Moderate Allocation Research Articles

Propeller control for takeoff of a heavily loaded coaxial compound helicopter

AbstractAlthough a coaxial compound helicopter can takeoff without propeller in the normal condition, the distance should be as short as possible for obstacle avoidance when the vehicle operates in a confined area with heavy loads. Therefore, a suitable propeller control is required to improve the takeoff performance while the total power consumption is no more than the available power. The path is predicted by applying trajectory optimisation. Several varying takeoff parameters, including attitude, liftoff speed and obstacle height, are considered for optimum global performance. Three path indicators are proposed. Apart from typical distance and pilot workload, path sensitivity is quantified based on deviation from takeoff parameter variation. Results indicated that low propeller thrust at hover and moderate allocation on the propeller through flight is recommended. The aircraft achieves significantly improved takeoff performance compared to flight with pure rotors while maintaining the maximum takeoff weight. The distance is shortened by 12.6%, and the longitudinal pilot workload is alleviated by 9.8% and 7.3% from mean and maximum power frequency aspects. Besides, the path is less sensitive to takeoff parameter variations, such as speed, altitude and height.

A performance evaluation of Chinese mutual funds

Purpose – The purpose of this paper is to examine the performance of Chinese mutual funds during the period of January 2000 to July 2013. Emerging market funds provide investors with alternative risk exposure for their portfolios. The Chinese market has developed rapidly and differs from developed markets regarding wide range of market and economic characteristics, including size, liquidity, and regulation. The performance of these funds is investigated by using various risk adjusted measures. The study also compares performances of mutual fund subgroups and explains the factors influencing their performances. Design/methodology/approach – This is an empirical paper using various risk performance measures. These measures include the Sharpe ratio, Information ratio, Treynor ratio, M-squared and Jensen’s α. The data comprises 1,037 funds. These funds are further divided into ten subgroup of funds based on their classification: equity (484); aggressive allocation (95 funds); conservative allocation (18 funds); moderate allocation (85 funds); aggressive bond (92 funds); normal bond (52 funds); guaranteed (29 funds); money market (53 funds); and QDII funds (119 funds). A cross-sectional analysis of fund performance is performed using Sharpe and Jensen’s measures as dependent variables and fund-specific variables (Age, Turnover, Tenure, Frontload, Redemption fees, and Management fees), market-specific variables (P/E ratio, P/B ratio, Market capitalization), and fund types as independent variables. Findings – The findings show that Chinese funds generate positive αs for their investors. The highest return is provided with aggressive allocation funds followed by moderately aggressive allocation funds. The average Jensen’s α is the highest in aggressive allocation funds. QDII funds do not provide significant positive αs; in several instances αs are negative. Further analysis of sub-periods show that Chinese funds do not consistently provide excess returns and show great variations. The study also finds that older funds, funds with higher fees, high price to book ratio, and smaller funds continue to perform better than other funds. Originality/value – This study adds value by focussing on Chinese funds and risk/return characteristics of these funds. The research will further explore factors explaining these returns.

Inactive lifestyles and obesity in Chilean youth: Individual costs in health-related choices

Objective: A recent economic approach suggests that people do not account for the long-term implications of unhealthy behaviours, preventing them from performing a fully rational trade-off between current benefits and future costs, leading to negative health outcomes. We examined whether the current allocation of time to physical activity among young people leads to outcomes that may affect their well being as youth and their longer–term life prospects. Design: The study group comprised a random sample of 1692 high-school students (14.8±0.7 years old) from urban Santiago, Chile attending private and non-private schools. Setting: We measured physical activity habits accounting for time spent in class, studying and screen-based entertainment, hours of daily recreational activity and hours of weekly scheduled exercise. Obesity and abdominal obesity were diagnosed according to CDC/NCHS 2000, NHANES III and IDF criteria, respectively. Method: Logistic regression analysis was performed to assess the relationship between current physical activity habits, confounders and the likelihood of suffering from obesity and abdominal obesity. Results: Young people reporting the lowest allocation of time to physical activity, scheduled exercise and active play showed a higher risk of obesity and abdominal obesity. Those reporting moderate allocation of time to physical activity, scheduled exercise and active play were more likely to suffer from central obesity as defined by IDF criteria. Study participants attending partially subsidized schools showed the highest risk of obesity and central obesity. Conclusions: In this sample, young people appear not to be employing optimal strategies for making weight-related choices, since reduced physical activity, obesity and central obesity are proximate causes of metabolic and cardiovascular disorders.