An Audit Logic for Accountability

We describe and implement a policy language. In our system, agents can distribute data along with usage policies in a decentralized architecture. Our language supports the specification of conditions and obligations, and also the possibility to refine policies. In our framework, the compliance with usage policies is not actively enforced. However, agents are accountable for their actions, and may be audited by an authority requiring justifications.Comment: To appear in Proceedings of IEEE Policy 200

An asymmetric high serial rate TDM-PON with single carrier 25 Gb/s upstream and 50 Gb/s downstream

We report a 2:1 rate asymmetric high serial rate time division multiplexing passive optical network (TDM-PON) with single carrier 25 Gb/s upstream and 50 Gb/s downstream. In the upstream, we present a first 25 Gb/s three-level modulated burst-mode receiver employing a 1/4-rate linear burst-mode avalanch photodiode transimpedance amplifier and a custom decoder IC. We successfully demonstrated burst-mode sensitivity of -20.4 dBm with 18 dB dynamic burst-to-burst for 25 Gb/s upstream links. In another direction, a downstream in upper O-band is proposed and demonstrated with three-level duo-binary modulation at 50 Gb/s in real time. The upstream and downstream transmission experiments show that the proposed asymmetric 50 G/25 G high serial rate TDM-PON can support >= 32 users while covering more than 20 km reach

Social innovation practices: focus on success factors for crowdfunding

This article explores what are the success factor for interaction with platforms of crowdfunding in Italy. Through a Principal Component Analysis we outline three variables and through a multiple regression analysis we demonstrate that the interaction on crowdfunding is positive correlated with socio-economic propensity and cultural level. The analysis has been conducted on a sample of 316 of projects funded in the Crowdfunding platform Produzioni dal Basso, the first platform born in Italy. We draw on SD logic and relationship marketing to underscore the importance of networks of actors and integration to create a co-creation of value. This view emphasizes the social and economic factors that influence, and are influenced by, crowdfundin

Framing purposeful evaluation through critical systems thinking

Two traditions of practice – evaluation and systems – share three significant concerns regarding development intervention: (i) making sense of complex interrelationships and the continual change brought about by such relationships; (ii) engaging with multiple (including exogenous and endogenous), often conflicting, perspectives on situations; and (iii) challenging vicious cycles of practice and understanding by cultivating a more radical learning culture. These challenges might be described successively in terms of cultivating a shift from (i) summative to formative evaluation (ii) positional bargaining to interest based negotiation, and (iii) purposive to purposeful action. Some ideas from traditions of social learning and critical systems thinking are presented to support a re-framing of intervention and evaluation from one serving the 'project state' towards one serving more radical transformative practice

Context-awareness for mobile sensing: a survey and future directions

The evolution of smartphones together with increasing computational power have empowered developers to create innovative context-aware applications for recognizing user related social and cognitive activities in any situation and at any location. The existence and awareness of the context provides the capability of being conscious of physical environments or situations around mobile device users. This allows network services to respond proactively and intelligently based on such awareness. The key idea behind context-aware applications is to encourage users to collect, analyze and share local sensory knowledge in the purpose for a large scale community use by creating a smart network. The desired network is capable of making autonomous logical decisions to actuate environmental objects, and also assist individuals. However, many open challenges remain, which are mostly arisen due to the middleware services provided in mobile devices have limited resources in terms of power, memory and bandwidth. Thus, it becomes critically important to study how the drawbacks can be elaborated and resolved, and at the same time better understand the opportunities for the research community to contribute to the context-awareness. To this end, this paper surveys the literature over the period of 1991-2014 from the emerging concepts to applications of context-awareness in mobile platforms by providing up-to-date research and future research directions. Moreover, it points out the challenges faced in this regard and enlighten them by proposing possible solutions

Mixed-integer-linear-programming-based energy management system for hybrid PV-wind-battery microgrids: Modeling, design, and experimental verification

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksMicrogrids are energy systems that aggregate distributed energy resources, loads, and power electronics devices in a stable and balanced way. They rely on energy management systems to schedule optimally the distributed energy resources. Conventionally, many scheduling problems have been solved by using complex algorithms that, even so, do not consider the operation of the distributed energy resources. This paper presents the modeling and design of a modular energy management system and its integration to a grid-connected battery-based microgrid. The scheduling model is a power generation-side strategy, defined as a general mixed-integer linear programming by taking into account two stages for proper charging of the storage units. This model is considered as a deterministic problem that aims to minimize operating costs and promote self-consumption based on 24-hour ahead forecast data. The operation of the microgrid is complemented with a supervisory control stage that compensates any mismatch between the offline scheduling process and the real time microgrid operation. The proposal has been tested experimentally in a hybrid microgrid at the Microgrid Research Laboratory, Aalborg University.Peer ReviewedPostprint (author's final draft

Making 'The Daily Me': Technology, economics and habit in the mainstream assimilation of personalized news

The mechanisms of personalization deployed by news websites are resulting in an increasing number of editorial decisions being taken by computer algorithms — many of which are under the control of external companies — and by end users. Despite its prevalence, personalization has yet to be addressed fully by the journalism studies literature. This study defines personalization as a distinct form of interactivity and classifies its explicit and implicit forms. Using this taxonomy, it surveys the use of personalization at 11 national news websites in the UK and USA. Research interviews bring a qualitative dimension to the analysis, acknowledging the influence that institutional contexts and journalists’ attitudes have on the adoption of technology. The study shows how: personalization informs debates on news consumption, content diversity, and the economic context for journalism; and how it challenges the continuing relevance of established theories of journalistic gate-keeping