Abstract

Abstract
An OFDM transmission system is reported based on a directly modulated blue LASER diode, for high bit rate under-water optical communication applications. The 256 subcarriers 16-QAM signal is transmitted over a total distance of 2.4 m underwater with an EVM lower than -28.5 dB for a 250 MHz bandwidth and -16.5 dB for a 2 GHz bandwidth, the BER being lower than the forward error corrector limit. At the maximum bandwidth of 2 GHz a transmission rate of 5.36 Gbit/s is achieved. © 2020 IEEE.

Abstract

Abstract
We live in an era where storage systems are of major importance. In this work, we focus on storing files for use in blockchain applications. A blockchain is a distributed, replicated system, that contains a ledger of operations and executes programs known as smart contracts. Although a blockchain may be considered a data storage system, public blockchains like Ethereum charge the users per each byte stored making them expensive to store large files. Therefore, applications based on blockchains often use an external file storage system, usually peer-to-peer (P2P). We propose P2CSTORE, a new storage system for blockchain applications using both P2P and cloud subsystems. This way we aim to provide application developers with the flexibility of choosing the best place for their files, depending on aspects such as the trust they place in peers and clouds. We show the benefits of the approach with a blockchain application that manages education certificates. The application stores hashes of the certificates in the cloud and the certificates themselves in our storage system. © 2020 IEEE.

Abstract

Abstract
The initial phase of the innovation process is widely accepted as an important driver of positive results for new products and for the success of businesses. The Front End of Innovation (FEI) is a multidisciplinary area that includes a variety of activities, such as ideation, opportunity identification and analysis, feasibility analysis, global trends analysis, concept definition, customer and competitor analysis, and even business model development. Due to the number and variety of FEI responsibilities, this phase entails a considerable level of complexity and decision making. This fact is reflected in the literature, where one finds a variety of FEI approaches and proposals, seldom overlapping and offering no clear consensual guidance. This work aimed at overcoming this gap by proposing an Ontology for the Front End of Innovation as a comprehensive knowledge representation of the FEI, the so-called Front End of Innovation Integrative Ontology (FEI2O). The ontology balanced the differences and addressed the shortcomings of the main FEI Reference Models and included contributions from the field. This research builds on a combination of qualitative and quantitative methodologies. It combines the qualitative methods of interviewing and focus group discussion to collect the views of domain experts, used to refine the artefact and later to evaluate the final ontology. Quantitative analysis of data was carried out using the Attribute Agreement approach. The FEI2O explicitly provides a description of a domain regarding concepts, properties and relations of concepts. The main benefit of the FEI2O is to provide a comprehensive formal reference model and a common vocabulary.