Sentiment-scaled CAPM and market mispricing

This study explores the conditional version of the capital asset pricing model on sentiment to provide a behavioural intuition behind the value premium and market mispricing. We find betas (β) and the market risk premium to vary over time across different sentiment indices and portfolios. More importantly, the state β derived from this sentiment-scaled model provides a behavioural explanation of the value premium and a set of anomalies driven by mispricing. Different from the static β–return relation that gives a flat security market line, we document upward security market lines when plotting portfolio returns against their state βs and portfolios with higher state βs earn higher returns.     

严寒地区高速铁路混凝土基床聚氨酯保温特性试验研究

基于严寒区京沈客专朝阳试验段路基基床的温度监测资料分析,研究不同厚度聚氨酯保温板对高速铁路路基混凝土基床温度变化特性影响.测试结果表明:①铺设聚氨酯保温板能够有效阻断严寒区环境与路基基床间的热量传递,保温效果与板厚相关;②地温大多数时间呈阳高阴低现象,同时阴、阳坡路基温差波动幅度随埋深逐渐减小;③基床表层阴、阳面各测点的温度变化起始时间一致,而阴面的冻结时间比阳面晚一个月.由此表明,保温板能够有效降低环境与混凝土道床之间的热交换,但是对路基阴、阳坡的影响存在差异.建议在严寒地区高速铁路路基阳、阴坡可以采取不同厚度的聚氨酯保温板,减小阴阳坡地温差异,保持季冻土路基温度变化稳定.     

粤港澳大湾区创新生态系统内部耦合时空演化及空间收敛分析

在构建以国内大循环为主体、国内国际双循环相互促进的新发展格局下，高效协同的区域创新体系有助于将粤港澳大湾区三地建设成为具有全球影响力的科技创新中心。通过构建创新生态系统综合评价指标体系，采用耦合协调模型和空间计量模型，实证检验大湾区10个城市2007-2019年创新生态系统内部耦合协调水平、时空跃迁特征以及收敛性。研究发现，大湾区整体及各城市耦合协调度呈上升趋势，基本实现从失调衰退区到协调过渡区的转化，具体可划分为4个等级层次；大湾区创新生态系统协调耦合度存在显著的绝对β与条件β收敛趋势，即最终收敛于同一稳态水平，且城市间差距逐渐缩小。其中，经济发展水平、对外交流水平、人力资本水平对创新生态系统协调耦合度起显著正向作用。     

The Engineer and The Plumber: Mediating Mumbai's Conflicting Infrastructural Imaginaries

Two decades ago, the rules governing the provision of piped municipal water supply in Mumbai became linked to the policy frameworks governing eligibility for a property titling scheme. This article outlines the ideological basis and practical implications of the shift, as well as the contradictions of the new regulatory regime. The article demonstrates how these contradictions have been mediated by the material and practical knowledge, embodied expertise, local authority and wide‐ranging socio‐political work of two sets of actors: municipal water engineers and a cast of characters known locally as ‘plumbers’. The social, political and hydraulic imaginaries animating the work of ‘plumbing’ are bound up with a temporal and spatial imaginary distinctly at odds with the network‐flow conception of hydraulic engineering within which the work of water supply planning and distribution in Mumbai is conceptualized, materialized and institutionalized. The hydraulic and legal contradictions of these clashing infrastructural idioms––of flow and event––have rendered the regulatory framework highly unstable. These contradictions eventually erupted in Mumbai's waterscape, leaving the city's water infrastructures suspended in a highly politicized state of limbo between dueling infrastructural imaginaries.     

Product line transformation,foreign sales,and firm value: Evidence from COVID-19 pandemic governance in urban China

Using a sample of Chinese firms, we examine stock market reaction to firms that announce a change in their product lines to those related to COVID-19 management (medical masks and ventilators, among others). We find the market reacts positively to the announcements. In addition, when a firm ordinarily has a large share of export sales, the stock market reaction is more salient, indicating that export sales provide a certification effect that positively signals investors. Additional analysis on moderating effects suggest that, conditional on foreign sales, prior experience with medical product lines or less uncertainty about supply availability enhances the cumulative announcement returns (CARs), while the adverse impact of firm size on CAR magnifies.     

Challenges faced by world tourism cities – London’s perspective

World tourism cities perform multiple functions and exhibit various characteristics that influence tourism development within their boundaries. They are the main gateway for tourists visiting a country and their success has a direct impact on the visitor economy of that destination. London, the focus of this research, has been one of the world’s top tourism cities for many years, and a key gateway for domestic and international visitors. But despite the important role tourism plays in the economy of the city, there is limited research on the development of this activity in the capital. Using London as an exploratory case study, this paper contributes to better understanding the challenges faced by policy makers when planning and managing tourism in world cities. The adopted research method offers the advantage of gathering insightful information using multiple data collection techniques. Examining this new evidence contributes to expanding the knowledge on the particularities of tourism development in one of the top world cities, which could help policy makers in their efforts to better prepare for potential challenges faced by these complex but important destinations.     

Effective HR implementation: the impact of supervisor support for policy use on employee perceptions and attitudes

Abstract

Effective implementation of human resource (HR) policies appears to depend on supervisors’ active involvement in the intervention process. Following recommendations of a recent intervention evaluation framework, we examine how perceived supervisor support during the implementation of a work-life intervention helps to change participants’ perceptions of organizational family supportiveness, and how this ultimately changes participants’ engagement and turnover intentions. A three-wave longitudinal study in a professional services firm (N = 434) that has formally involved supervisors in the process of a work-life intervention showed support for our study hypotheses. Supervisor support for policy use influenced employees’ positive work–home culture perceptions, which in turn strengthened employees’ work engagement and diminished their turnover intentions over time. We discuss practical implications and give recommendations on the future design of HR interventions and related policies.     

LT码新型度分布及其在电力线通信中的应用

Luby变换(Luby Transform,LT)码作为信道编码应用于电力线通信(Power Line Communication,PLC)，可实现电信号的可靠传输。度分布对LT码编译码性能的影响至关重要。为了得到更优的度分布，首先调整二进制指数分布(Binary Exponential Distribution,BED)中的度数比例，获得一种译码性能更优的改进的二进制指数分布(Improved BED,IBED)。然后，根据IBED在冗余度较小时译码成功率高，而冗余度增大后鲁棒孤子分布(Robust Soliton Distribution,RSD)的译码性能表现更佳的特点，通过求和归一化的方式将IBED与RSD两种度分布的优势进行有机结合，提出一种新型二进制鲁棒孤子分布(Binary RSD,BRSD)。仿真结果表明，与其他方法及传统的RSD相比，采用新度分布进行LT编码，可明显降低译码开销，并节约编译码耗时。将新型度分布应用于基于LT码的PLC系统中，能有效地抑制PLC信道中各种噪声对电信号的干扰，并提高通信效率。     

产业视角下环京津山区贫困县农业品牌建设路径研究*——以张家口市崇礼区为例

[目的]农业品牌建设是连接农业生产与市场消费的有效途径,是贫困地区特色农产品产销对接的重要抓手,在环京津贫困地区率先实现农业品牌建设的突破,示范意义重大。然而,针对贫困县的研究相对缺乏,农业品牌建设实践中脱离产业实际的问题比较常见,亟需路径探索。[方法]采用文献梳理、案例分析、实地和书面调研等方法,以张家口市崇礼区为例,对环京津山区贫困县农业品牌建设的现状进行分析,对路径与战略作出谋划。[结果]环京津山区贫困县的农业产业具有品质优势、错季优势和物流优势,受到资源短缺、投入不足、人才匮乏的限制,也面临居民消费升级、京津冀协同发展、产业扶贫等机遇。[结论]在产业视角下推进环京津山区贫困县农业品牌建设,应当重点实施品质农业发展行动,加强品牌营销,培育专业队伍,开展小而美、中高端、精准化的特色农业品牌建设。同时,建议上级有关部门在组织保障、政策倾斜、指导服务上给予有力支持。     

20kV及以下配电网工程造价的确定与有效控制方法分析

随着我国电网逐渐向智能电网迈进,信息技术在电能传输、转换、分配、调度等方面的应用,使电力企业可以进行结构调整,提高电力系统管理水平。据统计,2011年,我国电力信息化投资达220亿元,2012-2015年,电力工程建设稳步推进。为了促进电力企业全面开展项目成本核算和有效控制,提高电力工程项目的效益,确定了典型方案设计模块,通过定额规则库与典型方案设计相匹配的方法,解决了安装过程中定额第一版遗留的一些问题,并通过设计选型等措施加强了成本控制。