New Generalizations of Cosmography Inspired by the Pade Approximant

The current accelerated expansion of the universe has been one of the most important fields in physics and astronomy since 1998. Many cosmological models have been proposed in the literature to explain this mysterious phenomenon. Since the nature and cause of the cosmic acceleration are still unknown, model-independent approaches to study the evolution of the universe are welcome. One of the powerful model-independent approaches is the so-called cosmography. It only relies on the cosmological principle, without postulating any underlying theoretical model. However, there are several shortcomings in the usual cosmography. For instance, it is plagued with the problem of divergence (or an unacceptably large error), and it fails to predict the future evolution of the universe. In the present work, we try to overcome or at least alleviate these problems, and we propose two new generalizations of cosmography inspired by the Pad\'e approximant. One is to directly parameterize the luminosity distance based on the Pad\'e approximant, while the other is to generalize cosmography with respect to a so-called $y_\beta$-shift $y_\beta=z/(1+\beta z)$, which is also inspired by the Pad\'e approximant. Then, we confront them with the observational data with the help of the Markov chain Monte Carlo (MCMC) code emcee, and find that they work fairly well.Comment: 16 pages, 3 tables, 5 figures, revtex4; v2: discussions added, Eur. Phys. J. C in press; v3: published versio

A Parametric Sharpe Ratio Optimization Approach for Fuzzy Portfolio Selection Problem

When facing to make a portfolio decision, investors may care more about every portfolio’s performance on a return and risk trade-off. In this paper, a new low partial moment measurement that only punishes the loss risk is defined for selection variables based on L-S integral. Furthermore, a new performance measure for portfolio evaluation is proposed to generalize the Sharpe ratio in the fuzzy context. With the optimal performance criterion, a new parametric Sharpe ratio portfolio optimization model is developed wherein uncertain returns are presented as parametric interval-valued fuzzy variables. To make the proposed model easy to solve, we transform the fractional programming into an equivalent form and solve it with domain decomposition method (DDM). Finally, we apply the proposed performance measure into a portfolio selection problem, compare the computational results in different cases, and analyze the influence of different parameters on the optimal portfolio

糖尿病培训手册在培养糖尿病护士的应用

Objective: To explore the nursing service mode for specialized nurses in diabetes and its application effect. Methods:In view of the actual situation of our hospital, a special training manual named with Diabetes training manual was prior composed. 40 specialized nurses in diabetes were trained with the special training manual. Training lasted for 3 months. After the training, the specialized nurses were assessed with the specialty knowledge of Diabetes Mellitus, the skill of clinical procedures, and the knowledge about patients' health education. Results: The skill of the trained nurses was improved. The satisfaction of patients was enhanced.Conclusion: Diabetes training manual can be used for specialized nurses in diabetes.目的  探讨糖尿病护士培训方式。方法  对2013年1—10月本院内分泌科的40名糖尿病护士培训,根据以往医院的培训，结合本院实际，应用自编的糖尿病培训手册，最后考核糖尿病专科理论、操作及宣教能力考核，培训时间为3个月。结果  培训前与培训后比较差别有统计学意义（P＜0.05），理论、操作及健康宣教能力较培训前提高；提高了患者及新护士的满意度。结论  糖尿病培训手册可以用于培养糖尿病新护士