35 research outputs found

    Weakly-Private Information Retrieval

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    Private information retrieval (PIR) protocols make it possible to retrieve a file from a database without disclosing any information about the identity of the file being retrieved. These protocols have been rigorously explored from an information-theoretic perspective in recent years. While existing protocols strictly impose that no information is leaked on the file’s identity, this work initiates the study of the tradeoffs that can be achieved by relaxing the requirement of perfect privacy. In case the user is willing to leak some information on the identity of the retrieved file, we study how the PIR rate, as well as the upload cost and access complexity, can be improved. For the particular case of replicated servers, we propose two weakly-private information retrieval schemes based on two recent PIR protocols and a family of schemes based on partitioning. Lastly, we compare the performance of the proposed schemes

    Unsourced Multiple Access with Common Alarm Messages: Network Slicing for Massive and Critical IoT

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    We investigate the coexistence of massive and critical Internet of Things (IoT) services in the context of the unsourced multiple access (UMA) framework introduced by Polyanskiy (2017), where all users employ a common codebook and the receiver returns an unordered list of decoded codewords. This setup is suitably modified to introduce heterogeneous traffic. Specifically, to model the massive IoT service, a standard message originates independently from each IoT device as in the standard UMA setup. To model the critical IoT service, we assume the generation of alarm messages that are common for all devices. This setup requires a significant redefinition of the error events, i.e., misdetections and false positives. We further assume that the number of active users in each transmission attempt is random and unknown. We derive a random-coding achievability bound on the misdetection and false positive probabilities of both standard and alarm messages on the Gaussian multiple access channel. Using our bound, we demonstrate that orthogonal network slicing enables massive and critical IoT to coexist under the requirement of high energy efficiency. On the contrary, we show that nonorthogonal network slicing is energy inefficient due to the residual interference from the alarm signal when decoding the standard messages.Comment: IEEE Transactions on Communication

    La administración empresarial y la utilización de la inteligencia artificial y GPT-4 aportes y desafíos para la ingeniería del software y los sistemas de información

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    Among the current trends that companies are being forced to venture into as part of their administrative functions is the implementation of artificial intelligence. Artificial intelligence “is the simulation of human intelligence processes by machines, especially computer systems. The objective of this research is to know the way in which Artificial Intelligence and information systems called ChatGPT are used in the field of business administration.     The methodology used for this research has a qualitative approach. Implementing the technique of the state of the art, it is of a descriptive type. The results indicate that business management is becoming more complex every day due to the large amount of data that is generated day after day, so Artificial Intelligence turns out to be a great opportunity to optimize, automate and reduce processes, for the benefit of the company. business productivity. In conclusion, the scientific contribution that Software Engineering has made has turned out to be of great support, leaving as a legacy great contributions to society that with the passing of time have allowed many processes to be reduced, all for the benefit of humanity.Dentro de las tendencias actuales a la cual se están viendo obligadas las empresas a incursionar como parte de sus funciones administrativas se encuentra la implementación de inteligencia artificial. La inteligencia artificial “es la simulación de procesos de inteligencia humana por parte de máquinas, especialmente sistemas informáticos. El objetivo de esta investigación es conocer la forma en que la Inteligencia Artificial y los sistemas de información denominados ChatGPT, son usados en el ámbito de la administración de empresas. La metodología empleada para esta investigación tiene un enfoque cualitativo. Implementando la técnica del estado del arte, la misma es de tipo descriptiva. Los resultados señalan que la gestión empresarial, cada día se hace más compleja debido a la gran cantidad de datos que día tras día se generan, por lo que la Inteligencia Artificial resulta ser una gran oportunidad para optimizar, automatizar y reducir procesos, en beneficio de la productividad empresarial. En conclusión, el aporte científico que ha hecho la Ingeniería de Software ha resultado ser de gran apoyo, dejando como legado grandes aportes a la sociedad que, con el pasar del tiempo, han permitido que muchos procesos se reduzcan, todo en beneficio de la humanidad &nbsp

    The synovial and blood monocyte DNA methylomes mirror prognosis, evolution and treatment in early arthritis

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    Identifying predictive biomarkers at early stages of early inflammatory arthritis is crucial for starting appropriate therapies to avoid poor outcomes. Monocytes and macrophages, largely associated with arthritis, are contributors and sensors of inflammation through epigenetic modifications. In this study, we investigated associations between clinical features and DNA methylation in blood and synovial fluid (SF) monocytes in a prospective cohort of early inflammatory arthritis patients. Undifferentiated arthritis (UA) blood monocyte DNA methylation profiles exhibited significant alterations in comparison with those from healthy donors. We identified additional differences both in blood and SF monocytes after comparing UA patients grouped by their future outcomes, good versus poor. Patient profiles in subsequent visits revealed a reversion towards a healthy level in both groups, those requiring disease-modifying antirheumatic drugs (DMARDs) and those that remitted spontaneously. Changes in disease activity between visits also impacted DNA methylation, partially concomitant in the SF of UA and in blood monocytes of rheumatoid arthritis patients. Epigenetic similarities between arthritis types allow a common prediction of disease activity. Our results constitute a resource of DNA methylation-based biomarkers of poor prognosis, disease activity and treatment efficacy in early untreated UA patients for the personalized clinical management of early inflammatory arthritis patients

    Assessment of pollution risk ascribed to Santa Margarida Military Camp activities (Portugal)

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    Santa Margarida Military Camp (S.M.M.C.) is the only one Portuguese military training area, including firing ranges for tactical military manoeuvres of mechanised divisions. For this reason, various negative effects on the environment were expected due to the military activities, as the Military Camp’s area is classified as a high vulnerability area to pollution of its multilayer porous aquifers. The aim of this study was to identify and characterise local/regional geochemical impacts caused by the continuing military training activities performed at S.M.M.C. in the course of 52 years. An overview of the geochemical research issues as a basis for risk assessment is presented. A special attention has been put on the quality of local and regional surface waters, shallow groundwaters and groundwaters. Local soils and sediments as well as fragments of shells and bullets were sampled and analysed. The results so far obtained, indicated that none pollution effects were a consequence of the military training activities. Till now, the geochemical signatures such as, high levels of K, Cl and NO3 in waters, detected in particular sites, should be faced as tracers of diffuse pollution ascribed to urban waste disposal and cattle breading

    Reduced antioxidant defense in early onset first-episode psychosis: a case-control study

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    Background:Our objective is to determine the activity of the antioxidant defense system at admission in patients with early onset first psychotic episodes compared with a control group. Methods: Total antioxidant status (TAS) and lipid peroxidation (LOOH) were determined in plasma. Enzyme activities and total glutathione levels were determined in erythrocytes in 102 children and adolescents with a first psychotic episode and 98 healthy controls. Results: A decrease in antioxidant defense was found in patients, measured as decreased TAS and glutathione levels. Lipid damage (LOOH) and glutathione peroxidase activity was higher in patients than controls. Our study shows a decrease in the antioxidant defense system in early onset first episode psychotic patients. Conclusions: Glutathione deficit seems to be implicated in psychosis, and may be an important indirect biomarker of oxidative stress in early-onset schizophrenia. Oxidative damage is present in these patients, and may contribute to its pathophysiology

    Constellation optimization for coherent optical channels distorted by nonlinear phase noise

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    We consider the design of amplitude phase-shift keying (APSK) constellations, targeting their application to coherent fiber-optical communications. Phase compensation is used at the receiver to combat nonlinear phase noise caused by the Kerreffect. We derive the probability density function of the post-compensated observation for multilevel constellations. Optimal APSK constellations in terms of symbol error probability (SEP) are found assuming a two-stage detector. Performance gains of 3:2 dB can be achieved compared to 16-QAM at a SEP of 10-2. We optimize the number of rings, the number of points per ring, as well as the radius distribution of the constellation. For low to moderate nonlinearities, radius optimization only yields minor improvements over an equidistant spacing of rings. In the highly nonlinear regime, however, a smaller SEP can be achieved by “sacrificing” the outer ring of the constellation, in favor of achieving good SEP in the remaining rings

    Coded Slotted Aloha with Stopping Set Resolution: A Group Testing Approach

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    In this work, we explore the use of group testing techniques to steer a collision resolution phase in the context of coded slotted Aloha protocols. The problem can be defined as the discovery of stopping sets based on the residual collision pattern after successive interference cancellation decoding. We show how the application of the simple combinatorial orthogonal matching pursuit algorithm is sufficient to resolve a large number of the collisions that hinder the success of the iterative interference cancellation process. We highlight the design choices that have to be addressed to benefit from the proposed approach. Finally, we outline a few interesting directions for future developments

    On optimal TCM encoders

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    An asymptotically optimal trellis-coded modulation (TCM) encoder requires the joint design of the encoder and the binary labeling of the constellation. Since analytical approaches are unknown, the only available solution is to perform an exhaustive search over the encoder and the labeling. For large constellation sizes and/or many encoder states, however, an exhaustive search is unfeasible. Traditional TCM designs overcome this problem by using a labeling that follows the set-partitioning principle and by performing an exhaustive search over the encoders. In this paper we study binary labelings for TCM and show how they can be grouped into classes, which considerably reduces the search space in a joint design. For 8-ary constellations, the number of different binary labelings that must be tested is reduced from 8!=40320 to 240. For the particular case of an 8-ary pulse amplitude modulation constellation, this number is further reduced to 120 and for 8-ary phase shift keying to only 30. An algorithm to generate one labeling in each class is also introduced. Asymptotically optimal TCM encoders are tabulated which are up to 0.3 dB better than the previously best known encoders

    On the equivalence of TCM encoders

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