Embedded AM-FM Signal Decomposition Algorithm for Continuous Human Activity Monitoring

AM-FM decomposition techniques have been successfully used for extracting significative features from a large variety of signals, helping realtime signal monitoring and pattern recognition, since they represent signals as a simultaneous composition of amplitude modulation and frequency modulation, where the carriers, amplitude envelopes, and the instantaneous frequencies are the features to be estimated. Human activities often involve repetitive movements, such as in running or cycling, where sinusoidal AM-FM decompositions of signals have already demonstrated to be useful to extract compact features to aid monitoring, classification, or detection. In this work we thus present the challenges and results of implementing the iterated coherent Hilbert decomposition (ICHD), a particularly effective algorithm to obtain an AM-FM decomposition, within a resource-constrained and low-power ARM Cortex-M4 microcontroller that is present in a wearable sensor we developed. We apply ICHD to the gyroscope data acquired from an inertial measurement unit (IMU) that is present in the sensor. Optimizing the implementation allowed us to achieve real-time performance using less then 16 % of the available CPU time, while consuming only about 5.4 mW of power, which results in a run-time of over 7 days using a small 250 mAh rechargeable cell

Influence of process parameters and alloying type on properties of laser quenched PM-steels

Different alloyed PM steels have been laser quenched in industrial equipment laser diodes (4 kW, controlled by material surface temperature). The aim of this work is to investigate their responses to different process condition and different alloying metals, i.e. Cu, Ni, Mo, Cr and C. Furthermore the microstructure of hardened layer, heat affected zone (HAZ) and bulk zone Pre-alloyed, diffusion bonded and hybrid raw materials have been used. Design of Experiments has been the approach for evaluating the effect of treatment parameters (i.e temperature, spot size and speed) and to develop predictive models, correlating such parameters to hardening depth and scratch hardness number. Results demonstrated which valuable properties could be achieved, even through relatively low alloying. The promising results are encouraging since they allow to forecast a possible positive combination of high local hardness and wear resistance of high precision PM part

Actuators based on intrinsic conductive polymers/carbon nanoparticles nanocompositesElectroactive Polymer Actuators and Devices (EAPAD) 2013

New polyaniline (PANi) synthesis was performed starting from non-toxic N-phenil-p-phenylenediamine (aniline dimer) using reverse addition of monomer to oxidizing agent, the synthesis allows to produce highly soluble PANi. Several types of doped PANi were prepared to be used on electromechanical active actuators. Different techniques were used to include carbon nanoparticles such as carbon nanotubes and graphene. Bimorph solid state ionic actuators were prepared with these novel nanocomposites using a variety of supporting polymer

Comparing decision models for disaster restoration of interdependent infrastructures under uncertainty

As infrastructure systems are highly interdependent, one needs to analyze their disaster resilience and develop restoration plans with the consideration of infrastructure interdependencies. This study presents two probabilistic models for infrastructure decision-makers to simulate the recovery of interdependent systems in a post-disaster scenario. The models consider interdependencies related to damage, functionality, and restoration. To incorporate uncertainty in restoration, this study assumes that the actual duration of each restoration activity follows a random distribution. To simulate the decision-making process in the recovery, this study uses the PRAISys platform to implement two schemes with different restoration criteria. The first scheme uses the priority ranking of the damaged structure (based on its importance, criticality, etc.) as the criterion and the platform simulates the restoration plan under resource and dependency constraints. In contrast, the second uses the criterion of minimizing the restoration completion time by framing all restoration activities within a constrained optimization formulation, and the platform implements the optimal schedule as the restoration plan. To exemplify the applicability of the two schemes, this study simulates the recovery of interdependent systems after a hypothetical earthquake in the Lehigh Valley, a multi-county community in eastern Pennsylvania, USA.This work is part of the Probabilistic Resilience Assessment of Interdependent Systems (PRAISys) project (www.praisys.org). The support from the National Science Foundation through grant CMMI-1541177 is gratefully acknowledged. The authors would like to acknowledge contributions to the platform development from Baiyu Xiang, Robbin Yichen Xu, Zhiyu Chen, and Youshan Zhang. They also want to thank Chase Gallik, Faith Comlo, and Victoria Pasini for collecting infrastructure data in the testbed

Aggregating human judgment probabilistic predictions of COVID-19 transmission, burden, and preventative measures

Aggregated human judgment forecasts for COVID-19 targets of public health importance are accurate, often outperforming computational models. Our work shows aggregated human judgment forecasts for infectious agents are timely, accurate, and adaptable, and can be used as tool to aid public health decision making during outbreaks

Heart failure with preserved systolic function: prevalence and clinical features in a cohort of patients admitted to internal medicine units. The study PRESYF-HF Tuscany.

Background. There is uncertainty about the prevalence and clinical characteristics of heart failure (HF) patients with preserved systolic function (PRESYF). Aim. To analyze the prevalence and clinical characteristics of patients with PRESYF in an unselected cohort of subjects consecutively hospitalized for HF. Methods. The study cohort included 338 patients consecutively admitted for HF at 24 Internal Medicine units homogeneously settled in Tuscany area (Italy). We did not have any criteria for exclusion. All patients had an echocardiographic measure of left ventricular ejection fraction (LVEF) within 72 hours from hospital admission. Patients with LVEF > 50% were considered to have PRESYF. Results. The patients with PRESYF were 112 (33,1%), those with depressed systolic function (DESYF) 226 (66,9%). In the group PRESYF were prevalent female sex, hypertensive etiology, and elevated BMI. The distribution for classes of age shows a great frequency of PRESYF in the elderly. Conclusion. About one third of patients admitted for HF have a PRESYF. They are different compared to those with DESYF. A correct identification of this form of HF may be important in clinical practice for more targeted therapeutic options and for prognostic implications

A Stochastic Multi-scale Approach for Numerical Modeling of Complex Materials - Application to Uniaxial Cyclic Response of Concrete

In complex materials, numerous intertwined phenomena underlie the overall response at macroscale. These phenomena can pertain to different engineering fields (mechanical , chemical, electrical), occur at different scales, can appear as uncertain, and are nonlinear. Interacting with complex materials thus calls for developing nonlinear computational approaches where multi-scale techniques that grasp key phenomena at the relevant scale need to be mingled with stochastic methods accounting for uncertainties. In this chapter, we develop such a computational approach for modeling the mechanical response of a representative volume of concrete in uniaxial cyclic loading. A mesoscale is defined such that it represents an equivalent heterogeneous medium: nonlinear local response is modeled in the framework of Thermodynamics with Internal Variables; spatial variability of the local response is represented by correlated random vector fields generated with the Spectral Representation Method. Macroscale response is recovered through standard ho-mogenization procedure from Micromechanics and shows salient features of the uniaxial cyclic response of concrete that are not explicitly modeled at mesoscale.Comment: Computational Methods for Solids and Fluids, 41, Springer International Publishing, pp.123-160, 2016, Computational Methods in Applied Sciences, 978-3-319-27994-

Chronic constipation diagnosis and treatment evaluation: The "CHRO.CO.DI.T.E." study

Background: According to Rome criteria, chronic constipation (CC) includes functional constipation (FC) and irritable bowel syndrome with constipation (IBS-C). Some patients do not meet these criteria (No Rome Constipation, NRC). The aim of the study was is to evaluate the various clinical presentation and management of FC, IBS-C and NRC in Italy. Methods: During a 2-month period, 52 Italian gastroenterologists recorded clinical data of FC, IBS-C and NRC patients, using Bristol scale, PAC-SYM and PAC-QoL questionnaires. In addition, gastroenterologists were also asked to record whether the patients were clinically assessed for CC for the first time or were in follow up. Diagnostic tests and prescribed therapies were also recorded. Results: Eight hundred seventy-eight consecutive CC patients (706 F) were enrolled (FC 62.5%, IBS-C 31.3%, NRC 6.2%). PAC-SYM and PAC-QoL scores were higher in IBS-C than in FC and NRC. 49.5% were at their first gastroenterological evaluation for CC. In 48.5% CC duration was longer than 10 years. A specialist consultation was requested in 31.6%, more frequently in IBS-C than in NRC. Digital rectal examination was performed in only 56.4%. Diagnostic tests were prescribed to 80.0%. Faecal calprotectin, thyroid tests, celiac serology, breath tests were more frequently suggested in IBS-C and anorectal manometry in FC. More than 90% had at least one treatment suggested on chronic constipation, most frequently dietary changes, macrogol and fibers. Antispasmodics and psychotherapy were more frequently prescribed in IBS-C, prucalopride and pelvic floor rehabilitation in FC. Conclusions: Patients with IBS-C reported more severe symptoms and worse quality of life than FC and NRC. Digital rectal examination was often not performed but at least one diagnostic test was prescribed to most patients. Colonoscopy and blood tests were the "first line" diagnostic tools. Macrogol was the most prescribed laxative, and prucalopride and pelvic floor rehabilitation represented a "second line" approach. Diagnostic tests and prescribed therapies increased by increasing CC severity