Analyzing Consistency of Behavioral REST Web Service Interfaces

REST web services can offer complex operations that do more than just simply creating, retrieving, updating and deleting information from a database. We have proposed an approach to design the interfaces of behavioral REST web services by defining a resource and a behavioral model using UML. In this paper we discuss the consistency between the resource and behavioral models that represent service states using state invariants. The state invariants are defined as predicates over resources and describe what are the valid state configurations of a behavioral model. If a state invariant is unsatisfiable then there is no valid state configuration containing the state and there is no service that can implement the service interface. We also show how we can use reasoning tools to determine the consistency between these design models.Comment: In Proceedings WWV 2012, arXiv:1210.578

Consistency of UML based designs using ontology reasoners

Software plays an important role in our society and economy. Software development is an intricate process, and it comprises many different tasks: gathering requirements, designing new solutions that fulfill these requirements, as well as implementing these designs using a programming language into a working system. As a consequence, the development of high quality software is a core problem in software engineering. This thesis focuses on the validation of software designs. The issue of the analysis of designs is of great importance, since errors originating from designs may appear in the final system. It is considered economical to rectify the problems as early in the software development process as possible. Practitioners often create and visualize designs using modeling languages, one of the more popular being the Uni ed Modeling Language (UML). The analysis of the designs can be done manually, but in case of large systems, the need of mechanisms that automatically analyze these designs arises. In this thesis, we propose an automatic approach to analyze UML based designs using logic reasoners. This approach firstly proposes the translations of the UML based designs into a language understandable by reasoners in the form of logic facts, and secondly shows how to use the logic reasoners to infer the logical consequences of these logic facts. We have implemented the proposed translations in the form of a tool that can be used with any standard compliant UML modeling tool. Moreover, we authenticate the proposed approach by automatically validating hundreds of UML based designs that consist of thousands of model elements available in an online model repository. The proposed approach is limited in scope, but is fully automatic and does not require any expertise of logic languages from the user. We exemplify the proposed approach with two applications, which include the validation of domain specific languages and the validation of web service interfaces

Consistency of UML class, object and statechart diagrams using ontology reasoners

We propose an automatic approach to analyze the consistency and satisfiability of Unified Modeling Language UML models containing multiple class, object and statechart diagrams using logic reasoners for the Web Ontology Language OWL 2. We describe how to translate UML models in OWL 2 and we present a tool chain implementing this translation that can be used with any standard compliant UML modeling tool. The proposed approach is limited in scope, but is fully automatic and does not require any expertise about OWL 2 and its reasoners from the designer

Consistency of UML class, object and statechart diagrams using ontology reasoners

AbstractWe propose an automatic approach to analyze the consistency and satisfiability of Unified Modeling Language UML models containing multiple class, object and statechart diagrams using logic reasoners for the Web Ontology Language OWL 2. We describe how to translate UML models in OWL 2 and we present a tool chain implementing this translation that can be used with any standard compliant UML modeling tool. The proposed approach is limited in scope, but is fully automatic and does not require any expertise about OWL 2 and its reasoners from the designer

Performance Analysis of Raspberry Pi 3 IP PBX Based on Asterisk

IP-PBX have grown considerably in the telecoms and IT industries in recent times due to their low cost, high customizability, open source and hardware-independent nature. Unlike traditional PBX systems that are TDM-based and require a separate wired infrastructure to operate, an IP PBX can be attached to the local LAN and uses SIP with RTP over Internet Protocol (IP) for signaling and data transport, respectively. Asterisk-based IP PBX has become a de facto standard for open-source low-to-medium calling capacity requirements. Single Board Computers (SBCs) are attracting considerable attention from academics, hobbyists and the industry, due to their compact size, low cost, low power, portability and fair processing ability. Raspberry Pi series SBCs are the pioneer in the field, having Pi, Pi2, Pi3 and Pi Zero in production, supporting different processing and storage capabilities. An IP PBX embedded on the raspberry Pi SBC can serve an adequate number of users and provide a tiny platform that can fit in a pocket and be transported anywhere while preserving the functionality of a complete IP PBX. Such systems can be phenomenally successful in situations where large infrastructures cannot be taken, for instance, in warzones or disaster-affected areas where communication networks are damaged, necessitating an immediate requirement for an ad hoc-based communication system. In this paper, we aim to explore the performance of an Asterisk®-based IP PBX installed on a Raspberry Pi 3 (model B) platform in terms of concurrent call handling using different codecs