Computer Science and Engineering

Compensation is an error recovery mechanism for long-running transactions. Compensating CSP is a variant of the CSP process algebra with constructs for orchestration of compensations. We present a simple operational semantics for Compensating CSP and outline an encoding of this semantics in Prolog. This provides a basis for implementation and model checking of the language.

Business transactions involve multiple partners coordinating and interacting with each other. These transactions have hierarchies of activities which need to be orchestrated. Usual database approaches (e.g.,checkpoint, rollback) are not applicable to handle faults in a long running transaction due to interaction with multiple partners. The compensation mechanism [54] handles faults that can arise in a long running transaction. Based on the framework of Hoare's CSP process algebra [59], Butler et al [27], introduced

Building equivalences between different semantic models of a language strengthens the formal foundation of the language. This paper shows the derivation of denotational semantics from operational semantics of the language cCSP. The aim is to show the correspondence between the operational and trace semantics. We extract traces from operational rules and use structural induction to show the correspondence between the two semantics of cCSP.

In this paper, an approach to facilitate the treatment with variabilities in system families is presented by explicitly modelling variants. The proposed method of managing variability consists of a variant part, which models variants and a decision table to depict the customisation decision regarding each variant. We have found that it is easy to implement and has advantage over other methods. We present this model as an integral part of modelling system families.

Compensating CSP (cCSP) is a language defined to model long running business transactions within the framework of standard CSP process algebra. In earlier work, we have defined both traces and operational semantics of the language. We have shown the consistency between the two semantic models by defining a relationship between them. Synchronization was missing from the earlier semantic definitions which is an important feature for any process algebra. In this paper, we address this issue by extending the syntax and semantics to support synchronization and define a relationship between the semantic models. Moreover, we improve the scalability of our proof technique by mechanically verifying the semantic relationship using theorem prover PVS. We show how to embed process algebra terms and semantics into PVS and to use these embeddings to prove the semantic relationship.

Formal semantics offers a complete and rigorous definition of a language. It is important to define different semantic models for a language and different models serve different purposes. Building equivalence between different semantic models of a language strengthen its formal foundation. This paper shows the derivation of denotational semantics from operational semantics of the language cCSP. The aim is to show the correspondence between operational and trace semantics. We extract traces from operational rules and use induction over traces to show the correspondence between the two semantics of cCSP.

Compensating CSP (cCSP) is a language defined to model long running business transactions within the framework of standard CSP process algebra. In earlier work, we have defined both traces and operational semantics of the language. We have shown the consistency between the two semantic models by defining a relationship between them. Synchronization was missing from the earlier semantic definitions which is an important feature for any process algebra. In this paper, we address this issue by extending the syntax and semantics to support synchronization and define a relationship between the semantic models. Moreover, we improve the scalability of our proof technique by mechanically verifying the semantic relationship using theorem prover PVS. We show how to embed process algebra terms and semantics into PVS and to use these embeddings to prove the semantic relationship.

An approach to vectorizing binary image of engineering drawing, specially irregular shape is presented in this paper. The preliminary steps include detection and elimination of noise components and skewness. Lines, circles and arcs are detected using existing Hough, transform and chain method is used for both bounded and unbounded irregular shapes.

Proper management of requirements is crucial to successful development software within limited time and cost. Nonfunctional requirements (NFR) are one of the key criteria to derive a comparison among various software systems. In most of software development NFR have be specified as an additional requirement of software. NFRs such as performance, reliability, maintainability, security, accuracy etc. have to be considered at the early stage of software development as functional requirement (FR). However, identifying NFR is not an easy task. Although there are well developed techniques for eliciting functional requirement, there is a lack of elicitation mechanism for NFR and there is no proper consensus regarding NFR elicitation techniques. Eliciting NFRs are considered to be one of the challenging jobs in requirement analysis. This paper proposes a UML use case based questionary approach to identifying and classifying NFR of a system. The proposed approach is illustrated by using a Point of Sale (POS) case study.

Semantic web offers a smarter web service which synchronizes and arranges all the data over web in a disciplined manner. In data mining over web, the accuracy of selecting necessary data according to user demand and pick them for output is considered as a major challenging task over the years. This paper proposes an approach to mapping data over the web 3.0 through ontology and access the required data via an intelligent agent. The agent provides all the searched data related to user query from which user can find desired information. When the user does not have sufficient search parameter, knowledge can be perceived from the information provided by the agent. The derivation of such unknown knowledge from the existing can be achieved by semantic web mining. We present an intelligent agent-based web mining model where users' query is being searched by following existing traditional way, e.g. by Google. The intelligent agent checks the searched data and derives only those are the semantically related to users search parameter. A work-in-progress case study of University Faculty Information presented to examine the effectiveness of the proposed model.

Formal verification of variant requirements has gained much interest in the software product line (SPL) community. Feature diagrams are widely used to model product line variants. However, there is a lack of precisely defined formal notation for representing and verifying such models. This paper presents an approach to modeling and verifying SPL variant feature diagrams using first-order logic. It provides a precise and rigorous formal interpretation of the feature diagrams. Logical expressions can be built by modeling variants and their dependencies by using propositional connectives. These expressions can then be validated by any suitable verification tool. A case study of a Computer Aided Dispatch (CAD) system variant feature model is presented to illustrate the verification process.

Web services technology provides a platform on which we can develop distributed services. The interoperability among these services is achieved by various standard protocols. In recent years, several researches suggested that process algebras provide a satisfactory assistance to the whole process of web services development. Business transactions, on the other hand, involve the coordination and interaction between multiple partners. With the emergence of web services, business transactions are conducted using these services. The coordination among the business processes is crucial, so is the handling of faults that can arise at any stage of a transaction. BPEL models the behavior of business process interaction by providing a XML based grammar to describe the control logic required to coordinate the web services participating in a process flow. However BPEL lacks a proper formal description where the composition of business processes cannot be formally verified. Process algebra, on the other hand, facilitates a formal foundation for rigorous verification of the composition. This paper presents a comparison of web service composition between BPEL and process algebra, cCSP.

The fundamental issue in knowledge representation is to provide a precise definition of the knowledge that they possess in a manner that is independent of procedural considerations, context free and easy to manipulate, exchange and reason about. Knowledge must be accessible to everyone regardless of their native languages. Universal Networking Language (UNL) is a declarative formal language and a generalized form of human language in a machine independent digital platform for defining, recapitulating, amending, storing and dissipating knowledge among people of different affiliations. UNL extracts semantic data from a native language for Interlingua machine translation. This paper presents the development of a graphical tool that incorporates UNL to provide a visual mean to represent the semantic data available in a native text. UNL represents the semantics of a sentence as a conceptual hyper-graph. We translate this information into XML format and create a graph from XML, representi...

In recent modernized era, the number of the Facebook users is increasing dramatically. Moreover, the daily life information on social networking sites is changing energetically over web. Teenagers and university students are the major users for the different social networks all over the world. In order to maintain rapid user satisfactions, information flow and clustering are essential. However, these tasks are very challenging due to the excessive datasets. In this context, cleaning the original data is significant. Thus, in the current work the Fishers Discrimination Criterion (FDC) is applied to clean the raw datasets. The FDC separates the datasets for superior fit under least square sense. It arranges datasets by combining linearly with greater ratios of between-groups and within the groups. In the proposed approach, the separated data are handled by the Bigtable mapping that is constructed with Map specification, tabular representation and aggregation. The first phase organizes the cleaned datasets in row, column and timestamps. In the tabular representation, Sorted String Table (SSTable) ensures the exact mapping. Aggregation phase is employed to find out the similarity among the extracted datasets. Mapping, preprocessing and aggregation help to monitor information flow and communication over Facebook. For smooth and continuous monitoring, the Dynamic Source Monitoring (DSM) scheme is applied. Adequate experimental comparisons and synthesis are performed with mapping the Facebook datasets. The results prove the efficiency of the proposed machine learning approaches for the Facebook datasets monitoring.

Modelling software product line (SPL) features plays a crucial role to a successful development of SPL. Feature diagram is one of the widely used notations to model SPL variants. However, there is a lack of precisely defined formal notations for representing and verifying such models. This paper presents an approach that we adopt to model SPL variants by using UML and subsequently verify them by using firstorder logic. UML provides an overall modelling view of the system. First-order logic provides a precise and rigorous interpretation of the feature diagrams. We model variants and their dependencies by using propositional connectives and build logical expressions. These expressions are then validated by the Alloy verification tool. The analysis and verification process is illustrated by using Computer Aided Dispatch (CAD) system.

Feature Tree represents all the features along with their relationship of a Software Product Line. Any defect in feature model can diminish the benefits of product line approach. Hence, the analysis of feature model plays a key role towards the success of any Software Product Line. This paper presents various analysis rules for cardinality-based feature model of both dead and false optional features. These rules are then verified by using Bayesian Network Based inference mechanism. Such verification not only confirms the analysis rules of the feature trees but also ensures the applicability of probabilistic information into the feature trees.

Web service technology provides a platform that facilitates the development of distributed services. In order to support business to business interactions within the distributed environment a crying need is to aggregate web services and assemble them is a goal oriented infrastructure. With the emergence of web services, the coordination and interaction involved between multiple business partners are conducted by using the web services. Faults can arise at any stage of business transaction and handling such faults where multiple partners are involved is both crucial and difficult. Process algebras can be used to model concurrent and distributed interactive systems. Compensating CSP is a language defined to model business transactions within the framework of CSP process algebra. It has the facility to model faults within a transaction as compensations. However, the language lacks automated tool support to verify the service composition. Finite state Process (FSP), on the other hand, is designed to model the composition of web services and importantly, it has an automated tool support for verification of composition of services, however there is no construct for compensation. By combining the benefits the both cCSP and FSP, this paper illustrates a mechanism to model and verify the composition of services and compensation in FSP by following the mechanism adopted in cCSP. The verification of composition properties is performed by LTSA tool.

Web services technology provides a platform on which we can develop distributed services. The interoperability among these services is achieved by various standard protocols. In recent years, several researches suggested that process algebras provide a satisfactory assistance to the whole process of web services development. Business transactions, on the other hand, involve the coordination and interaction between multiple partners. With the emergence of web services, business transactions are conducted using these services. The coordination among the business processes is crucial, so is the handling of faults that can arise at any stage of a transaction. BPEL models the behavior of business process interaction by providing a XML based grammar to describe the control logic required to coordinate the web services participating in a process flow. However BPEL lacks a proper formal description where the composition of business processes cannot be formally verified. Process algebra, on the other hand, facilitates a formal foundation for rigorous verification of the composition. This paper presents a comparison of web service composition between BPEL and process algebra, cCSP.