Optically patternable light-emitting devices based on conducting polymers were fabricated and were characterized. The cathode of the devices is made with a semitransparent-Al film, which enables to photoinduced degradation of the polymers in air. The optically patternable devices were successfully made with poly (2-methoxy-5-dodecyloxy-p-phenylene vinylene) (MDOPPV), as well as with poly (3-dodecylthiophene) (PAT12). However, optical absorption study indicated that the patterning mechanism of the MDOPPV device is considerably different from that of the PAT12 device.

Short-circuit photocurrents (ISC) utilizing surface plasmon polariton (SPP) excitation were investigated for the merocyanine (MC) LB film photoelectric device. The device has a prism/MgF2/Al/MC LB film/Ag structure. In the attenuated total reflection (ATR) configuration, SPPs were resonantly excited at the interfaces between MgF2 and Al (MgF2/Al) and between Ag and air (Ag/air). The thickness and the dielectric constants of the layers were evaluated from the ATR measurements. Short-circuit photocurrents, ISCs, as a function of the incident angle of the laser beam were observed simultaneously during the ATR measurements. In the ISC curves, large and small peaks were observed, and the peak angles of the ISC almost corresponded to the dip angles of the ATR curves due to the SPP excitations. Electric fields and optical absorptions in the cell were calculated using the dielectric constants and the film thickness obtained from the ATR measurements. The calculated absorption in the MC layer as a function of the incident angle corresponded to the ISC curve. It was thought that the optical absorption in the MC layer affected directly to the profile of the ISC. Furthermore, the calculated absorption in the cell with the prism and the MgF2 layer exhibited much larger than that of the cell without them. It was estimated that the photocurrents were enhanced by the excitation of SPPs in the ATR configuration.

In the food, beverage and cosmetic industry and so on, odor sensing systems instead of human sensory test are demanded. We have developed odor sensing systems using QCM (quartz crystal microbalance) sensor array and pattern recognition method. Since the properties of the sensors depend on the gas sorption characteristics of the sensing films coated on them, the optimum films according to target odors should be selected. In this study, we tried to select sensing films appropriate for discrimination of slightly different apple flavors. The examples of typical apple flavors were prepared blending 9 compounds. The sensing films were extracted from various kinds of materials such as lipid, stationary phase material of GC (gas chromatography) and cellulose. The selection method under the condition of the small number of measurements was studied. We analyzed the data of steady-state sensor responses in terms of the Euclidean distance, and the films appropriate for apple flavor discrimination were successfully selected.

An efficient location management for mobile stations plays an important role in personal communication systems. The key elements of location management are location registration and paging. In this paper, we propose the improved movement-based registration method with a selective paging scheme which enables to minimize the signaling traffic such as a paging load and a registration load. For reducing the paging load, we newly establish a paging area and analyze its performance by modeling as one dimensional random walk model with a barrier state. Further, for decreasing the registration load, we also propose a new movement-based registration scheme by using a counter and a buffer which can store the number of cell boundary crossings and the cell identification, respectively. Through numerical results, we show that our proposed movement-based registration provides a better performance than the conventional movement-based registration.

An experimental 640-Gbit/s ATM switching system is described. The switching system is scalable and quasi-non-blocking and uses hardware self-rearrangement in a three-stage network. Hardware implementation results for the switching system are presented. The switching system is fabricated using advanced 0.25-µm CMOS devices, high-density multi-chip-module (MCM) technology, and optical wavelength-division-multiplexing (WDM) interconnection technology. A scalable 80-Gbit/s switching module is fabricated in combination with a developed scalable-distributed-arbitration technique, and a WDM interconnection system that connects multiple 80-Gbit/s switching modules is developed. Using these components, an experimental 640-Gbit/s switching system is partially constructed. The 640-Gbit/s switching system will be applied to future broadband ATM networks.

In many fields such as city administration and facilities management, there are an increasing number of requests for a Geographic Information System (GIS) that provides users with automated mapping functions. A mechanism which displays 3D views of an urban scene is particularly required because it would allow the construction of an intuitive and understandable environment for managing objects in the scene. In this paper, we present a new urban modeling system utilizing both image-based and geometry-based approaches. Our method is based on a new concept in which a wide urban area can be displayed with natural photo-realistic images, and each object drawn in the view can be identified by pointing to it. First, to generate natural urban views from any viewpoint, we employ an image-based rendering method, Image Walkthrough, and modify it to handle aerial images. This method can interpolate and generate natural views by assembling several source photographs. Next, to identify each object in the scene, we recover its shape using computer vision techniques (a geometry-based approach). The rough shape of each building is reconstructed from various aerial images, and then its drawn position on the generated view is also determined. This means that it becomes possible to identify each building from an urban view. We have combined both of these approaches yielding a new style of urban information management. The users of the system can enjoy an intuitive understanding of the area and easily identify their target, by generating natural views from any viewpoint and suitably reconstructing the shapes of objects. We have made a prototype system of this new concept of GIS, which have shown the validity of our method.

In the Internet and Mobile communication environment, authentication of the users is very important. Although at present password is extensively used for authentication, bare password transmission suffers from some inherent shortcomings. Several password-based authentication methods have been proposed to eliminate such shortcomings. Those proposed methods have relative demerits as well as merits. In this letter we propose a method where those demerits are eliminated. The prominent feature is security improvement apart from low processing, storage and transmission overheads compared to previous methods. This method can be used in several applications like remote login, encrypted and authenticated communication and electronic payment etc.

A simple phase compensation technique with improved power supply rejection ratio (PSRR) for CMOS opamps is proposed. This technique is based on feeding back a current proportional to a derivative of the voltage difference between an output and an input, and does not require a common-gate circuit or a noise-free bias for the circuit. The proposed technique requires only two additional transistors, which are connected to the differential pair of transistors in a cascade manner, and the compensation capacitor is connected to the source node of the additional transistor. Experimental results show an improvement of more than 20 dB in the PSRR at high frequencies, comparing the technique with a Miller compensation. This technique also improves the unity gain frequency and the phase margin from 0.9 MHz and 17 to 1.8 MHz and 44 for 200 pF load capacitance, respectively.

HRTFs (head-related transfer functions) are available for sound field reproduction with spatial fidelity, since HRTFs involve the acoustic cues such as interaural time difference, interaural intensity difference and spectral cues that are used for the perception of the location of a sound image. Generally, FIR filters are used in the simulation of HRTFs. However, this method is not useful for a simply system, since the orders of the FIR filters are high. In this paper, we propose a method using IIR filter for simply realization of sound image localization. The HRTFs of a dummy-head were approximated by the following filters: (A) fourth to seventh-order IIR filters and (B) third-order IIR filters. In total, the HRTFs of 24 different directions on the horizontal plane were used as the target characteristics. Sound localization experiments for the direction and the elevation angle of a sound image were carried out for 3 subjects in a soundproof chamber. The binaural signal sounds using the HRTFs simulated by FIR filters and approximated by IIR filters (A) and (B) were reproduced via two loudspeakers, and sound image localization on the horizontal plane was realized. As the result of the experiments, the sound image localization using the HRTFs approximated by IIR filters (A) is the same accuracy as the case of using the FIR filters. This result shows that it is possible to create sound fields with binaural reproduction more simply.

The essence of this work is to introduce an interaction between the physical layer and higher network layers, thus enabling a more practical utilization of multiuser detection and supporting services with different QoS parameters. In this paper, a new hybrid TDMA/ Multicode (MC)-CDMA medium access control utilizing multiuser detection is proposed and analyzed. Further, two traffic flow control approaches accompanied the TDMA/MC-CDMA system are proposed. One approach deterministically controls the flow of traffic into the TDMA slots, while the other statistically controls the flow of traffic depending on the instantaneous changes in the traffic load. The two approaches have been examined under a wide range of traffic characteristics where AWGN is only considered besides the mutual interferers from other intracell users. Both approaches show superiority as well as less sensitivity in terms of BER to the traffic changes compared with the conventional system.

In this paper, a new frequency transformation for complex analog filter design which is suitable for integration is discussed. Arbitrary specified passband and stopband edges are easily transformed into those of the normalized LPF by solving simultaneous equations with four unknowns. Different from previous methods, the proposed transformation provides better performance in active realization of complex filters.

This paper proposes a survivor-correction Viterbi algorithm (SCVA) and presents its application to an iterative sequence estimation in order to improve bit error rate performance of decision-feedback sequence estimation (DFSE) in the presence of intersymbol interference. The SCVA can mitigate erroneous survivor selections due to DFSE, because it modifies the add-compare-select operation to an add-correct-compare-select operation. Finally, it is confirmed by computer simulation that complexity of the proposed scheme is independent of delay of the main delayed ray and its performance is superior to that of DFSE at the same number of states.

This paper proposes a scheme which combines the conventional technique with a multi-level structure of Thai sentences for detection and segmentation for touching Thai printed characters. The proposed scheme solves problems of both horizontally and vertically touching characters. The complexity of a multi-level structure is employed to classify characters into three zones. The edge detection technique is applied to separate overlapping characters. Then, the horizontal touching characters are determined by using a statistical width of characters. The segmentation point of horizontal touching characters is determined using vertical projection combined with a statistical width of characters. The vertical touching characters are determined by considering the overlapping area of character boundary between zones. The height of line is used to separate the segment of vertical touching characters. Ambiguities are handle by using distinctive features of Thai characters. The effectiveness of the proposed scheme is tested with data from both newspapers and printed documents. The accuracy of 97 and 98 percents are obtained for newspaper and printed documents respectively.

Demand for power in Japan has been increasing year by year, and steep demand is projected during daily peak load periods: particularly in summer, due to growing demand for air conditioning. This has resulted in a large gap between day and night demand for power. The daily and seasonal regularity of this demand gap is placing pressure on power utilities to reduce service costs and create a more dependable power supply. This study demonstrates the feasibility of an energy storage system for load leveling based on the electric double-layer capacitor (EDLC). This device is safer, has a longer service life and needs far less maintenance than the secondary cell. The system works to store surplus energy from a commercial AC line in an EDLC bank during the night, and release this energy for use during the daytime peak load period, using a novel interface circuit. This paper focuses in particular on the working principles and experimental results of the interface circuit, which comprises a voltage control oscillator (VCO), a bi-directional DC/DC converter, a bi- directional inverter, and a coupling inductor. The whole circuit is subjected to PLL control, so that automatic connection between DC from an EDLC bank and AC from a commercial power line may take place in a simpler, more reliable and less costly manner. The system allows for energy transfer on the basis of DC voltage as if electric charging and discharging had taken place in a full DC system.

In this letter, a numerical design approach for FIR diamond-shaped filter banks (DFB) with perfect reconstruction (PR) and low delay for tree-structured HDTV coding is presented. The system delay of the designed DFB can be controlled below the category of the linear-phase. Moreover, the necessary conditions for the system delay of the designed DFB are derived. The considered problem is formulated as the minimization of the real and imaginary parts of weighted peak ripple errors of the designed analysis filters subject to PR constraints. Simulation example is provided to show the efficacy of this proposed design technique.

We present two estimation methods for camera rotation from two images obtained by the active camera before and after rotation. Based on the representation of the projected rotation group, quasi moment features are constructed. Camera rotation can be estimated by applying the singular value decomposition (SVD) or Newton's method to tensor quasi moment features. In both cases, we can estimate 3D rotation of the active camera from only two projected images. We also give some experiments for the estimation of the actual active camera rotation to show the effectiveness of these methods.

An optimum representative-frames (r-frames) selection method using step-wise function approximation has been developed to provide automatic indexing for a video-query-agent (VQA) system. It uses dynamic programming to simultaneously select the r-frames and corresponding segment boundaries. Experiments showed that the approximation error of the selected r-frames was less than that of two conventional methods. Retrieval experiments using a feature-based image-search engine showed that the proposed method is more robust and effective than the two conventional methods. The proposed method was implemented in a VQA system and processing time was evaluated. The results showed that the processing time for indexing was shorter than that of the conventional method.

We propose a new method for generating visual stereo images from the common two dimensional images without 3D reconstruction. The major novel contributions of this report are in two aspects. First, we address the detection of dominant motion presented in the given scenes, for doing so we borrow phase shift theorem and calculate the inverse Fourier transform of cross-power spectrum to find the maximum peak value whose position can be used to decide motion parameters. Secondly, unlike most of researchers study the stereo vision to recover 3D information for modeling and rendering, we address the visual stereo image generation without 3D reconstruction by applying the computed motion parameters to make decision of selecting two given images to form a stereo pair for left eye and right eye respectively. The proposed approaches can be employed for applications such as navigation in a virtual environment.

A broadband and flexible receiver architecture is investigated for the handheld software defined radio (SDR). The proposed SDR architecture is based on the direct conversion and low intermediate frequency (low-IF) principle with digital channel filtering, which provides the receiver with flexibility for the multi-standard application. This architecture also enables analog-to-digital converter activating essentially in baseband or low frequency so that the clock jitter, which serves as an important subject in the well-known IF sampling method, can be reduced. Basic performance of the proposed architecture has been confirmed by the experimental model.

We have developed spectral separation devices for processing femtosecond pulses. These devices are based on an optical coupler structure with fiber gratings. In a computer simulation, we confirmed that these devices could extract <1 nm bandwidth light with 80% efficiency. We fabricated the spectral separation devices using single mode fibers and highly Ge-doped fibers. These devices successfully extracted narrow spectral light of 0.3 nm bandwidth with 37% efficiency from femtosecond pulses of 40 nm bandwidth. We also fabricated 2-channel spectral separation devices, which could extract the light from each grating channel.