Helicopter Rotor Blade Monitoring using Autonomous Wireless Sensor Network

The advancement on Wireless Sensor Networks for vibration monitoring presents important possibilities for helicopter rotor health and usage monitoring. While main rotor blades account for the main source of lift for helicopters, rotor induced vibration establishes an important source for understanding the rotor performance and blade condition. A discussion on the dual character of blades as rotating structures results in two different interrogation strategies for external and internal dynamic loading on the blade. The first strategy aims for in-flight rotor performance monitoring, while the second pursues health assessment. An overview of different measurements performed on an actual helicopter blade is presented. The measurements include a complete modal analysis using a full wired instrumented blade and a comparison between wireless sensor nodes and wired instrumentation. Additionally, a numerical multibody dynamics model for damage simulation is presented. The experimental and numerical work contribute to the identification of several implications on the migration of condition and health monitoring techniques to a wireless setting

A Novel Ruminant Emission Measurement System: Part I. Design Evaluation and Description

Methane (CH4) generated by cattle is both a major source of greenhouse gas emissions and a powerful indicator of feed conversion efficiency; thus, accurate quantification of CH4 production is required for addressing future global food security without neglecting environmental impacts. A newly developed Ruminant Emission Measurement System (REMS) supports research on the relationships between bovine nutrition, genetics, and management strategies by measuring eructated CH4 emissions from ruminal activity. REMS is a substantial improvement and extension of the chamber technique, which is considered the standard method to quantify ruminant CH4 generation. Part I of this two-part series describes the design and evaluation of REMS. An uncertainty analysis of chamber emission rate (ER) was conducted to identify critical measurement component contributions to overall ER uncertainty and guide component selection. In Part II, REMS commissioning was performed and a method for system validation including overall emission uncertainty is reported. REMS consists of six positive pressure ventilated hood-type chambers individually equipped with a thermal environmental control subsystem, fresh air supply control subsystem, and gas sampling subsystem. Estimates of the standard uncertainty for each measurement parameter were quantified and propagated through the ER equation derived from CH4 and air mass flow balances. A sensitivity analysis was conducted to assess the contribution of each parameter to the emission rate standard uncertainty (absolute = ΔER; relative = %ΔER) under predicted normal operation by varying gas analyzer and ventilation measurement uncertainties as anticipated with REMS use. Results showed that expanded %ΔER (~95% confidence level) associated with the methane ER computation was approximately 5.9% for ER values between 3.5 and 17.2 g h-1. Ventilation rate and gas concentration measurements were the major sources of uncertainty, contributing about 69% and 29%, respectively, to the uncertainty associated with methane ER values. This work provides the foundation for future studies using respiration chambers to include a stated standard uncertainty associated with animal emission measurements

The allocation between EU member states of seats in the European Parliament

This note contains the recommendation for a mathematical basis for the apportionment of the seats in the European Parliament between the Member States of the European Union. This is the unanimous recommendation of the Participants in the Cambridge Apportionment Meeting, held at the instigation of the Committee on Constitutional Affairs at the Centre for Mathematical Sciences, University of Cambridge, on 28–29 January 2011

Bridge employment and full retirement intentions: the role of Person-Environment fit

Purpose - This study explores the relationship between different categories of Person-Environment fit and two types of retirement intentions (i.e. full retirement and bridge employment).Design/methodology/approach - Data were collected from a convenience sample of 357 executives aged 50 and over, employed in French private sector companies. Hypotheses were tested using structural equation modeling. Findings - Perceptions of value congruence at vocational level and needs and supplies fit at organizational and job levels were positively related to the intention to hold a bridge employment after retirement. The fit between older worker’s abilities and job demands was positively related to the two types of retirement intentions.Originality/value - The complexity of retirement transition is taken into account with the introduction of two types of retirement intentions. Person-Environment fit is proved to be an antecedent of career intentions after retirement

Individuals reentering the workforce: Biases, stereotypes, and gender roles.

The purpose of the proposed study aims to investigate the potential biases that individuals may experience when reentering the workforce after taking time off to raise children. The Ambiguity Aversion Theory (AAT) and the Role Congruity Theory (RCT) are possible theories to suggest reasons why individuals may engage in certain biases when selecting an applicant with or without a gap in the resume. Participants will be asked to either hire or not hire an applicant for a job based on the applicant’s qualifications described in a narrative. Gender of the applicant will vary across conditions. The narrative will include information about the applicant’s education and experience that clearly meets the requirements for the job. If an applicant has a gap in the resume, the narrative will also include either an explanation for the gap (i.e., is a time-out from the workforce to raise children), or there will not be an explanation for the gap. Depending on the pattern of results (i.e., participants’ decision to hire or not hire an applicant based on their qualifications described in the narrative) will provide an indication about which theory (or theories) best explain the results

The allocation between the EU member states of the seats in the European Parliament Cambridge Compromise

This Note contains the recommendation for a mathematical basis for the apportionment of the seats in the European Parliament between the Member States of the European Union. This is the unanimous recommendation of the Participants in the Cambridge Apportionment Meeting, held at the instigation of the Committee on Constitutional Affairs at the Centre for Mathematical Sciences, University of Cambridge, on 28-29 January 2011.Proportional Representation, degressive proportionality, apportionment, European Parliament. Classification

Evaluación de los Sistemas e-Learning: Estudio de las publicaciones realizadas en la Web Of Knowledge

El propósito de este estudio es analizar el crecimiento y desarrollo de la literatura sobre la evaluación de los sistemas e-Learning. La bibliografía publicada en 18 de las principales revistas de la base de datos ISI Web of Knowledge fue obtenida, de manera directa, a través de las palabras clave: “model”, “evaluation”, “e-Learning system”, con sus respectivos sinónimos. La información como autor, título, subtítulo, fuente, citas, etc., se registró en MS-Excel (2010) para su análisis e interpretación. El estudio encontró 127 artículos de esta temática, publicados en el período 2008-2012. Además, revela que el 2012 fue el año más prolífico, con 33 artículos. La revista más productiva es Computers & Education, con 15 artículos; se la puede considerar como una revista básica de consulta. Se encontró que Peter Shea y Temi Bidjerano, ambos de Estados Unidos, son los autores que más han publicado y realizado trabajos conjuntos. Podría ser una limitante del estudio que la información que se tomó fue restringida a un período de cinco años, tiempo que de manera general se acepta, en relación a la antigüedad de la producción bibliográfica. El documento proporciona información confiable y auténtica sobre el tema y es el primer estudio de este tipo

Perceptions about alcohol harm and alcohol-control strategies among people with high risk of alcohol consumption in Alberta, Canada and Queensland, Australia

Objectives: To explore alcohol perceptions and their association hazardous alcohol use in the populations of Alberta, Canada and Queensland, Australia. Methods: Data from 2500 participants of the 2013 Alberta Survey and the 2013 Queensland Social Survey was analyzed. Regression analyses were used to explore the association between alcohol perceptions and its association with hazardous alcohol use. Results: Greater hazardous alcohol use was found in Queenslanders than Albertans (p<0.001). Overall, people with hazardous alcohol were less likely to believe that alcohol use contributes to health problems (odds ratio [OR], 0.46; 95% confidence interval [CI], 0.27 to 0.78; p<0.01) and to a higher risk of injuries (OR, 0.54; 95% CI, 0.33 to 0.90; p<0.05). Albertans with hazardous alcohol use were less likely to believe that alcohol contributes to health problems (OR, 0.48; 95% CI, 0.26 to 0.92; p<0.05) and were also less likely to choose a highly effective strategy as the best way for the government to reduce alcohol problems (OR, 0.63; 95% CI, 0.43 to 0.91; p=0.01). Queenslanders with hazardous alcohol use were less likely to believe that alcohol was a major contributor to injury (OR, 0.39; 95% CI, 0.20 to 0.77; p<0.01). Conclusions: Our results suggest that people with hazardous alcohol use tend to underestimate the negative effect of alcohol consumption on health and its contribution to injuries. In addition, Albertans with hazardous alcohol use were less in favor of strategies considered highly effective to reduce alcohol harm, probably because they perceive them as a potential threat to their own alcohol consumption. These findings represent valuable sources of information for local health authorities and policymakers when designing suitable strategies to target alcohol-related problems