Hierarchical ordering of sequential processes

Summary One of the primary functions of an operating system is to rebuild a machine that must be regarded as non-deterministic (on account of cycle stealing and interrupts) into a more or less deterministic automaton. Taming the degree of indeterminacy in steps will lead to a layered operating system. A bottom layer will be discussed and so will the adequacy of the interface it presents. An analysis of the requirements of the correctness proofs will give us an insight into the logical issues at hand. A director-secretary relationship will be introduced to reflect a possible discipline in the use of sequencing primitives.     

一种基于点迹重构的异步序贯航迹融合算法

针对异步航迹融合问题,提出了一种基于伪点迹异步序贯航迹融合算法,伪点迹由局部估计结果重构形成,从而无需对局部估计间的相关误差进行处理。同时,对重构的异步伪量测数据情况采用序贯处理方式,这种串行合并式数据处理过程,不但避免了对异步数据进行时间校正的麻烦,反而利用了异步数据增加了多传感器系统的总体数据率,提高了多传感器系统对目标的跟踪精度。并用仿真结果证明了该算法的有效性。     

Deterministic buffer synchronization of sequential processes

Summary Co-operation of sequential processes is one of the most widely known organization principles for distributed systems. We shall consider the class of those systems of sequential processes which communicate deterministically by means of buffers and discuss proof rules to decide whether or not deadlocks can occur in a given system of this type.     

Asynchronous mediation for integrating business and operational processes

Integrating business and operational processes is necessary today to meet the market's increasingly demanding requirements. In particular, it allows rapid decision-making, customized production, and short time-to-market. To address these challenges, the authors built a mediation suite on top of a message-oriented middleware to help develop e-services based on industrial data. This software, based on a domain-specific component model, meets stringent market requirements and is being used in real-life service applications.     

AUTO_SAFE: An expert controller for sequential and batch sequential processes

It is generally recognised that industrial processes depend heavily on sequential control. Paradoxically, this technique of control has received from control theorists, less attention than it deserves. In view of its logical basis, this class of control is an ideal candidate for rule-based expert systems. Features of one such expert system are presented in this paper, along with observations related to the development of expert systems for process control.     

Asynchronous sequential machines with adversarial intervention: the use of bursts

Feedback controllers can automatically counteract the effects of adversarial interventions on the operation of asynchronous sequential machines. The use of bursts–fast outbursts of characters generated by a controlled machine during transition–helps broaden the conditions under which such controllers exist. Necessary and sufficient conditions for the existence of state feedback controllers that employ bursts to counteract the effects of adversarial interventions are presented. Design techniques for such controllers are also described.     

On processes, synchronization and redundant code in communicating sequential processes

A comparison of the communication aspect of CSP and an implementation COSPOL is presented. This is confined to a specific example employed in a cited paper. The main consideration is the effect that the communication mechanism can have upon the resultant structure of a solution.     

Communicating sequential processes for distributed constraint satisfaction

CSPCONS is a programming language that supports program execution over multiple Prolog processes with constraints. The language is an extended version of Csp-ii, a version of Prolog that supports channel-based communicating processes and TCP/IP communication, that is based on the CSP model introduced by Hoare. Cspcons inherits all the advanced features of Csp-ii and extends it by introducing constraint solving capabilities to the processes. In Cspcons each Prolog process has one or more solvers attached and each solver is independent from the others, following the original Csp-ii model, thus resulting to a communicating sequential constraint logic programming system. Such a model can facilitate greatly the implementation of distributed CLP applications. This paper describes the original Csp-ii system along with details of the extensions that resulted to the Cspcons system and presents an example demonstrating the applicability of the system to distributed constraint satisfaction problems.     

A proof technique for communicating sequential processes

Summary Proof rules are presented for an extension of Hoare's Communicating Sequential Processes. The rules deal with total correctness; all programs terminate in the absence of deadlock. The commands send and receive are treated symmetrically, simplifying the rules and allowing send to appear in guards. Also given are sufficient conditions for showing that a program is deadlock-free. An extended example illustrates the use of the technique.This research was supported in part by the National Science Foundation under grant MCS-7622360.     

CSP-i: An implementation of communicating sequential processes

Hoare's proposal for a notation for communicating sequential processes has led to the development of a number of concurrent languages based on the concept of message passing. CSP-i is a new language which reflects the design objectives of the original CSP notation more faithfully than most of these other languages. This paper describes the development of the language, as well as an implementation for a single processor, with simulated time-slicing providing pseudo-concurrency.     

Robustness of deadlock avoidance algorithms for sequential processes

Although deadlock avoidance issue has attracted much attention and has been extensively studied, most of the existing results assume reliable machines. This assumption makes it difficult to apply existing deadlock avoidance algorithms to real manufacturing systems with unreliable machines. This paper presents the results to apply an existing deadlock avoidance algorithm to systems with unreliable machines by analyzing the robustness of the deadlock avoidance algorithm. Sequential production processes are considered in this paper, and Petri Net is adopted as the tool for modeling and analysis of the sequential processes. Different types of tolerable machine failures under which liveness property can be preserved are characterized. Computational complexity of the proposed algorithm is analyzed.     

Extended sequential algorithms for detecting changes in actingstochastic processes

We present, analyze, and numerically evaluate extended algorithms for detecting changes from an acting stochastic process to a number of possible alternatives. The algorithms are sequential, requiring minimal memory capacity and operational complexity, and they incorporate decision thresholds. The performance of the algorithms is controlled by the selection of the thresholds. Asymptotically, the first algorithmic extension detects the acting process correctly in an expected stopping time sense. In addition, the probability of error induced by a reinitialization algorithmic extension converges asymptotically to zero, when the acting process changes infrequently (with order inversely proportional to the value of the decision thresholds). The presented algorithmic systems are quite powerful and their applications are numerous, ranging from industrial quality control to traffic and performance monitoring in highspeed networks     

Optimal sequential estimation of discrete processes with Markov interrupted observations

This short paper considers the problem of sequential estimation of discrete-time processes corrupted by additive noise when there is time-varying uncertainty regarding the presence of the process at each stage of the observation sequence. A recursive Bayes' optimal solution is derived that does not require a growing amount of memory and computation for its implementation but that, however, requires recursion on continuous functions to be performed. Digital computer implementation of the proposed algorithms is discussed and some simulation results are presented.     

Detection of parallelism between statements by decomposing into separate sequential processes

A new method of parallelism between statements is exploited. The method is to decompose a process into separate sequential processes that are connected through queues of message buffers. The conditions for decomposition are analyzed, and a decomposition algorithm is developed. PL/I is used to describe processes.     

Distributed implementation of nested communicating sequential processes: Communication and termination

A model for the distributed implementation of CSP programs, based on cooperation between communicating virtual processors, is defined. Emphasis is placed on the relations between nested parallel commands, communication, and process termination. We then present a protocol for process termination handling that guarantees the consistency of distributed structures and aims at optimizing the rate of communications among virtual processors. Finally, the adoption of the model in the implementation of the run-time support of a CSP-based language on the MuTEAM distributed multiprocessor is described.     

基于通信序列进程的UML序列图形式化方法

UML2.0序列图是一种描述对象之间动态协作和事件发展时间关系的视图,但是UML序列图缺乏精确的形式化语义,所以不利于对其所描述的系统进行形式化验证。为此,根据UML2.0语义文档及组合碎片包概念,基于通信序列进程(CSP)给出了UML序列图的基本元素和消息迹的形式化定义及生成规则,实现了UML序列图的形式化,为UML序列图在描述系统准确性和有效性方面提供了形式化的检验方法。最后通过ATM实例说明UML序列图这一过程的正确性。     

The transformation of collections of communicating sequential processes that represent pipeline configurations

The segments of a pipelined process can be represented as communicating sequential processes. The communication between the segments of the pipeline are represented as channel communication between the communicating sequential processes. It is possible to merge two communicating sequential processes (that would be adjacent in the pipeline) into one communicating sequential process. This is done by matching the output expressions of the first communicating sequential process (e.g. chlexpr) with the appropriate input expressions of the second communicating sequential process (e.g. ch?var) and replacing each pair by a single assignment statement (var = expr).     

Real time detection of acoustic anomalies in industrial processes using sequential autoencoders

Development of intelligent systems with the pursuit of detecting abnormal events in real world and in real time is challenging due to difficult environmental conditions, hardware limitations, and computational algorithmic restrictions. As a result, degradation of detection performance in dynamically changing environments is often encountered. However, in the next‐generation factories, an anomaly detection system based on acoustic signals is especially required to quickly detect and interfere with the abnormal events during the industrial processes due to the increased cost of complex equipment and facilities. In this study we propose a real time Acoustic Anomaly Detection (AAD) system with the use of sequence‐to‐sequence Autoencoder (AE) models in the industrial environments. The proposed processing pipeline makes use of the audio features extracted from the streaming audio signal captured by a single‐channel microphone. The reconstruction error generated by the AE model is calculated to measure the degree of abnormality of the sound event. The performance of Convolutional Long Short‐Term Memory AE (Conv‐LSTMAE) is evaluated and compared with sequential Convolutional AE (CAE) using sounds captured from various industrial manufacturing processes. In the experiments conducted with the real time AAD system, it is shown that the Conv‐LSTMAE‐based AAD demonstrates better detection performance than CAE model‐based AAD under different signal‐to‐noise ratio conditions of sound events such as explosion, fire and glass breaking.     

Asynchronous Mappings and Asynchronous Cellular Automata

The aim of this paper is the study of asynchronous automata, a special kind of automata which encode the independency relation between actions and which enable their concurrent execution. These automata, introduced by Zielonka (RAIRO Inform. Theor. Appl.21, 99-135 (1987)), constitute a natural extension of finite automata to the case of asynchronous parallelism. Their behaviour is described by trace languages, subsets of partially commutative monoids. The main result concerning this class of automata states that they accept exactly all recognizable trace languages. In this paper we give new improved constructions of asynchronous automata. In the final part of the paper we present a distributed system of messages with bounded time-stamps based on asynchronous automata.