随机需求环境下联产品系统价格与产量决策研究

基于固定比例生产技术和多产品随机需求的情形,研究了联产品制造商的两阶段产量和价格联合优化模型。通过反向倒推的优化求解,得到了联产品制造商的最优产量和价格决策以及变化规律。同时研究了需求服从均匀分布时,需求波动对均衡的影响。研究结果表明,在订货成本较低和一种产品的需求波动性较大时,当另外一种产品的波动增大,则该产品的最优订货量增大,同时价格下降。借助数值仿真,分析了价格敏感度和产出比例对最优决策和利润的影响。结果表明,在给定一种产品的价格敏感度时,另外一种的价格敏感度越大,那么该产品的价格就越低,制造商的订货量就下降。当一种产品的产出比例固定时,另一种产品的产出比例上升时,则该产品的价格下降,制造商的订货量下降,总利润上升。     

Deaf and disabled? (Un)Employment of deaf people in Belgium: a comparison of eighteenth-century and nineteenth-century cohorts

In this article, the employment characteristics of pre-industrial and industrial cohorts of deaf men and women are compared with each other, as well as with a cohort of non-disabled siblings. The aim is to determine the extent to which the employment patterns of deaf persons lined up with those of non-disabled people and to see how nineteenth-century industrialization processes influenced their employment opportunities. This article challenges the widely held assumption that the nineteenth century constituted a definitive break by arguing that the professional lives of deaf people were not necessarily better before industrialization. Moreover, I demonstrate that the development of deaf schools in the course of the nineteenth century opened a new range of career opportunities for deaf individuals.     

Changes in work and care trajectories during the transition to motherhood

In most mid- and high-income countries, there have been significant demographic, structural, and cultural changes in the past decades. However, we know little about how these changes have shaped women's work patterns during a key life stage: the transition to motherhood. Using longitudinal data from Chile, covering over 30 years of employment histories and three periods of first births (1980–2010), I conduct sequence analysis to identify women's work-care trajectories during an eight-year period of the transition to motherhood. Over time, I find that continuous care work at home has declined, for which education plays a key role, while the chances of working continuously have not changed over time. Instead, I find an increasing trend of unsteady paths that combine paid work with either caretaking or unemployment. I discuss how these changes, as well as their association with education, have important implications for both gender and social inequality.     

The disembedded digital economy: Social protection for new economy employment in China

This research focuses upon employment in the new economy, exploring labour protection and social protection in the digital age in China. Through an empirical survey conducted in three Chinese cities, social insurance and the labour rights of employees in the digital economic sector, such as gig employment, e-commerce, and various other forms of online employment, have been examined in-depth. This study reveals new regulatory loopholes in the digital labour market, which have substantially eroded the basis of social policy arrangements in China, “softening” participation in social insurance branches and compliance with labour regulations remarkably. Drawing upon the theoretical concepts of Polanyi on embeddedness and disembeddedness, we argue that the digital employment sector in China has been increasingly disembedded from social institutions and social control. The new configuration in the digital field of social policy requires novel conceptual models and institutional settings to cope with increasing social risks in virtual spaces.     

Wage and Non-Wage Compensation Among Young Alcoholic and Heavy Drinking Women: A Preliminary Analysis

The association between drinking and selected job characteristics among women aged 24 to 31 is examined. Using the 1989 NLSY, women are classified as alcohol abusers or dependent based on DSM-III-R criteria or as heavy drinkers based on reported frequency of six or more drinks. Heavy drinking is negatively associated with wage and non-wage compensation. These effects diminish when human capital measures are controlled. Current alcoholism and current and past heavy drinking are strongly negatively associated with years of schooling. The association between alcoholism and job compensation and characteristics is not as strong as that seen for heavy drinking. It is not known if this is a consequence of errors in identifying alcoholic women in population-based surveys.     

Middle School Children's Perceptions on Welfare and Poverty: An Exploratory, Qualitative Study

This study was undertaken to determine how middle school children assess the effects of welfare reform on their daily lives. The study consisted of thirty interviews with children and their mothers recruited from a middle school in a large, metropolitan area. From the children's perspective, multiple jobs and evening/night hours interfered with the child-parent relationship. Other consequences included grades going down and not getting to school on time. All the children stated that mothers should work, but most children felt mothers should only work when their children are in school. Welfare and poverty were issues about which children were teased at school.     

重庆市都市区人中就业现状及变化趋势

都市区作为重庆经济的核心区域,随着经济的快速发展以及城市化进程的加快,正对人口产生巨大的聚集效应,而人口就业将成为一个十分突出的问题。因此,准确把握劳动力供求变动趋势十分重要。为此通过模型运算,对2000-2020年的都市区劳动年龄人口和劳动力的供求变动趋势进行了预测分析。     

寻求就业增长点

在扩大内需的过程中保障就业位置的增加 ,使就业增长速度与经济增长速度保持同步 ,这是我国目前经济工作面临的重要问题。为此 ,作者提出了增加就业位置和就业机会的几点看法。     

知识经济与就业革命

知识经济的到来 ,对传统的就业方式提出了重大挑战 ,引起了就业领域中就业结构、就业机会、工作制等多方面的转变 ,一场有关就业的文明革命悄然兴起。中国应通过提高劳动者素质 ,转变劳动者就业观念 ,调整国家就业政策等多方面措施 ,改善就业环境 ,刺激就业增长 ,以缓解目前所面临的巨大就业压力 ,迎接知识经济的挑战     

盛世丹青——刘宇一和他的绘画创作

面对宇一的历年画作 ,可以排成一个大型的方阵 ,其中贯穿着一条线 ,就是对主题性绘画的追求和色调的清新明丽。诗人艾青说 :“我生活 ,故我歌唱。”那么 ,宇一呢 ,当然是奋挥手中的巨笔 ,再创新的辉煌。这是时代的要求 ,是中国美术史的一个新的篇章