Dynamic reliability models with conditional proportional hazards

A dynamic approach to the stochastic modelling of reliability systems is further explored. This modelling approach is particularly appropriate for load-sharing, software reliability, and multivariate failure-time models, where component failure characteristics are affected by their degree of use, amount of load, or extent of stresses experienced. This approach incorporates the intuitive notion that when a set of components in a coherent system fail at a certain time, there is a jump from one structure function to another which governs the residual lifetimes of the remaining functioning components, and since the component lifetimes are intrinsically affected by the structure function which they constitute, then at such a failure time there should also be a jump in the stochastic structure of the lifetimes of the remaining components. For such dynamically-modelled systems, the stochastic characteristics of their jump times are studied. These properties of the jump times allow us to obtain the properties of the lifetime of the system. In particular, for a Markov dynamic model, specific expressions for the exact distribution functions of the jump times are obtained for a general coherent system, a parallel system, and a series-parallel system. We derive a new family of distribution functions which describes the distributions of the jump times for a dynamically-modelled system.     

卫星光通信中平台抖动补偿技术研究

以卫星光通信系统为例,对空间光通信系统中光学平台的抖动进行了分析。研究了一种自调节前馈补偿技术,通过自适应信号处理或对前馈控制器进行直接优化,可对光学平台的抖动进行有效抑制。     

空间光通信ATP技术及其进展

对自由空间激光通信光束自动捕获、跟踪、瞄准（ＡＴＰ）系统的结构与系统主要技术指标进行了分析和讨论。通过对其中典型系统的介绍,进一步描述了ＡＴＰ技术的最新进展,论证了空间激光通信的可行性。     

Self‐Construal,Career Decision Self‐Efficacy,and Perceived Barriers Predict Mexican American Women's Life Satisfaction

This study used the social cognitive theory of well‐being (SCTW; Lent, 2004 ) to examine the role of career decision self‐efficacy (CDSE), perceived educational barriers, and independent self‐construal on the life satisfaction of 176 Mexican American college women. A 3‐step hierarchical regression analysis indicated that independent self‐construal, CDSE, and fewer perceived educational barriers significantly predicted greater life satisfaction among Mexican American college women above and beyond the influence of socioeconomic status and generational status. These findings are consistent with SCTW and highlight the need for counselors and researchers to be aware of the role that self‐construal, CDSE, and perceived educational barriers can have on Mexican American women's life satisfaction. Implications for practice at the secondary‐school and university levels are discussed.     

Utilization of Mixed Distributions in the Calculation of Polarization: The Case of Spain

Social Indicators Research - This study analyzes the evolution of salary polarization in the Spanish labor market. The paper proposes the use of mixed distributions to examine the consequences of...     

Social Entrepreneur: Same or Different from the Rest?

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - A social business responds to social problems usually ignored by institutions, mobilizing resources and generating...     

Assessing the relevance of higher education courses

The establishment of the European Higher Education Area has involved specifying lists of professional competencies that programs are expected to develop, and with this the need for procedures to measure how every course within a higher education program is aligned with the program's competencies. We propose an instrument for characterizing this alignment, a process that we call assessing the relevance of a course. Using information from the course syllabus (objectives, contents and assessment scheme), our instrument produces indicators for characterizing the syllabus in terms of a competence list and for assessing its coherence. Because assessment involves quality, the results obtained can also be used to revise and improve the course syllabus. We illustrate this process with an example of a methods course from a mathematics teacher education program at a Spanish university.     

Gay, lesbian, bisexual and transgendered (GLBT) experiences with Earth-spirited faith

Earth-spirited faiths (e.g., Pagan and Wiccan spiritualities) have been described as more affirmative toward gay, lesbian, bisexual, and transgendered (GLBT) members than mainstream Judeo-Christian faiths, but no research has explored Earth-spirited faiths' GLBT-affirming behaviors. This study investigated those behaviors as well as the faith experiences of GLBT Earth-spirited individuals. At time of coming out, participants who were affiliated with mainstream Judeo-Christian faiths reported greater faith conflict than those affiliated with Earth-spirited faiths; however, there were no differences in resolution of the conflict between the two groups, internalized homonegativity, or self-acceptance. In addition, Earth-spirited faiths engaged in many GLBT-affirming behaviors.     

Choice Functions: Rationality re-Examined

On analyzing the problem that arises whenever the set of maximal elements is large, and a selection is then required (see Peris & Subiza 1998), we realize that logical ways of selecting among maximals violate the classical notion and axioms of rationality. We arrive at the same conclusion if we analyze solutions to the problem of choosing from a tournament (where maximal elements do not necessarily exist). So, in our opinion the notion of rationality must be discussed, not only in the traditional sense of external conditions (Sen 1993), but in terms of the internal information provided by the binary relation.