Search results for "observer"

Validation of short term recall of mobile phone use for the Interphone study

2006

Aim: To validate short term recall of mobile phone use within Interphone, an international collaborative case control study of tumours of the brain, acoustic nerve, and salivary glands related to mobile telephone use. Methods: Mobile phone use of 672 volunteers in 11 countries was recorded by operators or through the use of software modified phones, and compared to use recalled six months later using the Interphone study questionnaire. Agreement between recalled and actual phone use was analysed using both categorical and continuous measures of number and duration of phone calls. Results: Correlations between recalled and actual phone use were moderate to high (ranging from 0.5 to 0.8 acros…

MicroRNAs and their role in the malignant transformation of oral leukoplakia: a scoping review

2021

Background MiRNAs are small non-coding RNAs that regulate gene expression at the post-transcriptional level and have been associated with malignant transformation of oral epithelial precursor lesions such as oral leukoplakia. The aim was to perform a scoping review of the contemporary literature about the different roles of miRNAs during the malignant transformation of oral leukoplakia. Material and Methods We conducted a systematic search with the following MeSH terms: ‘oral leukoplakia’, ‘carcinoma in situ’, ‘microRNAs’, ‘mouth neoplasms’ and ‘epithelial–mesenchymal transition’ in PubMed/MEDLINE, EMBASE and SpringerLink. Results Fifteen articles were included for analysis, among which in …

Analytical and experimental evaluation of a WECS based on a Doubly Fed Induction Generator fed by a matrix converter

2008

In this paper the control of a grid-connected Wind Energy Conversion System (WECS), based on a sensorless vector controlled Doubly-Fed Induction Generator (DFIG) fed by a matrix converter, is presented. The matrix converter is controlled using a space vector modulation algorithm. Stability issues related to the operation of the WECS connected to the grid using a matrix converter are also discussed in this work. The influence of a synchronous rotating filter in the dynamic of the proposed WECS is analysed. A Model Reference Adaptive System (MRAS) observer for sensorless control of the proposed WECS is used in this work. Using the speed estimated by the MRAS observer the electrical torque of …

A Rotor Flux and Speed Observer for Sensorless Single-Phase Induction Motor Applications

2012

It is usual to find single-phase induction motor (SPIM) in several house, office, shopping, farm, and industry applications, which are become each time more sophisticated and requiring the development of efficient alternatives to improve the operational performance of this machine. Although the rotor flux and rotational speed are essential variables in order to optimize the operation of a SPIM, the use of conventional sensors to measure them is not a viable option. Thus, the adoption of sensorless strategies is the more reasonable proposal for these cases. This paper presents a rotor flux and rotational speed observer for sensorless applications involving SPIMs. Computer simulations and the…

VII: Diagnosestudien: Einfache Maße für Validität und Reliabilität

2003

The evaluation of a new diagnostic or imaging device has to focus both on its diagnostic validity and reliability. Cohen's kappa coefficient can be used to assess the agreement of the new device's findings with those of an established diagnostic reference, it therefore presents a surrogate measure of validity. Additional measures of validity are sensitivity and specificity, which assess the order of agreement with the reference for positive and negative reference findings, respectively. The latter, however, can only be applied for binary reference findings. If discordant findings are observed, the McNemar test can be used to detect a diagnostic shift between diagnostic novum and reference. …

Reliability of Y-Balance Test y Wight Bearing Lunge Test for the clinical-functional evolution of plantar fasciitis

2018

[Resumen] Objetivos: Los objetivos de nuestro estudio han sido determinar en pacientes con FP unilateral la fiabilidad intraobservador del instrumento Y- Balance Test (YBT) y la prueba Wight Bearing Lunge Test (WBLT) medida con el inclinómetro de un telefono movil inteligente. Métodos: Estudio transversal y observacional, realizado con 16 pacientes (9 mujeres y 7 hombres). Resultados: Los resultados obtenidos revelan una excelente fiabilidad relativa intraobservador. El YBT mostró un CCI de 0’946; mientras que las medidas con inclinómetro obtuvieron un CCI de 0’992. En el YBT se apreció una asociación de variables estadísticamente significativa en la dirección posteromedial (p=0’004) y en e…

Surgical time for graft preparation using different suture techniques

2016

Background: The purpose of the present study was to compare the operative time for graft prepa- ration using different techniques for graft sutur- ing. Material and methods: Flexor profundus tendons were harvested from fresh pig hind-leg trotters. Three different suture techniques were investigat- ed: the Krackow stitch (K), the Whipstitch (W), and the Modified Finger-Trap suture (MFT). Ten- dons were sutured starting at 10 mm from the dis- tal free end of the tendon. The suture configura- tions of the Krackow stitch and Whipstitch were completed with five suture throws. According to the MFT technique, the suture was wrapped five times around the tendon over a distance of 30 mm. The time re…

Corrigendum to “Observer-Based Sliding Mode Control for Stabilization of a Dynamic System with Delayed Output Feedback”

2016

Quality of individually calibrated customary printers for assessment of typical dental diagnoses on glossy paper prints: a multicenter pilot study.

2007

Objective The objective of this study was to compare dental radiographs printed on glossy paper from calibrated low-cost printers with monitor display. Study design Three typical intraoral radiographs were selected and a questionnaire was developed with questions assessing accuracy and subjective quality. A test pattern was designed for printer calibration. After calibration, radiographs were printed on glossy paper with 3 ink-jet and 2 thermo-sublimation printers. Sixteen raters evaluated the printed radiographs, 9 of them also on standardized viewing monitors. Subjective ratings were compared, and an ROC-analysis based on expert-consensus monitor readings was performed. Results Low inter-…

Assessment of proliferative activity in breast cancer: MIB-1 immunohistochemistry versus mitotic figure count.

1999

Abstract The proliferative activity is one of the most important single prognostic parameters in breast cancer diagnosis and the time-honored measure of proliferative activity, the mitotic figure count, is an integral component of most combined prognostic scores. The detection of the cell cycle-specific antigens Ki-67, and the development of anti-Ki-67 antibodies, including the paraffin-reactive antibody MIB-1, have established immunohistochemical detection of cell cycle-specific antigens as a measure of proliferative activity in breast cancer diagnosis. The current study was performed to correlate mitotic figure counts with the proliferative activity as assessed by MIB-1 immunohistochemist…