电气继电保护装置的检修和运行维护探讨

在当前社会经济高速运转的时代,电力资源的需求量与日俱增,电力安全问题也越来越受到人们的重视,这就对电气继电保护装置提出了更高的要求,加强继电保护装置的检修和运行维护,可以极大地提升电力系统的运行效率,并保证电力运行的安全性.但是,就目前情况来说,我国电气继电保护装置的运行过程中还是存在一些故障问题,需要采取措施加以改进.基于此,本文将围绕电气继电保护装置运行中的常见故障展开分析,然后对继电保护装置的检修方法以及运行维护措施进行了详细的探讨与研究,以供相关人员参考.     

Evaluating museum visitor experiences based on user-generated travel photos

ABSTRACT

This research introduces online travel photos published on social media platforms as a complementary data resource to examine the behavior and experience of museum visitors. The practical value of online travel photos is demonstrated through a case study of popular Hong Kong museums, particularly by using the photo content and metadata available from the Flickr platform. The proposed approach is a generic method for understanding museum visitor behavior and preferences, and supports museum practitioners in developing improved products for visitors. The case study findings are particularly beneficial for tourism managers, especially those in Hong Kong, in promoting and attracting tourists to visit local museums.     

城市道路桥梁工程施工技术要点

整个道路桥梁工程施工质量从很大程度上受到施工技术合理性影响.城市道路桥梁关系着国民日常出行便捷与安全,为此需要做好施工技术合理选择,确保落实各项技术,保证施工项目质量,加强成本控制.通过明确道路桥梁施工技术要点有助于落实施工技术方案,有助于工程质量优化,促进企业未来发展.为此,应当在明确道路桥梁工程施工要点基础上,加强各项技术应用,并且加强施工质量管控,建设优质项目.     

互联网金融规制与市场有效性改善*——来自中国网络借贷行业的证据

中国的互联网金融经历了一个先创新发展后监管规制的过程，本文通过对网络借贷行业的实证研究，分析监管规则的出台实施对新型互联网融资市场有效性的影响。实证结果表明，网络借贷平台资金的银行存管、持有ICP证等强制性规定缓解了投资者、平台企业与借款人之间的信息不对称，对克服早期平台间通过竞相承诺高回报率来吸引投资者导致的“柠檬市场”问题、对解决网贷市场上缺乏平台风险性高低有效信号的问题都起到了正向作用，有助于互联网融资市场的有效性提高。     

Foreign direct investment subsidy in a dynamic stochastic general equilibrium model with heterogeneous firms

This study analyzes the macroeconomic impacts of subsidies to attract multinational corporations when firms are determining whether to enter or how to serve foreign markets. We show that a small FDI subsidy scheme induces consumption gains and delivers short‐term welfare improvement for the FDI host country if firms differ in productivity. However, the subsidy generates a new problem and results in the wealth reallocation effect, leading to welfare deterioration for the host country in the long run. Moreover, we find that a subsidy program induces a welfare improvement for the host country if it is offered to all domestic producers instead of foreign producers only in the host country.     

目的国服务贸易限制政策是否阻碍了中国企业出口规模扩张?

根据经合组织统计的各国服务贸易限制政策条款,先对具体政策条款赋值,接下来加权得到衡量服务贸易限制的STRI指标,最终检验目的 国服务贸易限制对中国企业出口规模的影响.研究发现:在控制引力模型的其他变量以及企业-产品层面的特征变量后,目的 国服务贸易限制政策显著阻碍了中国企业出口规模扩张,且阻碍作用对一般贸易企业、大中型企业更明显.对影响机制而言,服务贸易限制政策造成的固定成本阻碍了企业出口的扩展边际,而引起的可变成本阻碍了企业出口的集约边际,其中,对集约边际的阻碍作用更大;进一步对集约边际分解发现,目的 国服务贸易限制政策降低了企业出口产品数量,但提高了企业出口产品价格.另外,拓展研究发现,目的 国数字化服务贸易开放能够缓解服务贸易限制政策对企业出口的阻碍作用.     

A REVIEW OF THE EMPIRICAL LITERATURE ON FARMER COOPERATIVES: PERFORMANCE,OWNERSHIP AND GOVERNANCE,FINANCE, AND MEMBER ATTITUDE

The empirical literature on farmer cooperatives is now fast emerging and developing in the areas of performance, ownership and governance, finance, and member attitude. We discuss 56 peer‐reviewed publications to illustrate the main findings and conclusions while outlining challenges and opportunities for future research. Generally, cooperative membership is found to positively impact price, yield, input adoption, income, and other indicators of member performance, yet there is growing evidence of an uneven distribution of benefits for small and large producers. In terms of structure, evidence of a causal relationship of ownership and governance to performance has been elusive, yet there are now many findings of inherent equity and long‐term debt constraints, often in the context of consolidation to drive scale and scope economies. Further inefficiency is observed to be driven by increased heterogeneity in member attitudes and objectives, in particular in terms of commitment and participation. Thus, overall, empirical work portrays farmer cooperatives as flawed and complex business organizations which nonetheless have a strong positive impact on its members. While applied research may progress in various directions, a general improvement in empirical methodologies is needed to allow robust analysis of mixed objectives in dynamic environments.     

自动涂胶系统胶枪的热分析

为研究自动涂胶系统的胶枪最优材质、最佳热源位置和最佳测温位置,利用ANSYS Workbench软件对自粘胶胶枪进行数值模拟.通过分析不同材质胶枪的温度场分布情况,结合经济性和加热性能,选定最优胶枪基材.同时分析得出加热自粘胶至工作温度的时间和保持工作温度的加热功率,确定了热源和测温点位置,拟定了升温策略.进行自粘胶胶枪加热试验,验证了仿真分析结果的准确性.     

Pricing Defaultable Bonds Using a Lévy Jump‐Diffusion Model

This paper uses a reduced‐form approach to derive a closed‐form pricing formula for defaultable bonds. The authors specify the default hazard rate as an affine function of multiple variables which follow the Lévy jump‐diffusion processes. Because such specification allows greater flexibility in the generation of a valid probability of default, their pricing model should be more accurate than the valuation models in traditional studies, which ignore the jump effects. This paper also proposes a new method for estimating the parameters in a Lévy Jump‐diffusion process. The real data from the Taiwanese bond market are used to illustrate how their model can be applied in practical situations. The authors compare the pricing results for the influential variables with no jump effects, with jump magnitudes following the normal distribution, and with jump magnitudes following the gamma distribution. The results reveal that the predictive ability is the best for the model with the jump components. The valuation model shown in this paper should help portfolio managers more accurately price defaultable bonds and more effectively hedge their portfolio holdings.