Contraceptive Responsibility among Male University Students

Abstract

This paper assesses the male contribution to contraceptive mismanagement and unwanted pregnancy. The subjects were 109 students at the University of Melbourne. A high incidence of risk-taking was reported, and almost one-fifth of the sexually experienced men stated that they had been involved in an unwanted pregnancy. A small group of these reported more than one such incident. The underlying reasons for poor contraceptive technique seemed to be related to two beliefs: that contraception is a female responsibility, and that sexual intercourse should be entirely spontaneous and unplanned.     

钢桶螺纹盖机器人旋紧控制系统

为了解决人工操作或机械半自动化旋紧钢桶螺纹盖所带来的弊端,提出采用工业机械臂对其进行自动旋紧。运 用EtherCAT总线技术,通过CoDeSys开发软件,设计开发了一种机器人旋紧控制系统,使得机器人可以对钢桶螺纹盖进 行自动抓取、定位和旋紧,完成相应的工序。该设计实现了钢桶螺纹盖旋紧的自动化生产,提高了生产效率和加工质量。     

A time series model with random coefficients

There are many time series applications where an experi­menter observes the simultaneous responses of several sub­systems over time. In these instances one is often not interested in the parameters of individual subsystems, but rather in an overall characterization of the system in question. Under the assumption that subsystems are independent and first order autoregressive, the present paper presents two methods for estimating the distribution of the subsystem coefficients.     

Economic machine adjustment in the case of product screening

In the course of the rapid growth in automated manufacturing systems automatic control devices become more and more widespread, especially in electronic industry. A survey in US industry performed 1987 by the American Society for Quality Control has shown that 85% of the organisations used screening procedures. In this paper the results of economic adjustment designs for x-control charts in v. Collani et al. (1989) are extended to the case that all of the produced items are subject to acceptance sampling. A simple algorithm is developed for determination of approximate optimal adjustment designs.     

Stimulant medication use, misuse, and abuse in an undergraduate and graduate student sample

In this study, the authors investigated the characteristics of use, misuse, and abuse of stimulant medication (primarily methylphenidate and variants) among students at a northeastern US university. Researchers sent an invitation to take an Internet survey to student e-mail addresses and passed 150 paper surveys in undergraduate classes, analyzing 1,025 (975 electronically) returned surveys. Sixteen percent of respondents reported abusing or misusing stimulant medication. Ninety-six percent of respondents who specified a medication preferred to abuse or misuse Ritalin. Men and women reported similar use patterns. Most respondents who abused or misused stimulant medication swallowed pills; 40% used intranasally. Reasons for abusing or misusing stimulant medication included improving attention, partying, reducing hyperactivity, and improving grades. Consistent with previous studies, results suggest that abuse of stimulant medication is a concern on college campuses. The results point to various reasons for and methods of abusing and misusing stimulant medication that may direct future research, prevention, and intervention.     

Return variances of selected German stocks

Models with autoregressive conditional heteroskedasticity are used to describe the behavior of the variance of the rate of return on selected German stocks. The results show that these models are superior to the commonly used process with constant variance due to their increased flexibility in situations of changing volatility.     

世界的贫困问题

在讨论世界的贫困问题之前,我们首先应该区分绝对贫困和相对贫困这两个概念。绝对贫困是指衣、食、住和医疗等基本需求得不到满足;相对贫困指代的是一种不平等的概念,即不占有大多数人所消费的物品的人是贫困者。在本文中,发展中国家和转型国家中的贫困指的是绝对贫困,而发达国