The upper bounds on the Steiner k-Wiener index in terms of minimum and maximum degrees

Journal of Combinatorial Optimization - For $$k \in {\mathbb {N}},$$ Ali et al. (Discrete Appl Math 160:1845-1850, 2012) introduce the Steiner k-Wiener index $$SW_{k}(G)=\sum _{S\in V(G)} d(S),$$...     

结构式团体在临床护士心理压力调解中的应用

目的探讨应用结构式团体在临床护士心理压力调解中的改善效果。方法选择临床护士60例,均为2020年06月~2020年12月间我院在册在岗内科病区护士,依据护士入科先后顺序采取分组,即前期入科护理人员30例采取自我调节方式应用心理压力,观察组为后期入科护理人员30例,采取结构式团体干预模式进行心理压力调节,对比护士不同调节方式下,情绪分值变化及对自我职业的倦怠评分、心理健康状态评分,并采取科室设计的满意度问卷展开评估。结果由自评量表结果所示,观察组护理人员在干预前焦虑、抑郁分值均无明显变化(P>0.05),干预后观察组护理人员焦虑、抑郁分值有所下降,与对照组呈鲜明对比(P<0.05)。职业倦怠量表测评结果所示,观察组护理人员情绪衰竭、工作态度、个人成就感三个维度的分值均低于对照组,差异显著(P<0.05)。由科室自我设计满意度问卷所示,观察组对自我工作满意度较高,与对照组比值差异明显(P<0.05)。两组在SCL-90量表测评下,观察组护理人员各项指标得分低于对照组(P<0.05)。结论结构式团体在临床护士心理压力的调解中的应用效果值得肯定,可改善职业倦怠感,提高工作效率。     

Small Actions Can Make a Big Difference: Voluntary Employee Green Behaviour at Work and Affective Commitment to the Organization

In the workplace, discretionary pro-environmental actions made by employees are referred to as voluntary employee green behaviour (VEGB). This is increasingly recognised as a contribution to both the environmental and the financial sustainability of the organisation. However, the implications of VEGB beyond its original environmental domain largely remain underspecified, thus constraining the theoretical development of the field and advocacy for organisations in practice. This study thus investigates how VEGB associates with the employee outcome of affective commitment, which especially impacts the psychological relationships that employees develop with their organisations. Drawing on two studies, we found that VEGB was positively associated with affective commitment, as enabled by three mediating mechanisms that enhanced the sense of warm glow and moral credit for employees while protecting them against emotional exhaustion. Moreover, we found that perceived organisational support for the environment served as a boundary condition for VEGB and its mediation by moral credit and emotional exhaustion. Implications for theory and practice are discussed in the paper.     

基于委托代理关系的生态产业链均衡研究

研究生态产业链中委托代理结构和委托代理契约履约率对生态产业链的产品流量、利润和成本收益率影响等问题,指出生态产业链中的委托代理关系包括产品流通的委托代理关系和废弃物处理的委托代理关系,提出生态产业链的前导委托和后续代理关系结构。在此基础上,结合维持生态产业链运行的平衡条件,构建带有激励和委托代理契约履约率约束的生态产业链均衡的最优化模型,利用变分不等式模型解释生态产业链均衡的经济意义,并运用LINGO 9.0对鲁北生态工业园中的生态产业链进行模拟计算。结果表明,随着生态产业链中前导委托与后续代理之间履约率的增加,彼此间交易量、利润和成本收益率及整体生态产业链的利润和成本收益率都获得提升,计算结果与实际问题相符,验证了模型的有效性。     

From packing rules to cost-sharing mechanisms

Journal of Combinatorial Optimization - Bin packing is one of the most fundamental problems in resource allocation. Most research on the classical bin packing problem has focused on the design and...     

Benefits of and strategies to update premium rates in the US National Flood Insurance Program under climate change

The United States’ National Flood Insurance Program (NFIP) has accumulated over $20 billion in debt to the US Treasury since 2005, partly due to discounted premiums on homes in flood-prone areas. To address this issue, FEMA introduced Risk Rating 2.0 in October 2021, which is able to assess and charge more accurate and equitable rates to homeowners. However, rates must be continually updated to account for increasing flood damage caused by sea level rise and more intense hurricanes due to climate change. This study proposes a strategy to adopt updated premium rates that account for climate change effects and address affordability and risk mitigation issues with a means-tested voucher program. The strategy is tested in a coastal community, Ortley Beach, NJ, by projecting its future flood risk under sea level rise and storm intensification. Compared with using static rates for all the properties in Ortley Beach, the proposed strategy is shown to reduce the NFIP's potential losses to the community from 2020 to 2050 by half (from $4.6 million to $2.3 million), improve the community's flood resistance, and address affordability concerns. Sensitivity analysis of varying incomes, loan interest rates, and conditions for a voucher indicates that the strategy is feasible and effective under a wide range of scenarios. Thus, the proposed strategy can be applied to various communities along the US coastline as an effective way of updating risk-based premiums while addressing affordability and resilience concerns.