The role of the real-time simulation facility, SIMFAC, in the design, development and performance verification of the Shuttle Remote Manipulator System (SRMS) with man-in-the-loop

The SIMFAC has played a vital role in the design, development, and performance verification of the shuttle remote manipulator system (SRMS) to be installed in the space shuttle orbiter. The facility provides for realistic man-in-the-loop operation of the SRMS by an operator in the operator complex, a flightlike crew station patterned after the orbiter aft flight deck with all necessary man machine interface elements, including SRMS displays and controls and simulated out-of-the-window and CCTV scenes. The characteristics of the manipulator system, including arm and joint servo dynamics and control algorithms, are simulated by a comprehensive mathematical model within the simulation subsystem of the facility. Major studies carried out using SIMFAC include: SRMS parameter sensitivity evaluations; the development, evaluation, and verification of operating procedures; and malfunction simulation and analysis of malfunction performance. Among the most important and comprehensive man-in-the-loop simulations carried out to date on SIMFAC are those which support SRMS performance verification and certification when the SRMS is part of the integrated orbiter-manipulator system

Impact of macro-socioeconomic determinants on perinatal healthcare quality for very preterm infants

The WHO identified the importance of macro-socioeconomic determinants and the political context as interlinked key factors affecting health equity. The 2008 economic crisis was associated with a significant low-birth-weight increase in Portugal, 2007-2014. The Economic Adjustment Programme (EAP), implemented to economize non-essential health care costs (2011-2014), substantially affected healthcare delivery and occupational environment of Healthcare Professionals (HCPs). This study aims to analyse the impact observed by HCPs of the economic crisis and EAP on equitable quality of perinatal healthcare for very preterm infants in Portugal. A Qualitative study design with 21 HCPs in clinical settings equally distributed among Portuguese mainland were selected according to their response. Semi-structured interviews were conducted between October 2018-April 2019 until saturation point was achieved. A content analysis was performed using Nvivo2011 software. Preliminary results on macro-socioeconomic determinants, classified and conceptualized into a three-stage-effect framework, disclosed an interrelation between factors impacting perinatal healthcare quality, according to HCPs. Primary-stage: increase in working hours and patient-ratio per HCPs, cuts in salaries and investment, increasing waiting time and HCPs demotivation. Secondary-stage: burnout, work-absence, time constraints, decreasing quality and consultation availability. Tertiary-stage: HCPs Brain-drain to private sector, double-shifts in public-private sector, increasing inadequacy of transmissivity within sector communication. The economic crisis and EAP were perceived to have modified equitable perinatal healthcare quality for very preterm infants in Portugal. Increased private-public sector transparency to maximise quality assurance, equal HCP wage distribution to sustain capability, strengthening of social maternity protection strategies to enhance socioeconomic equity in perinatal healthcare, is recommended

Fronthaul evolution: From CPRI to Ethernet

It is proposed that using Ethernet in the fronthaul, between base station baseband unit (BBU) pools and remote radio heads (RRHs), can bring a number of advantages, from use of lower-cost equipment, shared use of infrastructure with fixed access networks, to obtaining statistical multiplexing and optimised performance through probe-based monitoring and software-defined networking. However, a number of challenges exist: ultra-high-bit-rate requirements from the transport of increased bandwidth radio streams for multiple antennas in future mobile networks, and low latency and jitter to meet delay requirements and the demands of joint processing. A new fronthaul functional division is proposed which can alleviate the most demanding bit-rate requirements by transport of baseband signals instead of sampled radio waveforms, and enable statistical multiplexing gains. Delay and synchronisation issues remain to be solved

Equitable perinatal healthcare for migrants, Portugal: comparative analysis of a self-assessment tool

Migration is seen as a common risk factor in obstetricmanagement. Migrants often have a higher risk of experience worse pregnancy outcomes, higher rates of operative delivery, and a higher likelihood to receive less adequate postpartum care when compared to native women. This study evaluates self-perceived assessment of migrant women and hospital directors on equitable migrant friendly perinatal healthcare quality and access during intrapartum and postpartum period at public maternity units across Portuguese mainland between 2017-2019. This cross-sectional study analyses perinatal health data from migrant women over 18 years giving birth in public maternity units from between April 2017 and March 2019 as part of the baMBINO project. Data on the assessments of maternity units’ directors on equitable migrant friendly healthcare was collected in a self-assessment tool. Two standards on healthcare access and on healthcare quality were developed by: 1) scoring 25 and 30 questions, respectively, from 0 (worst) to 5 (best); 2) calculating the average of each score. The OneSample Wilcoxon Test (non-parametric) was applied to compare the assessment of hospital directors with the migrant mothers and the Kruskal-Wallis one-way analysis of variance to test for regional differences. Significant differences between migrant woman and healthcare directors’ assessments on migrant friendly healthcare access and quality of care were found. Directors rated healthcare access with a median score of 2.4, twice as good as migrant women (1.3). Migrant women rated healthcare quality with a median score of 4.0 (directors: 3.2). Significant differences between the regions for quality of care and healthcare access were found. Statistically significant difference between migrants from Portuguese and non-Portuguese speaking countries was identified for healthcare access (p-value <0.001) and healthcare quality (p-value < 0.05).info:eu-repo/semantics/publishedVersio

Direct current (DC) resistivity and Induced Polarization (IP) monitoring of active layer dynamics at high temporal resolution

With permafrost thawing and changes in active layer dynamics induced by climate change, interactions between biogeochemical and thermal processes in the ground are of great importance. Here, active layer dynamics have been monitored using direct current (DC) resistivity and induced polarization (IP) measurements at high temporal resolution and at a relatively large scale at a heath tundra site on Disko Island on the west coast of Greenland (69 degrees N). At the field site, the active layer is disconnected from the deeper permafrost, due to isothermal springs in the region. Borehole sediment characteristics and subsurface temperatures supplemented the DC-IF measurements. A time-lapse DC-IP monitoring system has been acquiring at least six datasets per day on a 42-electrode profile with 0.5 m electrode spacing since July 2013. Remote control of the data acquisition system enables interactive adaptation of the measurement schedule, which is critically important to acquire data in the winter months, where extremely high contact resistances increase the demands on the resistivity meter. Data acquired during the freezing period of October 2013 to February 2014 clearly image the soil freezing as a strong increase in resistivity. While the freezing horizon generally moves deeper with time, some variations in the freezing depth are observed along the profile. Comparison with depth-specific soil temperature indicates an exponential relationship between resistivity and below-freezing temperature. Time-lapse inversions of the full-decay IF data indicate a decrease of normalized chargeability with freezing of the ground, which is the result of a decrease in the total unfrozen water and of the higher ion concentration in the pore-water. We conclude that DC-IP time-lapse measurements can non-intrusively and reliably image freezing patterns and their lateral variation on a 10-100 m scale that is difficult to sample by point measurements. In combination with laboratory experiments, the different patterns in resistivity and chargeability changes will enable the disentanglement of processes (e.g., fluid migration and freezing, advective and diffusive heat transport) occurring during freezing of the ground. The technology can be expanded to three dimensions and also to larger scale

Understanding participation in European cohort studies of preterm children: The views of parents, healthcare professionals and researchers

Background: Retention of participants in cohort studies is a major challenge. A better understanding of all elements involved in participation and attrition phenomena in particular settings is needed to develop effective retention strategies. The study aimed to achieve an in-depth understanding of participant retention in longitudinal cohorts focusing on participants’ and researcher’s perspectives, across three diverse socio-geographic and cultural settings. Methods: This study used a triangulation of multi-situated methods to collect data on cohort studies of children born with less than 32 weeks of gestation in Denmark, Italy and Portugal. It included focus groups and individual semi-driven interviewing with involved key actors (i.e. parents, staff, healthcare professionals, researchers) and a collaborative visual methodology. A purposive sample of 48 key actors (n = 13 in Denmark; n = 13 in Italy; n = 22 in Portugal) was collected. A triangulation of phenomenological thematic analysis with discourse analysis was applied. Cross-contextual and context-specific situational elements involved in participation and attrition phenomena in these child cohorts were identified at various levels and stages. Results: Main findings included: situational challenges affecting potential and range of possibilities for implementation strategies (geopolitical environment, societal changes, research funding models); situational elements related to particular strategies acting as deterrents (postal questionnaires) and facilitators (multiple flexible strategies, reminders, regular interaction); main motivations to enrol and participate (altruism/solidarity and gratitude/sense of duty to reciprocate); main motivational deterrents to participate to follow-up waves (lack of bonding, insufficient feedback); entanglement of clinical and research follow-up as facilitator and deterrent. Conclusions: The multi-situated approach used, addressing the interplay of the lived experience of individuals, was of most value to understand participation variability under different implemented strategies in-context. Cross-contextual and context-specific situational elements that have been influential factors towards participation and attrition in the cohorts were identified.info:eu-repo/semantics/publishedVersio

Analysis of Fourier transform valuation formulas and applications

The aim of this article is to provide a systematic analysis of the conditions such that Fourier transform valuation formulas are valid in a general framework; i.e. when the option has an arbitrary payoff function and depends on the path of the asset price process. An interplay between the conditions on the payoff function and the process arises naturally. We also extend these results to the multi-dimensional case, and discuss the calculation of Greeks by Fourier transform methods. As an application, we price options on the minimum of two assets in L\'evy and stochastic volatility models.Comment: 26 pages, 3 figures, to appear in Appl. Math. Financ

Randomly Crosslinked Macromolecular Systems: Vulcanisation Transition to and Properties of the Amorphous Solid State

As Charles Goodyear discovered in 1839, when he first vulcanised rubber, a macromolecular liquid is transformed into a solid when a sufficient density of permanent crosslinks is introduced at random. At this continuous equi- librium phase transition, the liquid state, in which all macromolecules are delocalised, is transformed into a solid state, in which a nonzero fraction of macromolecules have spontaneously become localised. This solid state is a most unusual one: localisation occurs about mean positions that are distributed homogeneously and randomly, and to an extent that varies randomly from monomer to monomer. Thus, the solid state emerging at the vulcanisation transition is an equilibrium amorphous solid state: it is properly viewed as a solid state that bears the same relationship to the liquid and crystalline states as the spin glass state of certain magnetic systems bears to the paramagnetic and ferromagnetic states, in the sense that, like the spin glass state, it is diagnosed by a subtle order parameter. In this review we give a detailed exposition of a theoretical approach to the physical properties of systems of randomly, permanently crosslinked macromolecules. Our primary focus is on the equilibrium properties of such systems, especially in the regime of Goodyear's vulcanisation transition.Comment: Review Article, REVTEX, 58 pages, 3 PostScript figure