Papers by Ryszard Janicki
Towards a theory of simulation for verification of concurrent systems
Lecture Notes in Computer Science, 1989
We here investigate whether it is possible to provide the designer of a concurrent system with a ... more We here investigate whether it is possible to provide the designer of a concurrent system with a sound and efficient simulation technique enabling reasoning about important behavioural properties of the system. We introduce the notion of a simulation defined as a subset of the possible execution paths generated by the system, and demonstrate that under some conditions the simulation provides
On Pairwise Comparisons Based Internal and External Measures for Software Evaluation
2013 Workshops on Enabling Technologies: Infrastructure for Collaborative Enterprises, 2013
ABSTRACT We show how pairwise comparisons paradigm can be used to improve many current methods of... more ABSTRACT We show how pairwise comparisons paradigm can be used to improve many current methods of software evaluation. Most of software metrics lack formal analysis of weights consistency, while inconsistency analysis is the crucial part of all decision making techniques based on the pairwise comparisons. We show how distance-based inconsistency, a measure of inconsistency often used when pairwise comparisons approach is applied, can improve accuracy of weights assignment for attributes used for software evaluation. If the phenomena are not well identified or the values and their ranges in the models dynamics are not known the external measures (weights) are introduced. While weights are external measures of attributes importance, pairwise comparisons explore their mutual internal structure.
On a Mereological System for Relational Software Specifications
Lecture Notes in Computer Science, 2002
ABSTRACT The concept of being a part of is defined and analysed in an algebraic framework and the... more ABSTRACT The concept of being a part of is defined and analysed in an algebraic framework and then apply to the algebra of relations. A motivation that comes from Software Engineering is discussed.
A Generalisation of a Relational Structures Model of Concurrency
Lecture Notes in Computer Science, 2005
ABSTRACT We show how complex concurrent behaviours can be modelled by relational structures ( X, ... more ABSTRACT We show how complex concurrent behaviours can be modelled by relational structures ( X, ¨, \sqsubsetX, \diamondsuit, \sqsubset), where X is a set (of event occurrences), ¨\diamondsuit (interpreted as commutativity), \sqsubset\sqsubset (interpreted as weak causality) are binary relations on X. The paper is a continuation of the approach initiated in [6,18,1,9] substantially developed in [10,12], and recently partially generalized in [7]. For the first time an axiomatic model for the most general case is given. The results can be interpreted as a generalisation of Szpilrajn Theorem [25].
On atomic nets and concurrency relations
Lecture Notes in Computer Science
We have attempted to present a formalization of decomposition of nets into indivisible sequential... more We have attempted to present a formalization of decomposition of nets into indivisible sequential components and to investigate different notions of concurrency. We feel that this paper presents a sound foundations for studying the concurrency relation in the case of the whole class of condition/event nets. All proofs will be published soon.
Formal studies of models of concurrency are usually focused on two major models: Inter-
The use of automata as a specification tool is analyzed. Trace Assertion Method (TAM) is used as ... more The use of automata as a specification tool is analyzed. Trace Assertion Method (TAM) is used as an example. TAM is a formal method for specifying module interfaces. It treats the module as a black box, and was designed as an alternative to an algebraic specification technique (1), and became quite popular in the software industry (13). Finiteness and concurrency issues are discussed.
Proceedings of the 1990 ACM annual conference on Cooperation - CSC '90, 1990
This paper studies parallel devices recognizing trace languages. We introduce a concept of an asy... more This paper studies parallel devices recognizing trace languages. We introduce a concept of an asynchronous automaton with Emoves and show that for a given regularly defined trace language there exists a simple version of an asynchronous automaton with E-moves recognizing this language.
Optimal simulations, nets and reachability graphs
Lecture Notes in Computer Science
... [] For every history H, let enabled(H) be the set of all steps such that o "A is a step ... more ... [] For every history H, let enabled(H) be the set of all steps such that o "A is a step sequence for at least one o~H. Proposition 2.1 Let H be a history, o,c0 H and AE enabled(H). (1) o and co lead to the same marking, ie maro=marco. ...
Lecture Notes in Computer Science, 2006
The Basic Mereology framework of [8] is enriched by adding colimit construction from Category The... more The Basic Mereology framework of [8] is enriched by adding colimit construction from Category Theory. The new framework is then used to model component-based software architecture.
Proceedings of the International Multiconference on Computer Science and Information Technology, 2010
In this paper, we propose the use of the pairwise comparisons (PC) method for selection of strate... more In this paper, we propose the use of the pairwise comparisons (PC) method for selection of strategies for software certification. This method can also be used to rank alternative software certification strategies. The inconsistency analysis, provided by the PC method, improves the accuracy of the decision making. Some current methods of software certification are presented as they could be modified by the proposed method. Areas of potential future research are discussed in order to make the software certification process more feasible and acceptable to industry.
Computing and Information: Proceedings of the International Conference (ICCI'89), Toronto, Canada, 23-27 May 1989
ABSTRACT
Maximally concurrent evolution of non-sequential systems
Lecture Notes in Computer Science, 1985
... (Vi=l, .... n) aGOps(Pi) ==> [iaGFS(Pi) o For every xGVFS(P)aa set of independent operatio... more ... (Vi=l, .... n) aGOps(Pi) ==> [iaGFS(Pi) o For every xGVFS(P)aa set of independent operationsAGInd(P) is said to be --concurrentl~ enabled at x if and only if every a@A is enabled at x. 3.1 COROLLARY For every x_@VFS(P): i. a~Ops(P) is enabled at x <==> xaGVFS(P), ...
Lecture Notes in Computer Science, 2008
Four quotient monoids over step sequences and one with compound generators are introduced and dis... more Four quotient monoids over step sequences and one with compound generators are introduced and discussed. They all can be regarded as extensions (of various degrees) of Mazurkiewicz traces [14] and comtraces of [10].
A method for developing concurrent systems
Lecture Notes in Computer Science, 1984
ABSTRACT
Lecture Notes in Computer Science, 1980
The paper concerns algebraic properties of Petr± nets. A wide class of ne~s, called simple nets, ... more The paper concerns algebraic properties of Petr± nets. A wide class of ne~s, called simple nets, is inwroduced and a lattice of these nets is defined. IV turns out tha~ nets representing sequential systems and processes are a~oms of this lat~ice~ and this fact provides the natural way of building nets representing° concurren~ systems as the superposit~on of nets representlng sequen-Zial system components. TNe notion of concurrency relatlon for large class of nets including cyclic nets is precisely defined. An influence of statmo, i.e. unmarked, structure of neZs on the class of "proper" markings is discussed. The notion of naZural markings, i.e. markings defined by the static (unmar~ed) s~ruc~ure of ne~s is introduced. Properties of safeness, compaoZness, fireability and K-densiSy of marked nets are discussed. A classification of nets is proposed and an attempZ of wne algebraic definition of net with properties requlred from "well defined" dynamlc concurren~ system is given.
Environment and Water Resource Management / 813: Modelling and Simulation / 814: Power and Energy Systems / 815: Health Informatics, 2014
Tabular expressions and the Software Cost Reduction (SCR) method are table-based specification te... more Tabular expressions and the Software Cost Reduction (SCR) method are table-based specification techniques. Both of them were successfully used in practice, especially to formally specify software requirements. Tabular expressions have rather precise semantics, while SCR semantics are more intuition based. In this paper, we want to improve SCR semantics. For that, we show how to convert the SCR tables into tabular expressions. The conversion that we came up with allows the SCR tables to inherit the semantics of tabular expressions. Hence, the converted tables are more readable, and more efficient.
Benefits of Using Tabular Expressions in Planning Health Services
An apparatus and method for verifying positive inflation of an inflatable element include electri... more An apparatus and method for verifying positive inflation of an inflatable element include electrical switches or sensors adapted to be actuated when sufficient element to borehole wall contact is achieved. The device may be a micro switch similar to that used in a calculator button, proximity switch or may employ a spear type arrangement wherein a spear is connected to one lead and is isolated from the other lead by insulation and wherein the spear is forced radially inwardly by the radially outwardly expansion of the cover on the element against the borehole wall. Upon piercing the insulation, the spear will have connected first and second leads that such connection being detectable via hard wire to the surface and electrical continuity whereby downhole electronics or intelligence whereby a downhole signal generator using any type of telemetry to communicate uphole. With each of the embodiments of the invention, the pressure of the element against the borehole wall may be predetermined in order to actuate the device of the invention.
Theoretical Computer Science, 1990
A transformation @ of sequential specifications into con,,, i riic a-lkrrnnt r~no;fir~t;nmc ;r rl... more A transformation @ of sequential specifications into con,,, i riic a-lkrrnnt r~no;fir~t;nmc ;r rln.fi-'4 ~ljri.*i-.s..".ia ." YI . . . . rti. The sequential specification is in the form of a regular expression extended with a declaration of the actions that are independent and have the potential for concurrent execution. The concurrent specification is in the form of a product of regular expressions. It is proved that a concurrent specification resulting from the application of the transformation @ to a sequential specification modified by inserting special actions, called synchronization guards, is behaviorally equivalent to the original specification. The programming language representation of a sequential specification is exemplified in a Pascal-like language, Banach. With the development of multiprocessors, such as the SEQUENT computer [38], research on concurrent systems has expanded immensely. There have been many attempts to define models of concurrent systems. On a more prsctical side, a number of programming languages providing constructs to express concurrency have been designed and implemented. Unfortunately, concurrent systems are difficult to deal with. For example, an analysis of a concurrent system requires the consideration of events that occur at the same time and with independent speeds. Similar difficulties are also apparent in the process of design of concurrent programs. This process appears to be rather complicated with the currently available concurrent languages, such as those based on the concept of a monitor, Modula [45], ascal-Plus [443, Mesa [29], and Concurrent Euclid [ 141, and those based on message passing, CSP [13], CSP/SO [27], occam [15-j, Planet [IS] and Joyce [6]. The rogrammer has to specify which actions are to be executed concurrently and the how those actions are to be synchronized. The latter specification is particularly cu eksome an error-prone. In many cases, to implement a concurrent system S, we extract the sequential components of S, implement these, and the mbine the sequential components into a complete implementation of S. Such a ethodology is convsk.ient for systems wit erent concurrent activities, for exa le operating syste s L& real-time 03043975/90/$03.50 @J 1990~Elsevier Science Publishers B.V. (North-Holland) ' Stefan Banach (1892-1945), Polish mathematician who g-..-'---A rL-A ,KVCIU)JCU WC lheory of functional analysis.
Science of Computer Programming, 2001
In 15, 22, 25, 26] P arnas et al. advocate the use of relational model for documenting the intend... more In 15, 22, 25, 26] P arnas et al. advocate the use of relational model for documenting the intended behaviour of programs. In this method, tabular expressions (or tables) are used to improve readability so that formal documentation can replace conventional documentation. Parnas 23] describes several classes of tables and provides their formal syntax and semantics. In this paper, an alternative, more general and more homogeneous semantics is proposed. The model covers all known types of tables used in Software Engineering.
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Papers by Ryszard Janicki