Nazir Ahmad Zafar

Nazir Ahmad Zafar
King Faisal University · Department of Computer Science

PhD, Computer Science, Kyushu University, Japan

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97
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752
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Publications

Publications (97)
Article
Full-text available
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 dis...
Article
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The formal modeling and verification of aircraft takeoff is a challenge because it is a complex safety-critical operation. The task of aircraft takeoff is distributed amongst various computer-based controllers, however, with the growing malicious threats a secure communication between aircraft and controllers becomes highly important. This research...
Article
Full-text available
VANETs have gained much attention from both industry and academia because of their characteristics, such as dynamic topology. There are various applications of VANETs that are classified on the basis of safety, efficiency, commercial usage, and productive areas. This paper presents an IoT-based formal model for vehicle-life integration enabling RSU...
Article
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. Unfo...
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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 signal...
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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 co...
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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 popu...
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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,...
Conference Paper
UML Activity Diagram has been widely used by practitioners to model dynamic aspects of any real world system. But UML is not based on firm mathematical semantics therefore it is unable to be checked for presence of errors. The latest version of UML released by Object Management Group (OMG) in 2015 still lacks standard formal semantics. Our earlier...
Conference Paper
One of the most focused area of research now-a-days is ad hoc networks. The most communal type of the ad hoc network is Mobile Ad hoc Networks (MANET). Several issues might encounter during the deployment of MANETs because of its infrastructure-less architecture and self-configuring behavior of the freely moving nodes. Mobility Management of mobile...
Conference Paper
Battlefield surveillance have come into attention to address the issue of national security. In battlefield not only weapons or firepower is required but also an effective command, control system, intelligent pre-planning, and run time decision capability for the effective use of firepower and weapons to win in the war. This increases burden on the...
Conference Paper
Agent-based Mobile Petri Nets are a powerful variant of classical Petri Nets which integrate mobile agent technology. A mobile agent migrates among heterogeneous platforms by acquiring their services to perform its goal. Agent-based Mobile Petri Nets effectively model mobility, concurrency and distributed nature of a mobile agent. However, security...
Conference Paper
Full-text available
In making the universities smart it is needed to efficiently manage the duty cycle operation of nodes. Currently, IEEE 802.15.4 recommends static use of duty cycle operation which is not suitable in university environment because the contents are always not the same for all applications. Thus, an algorithm is needed for the dynamic adjustment of no...
Conference Paper
The destruction caused by the earthquakes can be minimized using Wireless Sensor and Actors Networks (WSANs). Earthquake Management System (EQMS) is proposed in this work using WSANs which are deployed in the form of subnets in the areas which are vulnerable to earthquakes. The deployment in the form of subnets increases energy efficiency of the ne...
Conference Paper
UML Activity Diagram offers rich notations to model system dynamics of any real world system. But Activity Diagram lacks firm mathematical semantics hence impotent to be checked for potential inconsistencies and bugs. Coloured Petri Nets is a strong graphical Formal Methods having a wide range of tool support for model checking. This research artic...
Article
Full-text available
Wireless 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. Maintaini...
Conference Paper
Forests are important part of the ecosystem and play a significant role to preserve and maintain the environment. The main hazard is the forest fires because its consequences are terrible in nature. Therefore, there is a need to detect fire and extinguish before it spreads to destroy the resources. For this purpose, Forest Fire Detection and Exting...
Conference Paper
Rapid advancement in ad hoc networks and its variants, create a need for efficient and accurate routing decisions. As routing decisions for Mobile Ad hoc Networks has great impact on the overall performance of the network Quality of Service (QoS) parameters (delay, bandwidth, PDR etc.), optimized routing protocols need to be designed. One of the bi...
Conference Paper
With the passage of time the needs of an organization grow, therefore, the operational work and responsibilities are also grown. That is why there is a need of hiring more employees. Calculating salaries of many employees requires a lot of work and chances of occurring errors also increase. Automatic Payroll Processing System (APPS) simplifies the...
Conference Paper
The Resurrecting Duckling is a powerful security policy widely used in ad-hoc networks having devices with low processing capabilities. Focusing the master-slave relationship between any two network nodes, The Resurrecting Duckling is aimed at secure transient association. Hierarchical Coloured Petri Nets are descendants of Coloured Petri Nets whic...
Conference Paper
Flood is one of the major natural disasters affecting almost the whole world. In this paper, we propose a model of cloud computing based flood detection and management system (FDMS) using wireless sensor and actor networks (WSANs). Sensors and actors are deployed in connected subnets to localize the problem. As WSANs are limited in terms of resourc...
Article
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Mobile ad hoc and sensor networks (MAHSNs) are expected to become the fabric of modern societies. Despite considerable advancements, these networks are yet unable to surmount many operational challenges especially in safety-critical large-scale applications. Most of the published research focused on performance analysis of nonfunctional properties...
Conference Paper
Recently the interest in wireless sensor and actor networks has increased tremendously. Although there has been significant improvement in WSANs, but still many challenges are needed to overcome the issues of critical applications. In most of the published work the focus is on the performance analysis of non-functional properties but correctness of...
Conference Paper
The Field of Formal Methods (FM) is a growing field that uses mathematical notations for making accurate and unambiguous specifications, so that in the early phases of software development discrepancies and errors are identified. By using the popular kind of formal methods i.e. VDM, the quality of design, system specification and verification of so...
Conference Paper
Agent-based Mobile Petri Net (MPN) is an emerging variant of classical Petri Nets which allows graphical representation of system to be developed. In addition agent-based MPN integrates mobile agent technology for modeling concurrency and mobility. Unified Modeling Language (UML) has become a defacto standard for modeling any real world system. Unl...
Conference Paper
Software security is a thought-provoking issue for open and distributed systems. Regardless of the importance of outer securities of software systems, internal security has substantial impact on the entire security of the software systems. In this paper, internal security problems of software systems are focused. Internal security of software is de...
Article
Wireless sensor and actor networks (WSAN) are captivating significant attention because of their suitability for safety-critical applications. Efficient actor placement in such applications is extremely desirable to perform effective and timely action across the deployment region. Nonetheless, harsh application environment inherently favors random...
Article
In this paper, the thin film flow of a power law MHD fluid on a vertical cylinder for a drainage problem has been studied. The nonlinear differential equation has been derived from the momentum equation by Jeffrey's approach. Series solutions have been obtained for velocity, flow rate and thickness of the fluid film by Perturbation method. The grap...
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Timely segregation of critical/noncritical nodes is extremely crucial in mobile ad hoc and sensor networks. Most of the existing segregation schemes are centralized and require maintaining network wide information, which may not be feasible in large-scale dynamic networks. Moreover, these schemes lack rigorous validation and entirely rely on simula...
Conference Paper
Although, Unified Modeling Language (UML) has become a de-facto standard for design and specification of object oriented systems but its structures being semi-formal in nature have various disadvantages. The UML diagrams lack with defining semantics of the functionality of a system to be developed. Automata theory and formal methods are proved powe...
Article
In our previous articles we gave step by step refinement process towards the development of safety properties of moving block interlocking system (MBRIS). The refinement process started from abstraction to fuzzy based safety properties using Z and then fuzzy multi agent specification language. However, one dimensional control of train passing throu...
Article
Full-text available
In this work, the theoretical study of steady flow for lift and drainage of Power law MHD fluid on a vertical cylinder is presented. The governing nonlinear differential equation has been derived from the momentum equation. The resulting equation is then solved using Perturbation method. Series solutions have been obtained for velocity, flow rate a...
Conference Paper
Long Term Evolution (LTE) is the latest wireless standard for International Mobile Telecommunication (IMT) system. There are many issues that are yet to be improved due to dynamic complex nature of wireless systems, multimedia software applications and software requirements. Poor service quality, service disconnections due to mobility, seamless han...
Article
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Maintaining inter-actor connectivity is extremely crucial in mission-critical applications of Wireless Sensor and Actor Networks (WSANs), as actors have to quickly plan optimal coordinated responses to detected events. Failure of a critical actor partitions the inter-actor network into disjoint segments besides leaving a coverage hole, and thus hin...
Article
Railway interlocking is a safety critical system because its incorrect func-tioning may cause serious consequences. Modeling of a reliable interlocking has become a challenging problem due to its inherent complexity and introduction of new technologies. In this paper, formal analysis of safety properties of moving block interlocking is presented pr...
Article
The real world is a dynamic place where things change in an unexpected way. Software must be able to adapt these changes to work efficiently in the real world. Modeling of the multi-agent system implies modeling of the agent's dynamic structure and behavior, including their ability to communicate with other agent of the systems and dynamically orga...
Article
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In recent years, interest has been developed for the problem of mobile robot navigation system because of its applications in various disciplines. The software development of mobile robot navigation is a complex phenomena and it is passed through different stages of design. It can be modeled either for autonomous, usually, in an unknown environment...
Article
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Design and construction of an error-free compiler is a difficult and challenging process. The main functionality of a compiler is to translate a source code to an executable machine code correctly and efficiently. In formal verification of software, semantics of a language has more meanings than the syntax. It means source program verification does...
Article
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Compiler is a program whose functionality is to translate a computer program written in source language into an equivalent machine code. Compiler construction is an advanced research area because of its size and complexity. The source codes are in higher level languages which are usually complex and, consequently, increase the level of abstrac-tion...
Article
The safety critical systems are those whose failure may cause the loss of human life, serious injuries and financial disasters. The air traffic control system (ATC) is a safety critical system and rise in the air traffic volume make it more critical and complex which caused for the unwanted delay in the aircraft departure process. To ensure its saf...
Article
Previous work described by the authors was the use of promotion to link the global state (controller) with the local state (train system). In which the operation of a train makes changes in controller, based on the approach of promotion. However, the model did not apply to any of the critical interlocking components. This paper extends to provide...
Article
The need for robust, safe and reliable real life application requires the use of formal techniques in order to increase the confidence over the system to be developed. In this paper, we have used an approach of integration of X-machine and Z notation for modeling the agent-based traffic control system. The system is composed as a multi-agent system...
Article
Full-text available
Various protocols are proposed in Mobile Ad Hoc Networks (MANET) for finding the best route from source to destination however, there doesn't exist any real protocol considering all the parameters needed to attain acceptable level of Quality of Service (QoS) for real-time interactive applications. Consequently this is an open research problem and h...
Conference Paper
In recent years, the volume of air traffic has increased dramatically which caused for unwanted delay in flights at the airports during the departure and arrival process of aircrafts. In this paper we have proposed step by step modeling process for the departure of the aircraft with the coordination of the air traffic controllers. These controllers...
Article
Database systems are considered as an integral part of any software system, therefore, all complex systems maintain a database in different formats. Relational database management systems are based on relational model for creation and storage of databases. Database reverse engineering (DBRE) is a process of extracting the database requirements from...
Article
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Automata theory has played an important role in theoretical computer science since last couple of decades. The algebraic automaton has emerged with several modern applications, for example, optimization of programs, design of model checkers, development of theorem provers because of having certain interesting properties and structures from algebrai...
Article
Developing correct and complete real-world software applications is a difficult task in terms of the number and flexibility of the essential components and their interrelationship. As the field of agent-based computing matures, the requirements of well-founded techniques and methodology for such systems modeling will increased. This paper used inte...
Article
Functionalities and control behavior are both primary requirements in design of a complex system. Automata theory plays an important role in modeling behavior of a system. Z is an ideal notation which is used for describing state space of a system and then defining operations over it. Consequently, an integration of automata and Z will be an effect...
Article
Full-text available
Automata theory has proved to be a cornerstone in theoretical computer science since last couple of decades. It is playing an important role in modeling behavior of complex systems. The algebraic automaton which is an advanced form of automata, having properties and structures from algebraic theory, is emerging with several modern applications. Opt...
Conference Paper
Layering is a concept widely used in computer and software modeling. Many modern information systems are designed and built using a layered model where the function of each layer is specified and well defined. In this paper we will be discussing the layer whose responsibilities include data extraction, manipulation and provision of data to the rest...
Article
The design of a complex system requires both functional and behavior representation. Formal methods are mathematical based techniques used for specifications of properties hardware and software systems. The Znotation is a formal technique used for capturing functionality. Automata theory is a powerful tool to capture their control behavior. As a re...
Article
Full-text available
Automata theory has played an important role in computer science and engineering particularly modeling behavior of systems since last couple of decades. The algebraic automaton has emerged with several modern applications, for example , optimization of programs, design of model checkers, development of theorem provers because of having properties a...
Article
The railway interlocking system, being a safety-critical system, has achieved importance in the railway industry. Advanced technologies are being applied for its modelling, preventing collision and derailing of trains and at the same time allowing efficient movement of trains. In this study, we have applied Z notation by constructing a specificatio...
Article
Algebraic automaton has emerged with several modern applications in computer science and engineering. Design of theorem provers, development of model checkers, optimization of programs are some of its applications. The Z notation is suitable for modeling static while automata are powerful for describing dynamic parts of a system. Consequently, thei...
Article
Full-text available
The complexity of a system in terms of its state space and functional aspects enforces to choose most prolific and rigorous approaches to sustain the development of the software systems. Finite automaton is a formal and natural medium to describe the static and dynamic behavior of a complex system. Z notation is an ideal specification language havi...
Conference Paper
Automata have various applications and it plays an important role in computer science, particularly, in modeling behavior of systems. Z notation is an ideal one to be used defining state space of a system and then operations over it. Consequently, it requires an integration of automata and Z increasing its modeling power. Further, finite automata m...
Conference Paper
Automata theory has played an important role in modeling behavior of systems since last couple of decades. The algebraic automaton has emerged with several modern applications because of having properties and structures from algebraic theory. Design of a complex system not only requires behavior but it also needs to model its functionality. Z notat...
Conference Paper
Enterprise applications are frequently designed and developed using a layered approach where the entire application is divided into layers. Each layer in such architecture performs a specific and well defined function. The first and foremost of these layers is the presentation layer. Object oriented design patterns exist for this layer that provide...
Conference Paper
Automata play an important role in modeling behavior while Z is an ideal notation used for describing state space of a system. Consequently, an integration of automata and Z is required increasing their modeling power. Further, deterministic finite automata (DFA) may have different implementations and therefore it is needed to verify the transforma...
Article
Automata theory plays a vital role in modeling behavior while Z notation is an ideal specification language for describing state space of a system. Consequently, integration of automata and Z will be a useful tool for increasing modeling power of complex systems. Further, nondeterministic finite automata (NFA) may have different implementations and...