There is a problem with arranging many elements in the window in many applications. It is more di... more There is a problem with arranging many elements in the window in many applications. It is more difficult when the elements are dynamically created or selected from a particular set. There is then a risk of obstruction by objects, which reduces the legibility of the window. Such a problem arises when generating dynamic help for items in a window in the workflow management system designed by Syndatis laboratories. Artificial intelligence algorithms can be used for this purpose, but the obstacle is their long calculations, which in the described case should be completed in less than a second. We proposed to use the evolutionary algorithm with a limited number of generations, which gives satisfactory results.
Studies in computational intelligence, Mar 17, 2019
Static deadlock detection methods suffer from space explosion problem. Model checking and other s... more Static deadlock detection methods suffer from space explosion problem. Model checking and other static analysis techniques are very effective in verification, many of them have a linear complexity to the size of the reachability space. However, the elaboration of the space is time-consuming (usually exponential) and takes a large amount of memory.
The ERTMS/ETCS is the newest automatic train protection system. This is a system that supports th... more The ERTMS/ETCS is the newest automatic train protection system. This is a system that supports the driver in driving the train. It is currently being implemented throughout the European Union. This system’s latest specifications also provide additional functions to increase the energy efficiency of train driving in the form of ATO (automatic train operation). These functions of the ETCS will be valuable, provided they operate without failure. To achieve errorless configuration of the ETCS, a methodology for automatic system verification using the IMDS (Integrated Model of Distributed Systems) formalism and the temporal tool Dedan was applied. The main contribution is asynchronous and timed verification, which appropriately models the distributed nature of the ETCS and allows the designer not only to analyze time dependencies but also to define the range of train velocities in which the operational scenario is valid. Additionally, the novelties of the presented verification methodolo...
In building software architectures, the relations between elements in different diagrams are ofte... more In building software architectures, the relations between elements in different diagrams are often overlooked. The first stage of building IT systems is the use of ontology terminology, not software terminology, in the requirements engineering process. Then, when constructing software architecture, IT architects more or less consciously however introduce elements that represent the same classifier on different diagrams with similar names. These connections are called consistency rules and are usually not attached in any way in a modeling tool, and only a significant number of them in the models increase the quality of the software architecture. It is mathematically proved that the application of consistency rules increases the information content of software architecture. Authors show that increasing readability and ordering of software architecture by means of consistency rules have their mathematical rationale. In this article, we found proof of decreasing Shannon entropy while ap...
Relay-based traffic control systems are still used in railway control systems. Their correctness ... more Relay-based traffic control systems are still used in railway control systems. Their correctness is most often verified by manual analysis, which does not guarantee correctness in all conditions. Passenger safety, control reliability, and failure-free operation of all components require formal proof of the control system’s correctness. Formal evidence allows certification of control systems, ensuring that safety will be maintained in correct conditions and the in event of failure. The operational safety of systems in the event of component failure cannot be manually checked practically in the event of various types of damage to one component, pairs of components, etc. In the article, we describe the methodology of automated system verification using the IMDS (integrated model of distributed systems) temporal formalism and the Dedan tool. The novelty of the presented verification methodology lays in graphical design of the circuit elements, automated verification liberating the desig...
In building software architectures, the relations between elements in different diagrams are ofte... more In building software architectures, the relations between elements in different diagrams are often overlooked. The first stage of building IT systems is the use of ontology terminology, not software terminology, in the requirements engineering process. Then, when constructing software architecture, IT architects more or less consciously however introduce elements that represent the same classifier on different diagrams with similar names. These connections are called consistency rules and are usually not attached in any way in a modeling tool, and only a significant number of them in the models increase the quality of the software architecture. It is mathematically proved that the application of consistency rules increases the information content of software architecture. Authors show that increasing readability and ordering of software architecture by means of con-sistency rules have their mathematical rationale. In this article, we found proof of decreasing Shannon entropy while applying consistency rules in the construction of software architecture of IT systems. Therefore, it has been shown that marking selected elements in different diagrams with these same names is, therefore, an implicit way to increase the information content of software architecture while simultaneously improving its orderliness and readability. Moreover, this increase in the quality of the software architecture can be measured by entropy, which allows for checking whether the number of consistency rules is sufficient to compare different architectures, even of different sizes, thanks to entropy normalization, and checking during the development of the software architecture, what is the improvement in its orderliness and readability.
Relay-based traffic control systems are still used in railway control systems. Their correctness ... more Relay-based traffic control systems are still used in railway control systems. Their correctness is most often verified by manual analysis, which does not guarantee correctness in all conditions. Passenger safety, control reliability, and failure-free operation of all components require formal proof of the control system's correctness. Formal evidence allows certification of control systems, ensuring that safety will be maintained in correct conditions and the in event of failure. The operational safety of systems in the event of component failure cannot be manually checked practically in the event of various types of damage to one component, pairs of components, etc. In the article, we describe the methodology of automated system verification using the IMDS (integrated model of distributed systems) temporal formalism and the Dedan tool. The novelty of the presented verification methodology lays in graphical design of the circuit elements, automated verification liberating the designer from using temporal logic, checking partial properties related to fragments of the circuit, and fair verification preventing the discovering of false deadlocks. The article presents the verification of an exemplary relay traffic control system in the correct case, in the case of damage to elements, and the case of an incorrect sequence of signals from the environment. The verification results are shown in the form of sequence diagrams leading to the correct/incorrect final state.
Communication duality, expressed as the server view and the agent view of the verified system, is... more Communication duality, expressed as the server view and the agent view of the verified system, is the sound effect of the author’s work. In the specification, it is simply grouping of actions in servers or in agents.
The example of deadlock detection is presented for the system in which two distributed computatio... more The example of deadlock detection is presented for the system in which two distributed computations, each one running on its own server, use two semaphores.
2018 Baltic Geodetic Congress (BGC Geomatics), 2018
Autonomous Transit Network (ATN) is a public transport mode featuring automated vehicles operatin... more Autonomous Transit Network (ATN) is a public transport mode featuring automated vehicles operating on an elevated track. The quality of vehicle management algorithms, being a function of parameters of network operation, is measured as a time of waiting for a vehicle at a station. Recharging of vehicles creates additional factor which influences the quality of network behaviour. Previous papers analyse energy constraints in small ATN systems, with charging in capacitors or in stations. We propose a systematic analysis of ATN behaviour with energy constraints: more benchmarks are analysed and more charging manners are tested, including contactless power supply on the track. Some anomalies in network operation, resulting in rise of waiting time for cases with better charging possibility, are discussed.
There is a problem with arranging many elements in the window in many applications. It is more di... more There is a problem with arranging many elements in the window in many applications. It is more difficult when the elements are dynamically created or selected from a particular set. There is then a risk of obstruction by objects, which reduces the legibility of the window. Such a problem arises when generating dynamic help for items in a window in the workflow management system designed by Syndatis laboratories. Artificial intelligence algorithms can be used for this purpose, but the obstacle is their long calculations, which in the described case should be completed in less than a second. We proposed to use the evolutionary algorithm with a limited number of generations, which gives satisfactory results.
Studies in computational intelligence, Mar 17, 2019
Static deadlock detection methods suffer from space explosion problem. Model checking and other s... more Static deadlock detection methods suffer from space explosion problem. Model checking and other static analysis techniques are very effective in verification, many of them have a linear complexity to the size of the reachability space. However, the elaboration of the space is time-consuming (usually exponential) and takes a large amount of memory.
The ERTMS/ETCS is the newest automatic train protection system. This is a system that supports th... more The ERTMS/ETCS is the newest automatic train protection system. This is a system that supports the driver in driving the train. It is currently being implemented throughout the European Union. This system’s latest specifications also provide additional functions to increase the energy efficiency of train driving in the form of ATO (automatic train operation). These functions of the ETCS will be valuable, provided they operate without failure. To achieve errorless configuration of the ETCS, a methodology for automatic system verification using the IMDS (Integrated Model of Distributed Systems) formalism and the temporal tool Dedan was applied. The main contribution is asynchronous and timed verification, which appropriately models the distributed nature of the ETCS and allows the designer not only to analyze time dependencies but also to define the range of train velocities in which the operational scenario is valid. Additionally, the novelties of the presented verification methodolo...
In building software architectures, the relations between elements in different diagrams are ofte... more In building software architectures, the relations between elements in different diagrams are often overlooked. The first stage of building IT systems is the use of ontology terminology, not software terminology, in the requirements engineering process. Then, when constructing software architecture, IT architects more or less consciously however introduce elements that represent the same classifier on different diagrams with similar names. These connections are called consistency rules and are usually not attached in any way in a modeling tool, and only a significant number of them in the models increase the quality of the software architecture. It is mathematically proved that the application of consistency rules increases the information content of software architecture. Authors show that increasing readability and ordering of software architecture by means of consistency rules have their mathematical rationale. In this article, we found proof of decreasing Shannon entropy while ap...
Relay-based traffic control systems are still used in railway control systems. Their correctness ... more Relay-based traffic control systems are still used in railway control systems. Their correctness is most often verified by manual analysis, which does not guarantee correctness in all conditions. Passenger safety, control reliability, and failure-free operation of all components require formal proof of the control system’s correctness. Formal evidence allows certification of control systems, ensuring that safety will be maintained in correct conditions and the in event of failure. The operational safety of systems in the event of component failure cannot be manually checked practically in the event of various types of damage to one component, pairs of components, etc. In the article, we describe the methodology of automated system verification using the IMDS (integrated model of distributed systems) temporal formalism and the Dedan tool. The novelty of the presented verification methodology lays in graphical design of the circuit elements, automated verification liberating the desig...
In building software architectures, the relations between elements in different diagrams are ofte... more In building software architectures, the relations between elements in different diagrams are often overlooked. The first stage of building IT systems is the use of ontology terminology, not software terminology, in the requirements engineering process. Then, when constructing software architecture, IT architects more or less consciously however introduce elements that represent the same classifier on different diagrams with similar names. These connections are called consistency rules and are usually not attached in any way in a modeling tool, and only a significant number of them in the models increase the quality of the software architecture. It is mathematically proved that the application of consistency rules increases the information content of software architecture. Authors show that increasing readability and ordering of software architecture by means of con-sistency rules have their mathematical rationale. In this article, we found proof of decreasing Shannon entropy while applying consistency rules in the construction of software architecture of IT systems. Therefore, it has been shown that marking selected elements in different diagrams with these same names is, therefore, an implicit way to increase the information content of software architecture while simultaneously improving its orderliness and readability. Moreover, this increase in the quality of the software architecture can be measured by entropy, which allows for checking whether the number of consistency rules is sufficient to compare different architectures, even of different sizes, thanks to entropy normalization, and checking during the development of the software architecture, what is the improvement in its orderliness and readability.
Relay-based traffic control systems are still used in railway control systems. Their correctness ... more Relay-based traffic control systems are still used in railway control systems. Their correctness is most often verified by manual analysis, which does not guarantee correctness in all conditions. Passenger safety, control reliability, and failure-free operation of all components require formal proof of the control system's correctness. Formal evidence allows certification of control systems, ensuring that safety will be maintained in correct conditions and the in event of failure. The operational safety of systems in the event of component failure cannot be manually checked practically in the event of various types of damage to one component, pairs of components, etc. In the article, we describe the methodology of automated system verification using the IMDS (integrated model of distributed systems) temporal formalism and the Dedan tool. The novelty of the presented verification methodology lays in graphical design of the circuit elements, automated verification liberating the designer from using temporal logic, checking partial properties related to fragments of the circuit, and fair verification preventing the discovering of false deadlocks. The article presents the verification of an exemplary relay traffic control system in the correct case, in the case of damage to elements, and the case of an incorrect sequence of signals from the environment. The verification results are shown in the form of sequence diagrams leading to the correct/incorrect final state.
Communication duality, expressed as the server view and the agent view of the verified system, is... more Communication duality, expressed as the server view and the agent view of the verified system, is the sound effect of the author’s work. In the specification, it is simply grouping of actions in servers or in agents.
The example of deadlock detection is presented for the system in which two distributed computatio... more The example of deadlock detection is presented for the system in which two distributed computations, each one running on its own server, use two semaphores.
2018 Baltic Geodetic Congress (BGC Geomatics), 2018
Autonomous Transit Network (ATN) is a public transport mode featuring automated vehicles operatin... more Autonomous Transit Network (ATN) is a public transport mode featuring automated vehicles operating on an elevated track. The quality of vehicle management algorithms, being a function of parameters of network operation, is measured as a time of waiting for a vehicle at a station. Recharging of vehicles creates additional factor which influences the quality of network behaviour. Previous papers analyse energy constraints in small ATN systems, with charging in capacitors or in stations. We propose a systematic analysis of ATN behaviour with energy constraints: more benchmarks are analysed and more charging manners are tested, including contactless power supply on the track. Some anomalies in network operation, resulting in rise of waiting time for cases with better charging possibility, are discussed.
Warsaw University of Technology, Institute of Computer Science, Research Report No. 8/2002, 2002
The important feature of temporal model checking is the generation of counterexamples. In the rep... more The important feature of temporal model checking is the generation of counterexamples. In the report, the requirements for generation of counterexample (called critical tree) in model checking of CSM systems are described. The output of TempoRG model checker for QsCTL logic (a version of CTL) is presented. A contradiction between counterexample generation and state space reduction is commented.
In the ICS, WUT a platform for simulation of cooperation of physical and virtual mobile agents is... more In the ICS, WUT a platform for simulation of cooperation of physical and virtual mobile agents is under development. The paper describes the motivation of the research, an organization of the platform, a model of agent, and the principles of design of the platform. Several experimental simulations are briefly described.
In ICS, WUT a COSMA design environment is being developed. COSMA is based on Concurrent State Mac... more In ICS, WUT a COSMA design environment is being developed. COSMA is based on Concurrent State Machines (CSM) formalism of system specification. It contains a graphical tool for system design, various tools for the analysis (including a temporal model checker), simulator and code generator. In many projects, some common susbsystems take place. This concerns both complicated modules and simple counters. In the report, a concept of macrogeneration technique for building of libraries of automata is presented. The new technique will support a compactness of projects and reusability of modules.
DepCoS-RELCOMEX 2023: Dependable Computer Systems and Networks, 2023
The paper presents a modern approach to software development for multi-processor platforms. It fo... more The paper presents a modern approach to software development for multi-processor platforms. It focuses on sequential code structures that can be parallelized. Several structures were identified and then analyzed in detail. Such static analysis led to the algorithms determining whether specific pieces of code can be parallelized. The algorithms show how existing sequential structures can be converted to programs executed in parallel, if feasible. Our methodology also includes a dynamic evaluation that can determine the effectiveness of the generated parallel programs. The algorithms have been implemented as a tool for sequential programs in C#. Future solutions were discussed.
17th Conference on Computer Science and Intelligence Systems, 2022
Designing and implementing Web Services constitutes a large and constantly growing part of the in... more Designing and implementing Web Services constitutes a large and constantly growing part of the information technology market. Web Services have specific scenarios in which distributed processes and network resources are used. This aspect of services requires integration with the model checkers. This article presents the experimentation framework in which services can be specified and then formally analyzed for deadlock-freedom, achievement of process goals, and similar features. Rybu4WS language enriches the basic Rybu language with the ability to use variables in processes, service calls between servers, new structural instructions, and other constructions known to programmers while remaining in line with declarative, mathematical IMDS formalism. Additionally, the development environment allows simulation of a counterexample or a witness - obtained as a result of the model checking - in a similar way to traditional debuggers.
There is a problem with arranging many elements in the window in many applications. It is more di... more There is a problem with arranging many elements in the window in many applications. It is more difficult when the elements are dynamically created or selected from a particular set. There is then a risk of obstruction by objects, which reduces the legibility of the window. Such a problem arises when generating dynamic help for items in a window in the workflow management system designed by Syndatis laboratories. Artificial intelligence algorithms can be used for this purpose, but the obstacle is their long calculations, which in the described case should be completed in less than a second. We proposed to use the evolutionary algorithm with a limited number of generations, which gives satisfactory results.
Defining professional workflows within Workflow Management Systems (WfMS) is not a simple task. T... more Defining professional workflows within Workflow Management Systems (WfMS) is not a simple task. Typically, this activity is dedicated to professionals having a high level knowledge and skills in this field, because many aspects of the workflow need to be linked: data model, presentation forms, process flow, synchronization, logical constraints, etc. Therefore in this situation, the work of a specialist is a bottleneck that limits the possibilities of effective workflow creation. The paper is devoted to a new architecture of WfMS, where workflow is defined by means of a set of files describing particular graphically designed various aspects of the workflow, with the use of XML-grounded Domain Specific Languages (DSLs). Each of the aspects has its own XML schema, defining its structure and constraints. An important property is that separate DSLs with their own schemas allow to some extent developing independently individual aspects of workflows (separation of concerns). On the other hand, the process of defining the aspects of the workflow is integrated with an application ontology, which supports automatization of design, and preserves consistency between the schemas, assuring completeness of the workflow.
Proc. 2018 Baltic Geodetic Congress (BGC Geomatics), 2018
Autonomous Transit Network (ATN) is a public transport mode featuring automated vehicles operatin... more Autonomous Transit Network (ATN) is a public transport mode featuring automated vehicles operating on an elevated track. The quality of vehicle management algorithms, being a function of parameters of network operation, is measured as a time of waiting for a vehicle at a station. Recharging of vehicles creates additional factor which influences the quality of network behaviour. Previous papers analyse energy constraints in small ATN systems, with charging in capacitors or in stations. We propose a systematic analysis of ATN behaviour with energy constraints: more benchmarks are analysed and more charging manners are tested, including contactless power supply on the track. Some anomalies in network operation, resulting in rise of waiting time for cases with better charging possibility, are discussed.
Proc. Federated Conference on Computer Science and Information Systems, 2018
Integrated Model of Distributed Systems (IMDS) is a formalism for specification and verification ... more Integrated Model of Distributed Systems (IMDS) is a formalism for specification and verification of distributed systems, especially following IoT (Internet of Things) paradigm. The formalism emphasizes such features as asynchrony of actions and communication, locality of decisions, and autonomy in executing actions. In conjunction with model checking, IMDS allows to analyze such features of distributed systems as deadlocks or distributed termination. However, the nature of model checking allows to find one deadlock in a single run of the verifier (a counterexample). The conversion of IMDS specification to a Petri net is used to identify multiple deadlocks in one verification, using siphons. Model checking is used to verify if a siphon can become empty. Siphon analysis is typically used to investigate deadlocks in purely cyclic FMS (Flexible Manufacturing Systems). The extension of the verification by temporal checking of deadlock occurrence allows to cover systems with any structure: cyclic, terminating, or with a more complex structure. In addition, IMDS allows to easily identify processes participating in partial deadlocks. Two types of deadlock can be identified: communication deadlocks and resource deadlocks.
Deadlock, a situation in which a system or a part of it just stops and cannot continue successful... more Deadlock, a situation in which a system or a part of it just stops and cannot continue successfully is a typical error identified in distributed computer systems. However, verification of computer systems often requires some knowledge of the mathematical background and formal methods from the designer. In many institutions, formal verification is necessarily required, for example in avionics or NASA projects. On the other hand, many engineers and students give up formal verification because time and effort must be sacrificed to study formalism. In many cases, they only decide to test, without formal proofs of proper cooperation in distributed systems. The author offers original formalism - Integrated Distributed Systems Model (IMDS) - combined with model checking based on temporal logic. The formalism allows the designer a specification that emphasizes the natural features of distributed systems and allows automatic verification of the typical features of such systems, such as deadlock and termination. The verified system is defined in a uniform model that can be observed in two general perspectives highlighting different aspects of the system. The server view involves servers’ states and message exchange. The agent view presents distributed agents traveling by means of messages and collaborating through shared resources.
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Papers by Wiktor B Daszczuk
The author offers original formalism - Integrated Distributed Systems Model (IMDS) - combined with model checking based on temporal logic. The formalism allows the designer a specification that emphasizes the natural features of distributed systems and allows automatic verification of the typical features of such systems, such as deadlock and termination. The verified system is defined in a uniform model that can be observed in two general perspectives highlighting different aspects of the system. The server view involves servers’ states and message exchange. The agent view presents distributed agents traveling by means of messages and collaborating through shared resources.