Vienna Development Method Specification Language Research Articles

Blockchain-Based Formal Model for Food Supply Chain Management System Using VDM-SL

In modern society, the food supply chain management system has become an important research area realized nationally and internationally, which has established a collaborative relationship between producers, manufacturers, processors and retailers. Now, consumers are more interested in food quality, safety and the authentication of the products. Food safety has become an important issue in public health in the food market because people of all types and races around the world are affected due its poor quality. The traditional supply chains are centralized and face different issues such as lack of transparency, accountability and audit ability. The general issues in supply chain management include lack of communication, trust among the stakeholders, and interference of entities and wastage of food. A lot of work has been completed by researchers to address the above issues, but still, there is a need for effective mechanisms for the modeling of supply chain management systems. In this paper, a trusted, self-organized, traceable formal system based on blockchain and Internet of Things (IoT) is developed by using wireless sensors networks and finite automata. In the proposed model, smart contracts are designed to assure the automated payment procedures. The proposed model reduced the need for centralized authority. Unified Modeling Language (UML) is used to realize the requirements, and automata is used to capture behavior of the system. A blockchain-based model is used to provides the privacy and security mechanism for the transitions record. Wireless sensors are used to sense the information, and actors are used for decision making in case of any violation in the contact. A lot of work has been completed by researchers on smart contracts. Different smart contracts are designed to achieve the better traceability among producers, transporter/logistics and consumers. Our system provides the smart contract algorithm to show the interaction of entities in the food supply chain management system. Vienna Development Method-Specification Language (VDM-SL) is used to describe the formal system and the VDM-SL toolbox is used for the validation and analysis of the system.

Formal Modeling of IoT-Based Drone Network for Combating COVID-19 Pandemic

Coronavirus biologically named COVID-19 is a disease that is circulating throughout the world due to its viral nature. The interaction of people is a source of spreading of coronavirus. Millions of people have been affected by this virus, and most of them have lost their lives. At present, this viral disease has grown into a worldwide pandemic which is a troubling spot for the whole world. Few technologies are supporting to manage and solve the COVID-19 crisis. In this paper, unified modeling language (UML) will be used to describe requirements and behavior of the proposed system. Unmanned aerial vehicle (UAV) drones are flying mechanical devices without any human pilot that is efficient to reduce the spreading rate of COVID-19. In the proposed IoT-based model, a cluster-based drones’ network will be used to monitor and perform required actions to tackle the violations of standard operating procedures (SOPs). The drones will gather all data through embedded cameras and sensors and will communicate with the control room to operate the actions as required. In this model, a well-maintained and collision-free network of drones will be designed using graph theory. Drones’ network will observe the violation of SOPs in the targeted area and make decisions such as produce alarm sound to alert persons and through communications by sending people warning messages on their smartphones. Further, the persons having COVID symptoms such as high temperature and unbalance respiratory rates will be identified using wearable sensors that are deployed to the targeted area and will send information to the control room to perform required actions. Drones will be able to provide medical kits to the patients’ residences that are identified using wearable sensors to reduce interaction of people. The model will be specified using Vienna Development Method-Specification language (VDM-SL) and validated through the VDM-SL toolbox.

Formal Modeling of IoT-Based Distribution Management System for Smart Grids

The smart grid is characterized as a power system that integrates real-time measurements, bi-directional communication, a two-way flow of electricity, and evolutionary computation. The power distribution system is a fundamental aspect of the electric power system in order to deliver safe, efficient, reliable, and resilient power to consumers. A distribution management system (DMS) begins with the extension of the Supervisory Control and Data Acquisition (SCADA) system through a transmission network beyond the distribution network. These transmission networks oversee the distribution of energy generated at power plants to consumers via a complex system of transformers, substations, transmission lines, and distribution lines. The major challenges that existing distribution management systems are facing, maintaining constant power loads, user profiles, centralized communication, and the malfunctioning of system equipment and monitoring huge amounts of data of millions of micro-transactions, need to be addressed. Substation feeder protection abruptly shuts down power on the whole feeder in the event of a distribution network malfunction, causing service disruption to numerous end-user clients, including industrial, hospital, commercial, and residential users. Although there are already many traditional systems with the integration of smart things at present, there are few studies of those systems reporting runtime errors during their implementation and real-time use. This paper presents the systematic model of a distribution management system comprised of substations, distribution lines, and smart meters with the integration of Internet-of-Things (IoT), Nondeterministic Finite Automata (NFA), Unified Modeling Language (UML), and formal modeling approaches. Non-deterministic finite automata are used for automating the system procedures. UML is used to represent the actors involved in the distribution management system. Formal methods from the perspective of the Vienna Development Method-Specification Language (VDM-SL) are used for modeling the system. The model will be analyzed using the facilities available in the VDM-SL toolbox.

Formal Modeling of IoT and Drone-Based Forest Fire Detection and Counteraction System

Forests are an enduring component of the natural world and perform a vital role in protecting the environment. Forests are valuable resources to control global warming and provide oxygen for the survival of human life, including wood for households. Forest fires have recently emerged as a major threat to biological processes and the ecosystem. Unfortunately, almost every year, fire damages millions of hectares of forest land due to late and inefficient detection of fire. However, it is important to identify the forest fire at the initial level before it spreads to vast areas and destroys natural resources. In this paper, a formal model of the Internet of Things (IoT) and drone-based forest fire detection and counteraction system is presented. The proposed system comprises network maintenance. Sensor deployment is on trees, the ground, and animals in the form of subnets to transmit sensed data to the control room. All subnets are connected to the control room through gateway nodes. Alarms are being used to alert human beings and animals to save their lives, which will help to initially protect them from fire. The embedded sensors collect the information and transfer it to the gateways. Drones are being used for real-time visualization of fire-affected areas and to perform actions to control fires because they play a vital role in disasters. Graph theory is used to construct an efficient model and to show the connectivity of the network. To identify failures and develop recovery procedures, the algorithm is designed through the graph-based model. The model is developed by the Vienna Development Method-Specification Language (VDM-SL), and the correctness of the model is ensured using various VDM-SL toolbox facilities.

Formal Modeling of Responsive Traffic Signaling System Using Graph Theory and VDM-SL

Internet of things (IoT) is playing a major role in smart cities to make a digital environment. Traffic congestion is a serious road issue because of an increasing number of vehicles in urban areas. Some crucial traffic problems include accidents and traffic jams that cause waste of fuel, health diseases, and a waste of time. Present traffic signaling systems are not efficient in resolving congestion problems because of the lack of traffic signals. Nowadays, traffic signaling systems are modeled with fixed time intervals in which no proper mechanism for emergency vehicles is available. Such traffic mechanisms failed to deal with traffic problems effectively. The major objective is to establish a robust traffic monitoring and signaling system that improves signal efficiency by providing a responsive scheme; appropriate routes; a mechanism for emergency vehicles and pedestrians in real-time using Vienna Development Method Specification Language (VDM-SL) formal method and graph theory. A formal model is constructed by considering objects, such as wireless sensors and cameras that are used for collecting information. Graph theory is used to represent the network and find appropriate routes. Unified Modeling Language is used to design the system requirements. The graph-based framework is converted into a formal model by using VDM-SL. The model has been validated and analyzed using many facilities available in the VDM-SL toolbox.

Formal model of earthquake disaster mitigation and management system

Wireless sensor and actors networks (WSANs) have become an important research area due to its large number of applications in safety, security and mission-critical systems. Natural disasters such as earthquakes and floods have distressing effects on human lives, economy and environment particularly in the developing countries due to their high population and lack of infrastructure. Earthquake is one of the major such disasters which causes a huge loss in terms of deaths, environment damages and loss of property because of its unpredictable nature. There exists much work on earthquake prediction, disaster mitigation and management but mostly is based on simulation and testing techniques which have certain limitations. Formal methods are mathematical approaches which assure correctness of systems to overcome limitations of simulation and testing techniques. That is why a formal system of earthquake disaster mitigation and management using formal methods and WSANs is proposed. Sensors and actors are deployed in the earthquakes vulnerable areas in the form of subnets which increase energy efficiency of the network as the processing becomes localized at a subnet level. Firstly, graph theory is used to represent subnet-based model which is then transformed into a formal model. Vienna Development Method-Specification Language (VDM-SL) is used to describe and prove correctness of the formal specification. The developed specification is then validated and verified through VDM-SL Toolbox facilities by analyzing the pre/post conditions and invariants over the formal system.

Algorithm and Formal Model of Recovering Network Connectivity in Battlefield Surveillance

Battlefield surveillance requires mission-critical operations and tasks which can effectively be performed using Wireless Sensor and Actor Networks (WSANs). We have used clustering approach for deployment of WSAN to minimize energy consumption and to limit the processing cost. The adverse environment conditions in battlefield may cause a loss of connectivity but there is a need of continuous flow of information in this application. Therefore an algorithm for network recovering is proposed. Firstly, graphical model of the system is presented using graph theory which is then transformed into a formal model by developing formal specification using Vienna Development Method-Specification Language (VDM-SL). Invariants and pre/post-conditions are defined for its validation. The correctness of the formal specification is assured by an analysis through VDM-SL toolbox.

Hybrid subnet-based node failure recovery formal procedure in wireless sensor and actor networks

An unattended deployment of wireless sensor and actor networks in a harsh and inhospitable environment may cause its failure by partitioning it into the disjoint segments. Although many variants of this problem are addressed using different approaches, it still needs to be investigated due to its various applications. In this article, an efficient, localized, hybrid failure detection and recovery algorithm is proposed which assumes planned deployment of nodes. The algorithm is approximate and distributed as its topology is partitioned into subnets localizing failure recovery procedure and efficient as the time complexity is reduced from nondeterministic polynomial-time–hard to polynomial time. The algorithm is hybrid as pre-failure planning and post-failure recovery is assumed for the critical nodes. Graph-based model is designed to represent static part which is then transformed into a formal model using Vienna Development Method—specification language. The static model consists of subnets, circular topology, sensors, actors, and gateways as composite objects in Vienna Development Method—specification language. The dynamic model is developed by defining its state space, functions, and possible operations to describe the failure recovery procedure. Invariants are defined on static model to assure correctness, and pre/post conditions are used in the dynamic model to control the behavior preventing system to enter into an unwanted situation. The formal specification is analyzed using Vienna Development Method—specification language Toolbox to visualize the model.

Automated translation of VDM to JML-annotated Java

When a system specified using the Vienna Development Method (VDM) is realised using code-generation, no guarantees are currently made about the correctness of the generated code. In this technical report, we improve code-generation of VDM models by taking contract-based elements such as invariants and pre- and postconditions into account during the code-generation process. The contract-based elements of the Vienna Development Method Specification Language (VDM-SL) are translated into corresponding constructs in the Java Modelling Language (JML) and used to validate the generated code against the properties of the VDM model. VDM-SL and JML are both Design-by-Contract (DbC) languages, with the difference that VDM-SL supports abstract modelling and system specification, while JML is used for detailed specification of Java classes and interfaces. We describe the semantic differences between the contract-based elements of VDM-SL and JML and formulate the translation as a set of rules. We further demonstrate how dynamic JML assertion checks can be used to ensure the consistency of VDM’s subtypes when a model is code-generated. The translator is fully automated and produces JML-annotated Java programs that can be checked for correctness using JML tools. Specifically, it is shown how such analysis can be performed using the OpenJML runtime assertion checker. The translation is demonstrated using a case study example of an Automated Teller Machine and several other VDM-SL models, which have been used to validate and asses the translation.

Formal analysis of subnet-based failure recovery algorithm in wireless sensor and actor and network

AbstractWireless sensor and actor networks (WSANs) have various applications in safety and mission critical systems. Sensors are used for sensing the information whereas actors for taking intelligent decisions. Developing and modeling algorithms for WSANs have raised several research issues which have captured attention of the research community. Maintaining inter-actor connectivity or failure recovery is a critical issue in WSANs because these are deployed in harsh and inhospitable environment which may result into physical damage to actors loosing inter-actor connectivity. In case of failure of inter-actor connectivity, the topology of the network may be affected that might be inefficient to recover. Therefore an efficient subnet-based failure recovery algorithm (SFRA) is proposed in this work. It is assumed the partitioning of WSAN into subnets which localizes the failure recovery procedure at subnet level achieving objective of efficiency. Moreover, algorithm is hybrid as it assumes pre-failure planning and post-failure recovery. The proposed model is presented as a graph-based model to represent static part of the network topology. The graph model is transformed into a formal model using Vienna development method-specification language (VDM-SL). The static model is described by defining formal specification of subnets, network topology, sensors, actors and gateways as composite objects. The state space of the WSANs is described in the form of functions and operations as dynamic part of the model. Invariants are defined over the data types in static model for ensuring safety criteria and pre/post conditions are defined in functions and operations for changing state space of the system. The proposed model is validated and verified using VDM-SL Toolbox.

Formal specification and analysis of take-off procedure using VDM-SL

Abstract Purpose Air traffic management system is a complex adaptive and safety critical system which requires considerable attention for its modelling and verification. Currently Air traffic control (ATC) systems are heavily dependent upon human intervention at airport causing accidents and delays because of failure of communication. The purpose of this study is to develop, plan, manage and verify aircrafts movement procedures at the airport surface that prevent delays and collisions. Methods The airport surface is decomposed into blocks and represented by the graph relation. The state space of the system is described by identifying all the possible components of the system. The ground and local controls monitor queues of the aircrafts moving from taxiway to take-off. It is insured that once an aircraft is inserted into a queue, it is eventually removed from it after the next queue has become available. The take-off procedure is provided using graph theory and Vienna Development Method Specification Language (VDM-SL) and analyzed using VDM-SL toolbox. Results Formal specification of graph-based model, taxiways, aircrafts, runways and controllers is provided in static part of the model. The state space analysis describing take-off algorithms is provided by defining optimal paths and possible operations in dynamic model expediting the departure procedure. The model is developed by a series of refinements following the stepwise development approach. Conclusions The delays at airport surface require effective safety and guidance protocols to control air traffic at the airport. In static model, the safety criteria are described in terms of invariants over the data types carrying critical information. The safety is insured by defining pre/post conditions in description of operations for changing state space of the system. Although the proposed study is focussed more on the safety component, however, the efficiency is not ignored.

A VDM-based Approach for Specifying and Testing Requirements of Web-applications

The objective of this paper is to demonstrate the use of formal methods in a uniform way for functional as well as interface-requirements. We propose some add-ons to ‘Vienna Development Method Specification Language'syntaxes to cover the interface-requirements of a web-based application. We also propose a framework to support the transformation of the conventional SRS to a design specification, and a Finite State Machine based verification model, to test the design specification against the SRS.

VDM semantics of programming languages: combinators and monads

Abstract The Vienna Development Method (VDM) was developed in the early 1970s as a variant of denotational semantics. VDM descriptions of programming languages differ from the original Scott–Strachey style by making extensive use of combinators which have a fixed operational interpretation. After recalling the main features of denotational semantics and the Scott–Strachey style, we examine the combinators of the VDM specification language, and relate them to monads, which were introduced more than 15 years later. We also suggest that use of further monadic combinators in VDM could be beneficial. Finally, we provide an overview of published VDM semantic descriptions of major programming languages.

An agent system for collaborative version control in engineering

In this paper we present a system of distributed co‐operating agents whose goal is to manage change and organise version sets in an engineering environment. The agents are designed for full lifecycle support and inter‐operation across heterogeneous networks. The agent communication is based on common object request broker architecture (CORBA) but an extra messaging layer is developed which utilises a language built in Vienna development method‐specification language (VDM‐SL). Problems encountered in the use of engineering database management systems are investigated and solutions are proposed in the context of agents. A version model is presented in two ways; informally based on our assumptions on a general design process and formally in VDM‐SL. An industrial case study is presented and preliminary results shown.

The programming language standards scene, ten years on Paper 15: Vienna Development Method Specification Language (VDM-SL)

This paper, one of a simultaneously published set, describes the establishment in 1987 of the ISO standards project for the Vienna Development Method Specification Language (VDM-SL), and the progress of the project to the end of 1993.

VDM + CCS + Time = MOSCA

Abstract An experimental notation is presented that extends the applicability of the Vienna Development Method specification language VDM-SL into the area of developing distributed, parallel and real-time systems. As is generally known, plain VDM is not adequate for these application area’s since it lacks facilities to specify multiple threads of control and it does not allow the use of time within specifications. Our notation is designed to overcome these restrictions.

Developing ada programs using the vienna development method (VDM)

AbstractA method is presented for the systematic development of sequential Ada programs using the Vienna Development Method (VDM). The approach is based upon using the facilities of Ada for supporting parameterized abstract data types to implement the primitives of the VDM specification language. More experimental work is required to assess the utility of the method, but a systematic approach is promised for using features of Ada unfamiliar to most programmers (e.g. packages, generics and exceptions).Familiarity with Ada is assumed. An overview of VDM is presented so that unfamiliar readers can understand the example given in the paper.