Graduate Student Literature Review: Considerations for nutritional grouping in dairy farms

Each cow in a group has different nutritional requirements even if the group is formed by cows of similar age, number of lactations, and lactation stage. Common dairy farm management setup does not support formulating a diet that accurately matches individual nutritional requirements for each cow; therefore, a proportion of cows in the group will be overfed and another proportion underfed. Overfeeding and underfeeding cows increases the risk of metabolic diseases, decreases milk production, and increases nutrient waste. Consequently, profitability of dairy farms and the environment are negatively affected. Nutritional grouping is a management strategy that aims to allocate lactating cows homogeneously according to their nutritional requirements. Groups of cows with more uniform nutritional requirements facilitates the formulation of more accurate diets for the group. Current availability of large data streams on dairy farms facilitates the design of algorithms to implement nutritional grouping. Our review summarizes important factors to consider when grouping cows, describes nutritional grouping approaches, and summarizes benefits of implementing nutritional grouping in dairy farms.     

仪器仪表产品脉冲耐压试验要求和保护器件的选择

仪器仪表产品的脉冲耐压试验是产品型式试验、例行试验中的基本内容。通过对GB4793.1标准的整理,归纳了仪器仪表产品的脉冲耐压试验要求。通过对试验方法和设备特性的梳理,总结了特性参数,并介绍了应对脉冲耐压试验可采取的保护器件的类别及选用方法。     

基于实物期权的煤层气利用项目投资评价研究

实物期权法是对项目决策中的灵活性价值进行定量评估的一种方法，是对传统经济评价方法净现值法的修正补充。采用实物期权理论和方法，分析煤层气利用项目可研建设阶段和生产运营阶段的期权特征，确定出煤层气利用项目总价值为现金流量净现值与项目灵活性价值之和。采用二叉树期权定价方法，构建基于实物期权的煤层气利用项目投资评价方法和模型。并结合煤层气脱氧制液化天然气项目实例，在确定评价参数的基础上，分别用净现值法、基于实物期权的延迟期权方法、扩张期权方法及复合期权方法，计算煤层气项目投资价值，同时对评价方法主要影响参数进行敏感性分析。结果表明：实物期权法评价出的煤层气利用项目价值明显高于传统经济评价方法计算出的项目价值，而且组合期权能有效增加项目的价值；标的资产价值和期权执行价格对煤层气利用项目期权价值的影响最大。      

The paradox of technology innovativeness and risk perceptions – A profile of Asian smartphone users

Risk perceptions and technology innovativeness are the two primary factors related to the adoption of mobile technologies. The current study examines the role of technology innovativeness and risk perceptions on smartphone use and dependence in an Asian context. A total of 9086 participants were recruited through online surveys from ten Asian countries. Ordinary least squares regression analyses revealed the effects of technology innovativeness, information security, privacy concern, and their interactions on smartphone use and dependence. Moreover, based on users’ smartphone usage patterns and perceptions, this paper identified four homogeneous groups using cluster analysis. Results shows that Asian smartphone users can be segmented into four groups: innovators, conservatives, moderators, and laggards. The four clusters show significant differences in demographic features. Theoretical and practical implications are discussed based on these findings.     

Increasing inequalities in what we do online: A longitudinal cross sectional analysis of Internet activities among the Dutch population (2010 to 2013) over gender,age, education,and income

We investigate types of Internet activities among a representative sample of the Dutch population from 2010 to 2013. We examined usage patterns of seven types of Internet activities (i.e., information, news, personal development, commercial transaction, social interaction, leisure, and gaming) and related these patterns with gender, age, education, and income. Activities related to news, personal development, commercial transaction, and social interaction increased in popularity. For most capital enhancing activities, men, younger people, higher educated people, and people with higher than average incomes were prominent. These observations, however, are subject to change. The Internet seems to provide increasingly more capital-enhancing opportunities for those with higher education and income, which would accordingly reinforce their already strong positions in society.     

Determinants of social gratifications obtained by older adults moderated by public supports for Internet access in Spain

As the standard of living constantly improves, and as life expectancy increases in developed countries, the number of adults who want to have a gratifying life increases as well. Furthermore, although the Internet offers a world of potentially rewarding experiences, there is much heterogeneity among older people with respect to those who are able to benefit from its use. To reduce this gap, public access and digital literacy programs have been implemented. The aim of the study was to find out the extent to which these programs moderate the effects of age and socioeconomic status on social access to and use of the Internet in a sample of older users in Spain. Through quota sampling of retired users over 54 years of age in Spain (N = 560), who were regular users of public supports for Internet access, a structural equation modeling and multi-group analysis was conducted. The data showed a staggered association of access indicators (physical access, digital skills and social e-activities) on the social gratifications obtained, as well as the moderating role of institutional supports. This study provides empirical evidence of the ability of public supports to moderate the effect of socioeconomics inequalities on access and social exploitation of the Internet by older people. The findings point to the need to strengthen digital literacy actions, especially in supports that are more sensitive to the effect of age and socio-economic status.     

Rainbow over the Internet: How Internet use curtails homophobia in China

China, despite its rapid economic modernization and the lack of powerful conservative institutions, is not known for embracing diverse sexual orientation. The present study investigates whether and how Internet use, a increasingly important part of contemporary people's daily life, leads to changes in people's attitudes toward homosexuality in China, and relevant policy implications. Analyzing the Chinese General Social Survey data from 2010 to 2015, this paper develops an ordered probit model to quantify the influence of Internet use on homosexuality tolerance, adopts a substitution variable method to conduct the robustness check, and utilizes instrument variables to address the potential endogeneity in the regressions. The results show that Internet use has a significant positive impact on Chinese people's homosexuality tolerance. Further studies have found that the influence of Internet use on homosexuality tolerance is also heterogeneous to different populations. Besides, compared with traditional media, the Internet has a more significant impact on homosexuality tolerance. This paper provides some explanations for the rise in China's homosexuality tolerance from 2010 to 2015, and additional impetus for the international community to push for a liberal Internet policy in China.     

Towards zero carbon design in offices: Integrating smart facades,ventilation, and surface heating and cooling

This paper discusses an overall strategy for reducing energy demand in non-domestic buildings, mainly focusing on office developments. It considers four areas: reducing internal heat loads; addressing passive design through the building construction; using efficient and responsive HVAC systems and focusing on chilled (heated) surface systems; integrating renewable energy supply systems into the building design. The impact on energy use and carbon dioxide emissions will be discussed. The paper will draw from a range of design projects carried out in Europe, where this integrated approach has been applied, and then explore the benefits in relation to applications in the Middle East and China. Energy modeling results, to inform the design process will be presented, using energy simulation for three case study locations, in Zurich, the Chongqing and Abu Dhabi.     

A household dishwasher heated by a heat pump system using an energy storage unit with water as the heat source

Electricity usage by a household dishwasher can be reduced by using a heat pump system to heat the dishwasher cabinet, dishware and washing water. The evaporator obtains the energy from an energy storage unit which consists of a container filled with water which freezes to ice. The majority of the heat transfer from the energy storage to the evaporator occurs when ice is created in the energy storage unit. A transient simulation model of a dishwasher with a heat pump system was developed and compared to an experimental setup with good agreement. A simulation study of the compressor cylinder volume and the compressor operating time was performed. The results showed a 24% reduction in total electricity use compared to a dishwasher cycle using a traditional electric element.     

在役高炉炉缸状态的辨析、诊断与维护

在役高炉炉缸砖衬,由于其不同于原始设计的物性和特殊的结构形态,致使一些传统侵蚀管理模式失效,极端情况引发炉缸烧穿事故。从传热学角度看,炉缸烧穿现象是炉缸侧壁传热体系热平衡被打破后反复累积的极端表现形态。基于传热学理论和用后炉缸砖衬结构调查结果,从炉缸砖衬综合热阻视角,提出对在役高炉炉缸砖衬侵蚀状态的辨析和诊断方法,由此可准确判定在役炉缸的砖衬结构状态,为后续采取适当的维护措施提供决策依据,为高炉安全使用和延长寿命奠定基础。