Drug resistance in an age-of-infection model

ABSTRACT

In the case of a disease spreading over a time-scale comparable to the average lifetime in a host population, when the infectiousness of individuals depends on the tine since the onset of infection and when infections involve both drug-sensitive and drug-resistant strains of a pathogen, resistance may develop during the treatment of drug-sensitive strains. If increasing the treatment rate reduces the reproduction number of the drug-sensitive strain to a value below the reproduction number of the drug-resistant strain, then the disease may persist at a boundary equilibrium where only drug-resistant infection is present.     

Local composite quantile regression estimation of time-varying parameter vector for multidimensional time-inhomogeneous diffusion models

This paper is dedicated to the study of the composite quantile regression (CQR) estimations of time-varying parameter vectors for multidimensional diffusion models. Based on the local linear fitting for parameter vectors, we propose the local linear CQR estimations of the drift parameter vectors, and verify their asymptotic biases, asymptotic variances and asymptotic normality. Moreover, we discuss the asymptotic relative efficiency (ARE) of the local linear CQR estimations with respect to the local linear least-squares estimations. We obtain that the local estimations that we proposed are much more efficient than the local linear least-squares estimations. Simulation studies are constructed to show the performance of the estimations proposed.     

网络语境下的大学生榜样教育研

互联网的广泛应用使大学生榜样教育在形式上和内容上都得到了丰富和深化，但仍然存在网络推广方式还不能适应大学生成长要求、传统榜样的影响正在弱化等问题。运用问卷调查法，分析了当前网络语境下大学生榜样教育的现状以及存在的问题，剖析了榜样教育弱化的原因，进而提出了适合网络语境下的大学生榜样教育路径。     

利用数学软件复原碎纸片的方法

研究了碎纸片的拼接复原问题,建立了合理有效的碎纸片拼接复原的数学模型；给出了数学软件实现自动拼接的具体算法；结合人工拼接得出复原图片；最后,对所给的拼接方法提出了改进方向.     

胡塞尔“构造”概念的三种图式

“构造”概念是胡塞尔现象学的核心概念，它被用来刻画意义如何向我们显现。索科拉夫斯基认为，胡塞尔分别在静态现象学和发生现象学阶段采取了“静态构造”的形式-质料图式和“发生构造”的一元论图式。笔者将指出，随着后期胡塞尔现象学的推进，构造的含义将更加复杂，它同时指示了自我在世界视域之中的横向结构，以及绝对时间意识支持着世界经验、并与其相互交织的纵向结构。笔者也将在此基础上，提出第三种构造图式。     

Control or Autonomy? A Case Study of two Organizational Forms in the Zhangjiakou Internal Migrant Organization

Control often weakens autonomy in organizational theories. While many scholars focus on the paradox of control and autonomy, few pay attention to how an organization obtains both control and autonomy. By exploring Zhangjiakou Internal Immigrant Organization, this study finds two mechanisms can contribute to the balanced combination of control and autonomy. First, managers play ambidextrous official-merchant roles, which means superiors take both bureaucratic and autonomous management styles. Second, members have dual organizational goals for both political status and network support. In conclusion, the successful combination is shaped by the subjective interaction between the government, superior managers and subordinate members.     

无人机军事化利用的国际法规制

无人机从20世纪初初具雏形到今天运用于许多领域,其军事化发展进程总体上看从未停止。国际法上虽然承认军事化无人机存在的合法性,但当它被用于诉诸战争权的行使时却依然存在争议,并且自主无人机需要国际人道法考量。军事化无人机必须在国际法框架下行使。在用于诉诸战争权时,应该谨慎解释"国家同意""国家同意的限制""必要性""相称性"等概念,并且严格区分普通无人机与自主无人机对国际人道主义法的挑战,让军事化无人机可以更加规范地被利用。     

论胡乔木的新体咏物诗

胡乔木的新体咏物诗不仅数量多，而且质量高，是其新体诗的精华所在，有其独特的艺术个性和鲜明的艺术特征，诸如由物起兴、物显人情；托物抒怀、物人一体；借物述理、生动形象等等，极具艺术魅力，为新体诗的发展作出了重要的艺术贡献。     

注蒸汽水平井井筒内参数计算新模型

注入蒸汽在水平井筒内流动时，蒸汽沿着水平段的质量流量越来越小，且加速度压降不等于零，导致蒸汽的物性参数发生变化，而蒸汽物性对井筒内蒸汽的沿程参数分布有较大影响。依据质量守恒和能量守恒，建立了注入蒸汽干度沿水平段的变化方程，利用动量守恒原理，推导了沿水平井筒的蒸汽干度分布和压力分布计算公式，构建了摩擦力做功、湿蒸汽混合物密度、水平段吸汽量和井筒与油层之间的热传递计算模型，模型同时考虑了变质量流与蒸汽PVT参数的变化对计算结果的影响，采用按压力增量迭代的计算方法对模型进行求解。实例的模型计算结果与油藏数值模拟结果对比表明，新模型具有较高的计算精度。