The use of intelligent agents is on the rise, fueled by the unprecedented growth in the Internet and web based applications. Consequently, agent-oriented software is becoming large and complex. To support a systematic development of such software, an agent-oriented software development methodology is necessary. This paper focuses on the modeling phase of agent-oriented software life cycle and, presents an approach for agent modeling consisting of Agent Elicitation, Intra, and Inter Agent modeling methods. Agent Elicitation deals with identifying and extracting agents from "classes" in the real world. Intra Agent Modeling involves expressing agent characteristics - Goal, Belief, Plan and Capability - whereas, Inter Agent modeling incorporates agent mobility and communication in a multi-agent system.

This paper reports the implementation in three dimensions (3D) of diffusion models for low dose implanted dopants in silicon and the various numerical issues associated with it. In order to allow the end-users to choose between high accuracy or small calculation time, a conventional and 5-species diffusion models have been implemented in the 3D module DIFOX-3D belonging to the PROMPT plateform. By comparison with one and two-dimensional (1D and 2D) simulations performed with IMPACT-4, where calibrated models exist, the validity of this 3D models have been checked. Finally, the results obtained for a 3-dimensional simulation of a rapid thermal annealing step involved in the manufacturing of a MOS transistor are presented what show the capability of this module to handle the optimization of real devices.

The high accuracy which is necessary for modern process simulation often requires the use of Monte-Carlo ion implantation simulation methods with the disadvantage of very long simulation times especially for three-dimensional applications. In this work a new method for an accurate and CPU time efficient three-dimensional simulation of ion implantation is suggested. The approach is based on a combination of the algorithmic capabilities of a fast analytical and the Monte-Carlo simulation method.

The application of Technology CAD simulations for development of IC processes in foundry is presented. Examples include device design, Flash cell design and optical proximity correction for SRAM cell. The challenges of using TCAD tools in the IC foundry is also discussed.

A circuit-level electrothermal simulator, MICS (MItsubishi Circuit Simulator), is presented with parasitic bipolar transistor action and lattice heating taken into account. Diffusion capacitance in parasitic bipolar transistors is introduced to cover turn-on behavior under short rise-time current. Device temperatures are simulated from calculated electrical characteristics and the closed-form solution of the heat transfer equation. Simulation results show that this tool is valuable in evaluating electrostatic discharge (ESD) robustness in integrated circuits (ICs).

This paper presents the implementation of a 3 V low power multi-rate of 156, 622, and 1244 Mbps clock and data recovery circuit (CDR) for optical communications tranceiver using new parallel clock recovery architecture based on dual charge-pump PLL. Designed circuit recovers eight-phase clock signals which are one-eighth frequency of the input signal. While the typical system uses the method that compares the input data with recovered clock, the proposed circuit compares a 1/2-bit delayed input data with the serial data generated by the recovered eight-phase clock signals. The advantage of the circuit is that the implementation is easy, since each sub blocks have one-eighth frequency of the input data signal. Morevover, since the circuit works at one-eighth frequency of the input data, it dissipates less power than conventional CMOS recovery circuit. Simulation results show that this recovery circuit can work with power dissipation of less than 40 mW with a single 3 V supply. All the simulations are based on HYUNDAI 0.65 µm N-Well CMOS double-poly double-metal technology.

This paper analyses the performance of a joint receiving structure for DS-CDMA communications systems. To reduce undesirable performance degradation due to the multiple access interferences and the near-far problem in multipath fading channel environment, this paper exploits the receiving structure for the multiuser communication composed of a beamformer-RAKE receiver and a decorrelating multiuser detector. The proposed DS-CDMA receiving structure mitigates the performance impairment invoked from the noise enhancement and reveals less computational complexity by utilizing the multipath temporal combiner prior to accessing the decorrelating detection. Also an efficient block Toeplitz inversion technique using the matrix Levinson polynomials is introduced to further diminish the computational burden encountered from applying the decorrelating multiuser detection process as in usual. Simulation results are conducted to demonstrate the superior performance of the proposed multiuser detection structure in multipath fading CDMA channel.

Learning process is essential for good performance when a neural network is applied to a practical application. The backpropagation algorithm is a well-known learning method widely used in most neural networks. However, since the backpropagation algorithm is time-consuming, much research have been done to speed up the process. The block backpropagation algorithm, which seems to be more efficient than the backpropagation, is recently proposed by Coetzee in [2]. In this paper, we propose an efficient parallel algorithm for the block backpropagation method and its performance model in mesh-connected parallel computer systems. The proposed algorithm adopts master-slave model for weight broadcasting and data parallelism for computation of weights. In order to validate our performance model, a neural network is implemented for printed character recognition application in the TiME which is a prototype parallel machine consisting of 32 transputers connected in mesh topology. It is shown that speedup by our performance model is very close to that by experiments.

The ATM Wireless Access (AWA) System allows portable terminals such as notebook PCs to provide up to 10Mbits/s to each user. AWA will be one of the last hops of the fiber system; it seamlessly provides wireless terminals with most of the services available in the fiber system. A prototype is developed to confirm system realization and the technical feasibility of the radio transmission rate of 80 Mbit/s, the highest yet reported in wireless access systems, by employing ATM technology to support multimedia communication with different communication quality requirements. The prototype uses TDMA as the multiple access method. This paper proposes the system concept and technical issues of the AWA system. The design and performance of the AWA prototype are clarified. It is confirmed that the target performance of the prototype can be achieved and technical issues are feasible.

This paper proposes a fast implementation technique for RLS adaptive filters. The technique has an adjustable parameter to trade the throughput and the rate of convergence of the filter according to the applications. The conventional methods for improving the throughput do not have this kind of adjustability so that the proposed technique will expand the area of applications for the RLS algorithm. We show that the improvement of the throughput can be easily achieved by rearranging the formula of the RLS algorithm and that there are no need for faster PEs for the improvement.

In order to serve traffic hot spots, the hierarchical cellular systems or the hybrid TDMA/CDMA have been proposed, recently. In order to depress the multi-user interference and increase capacity, the forward link power control strategy is adopted in the macrocell/microcell hierarchical cellular system using code division multiple access (CDMA). Its effects are estimated in this paper. Especially, the impact of -th distance power control laws on the forward link outage probability and capacity plane for the hierarchical cellular system are investigated. The coverage area user capacity of the overlaid macrocell/microcell cellular system is obtained. The numerical results and discussions with previous published results are presented in detail.

We investigate the intrinsic current fluctuations in small Si-MOSFETs via the Monte Carlo device simulation. It is demonstrated that the temporal fluctuation of the drain current in Si-MOSFETs attains a significant fraction of the averaged drain current when the device width is scaled down to the deep sub-µm regime. This is caused by the drastic decrease in the number of channel electrons. This finding holds true whenever the device width is reduced to deep sub-µm, regardless of the channel length. Most importantly, current fluctuation is associated with the quasi-equilibrium thermal noise in the heavily-doped source and drain regions, whereas its magnitude with respect to the averaged drain current is directly related to the number of channel electrons underneath the gate.

A first-order investigation of the transport and energy-loss processes in silicon dioxide is worked out in the frame of the Spherical-Harmonics solution of the Boltzmann Transport Equation. The SiO2 conduction band is treated as a single-valley spherical and parabolic band. The relevant scattering mechanisms are modeled consistently: both the polar and nonpolar electron-phonon scattering mechanisms are considered. The scattering rates for each contribution are analyzed in comparison with Monte Carlo data. A number of macroscopic transport properties of electrons in SiO2 are worked out in the steady-state regime for a homogeneous bulk structure. The investigation shows a good agreement in comparison with experiments in the low-field regime and for different temperatures.

Since mobile communication systems using optical rays (optical mobile communication systems) do not radiate radio waves from the mobile terminals, they are expected to be used in environments containing sensitive electronic equipment. However, the placement and direction of the optical receivers must be suitably determined for mobile communication because light has high directivity. In optical mobile communication systems, the communication quality varies with the direction of the mobile terminal. Therefore, we examined the angle over which communication is possible at various measurement points and defined it as the communication angle. The mean opinion score (MOS) was obtained to assess the communication quality using the communication angle as a parameter. In this paper, the two situations, walking and sitting down, was considered the way optical mobile communication systems actually used. We found that for walking, when the communication angle was over 180 degrees, the MOS was over 3 and over 50% of users could communicate usefully. When used sitting down, the communication quality did not depend on the communication angle, but only on whether or not the user could communicate in the direction he/she was facing. Thus, if the communication angle in the service area is over 180 degrees, it is possible to communicate in practical situations, even while walking.

As scaling has been continued more than 20 years, it has yielded faster and denser chips with ever increasing functionality. The scaling will continue down to or beyond 0.1 µm as proposed in SIA Technical Road map. With scaling, device performance improves, however, interconnect performance is degraded. In this scaled deep submicron technology, however, interconnects limit the performance, packing density and yield, if not properly modeled. In order to properly model and design the interconnect-dominated circuits, accurate and proper interconnect modeling is a must to assure the performance and functionality of ever-increasing complex multi-million transistor VLSI circuits. In this paper, the overall flow of interconnect modeling in IC design is reviewed including interconnect characterization, various 2-D/3-D field solvers, 2-D/3-D interconnect model library generation, and parameter extraction. And advanced topics of interconnect modeling in deep submicron are reviewed; statistical interconnect modeling.

In this paper we develop a CORDIC-based floating-point vectoring algorithm which reduces significantly the amount of microrotation steps as compared to the conventional algorithm. The overhead required to accomplish this is minimized by the introduction of an angle selection function which considers only a few of the total amount of bits used to represent the vector being rotated. At the same time, the cost of individual microrotations is kept low by the utilization of a fast rotations angle base.

The Tikhonov regularization theory converts ill-posed inverse problems into well-posed problems by putting penalty on the solution sought. Instead of solving an inverse problem, the regularization theory minimizes a weighted sum of "data error" and "penalty" function, and it has been successfully applied to a variety of problems including tomography, inverse scattering, detection of radiation sources and early vision algorithms. Since the function to be minimized is a weighted sum of functions, one should estimate appropriate weights. This is a problem of hyperparameter estimation and a vast literature exists. Another problem is how one should compare a particular penalty function (regularizer) with another. This is a special class of model comparison problems which are generally difficult. A Hierarchical Bayesian scheme is proposed with multiple hyperparameters in order to cope with data containing subsets which consist of different degree of smoothness. The scheme outperforms the previous scheme with single hyperparameter.

Layer-by-layer sequential adsorption process of polyelectrolytes had conventionally been used for the fabrication of the ultra-thin organic film formed by various polymers with different polarity of charge. In this study, hydrophobic Ruthenium complex monomer (tris (bilyridyl) ruthenium (II) hexafluorophosphate) was micelle-wrapped with an anionic surfactant, sodium dodecylbenzenesulfonate, and was assembled with PAH (poly (allylamine hydrochloride)) which has the opposite charge on ITO substrates. With this method, we succeed in fabricating ultra-thin organic films even when the adsorption material is not polymer but monomer. Moreover it was found that the bilayer thickness of the self-assembled (Ru micelle/PAH) was systematically changed by adjusting the solution pH of each bath. By using this process, EL device was fabricated by depositing the thin film of micelle-wrapping ruthenium complex monomer on ITO and formed Bi electrode on top of the film. Light emission was observed by applying voltage to this device.

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.

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.