Socioeconomic,sociodemographic and attitudinal correlates of the tempo of divorce

The association between sociodemographic, demographic, and attitudinal measures and the timing or tempo of marital dissolution over a 14-year time span is examined. Separation is considered equivalent to divorce. Early and late divorce are differentiated by whether the event occurred before or after the average number of years married prior to divorce. Data were obtained on husbands and wives within childbearing years (up to 39 years) in the 1st years of the 1st marriage. A random stratified sample of 610 couples was drawn from records of marriages in a midwestern county between 1972-77. Reinterviews were conducted on 544 couples in April 1985. socioeconomic variables included educational attainment, occupational prestige, wife's employment status, wife's future work plans, husband's attitude to wife's future work plans, total family income, and level of satisfaction with current financial status. Demographic variables are age at marriage, number of children in 1985, marital duration, and desired family size. Attitudinal items were religiosity and gender role orientations (traditionalism, modernism, egalitarianism). Exposure to divorce was not equitably distributed for the 108 who divorced, but this was not statistically significant. The results indicate that those divorced earlier were wives who worked outside the home, worked at more prestigious jobs, planned to be employed throughout married life, and whose father had a higher level of educational attainment. This finding is not consistent with prior research which has shown that favorable socioeconomic conditions lower the probability of divorce. The timing of divorce was affected by the presence of children. Those married at younger ages divorced earlier and couples with children delayed divorcing longer than couples without children. These findings were consistent with earlier research. Catholic wives delayed divorce longer than non-Catholic wives. Males lower in sexual satisfaction divorced earlier. Divorce was postponed longer for husbands with traditional values and wives who had higher scores on egalitarianism. Wives with scores on modernism had earlier divorces than wives scoring lower on modernism. The tempo of divorce was in multiple classification analysis predicted best by wife's employment status and number of children. Cross-classification was not possible.     

Temporal dimensions of the fertility transition: an age-period-cohort analysis of frontier fertility

"This paper evaluates age, period, and cohort effects on marital fertility during onset of the Utah fertility transition (1880-1900). Computerized genealogies are used to derive age-period-cohort fertility rates for 49,842 once-married couples. Age, period and cohort effects on marital fertility are then estimated using Johnson's (1985) relational model. Declining marital fertility in Utah is shown to be explained by both lower fertility levels across periods and increasing age-specific limitation across cohorts. Direct cohort effects on fertility are insignificant. These results are consistent with prior research, and the view that fertility levels were adaptive (in part through birth spacing across ages) to immediate contexts of childbearing while age-specific fertility truncation increased across cohorts (in part through the more general diffusion of contraceptive innovations)."     

Today's second generation: evidence from the 1990 U.S. census

"The prospects for today's second generation will be considerably shaped by their current social, economic and demographic status. This article provides a statistical portrait of children of immigrants by analyzing data from the 1990 U.S. Census of Population and Housing. With the second generation defined as children under age 18 with at least one foreign-born parent, the study describes place of residence; household demographic, social and economic circumstances; household head's socioeconomic status; and characteristics of children themselves. Data on second-generation children are broken down by year of immigration of parents and child's nativity. Data for children with native-born parents are provided for comparison."     

Age at marriage,sex-ratios,and ethnic heterogamy

"This paper focuses on the effects of age at marriage and the sex-ratio on patterns of ethnic homogamy among Israeli women. We hypothesize that later marriages are more likely than early marriages to be heterogamous as the 'marriage market' shifts from school to the work-place. By the same token, when facing severe marriage squeezes women will be forced to out-marry. Employing data from the 1983 census, we model mate selection of women from Afro-Asian and Euro-American origin in various birth-cohorts. The results do not fully support our hypotheses: we find that in and of itself, age at marriage does not enhance ethnic heterogamy."     

The model of place utility revisited

"The purpose of this paper...is twofold: first, to specify a way of calculating place utility so that potential migrants could move to the place where overall place utility is maximized; and second, which is more important, to reveal how decision-makers in the real world, who are acting within 'bounded rationalities'...,make their decisions on where to migrate. This study is supported by an empirical survey of recent Chinese immigrants to Edmonton [Canada].... The findings reveal that when people evaluate different places, they do not necessarily look for the one that generates the highest overall value or utility across all properties.... The study further indicates that the assumption underlying most microeconomic models (that maximizing utility or benefit is the ultimate rule for choosing one location out of several) has not been verified." (SUMMARY IN FRE AND SPA)     

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系统设计分析

空间光束捕获、跟踪、瞄准（ＡＴＰ）技术在空间光通信中具有重要地位。文中讨论了空间光通信系统中的ＡＴＰ伺服系统的结构,并对系统稳态设计和系统动态综合等关键问题进行了详细的分析和研究。     

自由空间光通信ATP地面模拟系统研制

自由空间激光通信技术研究关键的步骤之一是通过其地面实验演示系统研究各项关键技术和整体优化技术,并验证它们的性能。文中描述了该地面实验演示系统的一个关键分系统—捕获、跟踪、瞄准（ＡＴＰ）系统的设计、预期达到的性能和未来升级的设想。     

Sex preference versus number preference: the case of Korea

The author argues that the effect of sex preference must be disentangled from the effect of number preference in Korea. This study tests--with hazard models--the effect of the number of previous children on the next birth according to the sex composition of previous children. Data were obtained from the 1974 Korean Fertility Survey. This paper also analyzes the timing of childbearing in recent periods in order to determine whether replacement-level fertility is temporary or permanent. The ideal number of children declined from 3.9 children in 1965 to 2.1 in 1991. The age-specific fertility rates for ages 20-24 years declined rapidly during the late 1980s. The fertility rates among women aged 25-29 years and 30-34 years increased during 1985-90. The proportion of fertility among women aged 20-29 years increased from 67.9% in 1975 to 86.6% in 1984. Women born in the late baby boom period of the late 1950s to mid-1960s reached prime reproductive age during the late 1980s and 1990s, but the crude birth rate remained about the same during 1985-92. A higher percentage of women (22.4%) born during 1955-59 remained single in 1990. During 1960-90, the percentage of women aged 20-24 years who were married declined. These trends indicate later age at childbearing and an explanation for the temporary nature of below-replacement fertility in the late 1980s. Korean women did not want to have more than 2 children, and the interval between first and second births increased since 1985. Among pregnancies of parity 2 conceived since 1985, over 90% of women with at least one son ended subsequent pregnancies by abortion compared to only 59% without sons. Hazard models of 1974 data reveal that son preference had an important effect on fertility. Fertility was higher among women with only daughters. Findings suggest that the value of sons must be measured at the societal and not at the individual level.