Multivariable Adaptive Harmonic Steady-State Control for Rejection of Sinusoidal Disturbances Acting on an Unknown System

This paper presents an adaptive harmonic steady-state (AHSS) controller, which addresses the problem of rejecting sinusoids with known frequencies that act on a completely unknown multi-input multi-output linear time-invariant system. We analyze the stability and closed-loop performance of AHSS for single-input single-output systems. In this case, we show that AHSS asymptotically rejects disturbances.Comment: 6 pages, 2016 American Control Conference (ACC). IEEE, 201

An operational measure of physician lifelong learning: its development, components and preliminary psychometric data

Despite the emphasis placed on physicians’ lifelong learning, no psychometrically sound instrument has been developed to provide an operational measure of the concept and its components among physicians. The authors designed this study to develop a tool for measuring physician lifelong learning, to identify its underlying components and to assess its psychometric properties. A 37-item questionnaire was developed, based on a review of literature and the results of two pilot studies. Psychometric analyses of the responses of 160 physicians identified 19 items that were included in the Jefferson Scale of Physician Lifelong Learning. Factor analysis of the 19 items showed five meaningful factors that were consistent with the definition and major features of lifelong learning. They were ‘need recognition’, ‘research endeavor’, ‘self-initiation’, ‘technical skills’ and ‘personal motivation’. The method of contrasted groups provided evidence in support of the validity of the five factors. The factors’ reliability was assessed by coefficient alpha. It is concluded that lifelong learning is a multifaceted concept, and its operational measure is feasible for evaluating different educational programs and for studying group differences among physicians

Development of an Instrument to Measure Lifelong Learning Among Physicians

No abstract available

Automated brain tumour detection and segmentation using superpixel-based extremely randomized trees in FLAIR MRI

PURPOSE: We propose a fully automated method for detection and segmentation of the abnormal tissue associated with brain tumour (tumour core and oedema) from Fluid- Attenuated Inversion Recovery (FLAIR) Magnetic Resonance Imaging (MRI). METHODS: The method is based on superpixel technique and classification of each superpixel. A number of novel image features including intensity-based, Gabor textons, fractal analysis and curvatures are calculated from each superpixel within the entire brain area in FLAIR MRI to ensure a robust classification. Extremely randomized trees (ERT) classifier is compared with support vector machine (SVM) to classify each superpixel into tumour and non-tumour. RESULTS: The proposed method is evaluated on two datasets: (1) Our own clinical dataset: 19 MRI FLAIR images of patients with gliomas of grade II to IV, and (2) BRATS 2012 dataset: 30 FLAIR images with 10 low-grade and 20 high-grade gliomas. The experimental results demonstrate the high detection and segmentation performance of the proposed method using ERT classifier. For our own cohort, the average detection sensitivity, balanced error rate and the Dice overlap measure for the segmented tumour against the ground truth are 89.48 %, 6 % and 0.91, respectively, while, for the BRATS dataset, the corresponding evaluation results are 88.09 %, 6 % and 0.88, respectively. CONCLUSIONS: This provides a close match to expert delineation across all grades of glioma, leading to a faster and more reproducible method of brain tumour detection and delineation to aid patient management

The spatial distribution of esophageal and gastric cancer in Caspian region of Iran: An ecological analysis of diet and socio-economic influences

Recent studies have suggested a systematic geographic pattern of esophageal cancer (EC) and gastric cancer (GC) incidence in the Caspian region of Iran. The aims of this study were to investigate the association between these cancers and the region's dietary and socioeconomic risk factors and to map EC and GC after adjustment for the risk factors and the removal of random and geographic variations from area specific age standardised incidence ratios (SIRs)

Development and validation of an instrument to measure nurse educator perceived confidence in clinical teaching

Teaching nursing in clinical environments is considered complex and multi‐faceted. Little is known about the role of the clinical nurse educator, specifically the challenges related to transition from clinician, or in some cases, from newly‐graduated nurse to that of clinical nurse educator, as occurs in developing countries. Confidence in the clinical educator role has been associated with successful transition and the development of role competence. There is currently no valid and reliable instrument to measure clinical nurse educator confidence. This study was conducted to develop and psychometrically test an instrument to measure perceived confidence among clinical nurse educators. A multi‐phase, multi‐setting survey design was used. A total of 468 surveys were distributed, and 363 were returned. Data were analyzed using exploratory and confirmatory factor analyses. The instrument was successfully tested and modified in phase 1, and factorial validity was subsequently confirmed in phase 2. There was strong evidence of internal consistency, reliability, content, and convergent validity of the Clinical Nurse Educator Skill Acquisition Assessment instrument. The resulting instrument is applicable in similar contexts due to its rigorous development and validation process

Variations in sturgeon populations in the coastal waters of the Caspian Sea (Guilan province)

The present study was conducted from autumn 2003 to summer 2005 with the objective to estimate distribution and relative abundance in different species of sturgeons as a function of seasons, and regions in the west coast of the Caspian Sea (Guilan province).Gillnets with a different mesh sizes (26, 33, 40, 60, 100, and 150 mm) were set up at different depths(2, 5, and 10 m) for 24 h. Data on variations in catch, catch per unit effort(CPUE) and length and age composition of sturgeon species were analyzed statistically. Data on CPUE in each region and depth and mean estimates of length and age in fish were reported for each season and each year of the study period. CPUE during 2004-2005 was 1.32 fish which was 30.1% lower than CPUE (1.89 fish) recorded in 2003-2004.CPUE for all species except A. nudiventris decreased during 2004-2005 as compared to that in 2003-2004. Acipenser persicus caught during 2003-2004 and 2004-2005 ranged from 15 to 45 cm in length and comprised 91.1 and 97.1% respectively of the total sturgeon catch. These fish belonged to the one year age class. Mean length recorded in sturgeon fish caught in 2004-2005 decreased as compared to that recorded in 2003-2004. Significant differences were recorded in total length of fish caught in 2003-2004 and 2004-2005. Results obtained from the present study reveal that the abundance of fish increased from west to east indicating a direct relationship between the general currents found in the Caspian Sea and the higher density of nutrients in the eastern region