335 research outputs found
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
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)
An operational measure of physician lifelong learning: its development, components and preliminary psychometric data
Despite the emphasis placed on physiciansâ 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 âneed recognitionâ, âresearch endeavorâ, âself-initiationâ, âtechnical skillsâ and âpersonal motivationâ. The method of contrasted groups provided evidence in support of the validity of the five factors. The factorsâ 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
Development and validation of an instrument to measure nurse educator perceived confidence in clinical teaching
Teaching nursing in clinical environments is considered complex and multiâfaceted. Little is known about the role of the clinical nurse educator, specifically the challenges related to transition from clinician, or in some cases, from newlyâgraduated 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 multiâphase, multiâsetting 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
The relationship between video display terminals (VDTs) usage and dermatologic manifestations : a cross sectional study
BACKGROUND: Recently, it has been observed that Video Display Terminals (VDTs) usage for long periods can cause some dermatological manifestations on the face. An analytical cross-sectional study was designed in order to determine this relationship. METHODS: In this study, 600 office workers were chosen randomly from an organization in Tehran (Iran). The subjects were then divided into two groups based on their exposure to VDTs. 306 workers were considered exposure negative (non VDT user) who worked less than 7 hours a week with VDTs. The remainders 294 were exposure-positive, who worked 7 hours or more with VDTs. The frequency of dermatologic manifestations was compared in these two groups. RESULTS: In the exposure-positive and exposure-negative groups, the frequency of these dermatologic manifestations were 27 and 5 respectively. After statistical analysis, a P.value of < 0.05 was obtained indicating a statistically significant difference between these two groups for dermatological manifestations. CONCLUSION: According to our study, there is a relationship between dermatologic manifestations on the face and exposure to VDTs
Predicting Students\u27 Performance on Licensing Examinations During Medical School and Afterwards
No abstract available
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