An Application of Syntactic Pattern Recognition to Seismic Discrimination

Two syntactic methods for the recognition of seismic waveforms are presented in this paper. The seismic waveforms are represented by strings of primitives. Primitive extraction is based on cluster analysis. Finite-state grammars are inferred from the training samples. The nearest-neighbor decision rule and error-correcting finite-state parsers are used for pattern classification. While both show equal recognition performance, the nearest-neighbor rule is much faster in computation speed. The classification of real data for earthquake/explosion is presented as an application example.     

A syntactic method for image segmentation and object recognition

In this paper, image segmentation and object recognition using syntactic methods are investigated. The segmentation process is embedded in the parsing algorithm. The approach can be described by a syntax-directed relaxation process. Previous error-correcting parsing algorithms, however, have not tackled the segmentation problem satisfactorily. Experimental results using Synthetic Aperture Radar (SAR) images are given.     

应用专家系统的机器人规划

本文介绍一个新开发的高层机器人规划系统——基于专家系统的机器人规划系统。模拟及比较结果表明,该系统既能改善规划性能,又可加快规划速度。     

Recursive contextual classification using a spatial stochastic model

In the past decade, there have been numerous attempts to develop systems for automatic interpretation of digital image data. None of the systems developed for this purpose have made extensive use of context information. Since even manual interpretation of isolated point or area targets is difficult without the use of context, a machine which does not use context has a fundamental limitation.In the course of using contextual information, the first task is to present a stationary stochastic process on a two-dimensional plane. This process is then used as a model, such that correlations between any pair of image cells can be extracted. The model is characterized by a spatial correlation parameter. A flexible coding technique is presented by which the spatial correlation parameter can be estimated. From the coded patterns used for estimating the spatial correlation parameter, a recursive contextual classification procedure is proposed. Some modifications and extensions of the model are specifically developed or substantially refined during this investigation to cover more general situations.Finally, extensive experimental results with remotely sensed multispectral scanner data using the developed model for contextual classification are reported. Both single-stage and recursive contextual classification procedures are tested on real data. The classification results do show the effectiveness and efficiency of the developed contextual classifier.     

A Pattern Classification System for the Identification of Irradiated Chromosomes

Monitoring health-related radiation damage is important for the future, and a system to detect chromosomal aberrations associated with radiation is extremely useful for monitoring populations exposed to radiation. In general, the most useful indicator of radiation damage at the cellular level is the occurrence of ring, dicentric, fragment, and fragment ring chromosomes.     

Contention-based MAC protocols with erasure coding for wireless data networks

Contention-based medium access control (MAC) protocol is a key component for the success of wireless data networks. Conventional random access protocols like ALOHA and Carrier Sense Multiple Access (CSMA) suffer from packet collision which leads to low throughput. Aimed at improving the throughput performance, we propose to integrate erasure coding with contention-based MAC protocols for recovering collided packets. To demonstrate the effectiveness of this approach, we focus on combining erasure coding with slotted ALOHA and slotted non-persistent CSMA in this paper. The performances of the resulting protocols are evaluated by both analytical model and simulation. Simulation results match very well with analytical results and show that the system throughput is increased for low to medium traffic loading. Packet loss ratio is also improved considerably with our scheme when the maximum number of packet retransmission times is limited. However, the delay for our scheme is higher due to the longer waiting time in our scheme for recovering collided packets. It is also shown that delay can be significantly reduced if we choose appropriate coding parameters though throughput will be sacrificed.     

Modeling rule-based systems by stochastic programmed production systems

A new tool, the stochastic programmed production system (SPPS), is proposed for representing rules and control mechanisms in rule-based systems. This approach is based on the stochastic programmed grammars, and its peculiarity is both its well-formalized semantics and its ability to represent most reasoning and control methods used in expert systems today. Since the proposed method is not limited by the particular heuristic organization of the rule-based system it is modeling, the SPPS is more general than existing knowledge-domain-independent expert-system development languages and may help bring a better understanding of the theory of expert systems.     

Learning control systems--Review and outlook

The basic concept of learning control is introduced. The following five learning schemes are briefly reviewed: 1) trainable controllers using pattern classifiers, 2) reinforcement learning control systems, 3) Bayesian estimation, 4) stochastic approximation, and 5) stochastic automata models. Potential applications and problems for further research in learning control are outlined.     

An efficient handoff management scheme for mobile wireless ATMnetworks

A new handoff management scheme for wireless ATM networks is proposed. In this scheme, all cells are connected to their neighboring cells by permanent virtual circuits (PVCs) and to the access switch (AS) by switched virtual circuits (SVCs) which are only for new calls. Some carefully chosen cells, called rerouting cells, are also connected to the AS by PVCs. In summary, if a mobile roams to an ordinary neighboring cell, its traffic path is simply elongated by a PVC connecting the old and new cells. If a mobile roams to a rerouting cell, its traffic path is rerouted to a PVC between the AS and rerouting cell. By using PVC's for handoff calls, we can guarantee fast and seamless handoff. At the same time, our scheme improves the path efficiency by limiting the maximum number of hops that a path can be extended. Also, allowing path rerouting at a suitable time means the network resources are more efficiently utilized