter proposed before, and clarifies that the transformer's leakage inductances deteriorate the static load regulation, but improve the dynamic stability by increasing the dumping factor.

As audio and video applications have proliferated on the Internet, transcoding proxy caching has been considered as an important technique for improving network performance, especially for mobile networks. Due to several new emerging factors in the transcoding proxy, existing methods for proxy placement for web caching cannot be simply applied to solve the problem of proxy placement for transcoding proxy caching. This paper addresses the problem of proxy placement for coordinated en-route transcoding proxy caching for tree networks. We propose a model for this problem by including the new emerging factors in the transcoding proxy and present optimal solutions for this problem with/without constraints on the number of transcoding proxies using dynamic programming. Finally, we implement our algorithm and evaluate our model on various performance metrics through extensive simulation experiments. The implementation results show that our model outperforms the existing model for transcoding proxy placement for linear topology, as well as the random proxy placement model. The average improvements of our model over the other models are about 7.2 percent and 21.4 percent in terms of all the performance metrics considered.

Our goal is to realize an extra-large stereoscopic display in the open air for use by the general public. We have developed a stereoscopic large display by use of a full-color LED panel. Although the developed display enables viewers to view the stereoscopic images without any special glasses, it is necessary for the viewers to move to stand within the viewing areas. Movements of the viewers are considered to depend on arrangements of viewing areas. The purpose of this paper is to investigate the movements of viewers who watch different designs of stereoscopic LED displays with a parallax barrier, including conventional designs to provide multiple perspective images and designs to eliminate pseudoscopic viewing areas, and evaluate the performance of different viewing areas based on the obtained paths of the viewers. We have developed a real-time measurement system of a viewer's position by use of a camera on the ceiling. We have recorded the viewing movements caused by the shift of viewing areas. It was found that the viewers moved to stand on orthoscopic viewing positions. The movements of viewers who move to find a viewing area have been recorded with different designs of stereoscopic LED displays that provide different viewing areas. We have calculated the lateral moving time of the viewers'movements. It is shown that the elimination of pseudoscopic viewing areas reduces the lateral moving time. Thus, the real-time measurement system of a viewer's position has been utilized for evaluation of performance of the different designs of stereoscopic LED displays.

This letter develops a practical sectorized antenna array using center-fed half-wavelength dipole antennas that are parallel to and a distance in front of a large ground plane reflector. Each element in the array is designed to provide coverage to isolate each 120sector from adjacent sectors. We derive a closed-form expression for spatial correlation function that can be used as guides in evaluating the effects of array spatial correlation on diversity performance in sectorized cellular communications.

This paper considers a motion planning method for humanoid robots. First, we review a modular state net which is a state net representing behavior of a part of the humanoid robots. Each whole body motion of the humanoid robots is represented by a combination of modular state nets for those parts. In order to obtain a feasible path of the whole body, a timed Petri net is used as an abstracted model of a set of all modular state nets. Next, we show an algorithm for constructing nonlinear dynamics which describes a periodic motion. Finally, we extend the state net in order to represent primitive periodic motions and their transition relation so that we can generate a sequence of primitive periodic motions satisfying a specified task.

This paper presents a new template matching method based on marker-controlled watershed segmentation (TMCWS). It is applied to recognize numbers on special metal plates in production lines where traditional image recognition methods do not work well. TMCWS is a shape based matching method that uses different pattern images and their corresponding marker images as probes to explore a gradient space of an unknown image to determine which pattern best matches a target object in it. Different from other matching algorithms, TMCWS firstly creates a marker image for each pattern, and then takes both the pattern image and its corresponding marker image as a template window and shifts this window across a gradient space pixel by pixel to do a search. At each position, the marker image is used to try to extract the contour of the target object with the help of marker-controlled watershed segmentation, and the pattern image is employed to evaluate the extracted shape in each trial. All of the pattern images and their corresponding marker images are tried and the pattern that best matches the target object is the recognition result. TMCWS contains shape extraction procedures and it is a high-level template matching method. Experiments are performed with this method on nearly 400 images of metal plates and the test results show its effectiveness in recognizing numbers in noisy images.

In this paper, we propose the Synchronized Mobile Multicast (SMM) scheme for the real-time multimedia service to achieve three most important characteristics that the traditional Home Subscription (HS) and Remote Subscription (RS) mobile schemes cannot support. First, the SMM scheme supports the scalable one-to-many and many-to-many synchronized multimedia multicast on mobile IP networks to achieves seamless playback of continuous media streams even when both the mobile sender and receivers handoff simultaneously. Second, it analyzes the minimal buffer requirements of the mobile sender, the core router, the foreign agents and the mobile receivers in the multicast tree and formulates the initial playback delay within a handoff Guarantee Region (GR). Further, combined with the fine granularity scalability (FGS) encoding approach in the MPEG-4 standard, the SMM scheme achieves superior multimedia QoS guarantees and unlimited numbers of handoffs of the mobile sender and receivers only at the cost of degraded video quality for a short period after handoff with minimal extra bandwidth.

Sensor nodes are prone to failure and have limited power capacity, so the evaluation of fault tolerance and the creation of technology for improved tolerance are among the most important issues for wireless sensor networks. The placement of sensor nodes is also important, since this affects the availability of nodes within sensing range of a target in a given location and of routes to the base station. However, there has been little research on the placement of sensor nodes. Furthermore, all research to date has been based on deterministic node placement, which is not suitable when a great many sensor nodes are to be placed over a large area. In such a situation, we require stochastic node placement, where the sensor-positions are in accord with a probability density function. In this paper, we examine how fault tolerance can be improved by stochastic node placement that produces scale-free characteristics, that is, where the degree of the nodes follows a power law.

A readout circuit involving new two step current mode background suppression is studied for 2-dimensional long wavelength infrared focal plane arrays (LWIR FPA's). Buffered direct injection (BDI) and feedback amplifier structure are adopted for input circuit and background suppression circuit, respectively. The pixel circuit is simple and has very small skimming error less than 0.1%. Enough calibration range over 50% as well as long integration time over 1.75 ms can be obtained using this readout circuit.