Grounding Functional Requirements Classification in Organizational Semiotics

An information system has its requirements rooted in organizational policies and behaviour, the complexity of which is governed by the hierarchy and the dependencies of the activities within the organization. This complexity makes requirements analysis for an envisioned information system an intricately challenging task. The absence of well‐defined body of knowledge clearly specifying which requirements must be looked for further deepens the challenge of requirements analysis. Though requirements are broadly classified as functional and non‐functional, a special concern is required for functional requirements as the information system is expected to meet the behaviour of the organization. We explore the role of organizational semiotics in extracting and analysing functional requirements for an envisioned information system. We also report the results of supervised learning to automatically extract the functional requirements from the existing available documentation

Smart Contracts Software Metrics: a First Study

© 2018 The Author(s).Smart contracts (SC) are software codes which reside and run over a blockchain. The code can be written in different languages with the common purpose of implementing various kinds of transactions onto the hosting blockchain, They are ruled by the blockchain infrastructure and work in order to satisfy conditions typical of traditional contracts. The software code must satisfy constrains strongly context dependent which are quite different from traditional software code. In particular, since the bytecode is uploaded in the hosting blockchain, size, computational resources, interaction between different parts of software are all limited and even if the specific software languages implement more or less the same constructs of traditional languages there is not the same freedom as in normal software development. SC software is expected to reflect these constrains on SC software metrics which should display metric values characteristic of the domain and different from more traditional software metrics. We tested this hypothesis on the code of more than twelve thousands SC written in Solidity and uploaded on the Ethereum blockchain. We downloaded the SC from a public repository and computed the statistics of a set of software metrics related to SC and compared them to the metrics extracted from more traditional software projects. Our results show that generally Smart Contracts metrics have ranges more restricted than the corresponding metrics in traditional software systems. Some of the stylized facts, like power law in the tail of the distribution of some metrics, are only approximate but the lines of code follow a log normal distribution which reminds of the same behavior already found in traditional software systems.Submitted Versio

Generation of model-based safety arguments from automatically allocated safety integrity levels

To certify safety-critical systems, assurance arguments linking evidence of safety to appropriate requirements must be constructed. However, modern safety-critical systems feature increasing complexity and integration, which render manual approaches impractical to apply. This thesis addresses this problem by introducing a model-based method, with an exemplary application based on the aerospace domain.Previous work has partially addressed this problem for slightly different applications, including verification-based, COTS, product-line and process-based assurance. Each of the approaches is applicable to a specialised case and does not deliver a solution applicable to a generic system in a top-down process. This thesis argues that such a solution is feasible and can be achieved based on the automatic allocation of safety requirements onto a system’s architecture. This automatic allocation is a recent development which combines model-based safety analysis and optimisation techniques. The proposed approach emphasises the use of model-based safety analysis, such as HiP-HOPS, to maximise the benefits towards the system development lifecycle.The thesis investigates the background and earlier work regarding construction of safety arguments, safety requirements allocation and optimisation. A method for addressing the problem of optimal safety requirements allocation is first introduced, using the Tabu Search optimisation metaheuristic. The method delivers satisfactory results that are further exploited for construction of safety arguments. Using the produced requirements allocation, an instantiation algorithm is applied onto a generic safety argument pattern, which is compliant with standards, to automatically construct an argument establishing a claim that a system’s safety requirements have been met. This argument is hierarchically decomposed and shows how system and subsystem safety requirements are satisfied by architectures and analyses at low levels of decomposition. Evaluation on two abstract case studies demonstrates the feasibility and scalability of the method and indicates good performance of the algorithms proposed. Limitations and potential areas of further investigation are identified

Monitoring oriented agile based web applications development methodology for small software firms in Jordan

Small software firms (SSF) is vital to the software industry in many countries as they provide substantial growth to their economy. In Jordan, most software companies that are involved with developing Web applications are small firms. However, the extent of applying best Web applications development and management practices in these firms is limited. Besides, the existing software development methods are still lack of monitoring the quality of process and product. As a result, the Web application being developed exceeds deadlines and budget, and not meeting user requirements. Therefore, this research aims to construct a new methodology referred as Monitoring Oriented Agile Based Web Applications Development (MOGWD) Methodology for SSF. This study introduced an Extended Agile Method by extending the Scrum method with Extreme Programming (XP) elements. The Extended Agile Method was improved by combining common steps of Web design method and incorporating the Goal Oriented Monitoring Method (GOMM). The GOMM has defined twenty goals. Each goal has one or more questions. The questions are answered through the defined metrics. There are 101 qualitative metrics for monitoring the process quality, and 37 quantitative metrics for monitoring the process and product quality. Moreover, the proposed MOGWD methodology defines four phases: Plan, Do, Check and Act. The MOGWD methodology was evaluated using expert review and case study. The evaluation results show that the MOGWD methodology has gained SSF practitioners’ satisfaction and found to be practical for the real environment. This study contributes to the field of Agile based development and Web applications measurement. It also provides SSF practitioners a development methodology that monitors the quality of the process and product for Web development

OBSERVER-BASED-CONTROLLER FOR INVERTED PENDULUM MODEL

This paper presents a state space control technique for inverted pendulum system. The system is a common classical control problem that has been widely used to test multiple control algorithms because of its nonlinear and unstable behavior. Full state feedback based on pole placement and optimal control is applied to the inverted pendulum system to achieve desired design specification which are 4 seconds settling time and 5% overshoot. The simulation and optimization of the full state feedback controller based on pole placement and optimal control techniques as well as the performance comparison between these techniques is described comprehensively. The comparison is made to choose the most suitable technique for the system that have the best trade-off between settling time and overshoot. Besides that, the observer design is analyzed to see the effect of pole location and noise present in the system

A Review of Resonant Converter Control Techniques and The Performances

paper first discusses each control technique and then gives experimental results and/or performance to highlights their merits. The resonant converter used as a case study is not specified to just single topology instead it used few topologies such as series-parallel resonant converter (SPRC), LCC resonant converter and parallel resonant converter (PRC). On the other hand, the control techniques presented in this paper are self-sustained phase shift modulation (SSPSM) control, self-oscillating power factor control, magnetic control and the H-∞ robust control technique