Application of genetic algorithms to the construction of exact D-optimal designs

This paper studies the application of genetic algorithms to the construction of exact D-optimal experimental designs. The concept of genetic algorithms is introduced in the general context of the problem of finding optimal designs. The algorithm is then applied specifically to finding exact D-optimal designs for three different types of model. The performance of genetic algorithms is compared with that of the modified Fedorov algorithm in terms of computing time and relative efficiency. Finally, potential applications of genetic algorithms to other optimality criteria and to other types of model are discussed, along with some open problems for possible future research.     

Gambling and Problem Gambling Across the Lifespan

Two national U.S. telephone surveys of gambling were conducted, an adult survey (age 18 and over, N = 2,631) in 1999–2000 and a youth (age 14–21, N = 2,274) survey in 2005–2007. The data from these surveys were combined to examine the prevalence of any gambling, frequent gambling and problem gambling across the lifespan. These types of gambling involvement increased in frequency during the teens, reached a high level in the respondents’ 20s and 30s, and then fell off in as the respondents aged. The notion that gambling involvement generally, and especially problem gambling, is most prevalent during the teens was not supported. A comparison of the age patterns of gambling involvement and alcohol involvement showed that alcohol involvement peaks at a younger age than gambling involvement; and thus, the theory that deviant behaviors peak at an early age applies more to alcohol than to gambling.     

Factors affecting adoption in China, 1950-87

Though adoption in China is known to have increased as more girls were abandoned and became available for adoption following the introduction of the country's one-child policy in the 1980s, little is known about Chinese adoption practices. This paper investigates the factors affecting adoption in China in the period 1950-87 using data from the National Two-Per-Thousand Sample Survey on Fertility and Contraception of 1988. The results show that the national adoption rate was 2.3 per cent. Childless women were more likely than women with children to adopt and did not show a sex preference. Women with children by birth used adoption to secure a child of the 'missing' sex. Women who had experienced the death of a child were more likely to adopt than those who had not. Women with children may have used adoption as a strategy to circumvent the strict family planning policies.     

Do We Need to Weight Item Satisfaction by Item Importance? A Perspective from Locke’s Range-Of-Affect Hypothesis

Importance weighting is a common idea in quality of life (QOL) measurement. Based on the common idea that important domains should have more contributions to individuals’ QOL total score, the weighting procedure of multiplying item satisfaction by item importance was adopted in many QOL instruments. However, in Locke’s [1969, Organizational Behavior and Human Performance 4, pp. 309–336; 1976, in: M.D. Dunnette (eds.), Handbook of Industrial and Organizational Psychology (Rand McNally, Chicago), pp. 1297–1343] range-of-affect hypothesis, he indicated that the satisfaction evaluation of an item was determined by the have–want discrepancy, importance and their interaction (discrepancy × importance), implying that item satisfaction has incorporated the judgment of item importance, therefore, weighting an item satisfaction score with an item importance score is unnecessary. The purpose of this study was to examine the range-of-affect hypothesis in the context of QOL research. Three hundred and thirty two undergraduate students at National Taiwan University (NTU) participated in the study. Item satisfaction, importance and perceived have–want discrepancy were measured for 12 different life-area items. Global life satisfaction was measured as well. Regression analysis results showed that item importance and perceived have–want discrepancy have a significant interaction effect on item satisfaction, supporting Locke’s range-of-affect hypothesis. In addition, regression analysis results also showed that item importance and item satisfaction did not have a significant interaction effect on global satisfaction, suggesting that weighting item satisfaction score by item importance value does not have advantages in predicting global satisfaction. In a summary, the findings revealed that item satisfaction has incorporated the judgment of item importance, and, thus, the procedure of importance weighting on item satisfaction is unnecessary.     

Private and Public Displays of Affection Among Interracial and Intra‐Racial Adolescent Couples*

Objective. This article examines variation in displays of affection between interracial and intra‐racial adolescent couples. Method. Using the National Longitudinal Study of Adolescent Health (Add Health), a nationally representative sample of adolescents in the United States, we estimate hierarchical linear models to compare characteristics of interracial and intra‐racial relationships among white, African‐American, Hispanic, Asian American, and Native American adolescents. In our comparisons we highlight three dimensions of relationship attributes: public display, private display, and intimate physical contact. Results. Our findings suggest that interracial couples are less likely than intra‐racial couples to exhibit public and private displays of affection, but are not different from intra‐racial couples in intimate displays of affection. Conclusions. Social barriers against interracial dating still exist such that even though interracial couples are similar to intra‐racial couples in their levels of intimacy in private, they are less comfortable displaying their feelings in public.     

影响高密度城市的城市更新因素——以香港为例

香港高密度城市发展模式闻名于世。这种模式的形成或是由于城市新的发展需要，或是由于城市更新，后者是目前香港政府为提高公众居住条件和建成环境质量所使用的主要手段。本文聚焦城市更新，旨在突出当前香港城市改造实践中的不足，并从文献中筛选出影响城市设计的主要考虑因素，阐析它们如何能够从各方面支持本地社区发展。笔者通过问卷调查及后期资料分析，搜集和评估了香港专业设计人士与市民的意见，提炼出提升城市更新项目可持续性的关键设计因素。但愿本文的结论能为香港的开发商、城市设计者以及政府官员在日后的可持续城市更新项目中带来启示。     

Using feminist ‘reflexive practice’ to explore stress and well-being of local researchers in South Sudan

ABSTRACT

This article discusses using feminist methods of reflexive practice to support and learn about the well-being of researchers working on gender-based violence research in South Sudan. In particular, we focus on the experiences of South Sudanese researchers undertaking this research in their own country. We share key findings and offer personal reflections on and suggestions for improving fieldwork. As feminists ourselves we placed a high value on sharing personal reflections on emotional challenges that the research team faced. However, our South Sudanese colleagues did not find these approaches very useful, preferring to discuss technical challenges, and placed emphasis on the importance of professionalism. This experience suggests the need for more culturally diverse feminist research tools, and for better recognition of the crucial role played by national researchers in international research projects. We end with recommendations.     

Walking the talk: An exploratory examination of executive leadership communication at startups in China

This study explored the under-researched topic of leadership communication in the context of startup companies in China. Specifically, this study examined the role of executive leadership in shaping corporate culture and leadership communication purposes, strategies, and channels in startups. Findings were derived through 25 in-depth interviews with entrepreneurs in China, and they suggested that 5 major corporate culture types are prevalent and can coexist at startups, including innovation/adventure, openness, inclusiveness/participation, supportiveness, and aggressiveness/competitiveness. The character and management style of startup leaders shape the culture of the organization. Leadership communication serves various internal and external purposes at the informational, motivational, and behavioral levels. Symmetrical, transparent, authentic, and visionary communications are found to be effective leadership communication strategies at startups. Startup leaders overall prefer using face-to-face communication and mobile social messengers (e.g., WeChat) to communicate with internal and external stakeholders, followed by email and phone. Implications of the findings are discussed.     

Opposing the toxic apartheid: The painted veil of the COVID‐19 pandemic,race and racism

This article is a personal reflection of how the coronavirus exposes ‘shocking’ levels of racism against us, and our vulnerability as Chinese women living in Britain. By reflecting our experiences of verbal and physical race‐based violence connected to coronavirus, we explore the fluidity of our racial identities, the taken‐for‐granted racial stereotypes and white privilege, and everyday racism in the UK. Can the vulnerable use vulnerability as an agent to shift the moment of helplessness? We contribute to the uncomfortable yet important debate on racism against Chinese women living in the UK through voicing up our embodied vulnerability as invisible and disempowered subjects to this viral anti‐Chinese racism. This is a form of resistance where we care for the racialized and marginalized others. In doing so, we lift the painted veil of the pandemic, race and racism to collectively combat racial inequalities.     

Investigating important interactions between water and food security for child health in Burkina Faso

Failures in either water systems or food systems, or a combination of system failures, could provide the underlying explanation for continued high levels of malnutrition in many regions. We focus on child health and offer the first spatially explicit analysis of the interaction between water source and food insecurity on children’s health in Burkina Faso, an African nation that continues to struggle with poor children’s health. We combine data from the 2010 Demographic and Health Survey, a small USAID water quality survey collected from community wells, and remotely sensed imagery. Results suggest that, in a few cases, reliable and clean water sources are positively correlated to children’s linear growth and weight gain, although in many regions, the interaction with community-level food production is critical to understanding health outcomes. The results also suggest that maternal health and nutrition during pregnancy and breastfeeding are foundational to the healthy development of young children. In all, the findings provide evidence of the importance of multi-sectoral interventions targeted at improving children’s health.