A novel adaptive motion vector quantization algorithm is presented in this letter. The algorithm effectively updates the set of motion vectors using gold-washing technique for block-matching according to the features of input image sequences. Simulation results show that the algorithm has both robust performance and low computational complexity for video coding.

This paper has two parts. In the first part of the paper, we note the property that under the para perspective camera projection model of a camera, the set of 2D images produced by a 3D point can be optimally represented by two lines in the affine space (α-β space). The slope of these two lines are same, and we observe that this constraint is exactly the same as the epipolar line constraint. Using this constraint, the equation of the epipolar line can be derived. In the second part of the paper, we use the "same slope" property of the lines in the α-β space to derive the affine structure of the human face. The input to the algorithm is not limited to an image sequence of a human head under rigid motion. It can be snapshots of the human face taken by the same or different cameras, over different periods of time. Since the depth variation of the human face is not very large, we use the para perspective camera projection model. Using this property, we reformulate the (human) face structure reconstruction problem in terms of the much familiar multiple baseline stereo matching problem. Apart from the face modeling aspect, we also show how we use the results for reprojecting human faces in identification tasks.

We have developed a new type electrical probing system based on an atomic force microscope. This method enables us to measure simultaneously the surface topography and surface potential of thin films containing the crystal grains. The obtained local potential changes give an insight into conduction through the grains and their boundaries.

In this paper, the LVQ (Learning Vector Quantization) model and its variants are regarded as the clustering tools to discriminate the natural seismic events (earthquakes) from the artificial ones (nuclear explosions). The study is based on the six spectral features of the P-wave spectra computed from the short period teleseismic recordings. The conventional LVQ proposed by Kohenen and also the Fuzzy LVQ (FLVQ) models proposed by Sakuraba and Bezdek are all tested on a set of 26 earthquakes and 24 nuclear explosions using the leave-one-out testing strategy. The primary experimental results have shown that the shapes, the number and also the overlaps of the clusters play an important role in seismic classification. The results also showed how an improper feature space partitioning would strongly weaken both the clustering and recognition phases. To improve the numerical results, a new combined FLVQ algorithm is employed in this paper. The algorithm is composed of two nested sub-algorithms. The inner sub-algorithm tries to generate a well-defined fuzzy partitioning with the fuzzy reference vectors in the feature space. To achieve this goal, a cost function is defined as a function of the number, the shapes and also the overlaps of the fuzzy reference vectors. The update rule tries to minimize this cost function in a stepwise learning algorithm. On the other hand, the outer sub-algorithm tries to find an optimum value for the number of the clusters, in each step. For this optimization in the outer loop, we have used two different criteria. In the first criterion, the newly defined "fuzzy entropy" is used while in the second criterion, a performance index is employed by generalizing the Huntsberger formula for the learning rate, using the concept of fuzzy distance. The experimental results of the new model show a promising improvement in the error rate, an acceptable convergence time, and also more flexibility in boundary decision making.

Two types of biomimetic chemical sensing systems are reviewed. One is an electronic nose and tongue which can recognize odor or taste from the output pattern of arrayed chemical sensors with different but overlapped specificities. The other is a chemical plume tracing system which has been developed to mimic the moth behavior in tracing the sexual pheromone from a female. We have created an odor/gas tracing robot and a compass, both of which can detect the direction from which an odor/gas is issuing.

There are methods used to test the optical purity of enantiomers; however, most of the simple methods are not precise and more complicated methods are better. As a result, these methods cannot be widely used for industrial purposes. The aim of this research is to design a sensor which can discriminate D-amino acids from L-amino acids. The designed sensor has chiral membranes and uses the technique of impedance change of these chiral membranes to discriminate the amino acids. We used a noise-FFT (Fast Fourier Transform) technique to determine the membrane impedance. When an enantiomer membrane resides in a chiral environment, (E*), diastereomeric interactions (E*-D) and (E*-L) are created, which may differ sufficiently in the arrangement of molecules of the membranes so as to permit the discrimination of optical substances due to the change in membrane characteristics. With increasing concentrations of the amino acids, the membrane resistance changes depended on the optical activity of the amino acids. The results suggest that the impedance changes of the chiral membrane with diastereomeric reaction can be used for the high-performance chemical sensor to measure the optical purity of different substances.

Channel-state-dependent (CSD) radio-resource scheduling algorithms for wireless message transport using a framed ALOHA-reservation access protocol are presented. In future wireless systems that provide Mbps-class high-speed wireless links using high frequencies, burst packet errors, which last a certain number of packets in time, would cause serious performance degradation. CSD resource scheduling algorithms utilize channel-state information for increasing overall throughput. These algorithms were comparatively evaluated in terms of average allocation plus transfer delay, average throughput, variance in throughput, and utilization of resources. Computer simulation results showed that the CSD mechanism has a good effect, especially on equal sharing (ES)-based algorithms, and also CSD-ES provides low allocation plus transfer delay, high average throughput, low variance in throughput, and efficient utilization of radio resources.

Given a set of still images taken from a hand-held camera, we present a fast method for mosaicing them into a single blended picture. We design time- and memory- efficient still image mosaicing algorithms based on geometric point feature matchings that can handle both arbitrary rotations and large zoom factors. We discuss extensions of the methodology to related problems like the recovering of the epipolar geometry for 3d reconstruction and object recognition tasks.

This paper describes an efficient simulation approach of a DSP controlled series-parallel resonant high frequency DC-DC power converter system. Proposed power conversion circuit simulation approach is based on a circuit equation, modeled by substituting time-varying switched resistor circuit in place of all the controllable and uncontrollable power semiconductor switching blocks of power converter circuits. An algebraic algorithm transforms the matrices of the circuit equation into the matrices of the state vector equation. Solution of state equation is by 3rd order Runge Kutta numerical integration method. Simulation results are illustrated and discussed together with experimental results.

The propagation characteristic of 670 nm laser light on the array of 10 µm diameter polystyrene micro-sphere was studied. For the linearly arranged array of micro-spheres from one to 12, the propagated light intensity was decreased from 700 mV to 45 mV. However, the propagated light intensity in the air was significantly decreased and it became 2 mV at 60 µm from the optical fiber light source. For the micro-sphere array on the curvilinear line, the light intensity at 12th micro-sphere became 35 mV. This fact means the light was propagated almost same as that on the linear line. Whereas it is expected that three dimensionally crossing optical wave-guide is possible to be fabricated by arranging the micro-spheres.

Photoacoustic spectroscopy (PAS) has recently received much attention especially for plant photosynthesis research, because this technique is capable of performing non-destructive measurement without any pre-treatment of specimens. So far we have developed a PAS system equipped with an open photoacoustic cell (OPC), which allows in situ and in vivo measurements of plant photosynthesis of intact undetached leaves. In this study, we have measured photosynthesis reaction using OPC and developed a Confocal Scanning Photoacoustic Microscopy (CSPAM) system, in which PAS is combined with confocal scanning laser microscopy. The system allows simultaneous measurement of acoustic signal and another signal such as fluorescence, and also gives two- and three- dimensional intensity distributions of these signals, thereby giving two- and three- dimensional information about photosynthetic activity of plants.

The sharpness of the roll-off response of bandpass filters is a major concern for wireless communication systems. Bandpass filters with attenuation poles provide sharp roll-off. This paper investigates the performance of a ceramic comb-line filter with attenuation pole resonators (APRs), and studies the effects of the attenuation pole resonators on the filter response. The presented APRs are improved versions of previous ones and they are modeled here. The obtained results show that the length of APRs can be miniaturized via the loading capacitance. The resultant volume is about 400 mm3, which is very small comparing to coaxial type filters with the same attenuation rate in the stopband. With attenuation pole resonators added, skirt attenuation is greatly improved. Narrow bandwidth bandpass filters with attenuation poles in the stopband are designed and tested. Two designed examples demonstrate the flexibility of the attenuation pole resonator in the filter configuration. Experiments show good agreement with simulation results.

Topographical changes induced by optical near-field around photo-irradiated nanoparticles were attained using a pulsed laser with a large peak power as a light source. The arrayed structure of nanoparticles was transcribed on urethane-urea azo copolymer film as dent structure. The experiments by the pulsed laser of different wavelength showed that the topographical change was caused by the light absorption. The dent diameter and the dent depth changed depending on the diameter of nanoparticles.

Numerical modeling of realistic engineering problems using the FDTD technique often requires smaller cell size, higher simulation accuracy and less computation resources. In this paper, we describe a high performance three-dimensional FDTD algorithm by using non-uniform mesh that allows flexible cell size to improve the accuracy of modeling, and computation resource also can be reduced greatly. In this paper, we will first explain the detailed formulation and algorithm of Non-Uniform Mesh. Next, examination of the reflection error from fine-coarse boundary because of the discontinuity is carried out. Then some test geometry are solved by using both uniform mesh and non-uniform mesh FDTD scheme to validate the results and check the accuracy of solution. We also examine the calculation accuracy due to mesh size ratio, and then investigation of how to determine the fine mesh region surrounding the object for a most small computation error will be carried out in this paper. In addition, the algorithm is demonstrated for several different antenna geometry.

The original DQRUMA/MC-CDMA protocol may suffer severe code collisions due to a limited number of request codes. An enhanced DQRUMA/MC-CDMA protocol using minislots for request accesses is proposed to reduce request collisions. In the proposed protocol, request attempts are transmitted concurrently with data packets of other calls. A random scheme (Scheme I) and a designated scheme (Scheme II) are distinguished depending on the methods which select a request code and a request minislot based on a lattice pool for request accesses (LPRA). Both schemes yield low request access delays due to few or no collisions during request accesses. In Scheme I one of request minislots is selected with a randomly chosen code, while in Scheme II the minislot and the code uniquely used in request attempts can resolve a code collision problem during request accesses. The performance of the proposed protocol is evaluated by simulation and the result shows that the proposed protocol outperforms the original DQRUMA/MC-CDMA protocol in terms of average total delay.

To provide a bounded-delay service with an end-to-end delay guarantee and utilize network efficiently, the admission control functions in a network require an adequate per-switch delay allocation policy to allocate end-to-end delay requirement to a set of local switches. This letter present an optimal delay allocation policy, according to a deterministic traffic model, and a rate-controlled scheduler. Empirical results indicate that the proposed policy perform better than EQ allocation policy, using the admission load region as index.

A new technique is proposed to generate the executable and synchronizable (i. e. , e-synchronizable) test sequence for the protocol implementation to be conformable to its data portion specification. The protocol's control portion is specified as a finite state machine (FSM), and its data portion is specified as a set of rules. The technique involves converting the FSM and the rules into the DuplexSelect digraph, from which we can generate test sequences which are both synchronizable (i. e. , encounter no synchronization problems) and executable (i. e. , associated with parameter values which do not violate the rules). The Selecting Chinese Postman Algorithm is then used for minimizing the cost of the e-synchronizable test sequence that verifies each rule at least once.

In long-haul wavelength-division-multiplexed (WDM) transmission systems, signals with shorter and longer wavelengths have self-phase modulation group-velocity-dispersion (SPM-GVD) penalty caused by to the dispersion slope even after the dispersion-compensation at the receiver has been optimized. As a countermeasure, we have already proposed both pre-compensation and post-compensation of chromatic dispersion at the transmitter and receiver for each channel. This method can decrease the channel variation of path-averaged chromatic dispersion along the transmission line, and it can improve the eye opening of the waveform after transmission. We investigated the optimized parameter of chromatic dispersion and chirping at the transmitter. The optimized pre-dispersion compensation parameter R was about 50%. The optimized chirping parameter α was about 3 when the signal wavelength was less than the mean zero-dispersion wavelength. In a single-channel, 5.3-Gbit/s NRZ signal transmission experiment over a 4,760-km straight line, this method decreased SPM-GVD penalty. In a 32-channel, 5.3-Gbit/s WDM transmission experiment over 9,879 km using a circulating loop, this method improved Q-factors for the 1st and 32nd channels by more than 1.5 dB.

This paper theoretically analyzed the performance of the RAKE combining (in the time domain), maximal ratio combining (in the spatial domain), and two-dimensional RAKE combining (in the spatial and time domains) techniques for multipath fading environments, where multipath waves are distributed in the spatial and time domains. The analysis was based on a diversity combining technique that employed the eigenvalues of the covariance matrix between branch signals. It was found that the performance of the fading mitigation was normalized by the beamwidth of an array antenna, for various parameters such as the number of antenna elements, angular spread, and angle of arrival.

Site diversity causes unfairness in packet reception that depends on the location of the mobile stations in the up-link of CDMA cellular packet communication systems. This paper proposes an adaptive transmit permission probability control scheme that reduces this unfairness in CDMA cellular slotted-ALOHA systems with site diversity. The proposed scheme adaptively controls the transmit permission probability according to the offered load and the location of the mobile stations. Successful packet reception rate, fairness coefficient and throughput performance are evaluated in fading environments with imperfect power control. Computer simulation shows that adaptive transmit permission probability control improves fairness of service for all mobile stations and throughput performance across all channel loads compared with the conventional scheme.