C2C市场上消费者从众决策研究——基于面板数据模型

电子商务市场蓬勃发展的同时,也存在严重的信息不对称现象,给消费者带来极大的购物风险。文章基于信息不对称理论,利用淘宝网交易数据对 C2C 市场上消费者的从众决策行为进行研究。研究发现 C2C 市场上店铺的日销量在店铺间存在二八分布的特征,说明网络消费者在购买商品时有从众行为。基于面板模型对店铺市场份额的研究表明,店铺历史销量信息对消费者选择店铺的决策有显著正向影响,而店铺信用对消费者决策的影响并不显著。因此,建议 C2C 交易平台增加退货量指标、动态销量图以及销量和价格的相互对应信息等,以促进消费者理性购物。     

A powerful and efficient algorithm for breaking the links between aliased effects in asymmetric designs

Fractional factorial (FF) designs are no doubt the most widely used designs in experimental investigations due to their efficient use of experimental runs. One price we pay for using FF designs is, clearly, our inability to obtain estimates of some important effects (main effects or second order interactions) that are separate from estimates of other effects (usually higher order interactions). When the estimate of an effect also includes the influence of one or more other effects the effects are said to be aliased. Folding over an FF design is a method for breaking the links between aliased effects in a design. The question is, how do we define the foldover structure for asymmetric FF designs, whether regular or nonregular? How do we choose the optimal foldover plan? How do we use optimal foldover plans to construct combined designs which have better capability of estimating lower order effects? The main objective of the present paper is to provide answers to these questions. Using the new results in this paper as benchmarks, we can implement a powerful and efficient algorithm for finding optimal foldover plans which can be used to break links between aliased effects.     

Personality profiles of factitious disorder imposed by mothers: A comparative analysis

Factitious Disorder Imposed by Another (FDIA) can be difficult to expeditiously identify. Understanding personality characteristics of FDIA perpetrators via psychological assessment may decrease the time between initial abuse and identification of FDIA. Personality characteristics of FDIA mother-perpetrators were examined through a comparative analysis of MMPI-2 profiles. It was predicted that mother-perpetrators would have significantly higher overall profile elevations on the MMPI-2 and elevations on specific clinical scales than a comparative control group. Results indicated that mother-perpetrators displayed significantly higher, elevations on the Psychasthenia (Pt) and Schizophrenia (Sc) scales and a trend toward significantly higher elevation on the Psychopathic Deviate (Pd) scale than the control group. These findings, along with the demographic information obtained, establish a preliminary foundation for understanding an overall profile of mother-perpetrators.     

Bootstrap methods for multivariate hypothesis testing

The nonparametric and parametric bootstrap methods for multivariate hypothesis testing are developed. They are used to approximate the null distribution of the test statistics proposed by Duchesne and Francq (2015 Duchesne, P., Francq, C. (2015). Multivariate hypothesis testing using generalized and {2}-inverses—with applications. Statistics 49:475–496.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]), resulting in bootstrap testing procedures. In the problem of testing for the mean vector of a multivariate distribution, the asymptotic validity of the bootstrap methods is proved. The finite sample performance of the new solutions is demonstrated by means of Monte Carlo simulation studies. They indicate that for small-sample size, the bootstrap tests provide a better finite sample properties than the asymptotic tests considered by Duchesne and Francq (2015 Duchesne, P., Francq, C. (2015). Multivariate hypothesis testing using generalized and {2}-inverses—with applications. Statistics 49:475–496.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]).     

Convergence rate of wavelet density estimator with data missing randomly when covariables are present

In this article, we study global L₂ error of non linear wavelet estimator of density in the Besov space B^s_pq for missing data model when covariables are present and prove that the estimator can achieve the optimal rate of convergence, which is similar to the result studied by Donoho et al. (1996) Donoho, D.L., Johnstone, I.M., Kerkyacharian, G., Picard, D. (1996). Density estimation by wavelet thresholding. Ann. Stat. 24:508–539.[Crossref], [Web of Science ®] , [Google Scholar] in complete independent data case with term-by-term thresholding of the empirical wavelet coefficients. Finite-sample behavior of the proposed estimator is explored via simulations.     

盐化产业发展低碳经济的机制研究——以自贡市为例

盐化产业作为高能耗、高污染和高排放的行业,面临巨大的节能减排压力;发展低碳经济已经成为盐化产业可持续发展的首要任务。对低碳发展的机制进行评述,分析自贡市盐化产业碳排放的现状,提出政府需要构建发展低碳经济的引导机制、驱动机制、规制机制和补偿机制,分析碳交易市场构建需要建立的定价机制、交易机制和产权机制,阐述行业部门可以构建的锦标机制、集群机制、认证机制和协调机制,而企业则必须完善激励机制、创新机制和协作机制;并就自贡市盐化产业在政府、市场、行业和企业四个维度下发展低碳经济的十四种机制进行具体分析。     

上海生态文明建设的激励和约束机制研究

生态文明建设是一项系统工程,需要通过整体推进,构筑规划、建设、管理、技术、产业、社会和合作协同发展的综合体系。未来上海应以建立和完善市场机制为核心,以法律机制为前提,以政府监管机制为保障,以能力建设机制为基础,以社会参与机制为监督,按照"引逼结合、多方合力、突出重点、先行先试"的原则,加快上海生态文明建设机制创新。主要途径有:完善碳排放交易试点,建立长效市场机制;推进分布式能源应用,提高清洁能源比重;加快新能源汽车推广,优化交通能源结构;培育发展再制造产业,推广先进制造理念。     

Diabetes education program for people with type 2 diabetes: An international perspective

BackgroundIn the Palestinian community, lifestyle changes, rapid urbanization and socioeconomic development, stress, smoking, and changes in food habits has increased the risk of non-communicable diseases especially diabetes mellitus. Diabetes complications can be prevented if the glycemic status of patients with diabetes is maintained within a nearly normal range. Therefore, patient education is critical in controlling blood glucose levels within the normal range.ObjectiveThis study aimed at measuring the effect of diabetes educational intervention program for patients suffering from type 2 diabetes attending the Diabetes Clinic in Tulkarim Directorate of Health.MethodsA short duration observational study involving pre- and post-test educational intervention program was carried out on a relatively small number of type 2 diabetes patients at the Diabetes Clinic in Tulkarim Directorate of Health. In total, 215 patients attended a group-based 4 h educational intervention session about diabetes. The program included explaining diabetes mellitus-symptoms, risk factors, types, treatment and complications and main aspects of self-care of the disease (foot care, eye care, and blood glucose monitoring), main aspects of dietary management, weight reduction, blood pressure, smoking cessation, periodic investigations, home monitoring and importance of physical activity. Knowledge evaluation questionnaire were evaluated pre- and post-study. Anthropometric measurements such as body weight (WT), body mass index (BMI) and laboratory tests such as fasting blood glucose (FBG), hemoglobin A1C (HbA1c), cholesterol (Chol), and triglycerides (TG) were measured both at the beginning and at the end of the study. Significance of the results was assessed by paired t-test at 95% confidence interval.ResultsThe participant’s mean age was 51.07 that ranged between 31 and 70 years. For a total of 215 participants, 41.4% were males and 58.6% were females. The mean weight before educational intervention was 80.81 ± 14.95 kg (82.6 kg for males and 79.5 kg for females) that decreased to 78.9 ± 14.33 kg (81.1 kg for males and 77.3 kg for females) after educational intervention program. The BMI also decreased significantly after educational intervention. The mean fasting blood sugar was 188.65 ± 71.45 mg/dL before educational intervention that decreased to 177.7 ± 66.11 mg/dL after the educational intervention (p = 0.049). The mean glycosylated hemoglobin was 8.57 ± 1.21 before educational intervention that decreased to 7.95 ± 1.42 after educational intervention. The mean value of cholesterol before educational intervention was 183.27 ± 37.74 mg/dL that decreased to 169.57 ± 34.23 mg/dL after educational intervention. The mean triglycerides value decreased after educational intervention from 209.85 ± 171.04 mg/dL to 183.28 ± 152.4 mg/dL (p = 0.025). The mean score of knowledge questionnaire before educational intervention was 60.6 ± 20.65 that increased to 78.1 ± 13.4 after conducting educational intervention.ConclusionsDiabetes education was found to be effective on BMI, FBG, HbA1c, Chol, TG, and knowledge.RecommendationsDiabetes education is a cornerstone in the management and care of diabetes and should be an integral part of health planning involving patient’s family, diabetes care team, community, and decision makers in the education process.     

气候变化背景下中国低碳制造发展研究

制造业是我国经济发展的重要支柱,也是实现低碳减排的主要战场。建立低碳制造评价指标体系,结合主成分分析法和层次分析法,可对我国制造业的低碳发展进行定量的研究评价,并从制造业低碳经济、低碳技术和低碳环境三方面分析对碳排放的影响。我国的低碳制造水平整体呈上升趋势,未来,我国的制造业既要保持高速发展,同时也要向低碳经济转型,发展低碳技术,调整能源结构。