大功率电子发射管的正确使用及延长其寿命的方法

大功率电子发射管广泛应用于广播电视发射设备及其他电子通信设备,文章介绍了采用冷打压老炼、灯丝电压调整、谐振匹配等技术方法延长电子管的使用寿命。     

Pensions reforms,workforce ageing and firm-provided welfare

This paper investigates the impact of an exogenous increase in the legal retirement age on the firms’ propensity to provide welfare services voluntarily to their employees. To this purpose we exploit a unique information derived from the Rilevazione su Imprese e Lavoro (RIL), a survey conducted in 2015 on a large and representative sample of Italian firms. Applying different regression models we show that firms which were forced to give up previously planned hirings because of the Law 201/2011 (the so-called ‘Fornero pension reform’), increased the probability of providing welfare services at workplace. By referring to the sociological, human resource management and economic literature we then argue that a sudden increase in the legal retirement age may motivate the employers to establish welfare schemes as a way to cope with an ageing workforce. Our findings also hold when propensity score matching methods are used in order to control for sample selection issues.     

Milk sales and dietary diversity among the Maasai

In Maasai culture, responsibilities are traditionally divided between genders. Men are in charge of grazing and managing the livestock herds. Women take care of the family, administer food supplies, and are responsible for milking. For them, balancing home consumption of milk (for the family and for the calves), milk sale, and food purchase is a major task. In this article, we first investigate how different milk sales groups vary regarding the use of different food items and the respective quantities consumed by the enkaji, i.e., a Maasai subhousehold. Then, we address the commercialization decision and assess the effect of milk sales on the enkaji's food item use and food consumption. Using the data of Maasai enkajijik in the milk catchment area of a milk collection center in Ngerengere, Tanzania, we estimate the effects by employing propensity score matching procedures. Our findings suggest that milk sellers, especially those selling to the milk collection center, have a more diverse diet. In terms of per person consumption, the groups are markedly similar. Therefore, we conclude that income generated by milk sales is invested in diet diversification rather than in increasing the quantity of food consumed, hence the enkajijik appear not to make use of caloric terms of trade.     

金融租赁公司的利率风险及管理对策

金融租赁公司所面临的诸多利率风险中,成熟期错配风险是最为关键的,久期模型是其通用的衡量方法。金融租赁公司的久期缺口分析是利用久期管理利率风险的主要方法,但久期模型运用中也存在着诸如久期对称成本高、利率风险免疫动态性及凸性等问题。金融租赁公司面对利率上升的风险,应采取设立风险管理部门、做好基础资料积累与分析、加强利率走势预测及对金融衍生工具的研究等对策措施。     

From quality to innovation: Evidence from two French Employer Surveys

In this article we investigate the impact of quality systems on innovation performance using the method of propensity matching. We use two French microeconomic surveys, the “Organizational Changes and Computerization” (COI 1997) and the “Community Innovation Survey” (CIS3 1998–2000). The first hypothesis indicating that quality (ISO 9000 certification) impacts positively on innovation is supported for certain areas of innovation performance. Furthermore, the second hypothesis states that different levels of quality differentially improve innovation performance. Results indicate that the innovation performance of firms with Top Quality Level is higher than that of firms with Medium Quality Level which is also higher than that of firms with Low Quality Level for certain areas of innovation. However, we found that the difference in innovation performance between firms with Medium and Low Quality Levels is not of a great magnitude. This study implies that in order to achieve a significant innovation performance improvement via quality systems, a very well-established quality system is needed within a firm.     

Corrigendum to “On randomized matching mechanisms” [Economic Theory 8(1996)377–381]

Ma (in Econ. Theory 8, 377–381, 1996) studied the random order mechanism, a matching mechanism suggested by Roth and Vande Vate (Econometrica 58, 1475–1480, 1990) for marriage markets. By means of an example he showed that the random order mechanism does not always reach all stable matchings. Although Ma's (1996) result is true, we show that the probability distribution he presented – and therefore the proof of his Claim 2 – is not correct. The mistake in the calculations by Ma (1996) is due to the fact that even though the example looks very symmetric, some of the calculations are not as “symmetric.” We thank two anonymous referees for their helpful comments. B. Klaus’s and F. Klijn’s research was supported by Ramón y Cajal contracts of the Spanish Ministerio de Ciencia y Tecnología. The work of the authors was also partially supported through the Spanish Plan Nacional I+D+I (BEC2002-02130 and SEJ2005-01690) and the Generalitat de Catalunya (SGR2005-00626 and the Barcelona Economics Program of CREA).     

股权激励存在持续性的激励效应吗？--基于倾向得分匹配法的实证分析

为克服样本选择偏误,本文采用倾向得分匹配法,在六年的时间框架内检验了股权激励效应的持续性问题。研究发现：整体而言,激励组的ROE和Tobin’s Q值均显著高于控制组,说明股权激励能有效地提高企业的财务绩效和市场价值;激励组的ROE在股权激励计划实施后的三年时间里均显著高于控制组,三年之后逐渐与控制组无显著差异,表明股权激励对企业财务绩效的提升作用能持续三年时间;激励组的Tobin’s Q值在实施的第一年与控制组无显著差异,但在随后的四年时间里均显著高于控制组,表明股权激励对企业市场价值存在长达四年的持续提升作用,但存在为期一年的时滞效应。     

分块自适应图像稀疏分解

针对图像稀疏分解的计算时间复杂度非常高这个问题，提出了分块自适应图像稀疏分解算法。该算法根据稀疏分解计算时间复杂度和待分解图像大小之间的关系。把待分解图像分成互不重叠的小块。然后对每个小块图像进行稀疏分解。根据每一块的复杂程度。自适应地决定稀疏分解的结束。实验结果表明。在分解原子个数相近或相同的条件下。新算法对稀疏分解后重建图像比在整幅图像上进行稀疏分解重建的图像质量下降0．5dB。但计算速度提高了约15倍。     

正确把握大思路 配套推进分税制——兼与“纵向分两段，横向分两块”的主张商榷

本文认为,以分税制为基础的分级财政是市场经济新体制所要求的财政体制,需要在统一市场构建中逐步贯通运行这一财政体制,过渡措施不应凝固为实现中长期目标的障碍,要正确把握大思路,配套推进分税制。     

新创企业成长阶段与高管行为整合的匹配性:案例研究

在对新创企业的成长阶段进行划分的基础上,采取典型案例研究方法,分阶段地探讨高管行为整合与新创企业成长阶段的匹配性。研究发现:新创企业的成长在青春期阶段与高管行为整合的关系为不匹配,在调整期阶段与高管行为整合的关系需要根据企业是否具有行为整合的条件来确定,在稳定期阶段与高管行为整合的关系为匹配。