The adaptive associative memory proposed by Ma is used to construct a new model of semantic network, referred to as associative semantic memory (ASM). The main novelty is its computational effectiveness which is an important issue in knowledge representation; the ASM can do inference based on large conceptual hierarchies extremely fast-in time that does not increase with the size of conceptual hierarchies. This performance cannot be realized by any existing systems. In addition, ASM has a simple and easily understandable architecture and is flexible in the sense that modifying knowledge can easily be done using one-shot relearning and the generalization of knowledge is a basic system property. Theoretical analyses are given in general case to guarantee that ASM can flawlessly infer via pattern segmentation and recovery which are the two basic functions that the adaptive associative memory has.

For Cable-To-The-Air network providing a seamless access network in both indoor and outdoor, direct optical switching CDMA scheme is newly proposed to multiplex any types of radio signals. In two types of connection methods, optical switch connection and optical coupler connection systems, the received carrier-to-interference-plus-noise power ratios are theoretically analyzed. It is clarified that in the optical switch connection connection system, by introducing the additional optical gain at each radio base station, the carrier-to-interference-plus-noise power ratios for all radio base stations and the connected number of radio base stations can be improved compared with the OC connection system.

In this paper a new general method for approximation of arbitrary multiband filter loss specifications, including all classical, maximally flat and equiripple approximations as special cases, is proposed. It is possible to specify different magnitude behavior (flat or equiripple of given degree) and different maximal losses in the different passbands and to optimize all transmission and attenuation zeroes positions or to have some of them fixed. The optimization procedures for adjustment of the filter response are based on modified Remez algorithm and are performed in s-domain what is regarded since recently as an advantage in the case of design of parallel allpass structures based IIR digital filters. A powerful algorithm and appropriate software are developed following the method and their efficiency is verified through design examples.

This paper proposes a novel representation scheme for self-healing networks, and estimates the performance of restoration algorithms in terms of survivability. This representation is based on that of ring networks. For an arbitrary topology, the network is partitioned into ring sub-networks which are independent of each other, and we consider an extended network constructed by the concatenation of the ring sub-networks. After the statement of the general case, examples of a self-healing ring and a Digital Cross-connect System(DCS)based network are described.

In this paper, we propose a new cooperative search algorithm based on pheromone communication for solving the Vehicle Routing Problems. In this algorithm, multi-agents can partition the problem cooperatively and search partial solutions independently using pheromone communication, which mimics the communication method of real ants. Through some computer experiments the cooperative search of multi-agents is confirmed.

A mobility management scheme that reduces signaling traffic load and connection setup time is a pivotal issue in designing future personal communication service (PCS) networks to satisfy Quality of Services requirements and use network resources efficiently. Particularly, required is scalable mobility management, to meet the explosive growth in number of users for the current second-generation wireless communication systems, and to materialize PCS concepts such as terminal, personal, and service mobility. Many mobility management schemes have been proposed for the reduction of signaling traffic. However, these schemes have not been sufficiently compared using a unified performance measure that is free of assumptions as to mobility model or database architecture. In this paper, we categorize the various mobility management schemes for advanced PCSs in distributed environments into four types and clarify the appropriate domain for each type. To do this, we settled on the number of signals at connection setup and location registration as a unified performance measure, since this value closely relates to connection setup time and network efficiency. We found two kinds of schemes with replicating and caching functions of user information that are extremely effective for reducing signaling load and hence connection setup time. These schemes are appropriate when the probability that a user is in his/her home area is relatively small or the connection setup rate is relatively high compared to the location registration rate. These are the most likely situations in the advanced PCS for global environments.

We demonstrate that the frequency modulated video signals in the subcarrier multiple access optical network can be satisfactorily transmitted using our proposed method, that broadens an optical spectrum by multiplying the subcarrier signals by an additional signal and that reduces optical beat interference, even if the wavelengths of four Fabry-Perot laser diodes are very close each other.

This paper proposes a novel bidirectional rod antenna (BIRA) comprising a collinear antenna and parasitic wires as a base station antenna for a street microcell. The spacing between the collinear antenna and the parasitic wire, and the length of the parasitic wires, which are the design parameters obtaining a bidirectional pattern, are investigated using the moment method. The results show that wide spacing enlarges the bandwidth obtaining the bidirectional pattern, however it decreases the gain. Furthermore, to enlarge the bandwidth, a BIRA with arc parasitic plates whose radius is the same as that of the radome is also proposed. The configuration can be constructed using the same exterior as the BIRA with parasitic wires. It is also shown that the arc parasitic plates enlarge the bandwidth in proportion to the area projected onto the tangential plane at the center of the arc. Finally, a prototype of the proposed antenna is shown.

In the future asynchronous transfer mode (ATM) networks, an efficient virtual path (VP) control strategy must be applied to guarantee the network has high throughput with tolerable node processing load. The multistage VP control may be the best candidate since the tasks in this method are shared by the central node and local nodes, and it allows us to track the traffic changes while maintain a good state of the VP topology by reconfiguring it at regular or need based intervals. In this paper, we focus on the VP topology optimization problem in the multistage VP control. We first present the problem formulation in which the tradeoff between the network throughput and processing costs is considered, and then employ an algorithm based on a route-neuron Hopfield neural network (HNN) model to solve this problem. The numerical results demonstrate the HNN can converge to optimal solutions with high probability and stability while in other cases to near optimal solutions if the values of the system parameters in the route-neuron model are chosen according to some empirical formulas provided in this paper.

An efficient algorithm is proposed for finding all solutions of bipolar transistor circuits. This algorithm is based on a simple test that checks the nonexistence of a solution using linear programming. In this test, right-angled triangles are used for surrounding exponential functions of the Ebers-Moll model, by which the number of inequality constraints decreases and the test becomes efficient and powerful.

This paper describes two dimensional (2D) equalization scheme of orthogonal coding multi-carrier CDMA for reverse link of mobile communication systems. The purpose of the 2D equalization is the reduction of Multiple Access Interference (MAI) which is caused by the random access and the different propagation path from each mobile station. The orthogonal coding multi-carrier CDMA multiplexes all mobile stations' data by Code Division Multiplexing (CDM). The 2D coding scheme spreads a preamble signal at time (in subchannel signals) and frequency (between subchannel signals) domains. The 2D decoding scheme estimates transmission delay time and instantaneous fading frequency from preamble signal for individual mobile stations and compensate the received data using these estimation values to reduce MAI.

For people with serious disability, it is most significant to be able to use the same communication methods, for instance a telephone and an electronic mail system (e-mail), as ordinary people do in order to get a normal life and communicate with other people for leading a social life. In particular, having communications access to an e-mail is a very effective method of communication that enables them to convey their intention to other people directly while at the same time keep their privacy. However, it takes them much time and effort to input an e-mail text on the computer. They also need much support by their attendants. From this point of view, we propose a multi-modal communication system that is composed of a voice recognizer, a pointing device, and a text composer. This system intend to improve the man-machine interface for people with physical disability. In this system, our voice recognition technology plays a key role in providing a good interface between disabled people and the personal computer. When generating e-mail contents, users access the database containing user keywords, and the guidance menu from which they select the appropriate word by voice. Our experimental results suggest that this communication system improves not only the time efficiency of text composition but also the readiness of disabled people to communicate with other people. In addition, our disabled subject on this paper is not able to move his body, legs and hands due to suffer from muscular dystrophy. And he is able to move only his fingers and speak command words with the assistance of a respirator.

This paper describes a theoretical foundation of fuzzy morphological operations and architectural extension of the shared-weight neural network (SWNN). The network performs shift-invariant filtering using fuzzy-morphological operations for feature extraction. The nodes in the feature extraction stage employ the generalized-mean operator to implement fuzzy-morphological operations. The parameters of the SWNN, weights, morphological structuring element and fuzziness, are optimized by the error back-propagation (EBP) training method. The parameter values of the trained SWNN are then implanted into the extended SWNN (ESWNN) which is a simple convolution neural network. The ESWNN architecture dramatically reduces the amount of computation by avoiding segmentation process. The neural network is applied to automatic recognition of a vehicle in visible images. The network is tested with several sequences of images that include targets ranging from no occlusion to almost full occlusion. The results demonstrate an ability to detect occluded targets, while trained with non-occluded ones. In comparison, the proposed network was superior to the Minimum-Average Correlation filter systems and produced better results than the ordinary SWNN.

This paper proves a general sampling theorem, which is an extension of Shannon's classical theorem. Let o be a closed subspace of square integrable functions and call o a signal space. The main aim of this paper is giving a necessary and sufficient condition for unique existence of the sampling basis {Sn}o without band-limited assumption. Using the general sampling theorem we rigorously discuss a frequency domain treatment and a general signal space spanned by translations of a single function. Many known sampling theorems in signal spaces, which have applications for multiresolution analysis in wavelets theory are corollaries of the general sampling theorem.

Subharmonically Injection-locked oscillators (ILO's) with very wide injection-locking ability are presented. Two types of ILO MMIC's with this ability are proposed. The oscillation frequency tuning function of the ILO MMIC is very useful for expansion of the injection locking range at higher subharmonics. One consists of a shunt varactor diode inserted into the oscillation loop, and the other incorporates a vector-combining configuration with in-phase divider and 90 degree hybrid. Using three-dimensional MMIC's technology which can offer miniature and high-density passive circuits, the vector-combining type ILO is formed in a very compact area of 1. 7 mm2. Fabricated 20 GHz-band ILO achieves a wide tuning ranges of 870 MHz, resulting in a very wide locking range for higher subharmonics. The wide frequency tuning ability also reduces phase noise, shortens a locking time and compensates the center frequency deviation against temperature, as well as increasing locking range. The measured results show that the ILO configuration is extremely suitable for realizing simple, fully monolithic and low phase noise millimeter-wave frequency synthesizers.

Two-dimensional (2-D) adaptive digital filters (ADFs) for 2-D signal processing have become a fascinating area of the adaptive signal processing. However, conventional 2-D FIR ADF's require a lot of computations. For example, the TDLMS requires 2N2 multiplications per pixel. We propose a new 2-D adaptive filter using the FFTs. The proposed adaptive filter carries out the fast convolution using overlap-save method, and has parallel structure. Thus, we can reduce the computational complexity to O(log2N) per pixel.

In this paper, we propose a new denoising algorithm based on the dyadic wavelet transform (DWT) for ECG signals corrupted with different types of synthesized noise. Using the property that DWT is overcomplete, we define some convex sets in the set of wavelet coefficients and give an iterative method of the projection on the convex sets. The results show that the noises are not only removed from ECG signals, but also the ECG signals are reconstructed, which is used in detecting QRS complex. The performance of the proposed algorithm is demonstrated by some experiments in comparison with the conventional methods.

This paper proposes an automatic structural programming system. Genetic Programming achieves success for automatic programming using the evolutionary process. However, the approach doesn't deal with the essential program concept in the sense of what is called a program in software science. It is useful that a program be structured by various sub-structures, i. e. subroutines, however, the above-mentioned approach treats a single program as one sequence. As a result of the above problem, there is a lack of reusability, flexibility, and a decreases in the possibility of use as a utilitarian programming system. In order to realize a structural programming system, this paper proposes a method which can generate a program constructed by subroutines, named formula, using the evolutionary process.

In this paper, we consider the selection of analysis filters used in the delayless subband adaptive digital filter (SBADF) and propose to use simple analysis filters to reduce the computational complexity. The coefficients of filters are determined using the components of the first order Hadamard matrix. Because coefficients of Hadamard matrix are either 1 or -1, we can analyze signals without multiplication. Moreover, the conditions for convergence of the proposed method is considered. It is shown by computer simulations that the proposed method can converge to the Wiener filter.

The second-generation CMOS current conveyors are developed for high-frequency analog signal processing. It consists of a source follower for the voltage input and a regulated current mirror for the current input and output. The voltage and current input stages are also coupled by a current mirror to reduce the impedance of the current input port. Simulations show that this architecture provides the high input/output conductance ratio and the inherent voltage and current transfer bandwidths extending beyond 100 MHz. The prototype chips fabricated using 0. 6 µm CMOS process have confirmed the simulated performances, though the voltage and current bandwidth are limited to 20 MHz and 35 MHz, respectively, by the built-in capacitances of the bonding pads.