大功率回旋管双阳极电子枪计算机辅助设计

根据回旋管对电子枪的要求,采用综合法和分析法设计了该双阳极磁控注入电子枪。编制了一套大型的计算程序;利用计算机辅助设计,给出了电极形状、电子轨迹与电子注参量。计算表明,这种电子枪具有速度零散小、层流性好、体积小等特点。该电子枪更能适应大电流工作情况,已经用于制管实验中。由热测实验表明,它具有明显的优点。     

Venezuelan Rainfall Data Analysed by Using a Bayesian Space–time Model

We consider a set of data from 80 stations in the Venezuelan state of Guárico consisting of accumulated monthly rainfall in a time span of 16 years. The problem of modelling rainfall accumulated over fixed periods of time and recorded at meteorological stations at different sites is studied by using a model based on the assumption that the data follow a truncated and transformed multivariate normal distribution. The spatial correlation is modelled by using an exponentially decreasing correlation function and an interpolating surface for the means. Missing data and dry periods are handled within a Markov chain Monte Carlo framework using latent variables. We estimate the amount of rainfall as well as the probability of a dry period by using the predictive density of the data. We considered a model based on a full second-degree polynomial over the spatial co-ordinates as well as the first two Fourier harmonics to describe the variability during the year. Predictive inferences on the data show very realistic results, capturing the typical rainfall variability in time and space for that region. Important extensions of the model are also discussed.     

Effectiveness of the Coral Tree Family Service family inpatient unit: a longitudinal study exploring change in family functioning

Child mental health disorders represent a major burden to public health in Australia due to high prevalence rates, the widespread impact across domains, and the potential for difficulties to persist into adolescence and adulthood. Extensive evidence exists for the use of parent management training and cognitive behavioural therapy to treat difficulties experienced by children; however, a proportion of children do not benefit as expected from these treatments. The use of complementary therapeutic approaches and variations to the mode and intensity of existing intervention is warranted; family inpatient units represent a unique example of this. The aim of this study is to evaluate the effectiveness of a well-established Australian inpatient unit that admits the whole family, for children aged 12 years and younger referred with mental health, behavioural, or emotional difficulties. This study's longitudinal within-subject study design utilised routinely collected outcome data from the systemic clinical outcome and routine evaluation, 15 item (SCORE-15)—a valid and reliable measure of family functioning—from a sample of 980 participants attending the Family Residential Program. This study reported significant improvement in family functioning across all outcome variables between baseline and post-intervention, with no variables returning to pre-intervention levels at follow-up. Clinically significant changes in overall family functioning showed that 37% of participant scores moved from the clinical range at baseline to the nonclinical range post-intervention. This study represents the first empirical evaluation of the Family Residential Program, and the reported results provide compelling evidence for the program to effect improvement in family functioning for families with long-standing and severe difficulties. Poor rates of questionnaire completion following intervention frequent the literature base of family inpatient units, with low post-intervention (56%) and follow-up (12%) rates evident in this study. This study uniquely contributes to the growing evidence base of family inpatient units using rigorous evaluation methods.     

Knowledge extraction from a large on-line survey: a case study for a higher education corporate marketing

For a higher education public institution, young in relative terms, featuring local competition with another private and both long-established and reputed one, it is of great importance to become a reference university institution to be better known and felt with identification in the society it belongs to and ultimately to reach a good position within the European Higher Education Area. These considerations have made the university governors setting up the objective of achieving an adequate management of the university institutional brand focused on its logo and on image promotion, leading to the establishment of a university shop as it is considered a highly adequate instrument for such promotion. In this context, an on-line survey is launched on three different kinds of members of the institution, resulting in a large data sample. Different kinds of variables are analysed through appropriate exploratory multivariate techniques (symmetrical methods) and regression-related techniques (non-symmetrical methods). An advocacy for such combination is given as a conclusion. The application of statistical techniques of data and text mining provides us with empirical insights about the institution members’ perceptions and helps us to extract some facts valuable to establish policies that would improve the corporate identity and the success of the corporate shop.     

The exponentiated Fréchet regression: an alternative model for actuarial modelling purposes

ABSTRACT

In this paper we introduce the exponentiated Fréchet regression for modelling positive responses having a long-tailed distribution in a regression model, which are common in actuarial statistics. We propose two parameterizations each of which links the regression parameters with the explanatory variables. We then discuss the maximum likelihood estimation of the parameters both theoretically and empirically. In order to meet the needs of an actuary, closed-form expressions for certain risk measures for the exponentiated Fréchet distribution are also derived. We employ the proposed model to a motorcycle claim size data set.     

国债市场利率期限结构波动的对偶变换建模

本文针对传统利率期限结构拟合曲线存在过度波动问题,构建定价误差绝对距离和波动曲率双重最优化模型,借助对偶几何程序转换为在线性约束区域内的绝对距离最小化问题,并运用负指数平滑立方L1样条和计算几何逼近算法求解模型参数,通过负指数立方L1样条、NSS模型和B样条进行样本内拟合与样本外预测能力的比较,证实负指数立方L1平滑样条对利率期限结构波动的定价精确度、结构性拟合和样本外预测能力均有明显的优势,丰富了国债市场利率期限结构波动与定价的理论基础和研究方法。     

School-level policies and the efficiency and equity trade-off in education

This paper identifies the relationship between pupils’ Family Background, their mathematics scores, and school-level policies, using the 2012 Programme of International Student Assessment for Italy and multilevel modelling. School-level policies have played a leading role in recent school reforms in many countries, but there is no straightforward empirical evidence for how they affect pupils’ outcomes and the equality of educational outcomes. Our findings show that that only some school policies intensify the Family Background Effect – (educational equity) and affect student outcomes (educational efficiency) simultaneously. We find that competitive schools are able to screen students by selecting higher socio-economic status parents, which mainly harms equity without having much effect on efficiency. There are some policies which allow some trade-off between aforementioned objectives, mainly policies related to management schools.     

The Leveraging Effect of Supervisory Competencies Towards the Performance in Indian Manufacturing Group: A Structural Equation Modelling Approach

The quick pace of technological changes, market and industry changes, demographic composition change and society changes requires that human resource managers should revitalize their proficiencies to go with these new challenges. The manager who is a liaison in the organizational hierarchy does a very important job in the organization to direct and channel the employee cluster towards its organization goal, and ensure that each member of the team should be dynamic and prolific. The study on supervisory competency analysis is a crucial and fundamental requirement for any organization. The current study ‘The leveraging effect of Supervisory competencies towards the performance in Indian manufacturing group’ is based on primary data collected from one hundred and fifty employees working in a paper manufacturing industry. The data collected were analysed using SPSS and SMART PLS software. The results of the study revealed that the impact of supervisory competencies towards his performance is huge which accounts to 81% (R²?=?0.810) and towards the growth of whole organization is 35% (R²?=?0.356). This implies that if the supervisory level employees are competent enough by possessing certain competencies, his individual performance will do extreme wonders and will create a strong bond between him and the organization and also create an impact on organization growth by clear strategy formulation, creating committed workforce, developing the organization as learning organization and stimulating individual and group productivity.     

Changing compatibility of cohabitation and childbearing between young British women born in 1958 and 1970

We investigate the effect of parenthood on whether non-marital unions led to marriage or parting for two cohorts of British women when they were aged between 16 and 29. We compare the effect of conceptions leading to births and the presence and characteristics of children on the odds that a cohabitation was dissolved, or that it was converted to marriage, for women born in 1958 and 1970. A multilevel, multiprocess, competing-risks model allows for multiple cohabitations per woman and endogeneity of fertility status. We find that cohabiting couples’ response to impending parenthood and the presence of children changed over time. In particular, the proportion of cohabiting couples who married before a birth decreased and, in the 1970 cohort only, the risk of dissolution declined during pregnancy. There is also evidence that the presence of a child cemented a cohabiting union for women from the 1970, but not the earlier, cohort.