A hybrid ARIMA and support vector machines model in stock price forecasting

Traditionally, the autoregressive integrated moving average (ARIMA) model has been one of the most widely used linear models in time series forecasting. However, the ARIMA model cannot easily capture the nonlinear patterns. Support vector machines (SVMs), a novel neural network technique, have been successfully applied in solving nonlinear regression estimation problems. Therefore, this investigation proposes a hybrid methodology that exploits the unique strength of the ARIMA model and the SVMs model in forecasting stock prices problems. Real data sets of stock prices were used to examine the forecasting accuracy of the proposed model. The results of computational tests are very promising.     

同种商品不同月份期货组合风险评价模型研究及应用

以期货合约的每一交易日的对数涨跌率来反映市场风险,借助VaR风险价值法,运用加权核估计技术(WKDE)和指数加权滑动模型(EWMA),建立了基于期货组合中持有头寸不同且可以进行风险对冲的期货组合市场风险非线性叠加评价模型,解决了同种商品、不同月份期货组合每一交易日最大损失的确定问题,并通过实证研究验证了模型的实用性.该模型的特点一是借助WKDE法预测组合中单个合约每一交易日涨跌率最大日亏损值,充分体现了期货合约涨跌率的实际走势,使VaR估计更加精确.二是通过动态迁移相关系数矩阵的计算保证了模型的精确性.采用EWMA模型预测动态变化的方差-协方差矩阵,从实证的角度得到更精准的动态迁移相关系数矩阵.三是考虑了组合中多头和空头不同头寸之间的风险对冲,避免了实际中期货组合风险的线性相加而造成放大风险或减少风险的不准确性,从而能较好地保证了模型的预测精度及准确性.四是通过基于风险非线性叠加建立的期货组合风险评价模型解决了SPAN系统中期货组合风险的线性叠加问题,从而得到更合理的组合风险预测值.     

Openness in adoption: Challenging the narrative of historical progress

One significant change in adoption practice that has occurred over the last four decades is the shift away from an expectation of confidentiality towards an expectation of openness in adoption. Openness is typically conceived in terms of the level of contact between adoptive and birth families following adoption or the extent to which adoption is openly discussed within the adoptive family. While these shifts in practice have generated controversy, they are largely supported by research evidence and have become a feature of contemporary adoptive family life. As a result, the narrative that has emerged in relation to openness in adoption is one of historical progress. In this paper, I argue that the lived reality of adoption is less straightforward than this narrative suggests. An analysis of the social and cultural context in which adoption operates suggests instead that the persistent feature of adoption throughout this historical period of increasing openness can be more accurately described as a state of enduring ambiguity regarding the nature of post‐adoption relationships. The paper highlights the potentially damaging consequences of overlooking this aspect of adoptive family life and comments on the role of policy in shaping openness in adoption.     

Gender‐Sensitive Research in a Chinese Community

The aim of this article is to foster an awareness of the need for gender‐sensitive research in the context of the methodological and ethical challenges posed by such research. We trace the development of gender sensitivity and masculinity in social work practice and research and connect this to an overview of the issues posed by research on sensitive topics. Reflecting on a research project involving Chinese male sexual abuse survivors, we draw conclusions illustrating and proposing a range of methodological practices and ethical safeguards. We underscore the importance of gender‐sensitivity in performing research on sensitive topics with men in a Chinese community.     

Tolerance of Uncertainty: Links to Happenstance,Career Decision Self‐Efficacy,and Career Satisfaction

This study investigated the extent to which tolerance of uncertainty affects the relationship between happenstance skills and career satisfaction via career decision self‐efficacy. Moderated mediation analysis was conducted on data collected from 321 graduates (175 men, 146 women) of Korean universities making the school‐to‐work transition. Results showed that career decision self‐efficacy fully mediated the relationship between happenstance skills and career satisfaction. Furthermore, the moderation effect of tolerance of uncertainty had a significant impact on the relationship between happenstance skills and career decision self‐efficacy. Tolerance of uncertainty should be considered an important variable in happenstance career theory and intervention. Unplanned influences should also be considered important factors in the career decision‐making process.     

Trust and health in Eastern Europe: Conceptions of a new society

Little attention has been paid to why trends and levels of mortality and morbidity differ in Eastern Europe and few studies have addressed people's own perceptions of their new political system – perceptions which per se may be important for social development. The aim of the present study was to analyse the extent to which trust and economic circumstances affect self‐rated health in Poland, Estonia and Russia and how much health differences between the countries can be explained by these factors. A better economy and higher trust were related to better individual health, while economic factors seemed most important for inter‐country differences. It is probable that both institutional factors and individual perceptions contribute to people's well‐being, but in terms of social policy, an improved welfare system may be the most effective way forward.     

RESEARCHING RELATIONSHIPS FROM AN ATTACHMENT PERSPECTIVE: THE USE OF BEHAVIOURAL,INTERVIEW, SELF‐REPORT AND PROJECTIVE MEASURES

Having demonstrated its credentials as one of the more elegant and robust conceptualisations of human relationships, attachment theory has considerable relevance to social work. Attachment‐based research has flourished over the past few years and it now includes an impressive array of studies across the lifespan. This article considers four different measures used in attachment‐based research, although more discussion is devoted to interview and projective measures because they specifically embrace a psychodynamic approach in their design and analytic focus. The aim of the article is to provide a brief overview of each measure and to offer some illustrative examples using practice‐related material.     

Attenuating Initial Beliefs: Increasing the Acceptance of Anthropogenic Climate Change Information by Reflecting on Values

Anthropogenic climate change information tends to be interpreted against the backdrop of initial environmental beliefs, which can lead to some people being resistant toward the information. In this article (N = 88), we examined whether self‐affirmation via reflection on personally important values could attenuate the impact of initial beliefs on the acceptance of anthropogenic climate change evidence. Our findings showed that initial beliefs about the human impact on ecological stability influenced the acceptance of information only among nonaffirmed participants. Self‐affirmed participants who were initially resistant toward the information showed stronger beliefs in the existence of climate change risks and greater acknowledgment that individual efficacy has a role to play in reducing climate change risks than did their nonaffirmed counterparts.     

Building a partnership for social service delivery in Indonesia: state and faith‐based organisations

Contrary to the secularisation processes in modernisation theory, religions and faith‐based organisations (FBOs) are thriving in contemporary Indonesia. Strongly supported by community members, religious organisations have begun to extend their services beyond the traditional areas of education and health to operate in disaster relief and poverty alleviation programmes. These FBOs have been offering assistance to the disadvantaged whose needs have not been adequately met by the state. Social programmes run by the FBOs are an important safety net at the grass‐roots level in Indonesia; how to effectively coordinate and offer such services are important social policy issues. This paper will show that the Indonesian Government is keen to remain the key provider of social services and often perceives the services of FBOs as a threat. Some recent state policies to regulate the funding sources of Islamic organisations have posed a significant logistical challenge for their future operation. In addition, theological differences across various religious groups have made it difficult to form inclusive and extensive partnerships among the FBOs, who tend to compete with each another resulting in rivalry. These socio‐political contexts have limited the formation of effective partnerships for offering coordinated social services.