A User-Centered Perspective for the blockchain Development

Blockchain technology is regarded as one of the most important digital innovations in the last two decades. Its applicability beyond cryptocurrencies has been a growing topic of research interest not only in computer science but also in other areas, such as marketing, finance, law, healthcare, etc. However blockchain is far from reaching the population on a larger scale. The dissertation evaluates the causes that are preventing successful implementation and adoption of blockchain technology at a larger scale, supporting infrastructure for public and private companies. The latest academic research suggests that the blockchain services are still in an early stage, and standards for developing blockchain-based applications have not been defined yet. Moreover the interaction with the blockchain technology is still complex, especially for non expert users, because it requires many technical skills. The dissertation focuses on this knowledge gap as a cause for the blockchain missing reach on society at a larger scale. This work aims to fill the gap by presenting innovative methodologies and user-centered models that could help the adoption of the blockchain technology by a larger number of private/public companies and individuals. Based on these models, specific tools for both expert and non-expert users are developed and discussed in the dissertation. First, tools for expert users, i.e., software developers, are proposed to analyze the smart contracts’ source code, to collect the smart contracts in a reasoned repository, and to identify code clones and boost the use of open source libraries for a better collective practice in developing and maintaining the blockchain. Second, tools for non-expert users, i.e. people with no technical knowledge, are proposed to suggest them the fairest fees to pay to have their transactions executed according to the price and waiting times they are willing to spend, and to identify malicious smart contracts that can deceive them, thus preventing them to trust the blockchain and use it again. Finally, visualization models for users with expertise in different disciplines are proposed to provide them with graphical representations that can foster the understanding of the blockchain underlying mechanisms

Retrieval-induced forgetting as motivated cognition

Recalling information from a particular category can reduce one's memory capability for related, non-retrieved information. This is known as the retrieval-induced forgetting effect (RIF; Anderson et al., 1994). The present paper reviews studies that show that the RIF effect is motivated. More specifically, we describe research showing that the need for closure (NFC; the motivation to attain epistemic certainty; Kruglanski and Webster, 1996) generally enhances the RIF, because this prevents uncertainty and confusion from the intrusion of unwanted memories during selective-retrieval. However, when the content of the to-be-forgotten information serves the retriever's goals, NFC reduces RIF. Overall, the present findings are consistent with the view that motivation can affect the magnitude of RIF effects which, in turn, can serve as a mechanism for reaching preferred conclusion

Advanced Vibro-Acoustic Techniques for Noise Control in Helicopters

Nowadays helicopters play a pivotal role in a wide variety of activities from important military missions to emergency medical transport, indeed it is a common experience that a helicopter may often be seen overhead. Originally, aircraft noise was not much of an issue because of the overarching requirement of improving vehicle performance in critical operational conditions. By the 1960s, noise and vibration control of helicopters has become more and more important and the next level technical challenge is to include new design parameters such as vibro-acoustic comfort and environmental impact in the design process of a modern rotorcraft. From one side, government regulations are imposed to contain noise pollution while on the other hand customers do not accept any longer a noisy product. On top of all this, the competitive pressure to bring products faster to market has made that NVH (Noise Vibration and Harshness) designers are looking for tools giving them an insight on where the noise is coming from. In this scenario, we want to present a modus operandi to tackle this issue by several advanced experimental methodologies, since the requirement of a quieter helicopter needs a systematic study of its NVH behavior. Experimental tests are carried and results are reported concerning two different helicopters: an EUROCOPTER EC-135 and an Agusta Westland W-109 helicopter. The proposed methodologies count several experimental NVH analyses and processing, which will be outline hereafter. It is interesting to note that although the presented methodologies concern particular helicopters, they have a general meaning, since they can be applied in a large variety of fields, as in aircraft fuselage, car or track interiors , etc. This work has to be intended as an analytical review of the authors’ research

The mediating role of national identification, binding foundations and perceived threat on the relationship between need for cognitive closure and prejudice against migrants in Malta

AbstractWhat mitigates the relationship between need for cognitive closure and prejudice against migrants? Addressing this question, we explored how national identification, endorsing binding moral foundations and the perception of threat mediate the relationship between need for cognitive closure and prejudice against migrants in Malta. It was hypothesized that individuals with a high need for cognitive closure are more prone to identify with being Maltese and more probable to endorse binding moral foundations and perceive high threat from migrants, leading to a more prejudiced attitude towards migrants living in Malta. Two hundred and twenty‐two individuals participated in this quantitative study. Results from this study showed that national identification, binding moral foundations and perceived threat mediate the relationship between need for cognitive closure and prejudice against migrants. The implications of the findings for theories about how need for cognitive closure contributes to increased prejudiced attitude in native population is discussed. Please refer to the Supplementary Material section to find this article's Community and Social Impact Statement

Followers’ satisfaction from working with group-prototypic leaders: promotion focus as moderator

What is the effect of followers’ promotion focus on their satisfaction from working with a leader who is prototypic of their group? We propose that high (vs. low) promotion-focused followers will respond more positively to a group-prototypic leader as a way to advance the in-group (“promote us”), which would increase their satisfaction from working with that leader. Results from an organizational survey and a scenario experiment supported the predicted two-way interaction between promotion focus and leaders’ group prototypicality: the positive relation between leaders’ group prototypicality and followers’ satisfaction from working with their leader was significantly greater for high than low promotion-focused employees. No such interactive effect was found for employees’ level of prevention focus. We discuss how these findings extend social identity theory’s analysis of leadership

Linear Embedding for a Quantitative Comparison of Language Expressiveness

Abstract We introduce the notion of linear embedding which refines Shapiro's notion of embedding by recasting it in a linear-space based semantics setting. We use this notion to compare the expressiveness of a class of languages that employ asynchronous communication primitives a la Linda. The adoption of a linear semantics in which the observables of a language are linear operators (matrices) representing the programs transition graphs allows us to give quantitative estimates of the different expressive power of languages, thus improving previous results in the field

The Epistemic Bases of Changes of Opinion and Choices: The Joint Effects of the Need for Cognitive Closure, Ascribed Epistemic Authority and Quality of Advice

This research investigates the epistemic underpinnings of changes of opinion and choices. Based on the Lay Epistemic Theory (Kruglanski et al., 2009) and consistent with relevant theories of persuasion (e.g., Chaiken, Liberman, & Eagly, 1989; Kruglanski, & Thompson, 1999; Petty & Cacioppo, 1986), we hypothesized that individuals with a high (vs. low) need for cognitive closure would be more influenced by the high (vs. low) level of the epistemic authority of an advisor, and would be less influenced by the quality of the provided advice. These hypotheses were supported in two experimental studies (Total N=352) within two different domains of decision-making (a legal case in Study 1 and consumer behavior in Study 2). The theoretical and practical implications of the results are discussed

How the mere desire for certainty can lead to a preference for men in authority (particularly among political liberals)

AbstractWomen are harmed by stereotypes about their fit for positions of authority and changing these stereotypes is not a simple task. As stereotypes have strong epistemic properties, individuals with a high need for cognitive closure (NCC; i.e., the desire for epistemic certainty) can be more likely to accept these stereotypes and, consequently, to prefer men in positions of authority. Consistent with the reactive liberal hypothesis, this effect could be actually more visible among individuals with both a high NCC and left‐wing political orientations. We supported these hypotheses in a series of three studies. In Study 1 (N = 217), we found that manipulated NCC predicted preference for men in authority through stereotypes of women as not being fit for authority in a measurement‐of‐mediation design. In Study 2 (N = 151), we supported this effect in a mediation‐as‐process design. In Study 3 (N = 391), we found the indirect NCC effect on preference for men in authority was more visible among political liberals. A major implication of this work is that ways of changing the effect of these stereotypes should take into account the NCC, but particularly among individuals with left‐wing beliefs