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1.
It is a wide-held assumption that professional development and change within purchasing and supply management (PSM) organisations can be explained and guided by a maturity model. In this paper the guidance which the maturity model concept offers to understand a PSM organisation's performance is assessed. The methodology is based on the outcomes of a literature review of PSM maturity models, development of an organisational change framework and the learning from three qualitative case studies. An alternative understanding of the development of the PSM organisation is offered through an organisational change framework, composing 1) movement transitions, 2) scalability of change, 3) acceptability of change, and 4) the substantive element of change. The research found that extant PSM maturity models are too rigid for PSM managers to apply, and although maturity models are commonly accepted in PSM literature, in practice, they may produce the opposite effect of what is promised. The PSM maturity models suggest that their application will lead to increased status and influence of PSM within the organisation; expectations that may not be met. PSM organisations’ change processes are subjected to a range of situational and contextual power relations which must be considered in order to advance the specific PSM organisation roles and responsibilities.  相似文献   
2.
我国大麦价格波动特征及其影响因素分析   总被引:1,自引:0,他引:1  
[目的]大麦价格剧烈波动会直接影响大麦种植户的生产积极性和大麦产业的平稳发展,研究大麦价格波动特征及其影响因素,有助于提升大麦产业链相关主体识别和应对市场风险的能力,促进大麦产业的健康发展。[方法]文章先采用HP滤波法和ARCH类模型分析了2011年4月至2017年2月我国大麦价格波动特征,然后采用脉冲响应函数分析了我国大麦价格波动影响因素。[结果]我国大麦价格波动存在明显的季节性和周期性,样本期内总体上呈现逐渐下降趋势;我国大麦价格具有显著的波动集聚性,我国大麦价格具有显著的不对称性;在该文选择的影响因素中,大麦进口量和国际大麦价格是影响我国大麦价格波动的主要因素。[结论]该文提出必须保障并提高国内大麦合理产能、完善大麦价格监测预警体系、加强国内大麦进口企业整合和推动大麦进口来源多元化的政策建议。  相似文献   
3.
In implementing its national strategy to achieve global leadership, China needs a new public administration theory that integrates political administration, economic management and social regulation. Even so, China has already started to promote its brand of political and economic development abroad. Therefore new comparative research and dialogue is called to explore the universality of Chinese and Western public administration ideas.  相似文献   
4.
In this article, I first expound John Kenneth Galbraith’s general theory of power. Galbraith always took into account phenomena of power in economics, and shed light on the power of economists in particular. I then show how the reaction of conservatives to the broadcasting of the Age of Uncertainty highlights the relevance of Galbraith’s theory. Letters exchanged by conservative Lords in an effort to fight against Galbraith’s ideas paradoxically illustrate his theory. This leads to questions about the status of economists, popularizers, and experts. Finally, I argue that convictions have a crucial role in scientific production, and that Robert Solow’s distinction between the “serious scholars” and the proselyte economist is irrelevant because of its incapacity to understand how economists produce knowledge.  相似文献   
5.
为了抑制脉冲噪声对电力线正交频分复用(OFDM)通信系统的影响,最常用的方法之一是在接收端OFDM解调器之前前置一个置零非线性单元,即传统置零法。然而,由于引入了非线性失真,其性能并不理想。针对传统置零法引起的非线性失真问题,提出了一种基于迭代消除非线性失真的改进置零法。首先,对接收到的时域OFDM信号进行脉冲噪声检测和置零处理;然后,在频域利用已检测的符号来重构时域置零处理引入的非线性失真,并通过迭代提高重构的准确性;最后,从频域接收信号中减去重构的非线性失真。仿真结果表明,所提改进算法与传统置零法相比,有非常大的性能提升,增强了电力线OFDM通信系统对脉冲噪声的抵抗能力。  相似文献   
6.
为了确保卫星系统电磁兼容性满足要求,设计了一款应用于卫星测控通信系统的小型化S频段高谐波抑制功率放大器。通过在功放输出端设置谐波抑制网络改善了电路的谐波抑制性能。采用集总与分布参数元件相结合匹配形式,实现了电路的小型化设计。电路尺寸38.5 mm×28.2 mm。通过对功放腔体结构进行细化建模仿真,确保了功放电路的稳定性。实测结果表明,当工作频率为2.52 GHz时,功放1 dB压缩点大于31 dBm,谐波抑制度大于61 dBc,功率附加效率高于35%,1 dB带宽大于320 MHz。与国内外同类产品相比,该功放在谐波抑制性能等方面具有明显优势。  相似文献   
7.
为了解决宏蜂窝与飞蜂窝构成的两层异构网络上行干扰与资源分配问题,提出了一种在认知型飞蜂窝的双层异构网中结合子信道分配和功率控制进行资源分配的框架。通过对异构网中跨层干扰问题进行分析与建模,将求解最优子信道分配矩阵和用户发射功率矩阵作为干扰管理问题的解决方法。模型中认知型飞蜂窝网络子信道和飞蜂窝网络用户构成非合作博弈,双方利用效用函数最优值进行匹配,构成初始信道分配矩阵;再由接入控制器根据接入条件从初始信道分配矩阵中筛选用户,并优化接入用户的发射功率矩阵,得到最优子信道分配矩阵和功率矩阵。仿真结果表明,优化框架提高了双层异构网络中飞蜂窝网络用户的吞吐量和接入率,降低了异构网中跨层干扰。  相似文献   
8.
Ram (2015. Hostility or hospitality? A review on violence, bullying and sexual harassment in the tourism and hospitality industry. Current Issues in Tourism. doi:10.1080/13683500.2015.1064364) posits that violence and harassment are areas of concern within the hospitality industry, and scholarly interest in abusive supervision in the workplace has grown since the last decade. This study extends Ram's (2015. Hostility or hospitality? A review on violence, bullying and sexual harassment in the tourism and hospitality industry. Current Issues in Tourism. doi:10.1080/13683500.2015.1064364) assertion by examining the effect of abusive supervision experiences on student employees’ turnover intentions in a hospitality and tourism context in a high power distance culture, Ecuador. The results showed that abusive supervision was positively related to turnover intentions, and its effect was stronger than co-worker support, with the abusive supervision–turnover intentions relationship being fully mediated by perceived organizational support (POS). In addition, co-worker emotional support was found to attenuate the negative effects of abusive supervision on POS. All in all, the findings highlight the roles of POS in explaining the relation between abusive supervision and turnover intentions and co-worker emotional support in buffering the negative effect of abusive supervision. The important role of culture is discussed.  相似文献   
9.
Finite mixtures offer a rich class of distributions for modelling of a variety of random phenomena in numerous fields of study. Using the sample interpoint distances (IPDs), we propose the IPD‐test statistic for testing the hypothesis of homogeneity of mixture of multivariate power series distribution or multivariate normal distribution. We derive the distribution of the IPDs that are drawn from a finite mixture of the multivariate power series distribution and multivariate normal distribution. Based on the empirical distribution of the IPDs, we construct a bootstrap test of homogeneity for other multivariate finite mixture models. The IPD test is applied to mixture models for matrix‐valued distributions and a test of homogeneity for Wishart mixture is presented. Numerical comparisons show that IPD test has accurate type I errors and is more powerful in most multivariate cases than the expectation–maximization (EM) test and modified likelihood ratio test.  相似文献   
10.
This study examines the impact of stock price crash risk on future CEO power. Using a large panel sample with 17,816 firm-year observations, we posit and find a significant negative impact of stock price crash risk on CEO power, suggesting that CEO power becomes smaller after stock price crashes. We also find that our results are stronger for firms with female CEOs and are largely driven by firms with shorter-tenure CEOs. In addition, we find that the significant negative impact of stock price crash risk on CEO power is diminished for firms with strong corporate governance. Our study responds to the call in Habib, Hasan, and Jiang (2018) by providing more empirical evidence on the consequences of stock price crash risk.  相似文献   
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