The Efficiency of Pension Plan Investment Menus: Investment Choices in Defined Contribution Pension Plans

Few previous studies have explored whether defined contribution retirement saving plans offer sufficiently diversified investment menus, though it is likely that these menus significantly shape workers’ accumulations of retirement wealth. This paper assesses the efficiency and performance of 401(k) investment options offered by a large group of US employers. We show that most plans are efficient compared to market benchmark indexes. Three performance measures underscore the fact that these plans tend to offer a sensible investment menu, when measured in terms of the menus’ mean-variance efficiency, diversification, and participant utility. The key factor contributing to plan efficiency and performance has to do with the types of funds offered, rather than the total number of investment options provided.

Effective pattern discovery for text mining

Many data mining techniques have been proposed for mining useful patterns in text documents. However, how to effectively use and update discovered patterns is still an open research issue, especially in the domain of text mining. Since most existing text mining methods adopted term-based approaches, they all suffer from the problems of polysemy and synonymy. Over the years, people have often held the hypothesis that pattern (or phrase) based approaches should perform better than the term-based ones, but many experiments did not support this hypothesis. This paper presents an innovative technique, effective pattern discovery which includes the processes of pattern deploying and pattern evolving, to improve the effectiveness of using and updating discovered patterns for finding relevant and interesting information. Substantial experiments on RCV1 data collection and TREC topics demonstrate that the proposed solution achieves encouraging performance

Dietary Change of English, French and Chinese Speaking Immigrants in Ottawa and Gatineau, Canada

Open Access Publication by JSciMed Central® is licensed under a Creative Commons Attribution 4.0 International License.Objectives: The multicultural study aims at examining Dietary Change (Dietary Behaviour Change and Dietary Belief Change) of English, French and Chinese speaking immigrants in Ottawa and Gatineau, Canada, and identifying demographic factors that correlate with the change and impact the change. Materials and Methods: In total, 810 immigrants of the three language sub-groups were recruited by purposive-sampling. Using self-reports, respondents answered questions regarding Behaviour Change and Belief Change in Nutritional Food Consumption and Junk and Processed Food Consumption, and Demography in Multicultural Lifestyle Change Questionnaire of English, French or Chinese version. Percentage, significance of difference, correlation, regression and factor analysis were performed respectively to analyze the data in Dietary Change. Results: Immigrants of different gender, language and category sub-groups exhibited different rates in nutritional food and junk and processed food consumption changes, increasing and decreasing rates in consumption of different nutritional foods, increasing and decreasing rates in consumption of different junk and processed foods, and rates in nutritional food and junk and processed food belief changes. However, no statistical difference between the rates, except significant differences between increasing and decreasing rates of different category sub-groups in consumption of different nutritional foods and consumption of different junk and processed foods. Dietary Change (Dietary Behaviour Change + Dietary Belief Change) was correlated positively with Speaking Languages, Age and Religion, and Dietary Behaviour Change was correlated negatively with Religion. Speaking Languages, Age and Religion significantly impacted Dietary Change, and Religion significantly impacted Dietary Behaviour Change. Speaking Languages and Age significantly impacted Dietary Belief Change. One factor (factor one: dietary behaviour change factor) significantly influenced Dietary Change. Other factor (factor two: dietary belief change factor) did not significantly impacted Dietary Change. Conclusion: Immigrants of different sub-groups in Canada experienced different Dietary Change. Religion was a main factor influencing Dietary Change. Speaking Languages and Age were important factors impacting Dietary Belief Change. Acculturation was a relating factor contributing Dietary Change. Data of immigrant dietary change can provide evidence for dietetic health policy-making and policy-revising in Canada

Mass flow in the circumbinary disk with gap around supermassive binary black holes

In this paper, we study the interaction between the supermassive binary black holes in elliptical orbit and their surrounding disk with a gap. The gap in the disk is a low density region formed due to the tidal effects of the less massive black hole. The binary we have investigated has a sub-parsec separation and is coplanar with the disk. We find that the maximum variation of the surface density in the gap reaches 50% during an orbital period. However, in other regions of the disk, the density variation is much less than 1%. Furthermore, we calculate the corresponding variation of spectral energy distribution within a period, but little variation is found. The reason for these results is that the viscosity timescale of the disk at the binary radius is much longer than the orbital period of the binary.Comment: 8 pages, 3 figure

Asteroseismology of KIC 8263801:Is it a member of NGC 6866 and a red clump star?

We present an asteroseismic analysis of the Kepler light curve of KIC 8263801, a red-giant star in the open cluster NGC 6866 that has previously been reported to be a helium-burning red-clump star. We extracted the frequencies of the radial and quadrupole modes from its frequency power spectrum and determined its properties using a grid of evolutionary models constructed with MESA. The oscillation frequencies were calculated using the GYRE code and the surface term was corrected using the Ball & Gizon(2014) prescription. We find that the star has a mass of $M/M_{\odot} = 1.793\pm 0.072$, age $t=1.48\pm 0.21$ Gyr and radius $R/R_{\odot} = 10.53\pm 0.28$. By analyzing the internal structure of the best-fitting model, we infer the evolutionary status of the star KIC 8263801 as being on the ascending part of the red giant branch, and not on the red clump. This result is verified using a purely asteroseismic diagnostic, the $\epsilon_{c}-\Delta\nu_{c}$ diagram which can distinguish red giant branch stars from red clump stars. Finally, by comparing its age with NGC 6866 ($t=0.65 \pm 0.1$ Gyr) we conclude that KIC 8263801 is not a member of this open cluster