1,863 research outputs found

    Complexity of Judgment Aggregation

    Get PDF
    We analyse the computational complexity of three problems in judgment aggregation: (1) computing a collective judgment from a profile of individual judgments (the winner determination problem); (2) deciding whether a given agent can influence the outcome of a judgment aggregation procedure in her favour by reporting insincere judgments (the strategic manipulation problem); and (3) deciding whether a given judgment aggregation scenario is guaranteed to result in a logically consistent outcome, independently from what the judgments supplied by the individuals are (the problem of the safety of the agenda). We provide results both for specific aggregation procedures (the quota rules, the premisebased procedure, and a distance-based procedure) and for classes of aggregation procedures characterised in terms of fundamental axioms

    Retailing 4.0: The New Era of E-commerce in Fast Moving Consumer Goods

    Get PDF
    The arrival of the online channel has initiated a new cycle in competitiveness among retailers characterized by shoppers' increasing nomadism around physical and digital touch points. The present work adopts a supply-side analytical approach to highlight drivers and perspectives of e-commerce development within the grocery sector. Research results emphasize that: (i) online-native retailers hold a well-established position of leadership worldwide and thus fundamentally influence e-grocery dynamics as a whole; (ii) the e-commerce channel is characterized by profit margins that are significantly lower than store-based channel ones. This represents the main limitation to online grocery sales growth, above all for offline-native retailers who maintain core business in their bricks & mortar stores

    Conceptual Design Generation Using Large Language Models

    Full text link
    Concept generation is a creative step in the conceptual design phase, where designers often turn to brainstorming, mindmapping, or crowdsourcing design ideas to complement their own knowledge of the domain. Recent advances in natural language processing (NLP) and machine learning (ML) have led to the rise of Large Language Models (LLMs) capable of generating seemingly creative outputs from textual prompts. The success of these models has led to their integration and application across a variety of domains, including art, entertainment, and other creative work. In this paper, we leverage LLMs to generate solutions for a set of 12 design problems and compare them to a baseline of crowdsourced solutions. We evaluate the differences between generated and crowdsourced design solutions through multiple perspectives, including human expert evaluations and computational metrics. Expert evaluations indicate that the LLM-generated solutions have higher average feasibility and usefulness while the crowdsourced solutions have more novelty. We experiment with prompt engineering and find that leveraging few-shot learning can lead to the generation of solutions that are more similar to the crowdsourced solutions. These findings provide insight into the quality of design solutions generated with LLMs and begins to evaluate prompt engineering techniques that could be leveraged by practitioners to generate higher-quality design solutions synergistically with LLMs.Comment: Proceedings of the ASME 2023 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference

    COMPLEXOS AGROINDUSTRIAIS, COOPERATIVAS E GESTÃO

    Get PDF
    This paper discusses the new articulation forms which were established between the agricultural and urban sectors due to the consolidation of the Brazilian agroindustrial complex in the end of the 1970’s. The following topics are highlighted in this discussion: a) the growing dependence that agriculture sector has on the urban sector as a consumer of goods and services; b) the transformation of a substantial part of agricultural output in raw material for urban industries; c) the oligopolistic and oligopsonic features of these commercial relationships; d) the integration of capitals and formation of great economic conglomerates; c) the ongoing globalization process. In such scenery, different social actors are identified as well as their differential capacity to influence the decision-making process inside the chains and in the ambit of the State. It also outlines the actors’ organizational capacity which is represented by collective actions, managerial efficiency, administrative professionalization, "systemic knowledge" and technological domain. The central question of this paper refers to the role that the agricultural cooperatives and other associativist forms can play as negotiation means inside and outside the productive chains, elevating farmers’ bargaining and claiming power. To answer this question several researches undertaken over the last two decades were examined. The most recent studies detect an effort to modernize cooperative management by turning them into more competitive organizations. However, this effort is sometimes interrupted by the process of manager’s succession. Interference of local political interests identified in the studies carried out in the 1980’s was also detected in the most recent researches and it is considered as one of the factors that limit the administrative dynamism of cooperatives. Although farmer associations are seen as an alternative means for family producers to adapt to the ongoing economic and social changes, the examined studies showed that as the business of those associations grow, managerial problems simultaneously rise.agoindustrial complex, productive chain, cooperative, social actors, interest articulation.,

    Hard X-ray emission from the galaxy cluster A2256

    Get PDF
    After the positive detection by BeppoSAX of hard X-ray radiation up to ~80 keV in the Coma cluster spectrum, we present evidence for nonthermal emission from A2256 in excess of thermal emission at a 4.6sigma confidence level. In addition to this power law component, a second nonthermal component already detected by ASCA could be present in the X-ray spectrum of the cluster, not surprisingly given the complex radio morphology of the cluster central region. The spectral index of the hard tail detected by the PDS onboard BeppoSAX is marginally consistent with that expected by the inverse Compton model. A value of ~0.05 microG is derived for the intracluster magnetic field of the extended radio emission in the northern regions of the cluster, while a higher value of \~0.5 microG could be present in the central radio halo, likely related to the hard tail detected by ASCA.Comment: 10 pages, 2 figures. To appear in ApJ

    In vitro assessment of a novel composite scaffold for articular cartilage restoration

    Get PDF
    Articular cartilage (AC) lesions are a particular challenge for regenerative medicine due to cartilage low self-ability repair in case of damage. Hence, a significant goal of musculoskeletal tissue engineering is the development of suitable structures in virtue of their matrix composition and biomechanical properties [1]. The objective of our study was to design in vitro a supporting structure for cartilage chondrocytes to treat focal articular joint defects. We realized a bio-hybrid composite scaffold combining decellularized Wharton’s jelly (W’s J) with the biomechanical properties of the synthetic hydrogel polyvinyl alcohol (PVA). The hydrogel itself and the more specific decellularized cartilage matrix were used as controls. Immunohistochemical analysis highlighted a similar histomorphology for W’s J and AC matrices. Human chondrocytes were isolated from articular cartilage by collagenase II digestion and then characterized by flow-cytometry and RT-PCR to assess the expression of specific markers. CD44+/CD73+/CD151+ chondrocytes were seeded on PVA, PVA/AC and PVA/W’s J scaffolds to test their ability to support cell colonization. According to SEM micrographs and MTT proliferation assay, PVA/W’s J revealed a singular attitude to sustain cell proliferation despite its aspecific origin. Our preliminary evidences highlighted the chance of using Wharton’s jelly in combination with PVA hydrogels as an innovative and easily available scaffold for cartilage restoration

    Exploring a tissue engineering strategy as a novel approach for haemophilic arthropathy treatment

    Get PDF
    Among the most disabling complications of Haemophilia, repeated and sponta- neous intra-articular haemorrhages may cause irreversible damage to the joint. This leads to haemophilic arthropathy, a polyarticular disease characterized by joint stiff- ness, chronic pain and a severely limited range of motion. Occurrence of haemophilic arthropathy can be avoided by the prophylactic administration of clotting factors to prevent articular haemorrhages, but it can also be addressed using anti-inflammatory drugs and surgery to alleviate the effects of articular damage, up to arthroplasty as resolute option [1]. However, innovative strategies for the prevention and treatment of this common and serious complication are still required, due to some important limits of current therapies, first of all inhibitor development. In this work, we inves- tigated a tissue engineering approach to regenerate articular focal lesions in Haemo- philic patients by in vitro development of an autologous bio-hybrid prosthesis. For this purpose, we isolated articular chondrocytes from Haemophilic patients (HaeCs) and characterized them for the first time in literature, to verify whether they were altered by blood exposure. Using healthy chondrocytes as control, optical microscope morphological analysis, flow cytometry immunophenotype evaluation and gene expression study by qRT-PCR were performed. After that, an innovative compos- ite scaffold was obtained by combining decellularized Wharton’s Jelly (W’s J) from human umbilical cord with a novel biodegradable polyvinyl alcohol (PVA) hydrogel [2]. Finally, we assessed HaeCs capacity to re-populate biosynthetic scaffolds by Scan- ning Electron Microscopy and MTT assay on cells seeded on supports. Taken togeth- er, our results contributed to define HaeCs phenotype, highlighting the possibility to use these cells for autologous implant. What is more, HaeCs capacity to growth and proliferate on composite scaffolds set the stage for planning the development of autologous tissue substitutes for haemophilic cartilage regeneration

    XIPE: the X-ray Imaging Polarimetry Explorer

    Full text link
    X-ray polarimetry, sometimes alone, and sometimes coupled to spectral and temporal variability measurements and to imaging, allows a wealth of physical phenomena in astrophysics to be studied. X-ray polarimetry investigates the acceleration process, for example, including those typical of magnetic reconnection in solar flares, but also emission in the strong magnetic fields of neutron stars and white dwarfs. It detects scattering in asymmetric structures such as accretion disks and columns, and in the so-called molecular torus and ionization cones. In addition, it allows fundamental physics in regimes of gravity and of magnetic field intensity not accessible to experiments on the Earth to be probed. Finally, models that describe fundamental interactions (e.g. quantum gravity and the extension of the Standard Model) can be tested. We describe in this paper the X-ray Imaging Polarimetry Explorer (XIPE), proposed in June 2012 to the first ESA call for a small mission with a launch in 2017 but not selected. XIPE is composed of two out of the three existing JET-X telescopes with two Gas Pixel Detectors (GPD) filled with a He-DME mixture at their focus and two additional GPDs filled with pressurized Ar-DME facing the sun. The Minimum Detectable Polarization is 14 % at 1 mCrab in 10E5 s (2-10 keV) and 0.6 % for an X10 class flare. The Half Energy Width, measured at PANTER X-ray test facility (MPE, Germany) with JET-X optics is 24 arcsec. XIPE takes advantage of a low-earth equatorial orbit with Malindi as down-link station and of a Mission Operation Center (MOC) at INPE (Brazil).Comment: 49 pages, 14 figures, 6 tables. Paper published in Experimental Astronomy http://link.springer.com/journal/1068
    • …
    corecore