Periodic and Chaotic Flapping of Insectile Wings

Insects use flight muscles attached at the base of the wings to produce impressive wing flapping frequencies. The maximum power output of these flight muscles is insufficient to maintain such wing oscillations unless there is good elastic storage of energy in the insect flight system. Here, we explore the intrinsic self-oscillatory behavior of an insectile wing model, consisting of two rigid wings connected at their base by an elastic torsional spring. We study the wings behavior as a function of the total energy and spring stiffness. Three types of behavior are identified: end-over-end rotation, chaotic motion, and periodic flapping. Interestingly, the region of periodic flapping decreases as energy increases but is favored as stiffness increases. These findings are consistent with the fact that insect wings and flight muscles are stiff. They further imply that, by adjusting their muscle stiffness to the desired energy level, insects can maintain periodic flapping mechanically for a range of operating conditions

Contributing to the Individual Income Tax Reform Debate in China: Is Family Based Filing of Individual Income Tax Returns a Feasible Solution to the Social Problems Arising from the Increasing Family Income Inequality in China?

China’s new wave of Individual Income Tax Reform is currently hotly debated. The Finance Minister, Lou Jiwei was reported to say that the relevant government departments in China – the State Council, the Ministry of Finance, and the State Administration of Finance had worked out a reform plan together in 2015. One goal of this plan is to move China’s scheduler individual income tax to a global structure, and to put in place policies that contribute to income redistribution that takes into consideration family related expenditure, such as looking after the elderly and childcare.A review of the literature shows that Chinese scholars and commentators suggest that China could learn directly from the US, adopt their global income tax system and allow family based filing of individual income tax returns. The literature does not provide reasons for this suggestion.This paper performs a feasibility study to assess whether China could adopt the suggestions proposed by the prevailing literature. The study is performed based on a “revenue neutrality” analysis that compares projected revenue from existing policies, and that collectable if China allows family based individual income tax filing.Results from a pilot study reports that the projected revenue from allowing family based individual income tax filing would be at a level that is closer to 40% of revenue collectable if China does not allow family based individual income tax filing. This result suggests that policy makers in China need to take careful considerations of costings before proceeding with thereform

Fiscal Considerations for Sustainable Public Funding of Urban Old-Age Pensions in the People’s Republic of China

China has well-established Old-age Pensions policies for the different segments of its population, both as part of the current welfare policies framework as well as continuing a long established tradition of care for the elderly. Urban Old-Age Pensions policies play an increasingly important role in the increasingly urbanised economy of the People’s Republic of China (PRC). The PRC government continued with tradition in the policies that led to the enactment of the Social Insurance Law of the People’s Republic of China[1], and promised to fully fund Urban Old-Age Pensions. A common theme reported in the prevailing literature is that the PRC government does not have the ability to sustainably fund Urban Old-Age Pensions, citing both substantive and administrative causes of the short fall, and calling for changes to the Social Insurance Contributions policies to make the Urban Old-age Pension schemes more sustainable. The prevailing literature, however, neglected the Chinese tradition that includes government policies to look after the elderly, and misconstrued the Social Insurance Contributions as insurance premiums. This thesis investigated whether changes to funding policies are needed in order to meet the stated obligation of fully funding Urban Old-Age Pensions. The thesis investigated the sources of funding by collating all sources of fiscal revenue and then calculating whether this sum collected would successfully fund the required level of disbursed Urban Old-Age Pensions. This thesis concludes that at current Urban Old-age Pension replacement rates[2], the PRC’s fiscal structure can adequately fund Urban Old-Age Pensions at present benefit levels. Current studies on the sustainability of funding need to consider the data gathered and arguments made in this thesis and to incorporate all sources of funding before stating that short falls in funding and lack of funding sustainability exist, or suggesting reform proposals. [1] Above note 2. [2] The Old-age Pension replacement rate is taken to be the rate Old-age Pensions is paid at as a percentage of National Average Wages Levels

Environmental correlates of sedentary behaviors and physical activity in Chinese preschool children:A cross-sectional study

Objective: This cross-sectional study examined environmental correlates of sedentary behavior (SB) and physical activity (PA) in preschool children in the urban area of Tianjin, China. Methods: Data were collected from the Physical Activity and Health in Tianjin Chinese Children study, involving healthy children 3–6 years old and their families. In all children (n = 980), leisure-time SB (LTSB) and leisure-time PA (LTPA) were reported in min/day by parents. In a subgroup (n = 134), overall sedentary time, light PA, and moderate-to-vigorous PA (MVPA) were objectively measured using ActiGraph accelerometry (≥3 days, ≥10 h/day). Environmental correlates were collected using a questionnaire that included home and neighborhood characteristics (e.g., traffic safety, presence of physical activity facilities) and children's behaviors. Potential correlates were identified using linear regression analysis. Results: Multiple linear regression analysis showed that “having grandparents as primary caregivers” (βs and 95% confidence intervals (95%CIs) for overall sedentary time: 29.7 (2.1–57.2); LTSB (ln): 0.19 (0.11–0.28)) and “having a television (for LTSB (ln): 0.13 (0.00–0.25)) or computer (for LTSB (ln): 0.13 (0.03–0.23)) in the child's bedroom” were both associated with higher SB. Furthermore, “having grandparents as primary caregivers” was associated with less MVPA (β (95%CI): −7.6 (−14.1 to −1.2)), and “active commuting to school by walking” correlated with more MVPA (β (95%CI): 9.8 (2.2–17.4)). The path model showed that “more neighborhood PA facilities close to home” was indirectly related to higher LTPA (ln), which was partly mediated by “outdoor play” (path coefficients (95%CI): 0.005 (0.002–0.008)) and “going to these facilities more often” (path coefficients (95%CI): 0.013 (0.008–0.018)). Traffic safety was not a correlate. Conclusion: Family structure and media exposure in the home maybe important factors in shaping preschoolers’ PA patterns. Built environmental correlates could indirectly influence preschoolers’ LTPA through parental help with engaging in active behaviors

Pulse Compression Probing for Tracking Distribution Feeder Models

A Pulse-Compression Probing (PCP) method is applied in time-domain to identify an equivalent circuit model of a distribution network as seen from the transmission grid. A Pseudo-Random Binary Pulse Train (PRBPT) is injected as a voltage signal at the input of the feeder and processed to recover the impulse response. A transfer function and circuit model is fitted to the response, allowing the feeder to be modeled as a quasi-steady-state sinusoidal (QSSS) source behind a network. The method is verified on the IEEE 13-Node Distribution Test System, identifying a second order circuit model with less than seven cycles latency and a signal to noise ratio of 15.07 dB in the input feeder current.Comment: 5 Pages, 6 Figures, Pending Publication at IEEE PESGM 202

Joint modeling of wind speed and wind direction through a conditional approach

Atmospheric near surface wind speed and wind direction play an important role in many applications, ranging from air quality modeling, building design, wind turbine placement to climate change research. It is therefore crucial to accurately estimate the joint probability distribution of wind speed and direction. In this work we develop a conditional approach to model these two variables, where the joint distribution is decomposed into the product of the marginal distribution of wind direction and the conditional distribution of wind speed given wind direction. To accommodate the circular nature of wind direction a von Mises mixture model is used; the conditional wind speed distribution is modeled as a directional dependent Weibull distribution via a two-stage estimation procedure, consisting of a directional binned Weibull parameter estimation, followed by a harmonic regression to estimate the dependence of the Weibull parameters on wind direction. A Monte Carlo simulation study indicates that our method outperforms an alternative method that uses periodic spline quantile regression in terms of estimation efficiency. We illustrate our method by using the output from a regional climate model to investigate how the joint distribution of wind speed and direction may change under some future climate scenarios.Comment: 29 pages, 15 figure