Exploring the relation between maternal mind‐mindedness and children’s symbolic play: A longitudinal study from 6 to 18 months

Relations between mothers’ mind‐mindedness (appropriate attunement to their infants’ internal states) at 6 and 12 months and infants’ early symbolic play during infant–mother pretense at 12 and 18 months were investigated in a sample of 43 mothers and infants. Mothers’ appropriate mind‐related comments were associated with average level, length, complexity, and maturity level of symbolic play. Specific sub‐categories of appropriate mind‐related comments were identified as independent predictors of children's symbolic play. Appropriate comments about desires and cognitions at 6 months were associated with average level and length of episodes, as well as with maturity level of symbolic play at 12 months. Longitudinal stability in the appropriateness and content of mothers’ mind‐related comments was also investigated. The results are discussed in terms of the proposal that attunement to specific types of internal state should vary as a function of infant age in order to index mind‐mindedness.     

基于次梯度投影的泛投资组合选择策略

在线投资组合选择(online portfolio selection)问题是当前量化投资领域一个重要的研究问题.近些年来,可投资标的的爆炸式增长急需能够有效计算的投资组合选择策略,而现有高绩效算法大多具有指数级或多项式级的时间复杂度,不利于在实际中应用.由此,本文提出了一种基于次梯度投影的泛投资组合选择策略SGP.将次梯度投影的思想应用到资产组合构建的过程中,得到策略的再平衡规则.理论上,本文分析了次梯度投影算法的竞争性能,证明了该策略是一个泛投资组合选择策略;并发现该算法具有线性时间复杂度.实证上,验证了SGP策略在美国与中国市场的表现.结果表明,SGP策略能够实现和最新的泛投资组合选择策略相当的收益率,而算法运行时间短于现有策略.参数敏感性分析表明SGP策略对参数选择不敏感;交易成本敏感性分析表明SGP策略能够承受合理的交易成本.     

文学史论楚辞兴起因缘之回顾探讨

今日台湾常见之九种中国文学史著作,在分析、探讨楚辞兴起之因缘时,有七种忽略了屈原对于“楚辞体”创造之重要地位,有一种对此论及之比重较少,只有王忠林等编写的《增订中国文学史初稿》对此论述得最为扼要、全面。结合当代楚辞研究的相关成果,反恩文学史针对此一议题之处理,有两点不容忽视：其一为楚辞名义问题,牵涉到作者采用的是广义或狭义的定义;其二为“南北之辨”,则是如何看待楚辞与南、北文化之间的渊源。     

高师院校不同学制毕业生就业竞争力比较研究

毕业生就业竞争力是衡量人才培养质量的一个重要指标,加强对不同学制毕业生就业竞争力研究,有利于提升办学质量。对不同学制毕业生的就业竞争力分析可从初次就业率、就业现状满意度、毕业半年后的月收入、工作与专业相关度、职业吻合度和半年内的离职率等方面进行比较。利用非参数检验法对某高师院校毕业生就业状况调查报告中的有关数据对比分析,发现五年制专科毕业生的就业竞争力与三年制专科毕业生无显著性差别。结果表明:五年制专科毕业生具有明确的专业定位、专业技能较强等优势,可适当扩大五年制专科招生规模。     

Is Household Wealth Sustainable? An Examination of Asset Poverty Reentry After an Exit

This paper analyzed the influence of financial behaviors on the duration out of asset poverty while controlling for households’ life cycle and demographic characteristics. We found evidence for the existence of structural barriers to asset acquisition. Asset accumulation at or above levels equal to nine-months worth of income at the income-poverty level was important for improving a household’s odds of permanently escaping asset poverty, but a linear relationship between asset accumulation and the likelihood of returning to asset poverty did not emerge. Moreover, minimizing debt and diversifying the asset portfolio to include more productive assets were positively related to maintaining assets; but households should also consider the risks associated with portfolio allocations.     

… Do as the Romans do. A model of conformity with the endogenous formation of preferences

This note is an answer to a previous model on conformity in public goods contributions developed by Carpenter (2004), where a population evolution is allowed according to the standard replicator dynamic (Taylor and Jonker, 1978, Maynard Smith, 1982). To confirm his theoretical prediction, Carpenter developed an experiment showing that free riding actually grows faster when agents have the information necessary to conform. The model and the experiment are, however, inherently different, for the time scales of the model are not able to capture the short run convergence of behavior in the experimental laboratory.We here present a model of conformity which offers the same laboratory results as Carpenter without resorting to evolutionary models, and also gives agents the chance to adopt different strategies implying various levels of cooperation.     

Designing from activities. The "ability /difficulty table", a useful tool to detect the "limit users" in the Design for All Approach

In the Design for All Approach (DfA), an important phase of the design process consists in the individuation of the so-called "limit users", that are that particular group of people with the most "critical" features for the autonomous fruition of a system or a product. Generally, however, it is not easy to identify them in a complete and objective way. A clear and complete outline of design requirements with respect to the "normal" use of a service, product or environment, moreover, is of fundamental importance in inclusive design. In fact, we know how bad design, that doesn't take in account the true "strategies of use", may lead to situations of handicap, also serious, temporary or permanent, regardless if the user is a "disabled" person or not. In relation to this scenario, the paper shows the results of a research which has developed the "Ability/Difficulty Table" ("A/D Table"), a new tool useful to identify the so-called "limit users" and their needs with respect to different activities, linking the main "difficulties", expressed by people, with the "abilities" required to carry out in autonomy the investigated activity.     

Usability in product design--the importance and need for systematic assessment models in product development--Usa-Design Model (U-D) ©

In product design, human factors are considered as an element of differentiation given that today's consumer demands are increasing. Safety, wellbeing, satisfaction, health, effectiveness, efficiency, and other aspects must be effectively incorporated into the product development process. This work proposes a usability assessment model that can be incorporated as an assessment tool. The methodological approach is settled in two stages. First a literature review focus specifically on usability and developing user-centred products. After this, a model of usability named Usa-Design (U-D?) is presented. Consisted of four phases: understanding the use context, pre-preliminary usability assessment (efficiency/effectiveness/satisfaction); assessment of usability principles and results, U-D? features are modular and flexible, allowing principles used in Phase 3 to be changed according to the needs and scenario of each situation. With qualitative/quantitative measurement scales of easy understanding and application, the model results are viable and applicable throughout all the product development process.     

M&A and diversification strategies: what effect on quality of inventive activity?

Journal of Management and Governance - The aim of this paper is to examine how an acquirer’s diversification strategy shapes the multiple dimensions of inventive activity. Differing from...