A semiparametric state space model

This paper considers the problem of estimating a linear univariate Time Series State Space model for which the shape of the distribution of the observation noise is not specified a priori. Although somewhat challenging computationally, the simultaneous estimation of the parameters of the model and the unknown observation noise density is made feasible through a combination of Gaussian-sum Filtering and Smoothing algorithms and Kernel Density Estimation methods. The bottleneck in these calculations consists in avoiding the geometric increase, with time, of the number of simultaneous Kalman filter components. It is the aim of this paper to show that this can be achieved by the use of standard techniques from Cluster Analysis and unsupervised Classification. An empirical illustration of this new methodology is included; this consists in the application of a semiparametric version of the Local Level model to the analysis of the wellknown river Nile data series

The econometrics of randomly spaced financial data: a survey

This paper provides an introduction to the problem of modeling randomly spaced longitudinal data. Although Point Process theory was developed mostly in the sixties and early seventies, only in the nineties did this field of Probability theory attract the attention of researchers working in Financial Econometrics. The large increase, observed since, in the number of different classes of Econometric models for dealing with financial duration data, has been mostly due to the increased availability of both trade-by-trade data from equity markets and daily default and rating migration data from credit markets. This paper provides an overview of the main Econometric models available in the literature for dealing with what is sometimes called tick data. Additionally, a synthesis of the basic theory underlying these models is also presented. Finally, a new theorem dealing with the identifiability of latent intensity factors from point process data, jointly with a heuristic proof, is introduced

Evolução e contributo dos sistemas de distribuição de medicamentos para a segurança do doente

A distribuição de medicamentos é uma função da farmácia hospitalar que, com metodologia e circuitos próprios, torna disponível o medicamento correto, na quantidade e qualidade certas, para cumprimento da prescrição médica proposta, para cada doente e todos os doentes do hospital. Assim, um sistema de distribuição de medicamentos é o método que abrange os procedimentos que ocorrem entre a prescrição e a administração de um medicamento. Um sistema de distribuição de medicamentos deve ser racional, eficiente, económico, organizado, seguro e estar de acordo com o esquema terapêutico prescrito. No final da década 50, os sistemas tradicionais de distribuição de medicamentos necessitavam de ser repensados, visando melhorar a segurança na distribuição e administração de medicamentos. Nos anos 60, farmacêuticos hospitalares apresentaram um novo sistema: a dose unitária, capaz de diminuir a incidência de erros de medicação. Estes sistemas podem dividir-se então em coletivos (sistema de distribuição tradicional e sistema de reposição de stocks nivelados) ou individuais (sistema de distribuição personalizada e sistema de distribuição por dose unitária). Os seus objetivos são reduzir os erros de medicação, racionalizar a distribuição, aumentar o controlo sobre os medicamentos, reduzir os custos com os medicamentos e aumentar a segurança para os doentes. Há, portanto, necessidade de cada hospital manter um sistema de distribuição de medicamentos adequado às suas necessidades. Sendo o erro de medicação qualquer discrepância entre a medicação prescrita e a administrada, a verificação da qualidade de qualquer sistema de distribuição tem como um dos indicadores a incidência dos erros de medicação. A ASHP, nas Guidelines on Preventing Medication Errors in Hospitals, refere que, para minimizar o erro, devem ser projetadas formas seguras de requisitar, dispensar e administrar os medicamentos. Objectivo do estudo: descrever e comparar os diferentes sistemas de distribuição de medicamentos, utilizados em meio hospitalar, notando a sua evolução e utilização ao longo dos tempos, bem como salientar o seu contributo para a segurança do doente (segurança da medicação)

Efficient entanglement purification based on noise guessing decoding

In this paper, we propose a novel bipartite entanglement purification protocol built upon hashing and upon the guessing random additive noise decoding (GRAND) approach recently devised for classical error correction codes. Our protocol offers substantial advantages over existing hashing protocols, requiring fewer qubits for purification, achieving higher fidelities, and delivering better yields with reduced computational costs. We provide numerical and semi-analytical results to corroborate our findings and provide a detailed comparison with the hashing protocol of Bennet et al. Although that pioneering work devised performance bounds, it did not offer an explicit construction for implementation. The present work fills that gap, offering both an explicit and more efficient purification method. We demonstrate that our protocol is capable of purifying states with noise on the order of 10% per Bell pair even with a small ensemble of 16 pairs. The work explores a measurement-based implementation of the protocol to address practical setups with noise. This work opens the path to practical and efficient entanglement purification using hashing-based methods with feasible computational costs. Compared to the original hashing protocol, the proposed method can achieve some desired fidelity with a number of initial resources up to one hundred times smaller. Therefore, the proposed method seems well-fit for future quantum networks with a limited number of resources and entails a relatively low computational overhead.Comment: 16 page

Using multivariate statistics on detection of particular signals during production of knitwear

This paper reports the recent developments in the pursuit to correctly locate, identify and distinguish faults during production of weft knitted fabrics. For this purpose a major textile parameter – yarn input tension (YIT) - is analyzed by means of signal processing techniques. An overview of the entire process of gathering the information and fault detection is presented. For the purpose of distinguishing faults, Multivariate statistical methods, namely cluster and discriminant analysis are used, results presented and discussed. Finally, some conclusions are drawn from the obtained results and future developments are addressed.Fundação para a Ciência e a Tecnologia (FCT) - project POSI/SRI/39824/2001

Surveillance and control of the yarn input tension on circular weft knitting machines : new approaches

The Yarn Input Tension - YIT is one of the most important parameters in weft knitting industry. This parameter must be maintained between limits in order to produce knitted fabric without faults. However, YIT is not the only parameter to control and monitor for preventing faults. The knitting elements and the knitting machine itself should be monitored to improve productivity and quality. The monitoring of the YIT can be used to detect the faults and at the same time controlled inside tight limits to prevent machine’s premature stop due to yarn break . This paper will present the recent developments made for monitoring and control the YIT. A surveillance system will be presented, a low cost force sensor will be suggested to substitute the present industrial solutions, and a new actuator for control of the YIT will be introduced.FCT - Fundação para a Ciência e a Tecnologia POSI/SRI/39824/200

Throughput limits of two 802.15.4 wireless networks applications for signal acquisition

This work describes the development and test of a wireless sensor network used by a biomedical signal monitoring system. Data communication is based on a body area network (BAN) materialized as a wireless network in two versions, one based on the 802.15.4 specification and another on a higher-level Zigbee protocol. The system was developed using the Jennic JN5148 microcontroller, Jennics ZBPro stack and the JenOs RT kernell. The final system was tested with the devices at different distances, and with a varying number of sensor nodes communicating simultaneously. For each of these combinations the signal quality and frequency of communication errors were recorded. The version implemented using Zigbee protocol was able to acquire and send sensor signals at a sample rate of 7 kSamples/s (12-bit samples, final net rate of 84 kbps) with a percentage of lost frames below 4%. It was also shown that the system supports simultaneous communication of three sensor nodes at 3 kS/s (36 kbps) each, with a percentage of losses of less than 4%. These results are important since they support the possibility of having several sensors acquiring fast biomedical signals and sending them to a central unit in real time.Fundação para a Ciência e a Tecnologia (FCT) - Projeto Bioswi

The central nervous system source modulates microglia function and morphology in vitro

The regional heterogeneity of microglia was first described a century ago by Pio del Rio Hortega. Currently, new information on microglia heterogeneity throughout central nervous system (CNS) regions is being revealed by high-throughput techniques. It remains unclear whether these spatial specificities translate into different microglial behaviors in vitro. We cultured microglia isolated from the cortex and spinal cord and analyzed the effect of the CNS spatial source on behavior in vitro by applying the same experimental protocol and culture conditions. We analyzed the microglial cell numbers, function, and morphology and found a distinctive in vitro phenotype. We found that microglia were present in higher numbers in the spinal-cord-derived glial cultures, presenting different expressions of inflammatory genes and a lower phagocytosis rate under basal conditions or after activation with LPS and IFN-γ. Morphologically, the cortical microglial cells were more complex and presented longer ramifications, which were also observed in vivo in CX3CR1+/GFP transgenic reporter mice. Collectively, our data demonstrated that microglial behavior in vitro is defined according to specific spatial characteristics acquired by the tissue. Thus, our study highlights the importance of microglia as a source of CNS for in vitro studies.This work was funded by the Santa Casa Neuroscience Awards—Prize Melo e Castro for Spinal Cord Injury Research (MC-18-2021), and it was partially funded by the Wings for Life Spinal Cord Research Foundation (WFL-ES-03/19). This work was also funded by national funds through the Foundation for Science and Technology (FCT)—projects UIDB/50026/2020, UIDP/50026/2020, and EXPL/MED-PAT/0931/2021, and by the project NORTE-01-0145-FEDER-000039, supported by the Norte Portugal Regional Operational Programme (NORTE 2020) under the PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund (ERDF). We would like to acknowledge the support given by the Portuguese Foundation of Science and Technology to AGP (2020.07534.BD), AM (UMINHO/BIL-CNCG/2022/16), SM (CEECIND/01902/2017), and NAS (CEECIND/04794/2007)