Optimal control strategies for dividend payments and capital injections in compound Markov binomial risk model with penalties for deficits

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.     

空间批评视角下的《生日》

从空间批评视角看,文本中的空间不再是静止的＂容器＂,而是一种蕴含多维文化信息的指涉系统,注重文本中空间的社会、文化属性。在美国华裔作家雷祖威的短篇小说《生日》中,与华裔青年华莱士·王的爱情故事相关的几个空间场景不仅再现了华裔的现实生活世界,更充分展示了他们居于社会边缘的处境与内心疏离的痛苦。     

College students with congenital heart disease: A critical time for transition

As medical and surgical advances improve, more young adults with congenital heart disease (CHD) are attending college. This case study illustrates some of the issues that these young adults may face as they attend college and discusses the role that college health practitioners can play in easing that transition. Participants: A case of a male with CHD presenting to the college health clinic with a new onset headache. Methods: The authors discuss some of the unique challenges that college health practitioners may face when caring for students with CHD. In addition, they make recommendations on how best to care for these patients and how best to coordinate care with CHD students other care providers. Results: This student with a history of coarctation of the aorta presented with new onset headaches and was found to have high blood pressure. He was diagnosed with recurrent coarctation, underwent percutaneous treatment with stenting and quickly resumed classes. Conclusions: As more students with CHD enter college, college health providers will need to understand some of the health risks that CHD students face. In addition, understanding some of the optimal ways to coordinate care with CHD providers can ease the transition that CHD students face as they enter college.     

Contents of heavy metals in arable soils and birth defect risks in Shanxi, China: a small area level geographic study

The burgeoning demands of China’s urbanization and industrial development put pressure on the resources of the entire country and have direct and indirect effects on the health of individuals, at times in areas far removed from cities themselves. Current evidence suggests that heavy metal pollution in soil, a common by-product of coal mining and other industrial activities, may be linked to risk of birth defects. We examine this hypothesis using small area level data including soil samples and detailed birth records from 2002 to 2004 from 97 villages in Shanxi province, a heavy coal-mining region. We find that soils containing arsenic, lead, and nickel are significantly correlated with the incidence of birth defects. In particular, we find a strong positive dose-dependent association of birth defects with lead, a moderate positive effect with arsenic, and a dose-dependent negative association with nickel. These results are consistent with the postulated link between arsenic and lead and human birth defects, but raise questions about the effects of nickel in this context. China’s rapid urbanization underscores the need for closer attention to the relationship between the health and the environment.     

试论藏传佛教微型雕塑"嚓嚓"在藏区的传入与发展

藏传佛教微型雕塑“嚓嚓”原为古印度佛教艺术品,在佛教传入藏区的过程中,以其直观、真实的形象冲破语言、文字障碍,对佛教教义的传播起到了至关重要的作用,并在整个藏区使其类型和内容不断得以延续和扩充,丰富了藏区佛教艺术的表现手法和形式。     

关于族群关系、民族关系与社会关系的关系

"族群"与"民族"概念上存在着交叉关联.族群关系、民族关系都是一种社会关系,但社会关系不一定都构成民族关系,民族关系有时也不一定能够准确地表述特殊的社会关系,族群关系却可以化解民族关系表述的"潜在危机".族群关系、民族关系与社会关系的关系具有多向性、非对称性和动态性的特点.     

浅谈维吾尔爱情叙事诗中"殉情母题"及其文化内涵--以尼扎里爱情叙事诗为例

"殉情"是古今中外文学中一个重要的叙事母题,它触及人类共同遭到的悲惨命运与人类的集体心理深层.在世界各民族文学中,无论作家文学还是民间文学,都存在殉情故事.维吾尔社会中,曾在封建婚姻制度与伊斯兰教道德教义的残酷迫害之下,无数个青年男女走投无路,走上自尽殉情的道路.80年代,由于父母包办婚姻的原因,维吾尔社会中酿成了一些青年男女自杀殉情的悲剧.     

藏汉拟声词之异同比较

拟声词作为一种重要的修辞手段和构词法,在藏、汉修辞学和构词法中占有重要地位。文章通过对藏、汉学者们一直以来对拟声词的指称和归属问题的不同介定进行的总结和评析,以及对藏、汉拟声词使用上的异同和藏、汉拟声词汇的一般对照情况进行的分析,从修辞学、语言学和心理学的角度剖析和落实了藏、汉拟声词的语言属性,并且探讨和归纳出了藏语拟声词的组词规律。     

维吾尔族Yat巫祝的观念初探

Yat巫祝即扎达巫祝,我国北方阿尔泰语系民族之中流传比较典型的民俗习俗之一。其中维吾尔族的Yat巫祝的历史悠久,影响很深,保存了独特的特征。     

有机硼交联HPG压裂液超低温破胶剂室内研究

对埋藏浅,油层温度低的油藏进行压裂改造,需解决压裂液低温破胶水化的问题。采用活化剂来提高过硫酸铵(APS),酶,胶囊破胶剂的低温破胶能力。通过对有机硼交联的羟丙基瓜胶(HPG)压裂液低温下破胶后粘度损失率的测定,筛选出用于50℃下的APS/活化剂破胶系统及胶囊破胶剂。结果表明:在APS/活化剂破胶系统的作用下,采用有机硼作交联剂的HPG压裂液在较低温度条件下能彻底破胶水化。