特种设备维修器材中心逼近式灰色预测建模研究

为提高特种设备维修器材消耗预测精度,构建中心逼近式灰色GM(1,1)预测模型,改善传统灰色GM(1,1)模型对特种设备维修器材中呈指数型消耗数据预测精度低甚至不适用的情况。通过计算对比,对某特种设备2016年维修器材消耗量的初步预测值进行了修正调整,并最终确定消耗预计值。     

基于组合预测模型的常耗车辆器材消耗规律研究

本文运用灰色理论和神经网络的广义加权平均组合预测模型对常耗器材消耗规律进行研究,建立了常耗器材消耗规律的数学模型,利用现有的常耗器材消耗统计数据,对所建模型进行验证,并结合发展趋势进行修正,最终得到符合实际的常耗车辆器材消耗规律.     

融合灰色理论与马尔科夫链的青岛市物流需求量预测

物流需求预测的准确性对物流基础设施投入和物流政策制定是至关重要的。根据物流需求受经济、社会发展和环境政策等不确定因素影响的特点,融合灰色理论与马尔科夫链,用灰色预测揭示系统时序变化的总体趋势,马尔科夫方法预测序列的随机波动的范围,能够优化灰色预测结果,提高预测的精度。以货运量为物流需求度量指标,建立灰色状态马尔科夫组合预测模型,对十二五期间青岛市物流需求量进行预测,预测结果可为青岛市十二五期间物流发展战略制定、物流服务体系构建和物流园区建设等工作提供理论参考和数据支撑。     

装备维修器材平时消耗预测方法研究

基于装备维修器材平时消耗的影响因素分析,建立了装备维修器材消耗的因果关系模型和系统动力学模型。针对不同故障率情况,分析所生成的器材消耗预测数据,并与实际数据相比较,验证了模型的适用性和方法的可行性,为科学预测装备维修器材消耗、做好维修器材保障工作提供了新的方法指导。     

灰色预测在航材消耗预测上的应用

针对航材种类繁多、规格复杂、准确预测航材消耗比较困难的问题,提出利用灰色系统理论中的GM(1,1)模型,根据历年航材消耗数据,确定其预测模型。算例表明本模型具有较大的准确性和实用性。     

基于灰色马尔科夫模型的道路施工期交通量预测

针对城市道路施工期,交通量历史数据少的特点,建立灰色马尔科夫交通预测模型,并以崇川路由西向东断面的交通量数据为例进行研究。结果表明,此模型相比于传统的GM1,1模型预测交通量具有更高的预测精准度,能够更好地研究道路施工期交通量的发展趋势。     

基于马尔科夫分析的航材消耗预测

准确预测航材消耗量对保障飞行意义重大,航材消耗的特点符合马尔科夫过程。马尔科夫预测是关于事件发生概率预测的方法,通过示例分析表明在样本数据符合条件的情况下运用马尔科夫分析对航材消耗进行预测能够取得较好的预测效果。     

基于组合灰色预测模型的物流企业运营成本预测

运营成本预测是物流企业制定企业发展战略的基础。文章基于GM(1,1)模型、Verhulst模型和SCGM(1,1)c模型建立组合灰色预测模型,运用预测有效度方法确定组合预测模型的权重系数,对物流企业运营成本进行预测。选用P物流企业2000—2009年的运营成本实际值作为原始数据,利用各预测模型预测2010—2012年物流企业运营成本。预测结果表明,组合灰色预测模型比单一预测模型具有更高的预测精度。在验证组合灰色预测模型可行性的基础上,进一步预测物流企业2013—2017年运营成本,为成本预测及相关领域提供理论及方法借鉴。     

基于优化灰色-马尔可夫链模型的铁路货运量预测

在传统的灰色预测模型中,传统背景值公式和初始值的选取方法会造成模型产生偏差。通过对背景值公式的改进和初始值选取方法的变化,构造出预测精度更高的灰色模型,即优化GM(1,1),并将优化GM(1,1)与马尔可夫链预测相结合,对我国的铁路货运量进行了预测分析,得出了相应的预测区间及其发生概率。通过理论分析和算例表明,该方法的预测结果比传统灰色模型预测结果更加可靠。     

支持向量回归机在装备维修器材消耗预测中的应用

首先介绍了ε-支持向量回归机(ε-SVR)的基本原理,而后把它引到装备维修器材的消耗分析当中,建立了预测模型,并结合例子进行仿真实验。仿真结果表明,模型可行、准确。     

Incumplimiento del salario mínimo en Europa central y oriental

En este estudio se analiza el incumplimiento del salario mínimo durante el periodo 2003–2012 en diez países de Europa central y oriental con salario mínimo obligatorio nacional. A partir de los datos de EU‐SILC y la metodología propuesta por Bhorat, Kanbur y Mayet (2013), se cuantifica la incidencia y magnitud del incumplimiento. Se realizan análisis de regresión sobre determinantes individuales, laborales y macroeconómicos. Aunque la incidencia permanece relativamente baja, los trabajadores a los que se dirigen las políticas de salario mínimo parecen los más expuestos a su incumplimiento. Con el tiempo, una mayor incidencia se asocia a una razón más alta entre salario mínimo y salario medio.     

Cultural Economy Planning in Creative Cities: Discourse and Practice

While a growing body of research analyses the functional mechanisms of the cultural or creative economy, there has been little attention devoted to understanding how local governments translate this work into policy. Moreover, research in this vein focuses predominately on Richard Florida's creative class thesis rather than considering the wider body of work that may influence policy. This article seeks to develop a deeper understanding of how municipalities conceptualize and plan for the cultural economy through the lens of two cities held up as model ‘creative cities’ — Austin, Texas and Toronto, Ontario. The work pays particular attention to how the cities adopt and adapt leading theories, strategies and discourses of the cultural economy. While policy documents indicate that the cities embrace the creative city model, in practice agencies tend to adapt conventional economic development strategies for cultural economy activity and appropriate the language of the creative city for multiple purposes.     

Input/output ranges and performance: an examination of US machine tool producers

Despite the establishment of high-tech multinational enterprises (MNEs) in Ireland since the late 1950s, the country did not succeed in closing the technological gap with most of its EU counterparts. The weak National System of Innovation (NSI), and in particular low business and government R&D levels, combined with a lack of research and technology linkages between MNEs and indigenous firms, explain these poor results. However, the Shannon region in the West of the country presents some specific institutional characteristics that could theoretically make the region a strong technological enclave. The various actors in the region - i.e. the administrative, financial, political and research institutions, as well as the business organizations - have indeed infused a new type of economic development. After a brief review of the available concepts and models articulated around these actors and their interrelationships, the paper analyses whether the Shannon region, taken as an illustrative example, mirrors a specific economic and technological localized setting. The study is based on a survey of indigenous and foreign firms.     

Sixty years of discrimination and diversity research in human resource management: A review with suggestions for future research directions

This article reviews discrimination and diversity research published in Human Resource Management (HRM) over the past 60 years. While discrimination and diversity are very different constructs, it is often informative to study them together, because when people recognize each other's diversity, this can result in bias, stereotyping, and discrimination. We conducted bibliographic searches for terms related to discrimination and diversity as well as a manual search through every title and abstract published in HRM over the last 60 years to assess article relevance. The search resulted in 135 research articles with 136 unique studies (i.e., samples) which are reviewed in this article. Sex and race are the demographics that have been examined the most in HRM, while religion has been examined the least. Moreover, the number of studies examining lesbian, gay, bisexual, transgender, and queer (LGBTQ) employees in the workplace in HRM has grown quickly within the past 10 years, culminating in a recent meta‐analysis. Our review looks at some of the earliest research published, the most recent research published, and the overall trends we identified in the research over the years for both discrimination and diversity articles. We then make future research suggestions and recommendations to advance the study of discrimination and diversity in the coming years.     

The Early History of the Cumulants and the Gram-Charlier Series

The early history of the Gram-Charlier series is discussed from three points of view: (1) a generalization of Laplace's central limit theorem, (2) a least squares approximation to a continuous function by means of Chebyshev-Hermite polynomials, (3) a generalization of Gauss's normal distribution to a system of skew distributions. Thiele defined the cumulants in terms of the moments, first by a recursion formula and later by an expansion of the logarithm of the moment generating function. He devised a differential operator which adjusts any cumulant to a desired value. His little known 1899 paper in Danish on the properties of the cumulants is translated into English in the Appendix.     

Capturing the Implications of Services Trade Liberalization

This paper evaluates the impact of service sector trade liberalization on the world economy by a ten-region, eleven-sector CGE model with import embodied technology transfer from developed countries to developing countries. Simulation results show that service sector trade liberalization not only directly affects world service production and trade, but also has significant implications for other sectors in the economy. The major channel of the impact is through inter-industry input-output relations and TFP growth induced from services imported by developing countries from developed countries, which may be embodied with new information and advanced technology.     

City Children and Genderfied Neighbourhoods: The New Generation as Urban Regeneration Strategy

Former industrial cities in the West are employing gentrification as urban policy. In these policies, women and families currently play an important role as gentrification pioneers. In my analysis of Rotterdam in the Netherlands, I propose the term genderfication to understand the gender dimensions of this process. Genderfication refers to the production of space for different gender relations. I analyse Rotterdam's urban planning program for becoming a ‘child‐friendly city’, which entails replacing existing urban dwellings with new, larger and more expensive ‘family‐friendly homes’ as a strategy for urban re‐generation. Urban re‐generation supplements regeneration in the form of material and economic restructuring, and refers to the replacement of part of the current population by a new and better suited generation. The ‘child‐friendly city program’ is considered in tandem with punitive ‘youth policies’.     

Hierarchical Models in Environmental Science

Environmental systems are complicated. They include very intricate spatio-temporal processes, interacting on a wide variety of scales. There is increasingly vast amounts of data for such processes from geographical information systems, remote sensing platforms, monitoring networks, and computer models. In addition, often there is a great variety of scientific knowledge available for such systems, from partial differential equations based on first principles to panel surveys. It is argued that it is not generally adequate to consider such processes from a joint perspective. Instead, the processes often must be considered as a coherently linked system of conditional models. This paper provides a brief overview of hierarchical approaches applied to environmental processes. The key elements of such models can be considered in three general stages, the data stage, process stage, and parameter stage. In each stage, complicated dependence structure is mitigated by conditioning. For example, the data stage can incorporate measurement errors as well as multiple datasets with varying supports. The process and parameter stages can allow spatial and spatio-temporal processes as well as the direct inclusion of scientific knowledge. The paper concludes with a discussion of some outstanding problems in hierarchical modelling of environmental systems, including the need for new collaboration approaches.     

Multinomial distributions applied to random sampling of particulate materials

When sampling a batch consisting of particulate material, the distribution of a sample estimator can be characterized using knowledge about the sample drawing process. With Bernoulli sampling, the number of particles in the sample is binomially distributed. Because this is rarely realized in practice, we propose a sampling design in which the possible samples have a nearly equal mass. Expected values and variances of the sample estimator are calculated. It is shown that the sample estimator becomes identical to the Horvitz–Thompson estimator in the case of a large batch-to-sample mass ratio and a large sample mass. Simulations and experiments were performed to test the theory. Simulations confirm that the round-off error due to the discrete nature of particles is negligible for large sample sizes. Sampling experiments were carried out with a mixture of PolyPropylene (PP) and PolyTetraFluorEthylene (PTFE) spheres suspended in a viscous medium. The measured and theoretical variations are in good agreement.