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191.
In this article, we calibrate the Vasicek interest rate model under the risk neutral measure by learning the model parameters using Gaussian processes for machine learning regression. The calibration is done by maximizing the likelihood of zero coupon bond log prices, using mean and covariance functions computed analytically, as well as likelihood derivatives with respect to the parameters. The maximization method used is the conjugate gradients. The only prices needed for calibration are zero coupon bond prices and the parameters are directly obtained in the arbitrage free risk neutral measure.  相似文献   
192.
One-sided confidence regions for continuous cumulative distribution function are constructed using empirical cumulative distribution functions and the generalized Kolmogorov-Smirnov distance. The band width of such regions becomes narrower in the right or left tail of the distribution. Significance levels necessary for implementation are given. Some other K-S type distances useful in constructing a confidence region with nonconstant width are also included.  相似文献   
193.
We consider the compound Markov binomial risk model. The company controls the amount of dividends paid to the shareholders as well as the capital injections in order to maximize the cumulative expected discounted dividends minus the discounted capital injections and the discounted penalties for deficits prior to ruin. We show that the optimal value function is the unique solution of an HJB equation, and the optimal control strategy is a two-barriers strategy given the current state of the Markov chain. We obtain some properties of the optimal strategy and the optimal condition for ruining the company. We offer a high-efficiency algorithm for obtaining the optimal strategy and the optimal value function. In addition, we also discuss the optimal control problem under a restriction of bounded dividend rates. Numerical results are provided to illustrate the algorithm and the impact of the penalties.  相似文献   
194.
The transition from primary to secondary school challenges children's psychological well‐being. A cross‐transitional longitudinal study (N = 306; mean age = 12.2 years) examined why some children's self‐esteem decreases across the transition whereas other children's self‐esteem does not. Children's expected social acceptance in secondary school was measured before the transition; their actually perceived social acceptance was measured after the transition. Self‐esteem and Big Five personality traits were measured both pre‐ and posttransition. Self‐esteem changed as a function of the discrepancy between children's expected and actually perceived social acceptance. Furthermore, neuroticism magnified self‐esteem decreases when children's ‘hopes were dashed'—when they experienced disappointing levels of social acceptance. These findings provide longitudinal support for sociometer theory across the critical transition to secondary school.  相似文献   
195.
陈丛兰 《唐都学刊》2012,28(4):23-27
《贞观政要》继承和发展了儒学政治哲学的人性理论。其官德保障机制体现在内修与外治两个方面,一则从非制度的内在层面强调官吏通过思、慎和学的途径修身养德,二则从制度的外在层面加强旨在预防、考课与奖惩官员的吏治建设。体现自律与他律、儒学政治哲学与法家政治理念的统一,完善了中国传统政治外儒内法的基本模式。  相似文献   
196.
This paper addresses gender differences in the social capital of entrepreneurs in a developing country. Social networks are often an important asset for accessing resources; however, they may also be a liability in developing countries, since entrepreneurs are often expected to support their contacts. Using a recent survey among urban and rural Ugandan entrepreneurs, we focus on the financial resources that entrepreneurs can obtain from their contacts on the one hand, and requests for financial support made to the entrepreneurs from these contacts on the other hand. Our results show that there are gender differences associated with access to, and requests for, financial resources.  相似文献   
197.
在博士论文中,马克思确立了自我意识哲学的主体地位。表面看是在阐释伊壁鸠鲁哲学,实际上"已经显示出了马克思的创造的智慧"。在他的理论视域内,自我意识是一个伦理原则,有着丰富的伦理内涵,展现了其在走向社会批判以前"伦理批判"的思想特质。  相似文献   
198.
本文从语言学、教育学、心理学、英语教学法及英语教学实践等的角度 ,多方阐述了专科英语教学中口语训练的重要性 ,并论证了专科英语应用能力测试中增加口试的必要性  相似文献   
199.
高中数学有效教学的涵义即在数学课程标准基本理念的指导下,促进学生数学学习、提高学生数学素养、促成学生终身发展.高中数学有效教学的主要特征是教学目标有效、教学过程有效、教学方式有效、教学结果有效。主要实施策略是,以引导探究为依托,实现有效的知识建构;以暴露思维作平台,实现有效的思维训练;以激发兴趣作前提,实现有效的情意驱动.  相似文献   
200.
ABSTRACT

African American adolescents continue to be disproportionately impacted by HIV, sexually transmitted infections (STIs), and unanticipated pregnancies. In-depth, face-to-face interviews among a convenience sample of 32 African American adolescents (16 male and 16 female) were used to explore the reasons why some adolescents decided to engage in sex while others chose to delay sexual debut. Data were analyzed using a thematic analysis. Among the overall sample, psychological motivations, external pressure, physical pleasure seeking, and relationship-related motivations were the major themes cited for engaging in sex by participants and their friends. External support, motivation to avoid negative consequences, not feeling ready or lacking interest in sex, and having negative views about sex were among the major reasons for delaying sex. Several of the emergent themes showed gender differences. Suggestions for future research include the need for sexual education, and STI/HIV prevention programs that are gender sensitive and flexible enough to accommodate multiple factors related to sexual debut.  相似文献   
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