This paper describes two freely available convolutional decoders written in the C language. One implements the Fano algorithm for sequentially decoding three rate l/2 K=32 codes while the other implcmcnts the Viterbi algorithm for maximum likelihood decoding of the rate l/2 K=7 NASA Standard code. Both support 8-W soft-decision decoding with arbitrary metric tables and perform according to theory.

In this paper we define a translation from the User Action Notation (UAN) to the process algebra Communicating Sequential Processes (CSP). UAN is an informal notation, used for task modeling and design. Translating a UAN task description to CSP provides a basis for rigorous development of an interactive system. The resulting CSP description is a suitable abstract starting point for development,...

This paper presents a case study for automatic verification using the Communicating Sequential Processes formalism. The case study concerns the Futurebus+ cache coherency standard; we develop a formal model of the protocol and perform some verification tasks upon it. In the process of doing so, we extend the previous solution by developing a formal specification of cache coherence that is suita...

Studying industrial systems by simulation enables the designer to study their dynamic behaviour and to determine characteristics of the system. Unfortunately, simulation also has some disadvantages. These can be overcome by using formal methods. Formal methods allow a thorough analysis of the possible behaviours of a system, parameterised system analysis and a modular approach to the analysis o...

For supporting the analysis of railway interlocking systems in the early stage of their design we propose the use of model checking. We investigate the use of the formal modelling language CSP and the corresponding model checker FDR. In this paper, we describe the basics of this formalism and introduce our formal model of a railway interlocking system. Checking this model against the given safe...

In this report we consider some aspects of the general problem of encoding and decoding for time-discrete, amplitude-continuous memoryless channels. The results can be summarized under three main headings. 1. Signal Space Structure: A scheme for constructing a discrete signal space, for which sequential encoding-decoding methods are possible for the general continuous memoryless channel, is des...

E-learning systems store large amount of data based on the history of users’ interactions with the system. These pieces of information are usually used for further course optimization, finding e-tutors in collaboration learning, analysis of students’ behavior, or for other purposes. The paper deals with an analysis of students’ behavior in learning management system. The main goal of the paper ...