Process software simulation model of Lean-Kanban Approach

Software process simulation is important for reducing errors, helping analysis of the risks and for improving software quality. In recent years, the Lean-Kanban approach has been widely applied in software practice including software development and maintenance. The Lean-Kanban approach minimizes the Work-In-Progress (WIP), which is the number of items that are worked on by the team at any given time. It has been demonstrated that such approach can help to improve software maintenance and development processes in industrial environments. The goal of the simulation model itself is to increase the understanding and to support decisions for planning such kind of projects. Considering the threats to validity of the study, the accuracy and reliability of the simulation model could be shown and the simulation model implementation allows for deriving hypothesis on the impact of distribution on parameters such as throughput. In this thesis, we describe our simulation studies, which show that the Lean-Kanban approach can indeed help to reduce the average time needed to complete maintenance or development issues. This simulation model can simulate existing maintenance and development processes that does not use a WIP limit, as well as a maintenance and development processes that adopt a WIP limit. We performed some case studies using real data collected from different projects. The results confirmthat the WIP-limited process as advocated by the Lean- Kanban approach could be useful to increase the efficiency of software maintenance and development, as reported in previous industrial practices

A real-time FFT-KLT implementation for SETI research at the Sardinia Radio Telescope

The Search for ExtraTerrestrial Intelligence (SETI) is a project whose goal is to find possible life signatures emitted (intentionally or unintentionally) by possible civilizations from other habitable planets. Historically, the narrow-band FFT approach has been used, since a quasi-monochromatic signal is the most probable signal one would use to send a message to another world, that is in the case of intentionally- transmitted signals. Nevertheless, we could receive an unintentionally-transmitted signal as well. In that case, it would most certainly not be a quasi-monochromatic signal, but would probably be similar (with a wider bandwidth, of the order of MHz) to the signals that we use for conventional communications on Earth. The Kahrunen-Loève Transform (KLT) is a powerful algorithm for such a kind of research. However, a real-time implementation of the KLT has thus far not worked due to a lack of technological resources. We describe a hardware-software infrastructure at the Sardinia Radio Telescope (SRT) that, in real-time, makes it possible to perform the KLT in parallel to the FFT

A real-time KLT implementation for radio-SETI applications

SETI, the Search for ExtraTerrestrial Intelligence, is the search for radio signals emitted by alien civilizations living in the Galaxy. Narrow-band FFT-based approaches have been preferred in SETI, since their computation time only grows like N*lnN, where N is the number of time samples. On the contrary, a wide-band approach based on the Kahrunen-Lo`eve Transform (KLT) algorithm would be preferable, but it would scale like N*N. In this paper, we describe a hardware-software infrastructure based on FPGA boards and GPU-based PCs that circumvents this computation-time problem allowing for a real-time KLT

Blockchain oracles for document certification: A case study

The use of blockchain oracles is becoming increasingly widespread as it responds to the problem of providing the blockchain with external data automatically. In this paper, we focus on the use of blockchain oracles for the certification of articulated data. In particular, we show how it is possible to design and implement a DApp capable of providing documents on request without these data permanently residing on the blockchain. We present a case study of the on-demand provision of university curriculum, fully managed via a blockchain oracle. In this system, the smart contract will not record data permanently but only for the time necessary for its use. The system is intended to allow a user to request and obtain data only about herself. The paper also presents a classification of the types of blockchain oracles and their most common applications. The case study will be presented as blockchain-oriented software, and in terms of architecture and dynamics using UML diagrams, the benefits and drawbacks of the approach are discussed

A New Approach for Knowledge Management and Optimization using an Open Source Repository

The Institutional Repositories (Irs) based on Open Archives represent one of the main free access tools for the results of scientific research, and their diffusion is continuously growing. In the context of the “Analytic Sound Archive of Sardinia” project, that aims to create an institutional archive with a linguistically annotated electronic corpus, this work proposes a new approach for management of knowledge using the tool Dspace (an open source software package developed in 2000 in the context of a joint project of the Massachusetts Institute of Technology with Hewlett-Packard): the purpose is to offer an original way to associate linguistic annotations (information associated to specific text portions) to the corpus by treating them as metadata, so as to insert and manage them in the archive of choice after formalizing them in XML. The formalization level of this approach allows for effective text retrievals through a metadata schema and easy, quick corpus interrogations, by formalizing linguistic annotation as a structured metadata schema. There is, thus, the need to have an efficient tool that could classify and store the vast amount of knowledge contained in an electronic corpus of spoken texts of Sardinian language, linguistically annotated at various levels, and that could allow a high usability in terms of ease of reference as well as ease of query and communication

Using an ontology for multimedia content semantics

In recent years, we witnessed the diffusion and rise in popularity of software platforms for the User Generated Content (UGC) management, especially multimedia objects. These platforms handle a large amount of unclassified information. UGC websites (e.g. YouTube and Flickr) do not force the users to perform classification operations and metadata definitions, leaving space to a logic of free-tags (Folksonomies). We analyzed the standards used in UGC websites for the management of the multimedia contents and their metadata. We defined an ontology to represent the semantics of these multimedia contents, so that in turn the metadata classification can give an unambiguous meaning. In order to unify metadata coming from different sources we defined all rules of mapping toward a structure defined by sources such as YouTube and Flickr. The innovation is in the approach for the formalization of web semantics for multimedia content: we used standards such as Dublin Core, Exif, IPTC and in particular the Adobe XMP standard as a starting point of this domain. With the proposed approach, once can categorize and catalog all non-standard and unclassifiable information inside the ontology, using pre-made schemas

Implementing a Microservices System with Blockchain Smart Contracts

Blockchain technologies and smart contracts are becoming mainstream research fields in computer science and researchers are continuously investigating new frontiers for new applications. Likewise, microservices are getting more and more popular in the latest years thanks to their properties, that allow teams to slice existing information systems into small and independent services that can be developed independently by different teams.A symmetric paradigm applies to smart contracts as well, which represent well defined, usually isolated, executable programs, typically implementing simple and autonomous tasks with a well defined purpose, which can be assumed as services provided by the Contract. In this work we analyze a concrete case study where the microservices architecture environment is replicated and implemented through an equivalent set of smart contracts, showing for the first time the feasibility of implementing a microservices-based system with smart contracts and how the two innovative paradigms match together.Results show that it is possible to implement a simple microservices-based system with smart contracts maintaining the same set of functionalities and results. The result could be highly beneficial in contexts such as smart voting, where not only the data integrity is fundamental but also the source code executed must be trustable