Sher Afzal Khan

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Computer programming is the core of computer science curriculum. Several programming languages have been used to teach the first course in computer programming, and such languages are referred to as first programming language (FPL). The pool of programming languages has been evolving with the development of new languages, and from this pool different(More)
Proteins are the executants of biological functions in living organisms. Comprehension of protein structure is a challenging problem in the era of proteomics, computational biology, and bioinformatics because of its pivotal role in protein folding patterns. Owing to the large exploration of protein sequences in protein databanks and intricacy of protein(More)
The most expedient unit of the human body is its cell. Encapsulated within the cell are many infinitesimal entities and molecules which are protected by a cell membrane. The proteins that are associated with this lipid based bilayer cell membrane are known as membrane proteins and are considered to play a significant role. These membrane proteins exhibit(More)
Railway interlocking is a safety critical system because its incorrect functioning 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 preventing(More)
Current World Wide Web means to display pages to end user, while the Semantic Web is a vision of a next-generation network focuses on "Meaning" instead of merely pasting arbitrary text on a page. An intelligent software agents use information to organize and filter data to meet the user's needs. DAML+OIL and Web Ontology Language OWL are the current(More)
Railway interlocking system is a distributed, safety, monetary and environmentally critical system and its failure may cause the loss of human life, severe injuries, loss of money and environmental damages. The complexity of this system requires formal modeling and step by step refinement for its construction and development. The formal specification-based(More)
This paper presents a biometric technique for identification of a person using the iris image. The iris is first segmented from the acquired image of an eye using an edge detection algorithm. The disk shaped area of the iris is transformed into a rectangular form. Described moments are extracted from the grayscale image which yields a feature vector(More)
The paper presents the vector-host disease with a variability in population. We assume, the disease is fatal and for some cases the infected individuals become susceptible. We first show the local and global stability of the disease-free equilibrium, for the case when R 0 < 1. We also show that for R 0 < 1, the disease free-equilibrium of the model is both(More)