The k-mutual exclusion problem is the problem of guaranteeing that no more than k computing nodes enter a critical section simultaneously. The use of a k-coterie, which is a special set of node groups, is known as a robust approach to this problem. In general, k-coteries are classified as either dominated or nondominated, and a mutual exclusion mechanism has maximal availability when it employs a nondominated k-coterie. In this paper, we propose two new schemes called VOT and D-VOT for constructing nondominated k-coteries. We conduct a comparative evaluation of the proposed schemes and well-known previous schemes. The results clearly show the superiority of the proposed schemes.

To enhance safety and traffic efficiency, a driver assistance system and an autonomous vehicle system are being developed. A preceding vehicle recognition method is important to develop such systems. In this paper, a vision-based preceding vehicle recognition method, based on supervised learning from sample images is proposed. The improvement for Modified Quadratic Discriminant Function (MQDF) classifier that is used in the proposed method is also shown. And in the case of road environment recognition including the preceding vehicle recognition, many researches have been reported. However in those researches, a quantitative evaluation with large number of images has rarely been done. Whereas, in this paper, over 1,000 sample images for passenger vehicles, which are recorded on a highway during daytime, are used for an evaluation. The evaluation result shows that the performance in a low order case is improved from the ordinary MQDF. Accordingly, the calculation time is reduced more than 20% by using the proposed method. And the feasibility of the proposed method is also proved, due to the result that the proposed method indicates over 98% as classification rate.

We describe a theoretically optimal algorithm for computing the homography between two images. First, we derive a theoretical accuracy bound based on a mathematical model of image noise and do simulation to confirm that our renormalization technique effectively attains that bound. Then, we apply our technique to mosaicing of images with small overlaps. By using real images, we show how our algorithm reduces the instability of the image mapping.

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.

A highly reliable and available network which automatically can restore itself from failures is an important concept for the future high capacity broadband networks. Self-healing algorithm, restoring the failed VPs (Virtual Paths) in the backbone ATM networks, is an indispensable technique to meet these requirements. In this paper we propose a coordination-based restoring self-healing algorithm called C-TRUS, which meets different requirements of service classes of survivability by using a simple rerouting and capacity reserving protocols. The simulation results show that the proposed algorithm can restore VPs quickly and improve the restoration time in case of multi-failures by using network resources very efficiently. Furthermore, C-TRUS outperforms the combination method in both restoration ratio and restoration time. In addition, the significant improvement of restoration ratio in the multi-failure scenario has been achieved.

A novel method is proposed to retrieve image sequences with the goal of forecasting complex and time-varying natural patterns. To that end, we introduce a framework called Memory-Based Forecasting; it provides forecast information based on the temporal development of past retrieved sequences. This paper targets the radar echo patterns in weather radar images, and aims to realize an image retrieval method that supports weather forecasters in predicting local precipitation. To characterize the radar echo patterns, an appearance-based representation of the echo pattern, and its velocity field are employed. Temporal texture features are introduced to represent local pattern features including non-rigid complex motion. Furthermore, the temporal development of a sequence is represented as paths in eigenspaces of the image features, and a normalized distance between two sequences in the eigenspace is proposed as a dissimilarity measure that is used in retrieving similar sequences. Several experiments confirm the good performance of the proposed retrieval scheme, and indicate the predictability of the image sequence.

We propose a new sampling control system on image sensor array. Contrary to the random access pixels, the proposed sensor is able to read out spatially variant sampled pixels at high speed, without inputting pixel address for each access. The sampling positions can be changed dynamically by rewriting the sampling position memory. The proposed sensor has a memory array that stores the sampling positions. It can achieve any spatially varying sampling patterns. A prototype of 64 64 pixels are fabricated under 0.7 µm CMOS precess.

In this paper, we propose an elegant approach for illumination invariant face recognition based on the photometric stereo technique. The basic idea is to reconstruct the surface normal and the albedo of a face using photometric stereo images, and then use them as the illumination independent model of the face. And, we have investigated the optimal light source directions for accurate surface shape reconstruction, and the robust estimation technique for the illumination direction of an input face image. We have tested the proposed algorithm with 125 real face images of 25 persons which are taken under 5 quite different illumination conditions, and achieved the success rate of more than 80%. Comparison results of conventional face recognition methods and the proposed method are also evaluated. These results demonstrate that the proposed technique have a great potential for the robust face recognition even when the lighting condition changes severely.

Vanadyl-phthalocyanine (VOPc) single crystals were prepared on KBr substrate by molecular beam epitaxy (MBE). Their maximum size is 1380.16 µm3. The morphology of the VOPc single crystal was investigated from the results of UV/VIS spectra and RHEED. They suggest that the VOPc single crystal may be grown with pseudomorphic layers. The growing process was expained by Volmer-Weber model. The third order nonlinear optical property of VOPc single crystal was measured with Maker fringe method. The value of the third order optical susceptibility (χ(3)) of VOPc single crystal was estimated to be about 10-9 esu from the result of Maker fringe.

In order to examine the validity of Mott-Schottky model at organic/metal interfaces, the position of the vacuum level of N,N'-bis(3-methylphenyl)-N,N'-diphenyl -[1,1'-biphenyl]-4,4'-diamine (TPD) film formed on various metal substrates (Au, Cu, Ag, Mg and Ca) was measured as a function of the film-thickness by Kelvin probe method in ultrahigh vacuum (UHV). TPD is a typical hole-injecting material for organic electroluminescent devices. At all the interfaces, sharp shifts of the vacuum level were observed within 1 nm thickness. Further deposition of TPD up to 100 nm did not change the position of the vacuum level indicating no band bending at these interfaces. These findings clearly demonstrate the Fermi level alignment between metal and bulk TPD solid is not established within typical thickness of real devices.

In conventional methods for detecting vanishing points and vanishing lines, the observed feature points are clustered into collections that represent different lines. The multiple lines are then detected and the vanishing points are detected as points of intersection of the lines. The vanishing line is then detected based on the points of intersection. However, for the purpose of optimization, these processes should be integrated and be achieved simultaneously. In the present paper, we assume that the observed noise model for the feature points is a two-dimensional Gaussian mixture and define the likelihood function, including obvious vanishing points and a vanishing line parameters. As a result, the above described simultaneous detection can be formulated as a maximum likelihood estimation problem. In addition, an iterative computation method for achieving this estimation is proposed based on the EM (Expectation Maximization) algorithm. The proposed method involves new techniques by which stable convergence is achieved and computational cost is reduced. The effectiveness of the proposed method that includes these techniques can be confirmed by computer simulations and real images.

Micropatterning of organosilane self-assembled monolayers (SAMs) was demonstrated on the basis of photolithography using an excimer lamp radiating vacuum ultra-violet (VUV) light of 172 nm in wavelength. This lithography is generally applicable to micropatterning of organic thin films including alkyl and fluoroalkyl SAMs, since its patterning mechanism involves cleavage of C-C bonds in organic molecules and subsequent decomposition of the molecules. In this study, SAMs were prepared on Si substrates covered with native oxide by chemical vapor deposition in which an alkylsilane, that is, octadecyltrimethoxysilane [CH3(CH2)17Si(OCH3)3, ODS] or a fluoroalkylsilane, that is, 1H, 1H, 2H, 2H-perfluorodecyltrimethoxy-silane [CF3(CF2)7CH2CH2Si(OCH3)3, FAS] were used as precursors. Each of these SAMs was photoirradiated through a photomask placed on its surface. As confirmed by atomic force microscopy and x-ray photoelectron spectroscopy, the SAMs were decomposed and removed in the photoirradiated area while the masked areas remained undecomposed. A micropattern of 2 µm in width was successfully fabricated. Furthermore, microstructures composed of two different SAMs, that is, ODS and FAS, were fabricated as follows. For example, an ODS-SAM was first micropatterned by the VUV-lithography. Since, the VUV-exposed region on the ODS-SAM showed an affinity to the chemisorption of organosilane molecules, the second SAM, i. e. , FAS, confined to the photolithographically defined pattern was successfully fabricated. Due to the electron negativity of F atoms, the FAS covered region showed a more negative surface potential than that of the ODS surface: its potential difference was ca. 120 mV as observed by Kelvin probe force microscopy.

A new type of Meteor Burst Communication (MBC) network is developed. Each unit of the network is based on a DSP board running a modem software. All the fundamental blocks and functions of a modem are implemented in software. Unlike hardware modems, this software modem has flexibility of system configuration and operation. The system implements adaptability in terms of modulation type (number of phases in MPSK) using a unique dynamic channel estimation scheme appropriate for MBC channel. An MBC network protocol is implemented within the modem software. Some preliminary experiments were carried out for differential BPSK and differential QPSK modulations over a practical meteor burst link, and the results are presented.

This paper introduces the construction of a family of complex-valued scaling functions and wavelets with symmetry/antisymmetry, compact support and orthogonality from the Daubechies polynomial, and applies them to solve electromagnetic scattering problems. For simplicity, only two extreme cases in the family, maximum-localized complex-valued wavelets and minimum-localized complex-valued wavelets are investigated. Regularity of root location of the Daubechies polynomial in spectral factorization are also presented to construct these two extreme genus of complex-valued wavelets. When wavelets are used as basis functions to solve electromagnetic scattering problems by the method of moment (MoM), they often lead to sparse matrix equations. We will compare the sparsity of MoM matrices by the real-valued Daubechies wavelets, minimum-localized complex-valued Daubechies and maximum-localized complex-valued Daubechies wavelets. Our research summarized in this paper shows that the wavelets with smaller signal width will result in a more sparse MoM matrix, especially when the scatterer is with many corners.

This paper proposes a private communication system with chaos using fixed-point digital computation. When fixed-point computation is adopted, chaotic properties of the modulated signal should be checked carefully as well as calculation error problems (especially, overflow problems). In this paper, we propose a novel chaos modem system for private communications including a chaotic neuron type nonlinearity, an unstable digital filter and an overflow function. We demonstrate that the modulated signal reveals hyperchaotic property within 10,000 data point fixed-point computation, and evaluate the security of this system in view of the sensitivity of coefficients for demodulation.

This paper conducts performance evaluation for a code division multiple access (CDMA) system when channel bands of multiple neighboring CDMA/DSSS are overlapped in frequency domain. It is assumed that all systems adopt direct-sequence spread-spectrum (DSSS) technique and are BPSK modulated by the different carrier frequencies. Automatic power control (APC) is also applied in the interfered system such that the receiver gets the same power from all users. Without loss generality, an additive white Gaussian noise (AWGN) channel is also assumed during analysis. In this paper, the analytic solution of the signal to noise ratio (SNR) is first derived in which both CDMA systems are modulated by different carrier frequencies. This analysis is good for general cases; and the result shows an excellent computational performance. In particular, the result is very close to Pursly's result, when the systems have the same code length with no carrier difference.

PARAdeg has been defined to try to measure parallelism inherent in a program net. Studies on computation of PARAdeg have been done, but the quantitative evaluation, on how much PARAdeg fits parallelism of program nets, has not been studied. In this paper, we do the evaluation by applying genetic algorithm to measure firing completion times when PARAdeg processors, and less and more processors are provided for 400 program nets. Our experimental results show that the firing completion times decrease rapidly with increase of processors till PARAdeg and slowly when processors are increased to more than PARAdeg, which implies PARAdeg is a reasonable standard to measure parallelism of program nets.

This paper investigates the turbo equalization techniques for wireless cellular systems. Simulation results over three GSM channel models are presented.

This article shows a Boolean Multivalued logical model of varying confirmation by observation of events in human inference and, as an introductory example, applies the model to solve Hempel's paradox of the ravens.

The sign-language can be used as a communication means between avatars having no common language. As a trial to overcome the linguistic barrier, we have previously developed a 2D model-based sign-language chatting system between Korean and Japanese on the the Internet. In that system, there have been some problems to be solved for natural animation and real-time transmission. In this paper, we employ a 3D character model for stereoscopic gestures in the sign-language animation. We also utilize CG animation techniques which use the variable number of frames and a cubic spline interpolation in order to generate realistic gestures. For real-time communication, on the other hand, we make use of an intelligent communication method on a client-server architecture. We implement a preliminary communication system with Visual C++ 5.0 and Open Inventor on Windows platforms. Experimental results show a possibility that the system could be used for avatar communications between different languages.