A formal methodology for acquiring and representing expert knowledge

The process of eliciting knowledge from human experts and representing that knowledge in an expert or knowledge-based system suffers from numerous problems. Not only is this process time-consuming and tedious, but the weak knowledge acquisition methods typically used (i.e., interviews and protocol analysis) are inadequate for eliciting tacit knowledge and may, in fact, lead to inaccuracies in the knowledge base. In addition, the intended knowledge representation scheme guides the acquisition of knowledge resulting in a representation-driven knowledge base as opposed to one that is knowledge-driven. In this paper, a formal methodology is proposed that employs techniques from the field of cognitive psychology to uncover expert knowledge as well as an appropriate representation of that knowledge. The advantages of such a methodology are discussed, as well as results from studies concerning the elicitation of concepts from experts and the assignment of labels to links in empirically derived semantic networks.     

A probabilistic approach to incorporating domain knowledge for closed-room people monitoring

We propose a novel probabilistic approach to recognizing people entering and leaving a closed room in human work place or living environment. Specifically, people in the view of a monitoring camera are first tracked and represented using low-level color features. Based on a new color similarity measure, optimal recognition of people leaving and entering the room is carried out by probabilistic reasoning under the constraints imposed by the domain knowledge, e.g., a person currently inside a room cannot enter again without first leaving it, and vice versa. The novelty of our work mainly lies in the development of a systematic way to incorporate the correlation and constraint among a sequence of people observations, and the optimality of recognition is achieved by maximizing a joint posterior probability of the observations. Experimental results of real and synthetic data are presented to show the efficacy of the proposed approach.     

一种管理XML文档集合的高效方法

分析了XML语言特点以及XML Schema之间的相似性,提出一种新的XML Schema分类合并算法组织大规模XML文档集合.     

Agent-based evolutionary approach for interpretable rule-based knowledge extraction

An agent-based evolutionary approach is proposed to extract interpretable rule-based knowledge. In the multiagent system, each fuzzy set agent autonomously determines its own fuzzy sets information, such as the number and distribution of the fuzzy sets. It can further consider the interpretability of fuzzy systems with the aid of hierarchical chromosome formulation and interpretability-based regulation method. Based on the obtained fuzzy sets, the Pittsburgh-style approach is applied to extract fuzzy rules that take both the accuracy and interpretability of fuzzy systems into consideration. In addition, the fuzzy set agents can cooperate with each other to exchange their fuzzy sets information and generate offspring agents. The parent agents and their offspring compete with each other through the arbitrator agent based on the criteria associated with the accuracy and interpretability to allow them to remain competitive enough to move into the next population. The performance with emphasis upon both the accuracy and interpretability based on the agent-based evolutionary approach is studied through some benchmark problems reported in the literature. Simulation results show that the proposed approach can achieve a good tradeoff between the accuracy and interpretability of fuzzy systems.     

An approach to control laws for arm motion

This paper is concerned with the investigation of arm motion between fixed boundary conditions within a two-dimensional space. An approach to the mathematical modeling and formulation ofthe control laws which govern arm reaching motion is presented.     

An alternate approach to syndrome algebra for diagnostics

It is shown that the syndrome of a Boolean function F (for diagnostics) can be nicely modeled to be F in a special pseudo-Boolean algebra at that point in state space where all variables are equal to $\text{1}\text{2}$ or as the probability of F being 1 in case all its variables appear with probability $\text{1}\text{2}$. Results are useful wherever the number of minterms of a switching function is needed.     

The FMEDA approach to improve the safety assessment according to the IEC61508

According to the Standard IEC61508, the paper presents a case study concerning the evaluation of both the safe failure fraction (SFF) and the probability of failure on demand (PFD) for a complex system. After a preliminary presentation of the criteria for the safety integrity level (SIL) verification, the work focuses the attention on the method to achieve the PFD. In particular, an approach based on failure modes, effects and diagnostic analysis (FMEDA) is proposed and then a comparison with the approach described in the Standard. The paper aims to clarify both the knowledge and the application of the IEC61508 and proposes a technique to satisfy the hardware safety integrity requirements.     

An approach to determining an equivalent circuit for HEMTs

A simple way to determine a small-signal equivalent circuit of High Electron Mobility Transistors (HEMTs) is proposed. Intrinsic elements determined by a conventional analytical parameter transformation technique are described as functions of extrinsic elements. Assuming that the equivalent circuit composed of lumped elements is valid over the whole frequency range of the measurements, the extrinsic elements are iteratively determined using the variance of the intrinsic elements as an optimization criterion. Measurements of S-parameters up to 62.5 GHz at more than 100 different bias points confirmed that the HEMT equivalent circuit is consistent for all bias points     

An evolutionary approach to visual sensing for vehicle navigation

This paper presents an evolutionary approach able to process a digital image and detect tracks left by preceding vehicles on ice and snow in Antarctica. Biologically inspired by a colony of ants able to interact and cooperate to determine the shortest path to the food, this approach is based on autonomous agents moving along the image pixels and iteratively improving an initial coarse solution. The unfriendly Antarctic environment makes this image analysis problem extremely challenging, since light reflections, abruptly varying brightness conditions, and different terrain slopes must be considered as well. The ant-based approach is compared to a more traditional Hough-based solution and the results are discussed.     

An approach to define parameters for localization of thunderstorms

The basic topic of this paper is the localization of the thunderstorm center. It concentrates on the development of a method to analytically determine the range, the geometric factor, and the angular parameters. An electrical dipole of arbitrary spatial orientation is used as model of the discharge between a cloud and the Earth.     

An impedance-based approach to predict the state-of-charge for carbon-based supercapacitors

The impedance behavior of supercapacitors is not only a key issue for the parameterize modeling of the supercapacitor, but also an important factor for the design processes of an intelligent energy-management system which monitors the state of the supercapacitor and predicts its performance. In this paper, a simple equivalent circuit model and convolution algorithm based on impedance analysis were presented to assess state-of-charge, terminal voltage and charge/discharge capability of supercapacitors. Furthermore, an impedance function based on the equivalent impedance model was established to simulate the dynamic performance of a supercapacitor. The results can be used to control the reliable prediction of supercapacitors performance in electric vehicles, hybrid electric vehicles, fuel cell vehicles and classical automotive applications.     

An information-spectrum approach to capacity theorems for thegeneral multiple-access channel

The paper deals with the capacity problems for the general multiple-access channel, where the channel transition probabilities are arbitrary for every blocklength n. The approach used here, which is called the information-spectrum approach, is quite different from the standard typical-sequence and/or AEP techniques. The general formula for the capacity region for the general multiple-access channel is thus established. In order to examine the potentiality, we apply it to the mixed channel to obtain the formula for its capacity region. The case where input cost constraints are imposed is also considered     

An engineering approach to Bayes estimation for the Weibull distribution

In this paper an engineering approach to Bayes reliability analysis of Weibull failure data collected under a randomly censored sampling is proposed. The posterior distribution of several decision variables, such as the meanlife, the reliability function, the reliable life, and the hazard rate, are derived, when either a prior information on the reliability or a prior information on the hazard rate is available. Point estimates of the selected decision variables are given, by assuming both symmetric and asymmetric loss functions. Finally, numerical examples are presented to illustrate the proposed estimation procedures.     

An efficient systematic approach to model extraction for passivemicrowave circuits

This paper introduces a new systematic approach to equivalent circuit model extraction for linear microwave passive circuits directly from full-wave frequency domain simulation. The devices being modeled may be either lossless or lossy. Adaptive frequency sampling is used to minimize the computational effort of EM simulation while critically assisting in determining the pole locations of an RF circuit. A simple circuit model for lossy RF circuits along with a determined starting point of optimization of lumped element component values is also presented in detail. The overall result is an efficient and accurate means to produce a complete equivalent lumped element model for RF circuits that is suitable for use in conventional SPICE-like simulation software     

An approach to the multifunction graphic terminal for the ISDNenvironment

The authors describe the current environment of ISDN-like services or trials and predict a likely and promising service menu, based on two years of experience monitoring the INS model system and commercial service in Japan. They propose the integration of various terminal functions into six categories of multifunction terminals that handle voice, data, graphics, and video signals and that could meet the needs of ISDN customers. They describe a prototypical multifunction graphic terminal and the communication services, that it must support     

An evolutionary approach to designing complex spreading codes for DS-CDMA

This paper proposes a novel evolutionary approach to spreading code design in direct sequence code division multiple access (DS-CDMA). Specifically, a multiobjective evolutionary algorithm (EA) is used to generate complex spreading sequences that are optimized with respect to the average mean-square cross- and/or autocorrelation (CC and/or AC) properties. A theoretical model is developed in order to demonstrate the optimality of the generated codes. The proposed algorithm enables spreading code design with no constraints on the code length. Furthermore, it is possible to generate K/spl ges/N codes of length N with very little cost in correlation properties. This results in significant capacity enhancement in DS-CDMA systems.     

城市有线电视网的探讨（上）

本文简要介绍了有线电视的发展，并从有线电视的传输手段、网络功能，结构、工程，以及邻频与双向传输等各个方面，研究探讨了城市有线电视网的技术问题，以供同行参考。