46 research outputs found
Preserving Co-Location Privacy in Geo-Social Networks
The number of people on social networks has grown exponentially. Users share
very large volumes of personal informations and content every days. This
content could be tagged with geo-spatial and temporal coordinates that may be
considered sensitive for some users. While there is clearly a demand for users
to share this information with each other, there is also substantial demand for
greater control over the conditions under which their information is shared.
Content published in a geo-aware social networks (GeoSN) often involves
multiple users and it is often accessible to multiple users, without the
publisher being aware of the privacy preferences of those users. This makes
difficult for GeoSN users to control which information about them is available
and to whom it is available. Thus, the lack of means to protect users privacy
scares people bothered about privacy issues. This paper addresses a particular
privacy threats that occur in GeoSNs: the Co-location privacy threat. It
concerns the availability of information about the presence of multiple users
in a same locations at given times, against their will. The challenge addressed
is that of supporting privacy while still enabling useful services.Comment: 10 pages, 5 figure
Modeling Performance of Microservices Systems with Growth Theory
Context The microservices architectural style is gaining momentum in the IT industry. This style does not guarantee that a target system can continuously meet acceptable performance levels. The ability to study the violations of performance requirements and eventually predict them would help practitioners to tune techniques like dynamic load balancing or horizontal scaling to achieve the resilience property. Objective The goal of this work is to study the violations of performance requirements of microservices through time series analysis and provide practical instruments that can detect resilient and non-resilient microservices and possibly predict their performance behavior. Method We introduce a new method based on growth theory to model the occurrences of violations of performance requirements as a stochastic process. We applied our method to an in-vitro e-commerce benchmark and an in-production real-world telecommunication system. We interpreted the resulting growth models to characterize the microservices in terms of their transient performance behavior. Results Our empirical evaluation shows that, in most of the cases, the non-linear S-shaped growth models capture the occurrences of performance violations of resilient microservices with high accuracy. The bounded nature associated with this models tell that the performance degradation is limited and thus the microservice is able to come back to an acceptable performance level even under changes in the nominal number of concurrent users. We also detect cases where linear models represent a better description. These microservices are not resilient and exhibit constant growth and unbounded performance violations over time. The application of our methodology to a real in-production system identified additional resilience profiles that were not observed in the in-vitro experiments. These profiles show the ability of services to react differently to the same solicitation. We found that when a service is resilient it can either decrease the rate of the violations occurrences in a continuous manner or with repeated attempts (periodical or not). Conclusions We showed that growth theory can be successfully applied to study the occurences of performance violations of in-vitro and in-production real-world systems. Furthermore, the cost of our model calibration heuristics, based on the mathematical expression of the selected non-linear growth models, is limited. We discussed how the resulting models can shed some light on the trend of performance violations and help engineers to spot problematic microservice operations that exhibit performance issues. Thus, meaningful insights from the application of growth theory have been derived to characterize the behavior of (non) resilient microservices operations
Towards Risk Modeling for Collaborative AI
Collaborative AI systems aim at working together with humans in a shared
space to achieve a common goal. This setting imposes potentially hazardous
circumstances due to contacts that could harm human beings. Thus, building such
systems with strong assurances of compliance with requirements domain specific
standards and regulations is of greatest importance. Challenges associated with
the achievement of this goal become even more severe when such systems rely on
machine learning components rather than such as top-down rule-based AI. In this
paper, we introduce a risk modeling approach tailored to Collaborative AI
systems. The risk model includes goals, risk events and domain specific
indicators that potentially expose humans to hazards. The risk model is then
leveraged to drive assurance methods that feed in turn the risk model through
insights extracted from run-time evidence. Our envisioned approach is described
by means of a running example in the domain of Industry 4.0, where a robotic
arm endowed with a visual perception component, implemented with machine
learning, collaborates with a human operator for a production-relevant task.Comment: 4 pages, 2 figure
Multimodality Imaging in Sarcomeric Hypertrophic Cardiomyopathy: Get It Right…on Time
Hypertrophic cardiomyopathy (HCM) follows highly variable paradigms and disease-specific patterns of progression towards heart failure, arrhythmias and sudden cardiac death. Therefore, a generalized standard approach, shared with other cardiomyopathies, can be misleading in this setting. A multimodality imaging approach facilitates differential diagnosis of phenocopies and improves clinical and therapeutic management of the disease. However, only a profound knowledge of the progression patterns, including clinical features and imaging data, enables an appropriate use of all these resources in clinical practice. Combinations of various imaging tools and novel techniques of artificial intelligence have a potentially relevant role in diagnosis, clinical management and definition of prognosis. Nonetheless, several barriers persist such as unclear appropriate timing of imaging or universal standardization of measures and normal reference limits. This review provides an overview of the current knowledge on multimodality imaging and potentialities of novel tools, including artificial intelligence, in the management of patients with sarcomeric HCM, highlighting the importance of specific "red alerts" to understand the phenotype-genotype linkage
Comprehensive and Integrated Impact Assessment Framework for Development Policies Evaluation: Definition and Application to Kenyan Coffee Sector
The coexistence of the need to improve economic conditions and the conscious use of environmental resources plays a central role in today’s sustainable development challenge. In this study, a novel integrated framework to evaluate the impact of new technological interventions is presented and an application to smallholder coffee farms and their supply chains in Kenya is proposed. This methodology is able to combine multiple information through the joint use of three approaches: supply chain analysis, input-output analysis, and energy system modeling. Application to the context of the Kenyan coffee sector enables framework validation: shading management measures, the introduction of eco-pulpers, and the exploitation of coffee waste biomass for power generation were compared within a holistic high-level perspective. The implementation of shading practices, carried out with fruit trees, shows the most relevant effects from the economic point of view, providing farmers with an additional source of income and generating 9k) invested in this solution. The same investment would save up to 1.46 M m3 of water per year with the eco-pulpers technology. Investing the same amount in coffee-biomass power plants would displace a small portion of production from heavy-duty oil and avoid importing a portion of fertilizer, saving up to 11 tons of CO2 and around 100m budget, which can be affected by adding additional constraints on minimum environmental or social targets in line with sustainable development goals
Organic Electrochemical Transistor Immuno-Sensors for Spike Protein Early Detection
The global COVID-19 pandemic has had severe consequences from the social and economic perspectives, compelling the scientific community to focus on the development of effective diagnostics that can combine a fast response and accurate sensitivity/specificity performance. Presently available commercial antigen-detecting rapid diagnostic tests (Ag-RDTs) are very fast, but still face significant criticisms, mainly related to their inability to amplify the protein signal. This translates to a limited sensitive outcome and, hence, a reduced ability to hamper the spread of SARS-CoV-2 infection. To answer the urgent need for novel platforms for the early, specific and highly sensitive detection of the virus, this paper deals with the use of organic electrochemical transistors (OECTs) as very efficient ion-electron converters and amplifiers for the detection of spike proteins and their femtomolar concentration. The electrical response of the investigated OECTs was carefully analyzed, and the changes in the parameters associated with the transconductance (i.e., the slope of the transfer curves) in the gate voltage range between 0 and 0.3 V were found to be more clearly correlated with the spike protein concentration. Moreover, the functionalization of OECT-based biosensors with anti-spike and anti-nucleocapside proteins, the major proteins involved in the disease, demonstrated the specificity of these devices, whose potentialities should also be considered in light of the recent upsurge of the so-called "long COVID" syndrome