全球稀土消费预测模型研究

为了准确把握全球稀土消费变化,本文在分析单整自回归移动平均(ARIMA)模型与非线性灰色伯努利(NGBM)模型特点的基础上,采用粒子群优化算法(PSO)对非线性灰色伯努利模型的参数进行了优选,建立了ARIMA耦合PSO-NGBM的全球稀土消费的时间序列预测模型。该模型将全球稀土消费时间序列的数据结构分解为线性自相关主体和非线性残差两部分,首先用ARIMA模型预测序列的线性主体,然后用PSO-NGBM模型对其非线性残差进行估计,最终合成为整个序列的预测结果。预测结果表明,耦合模型的预测准确率显著高于单一的ARIMA模型的预测准确率,从而证实了耦合模型用于全球稀土消费预测的有效性。     

基于ARIMA-RF组合模型的国内动力煤价格预测

选取秦皇岛港口动力煤价格作为研究对象,搜集10年间煤价数据并分析其影响因素,确定煤炭产量、港口库存、运输成本、火力发电量及社会用电量为主要影响因素;分别建立ARIMA(2,1,2)模型和RF(随机森林)模型并优化,通过加权平均法得到ARIMA和RF模型权重,建立ARIMA-RF组合模型。该模型较深度神经网络模型(DNN)、支持向量回归模型(SVR)、ARIMA模型、RF模型预测的煤价准确度更高,可准确预测动力煤价格走势,为调控能源消费强度、深化能源体制机制改革政策制定提供参考。     

基于消费强度分析的钢材需求预测

以1982—2011年的数据为样本,建立了钢材消费强度预测的ARIMA模型和回归模型;并基于2012—2020年的测试样本数据对模型预测效果进行了评估和比较,发现回归模型取得了较好的预测效果;结合权威机构对2025年相关变量数据的预测,利用该模型估计2025年钢材消费强度约为0.07,届时钢材表观消费量将在96000万吨左右。     

辽宁省水资源需求量预测分析

结合辽宁省水资源需求的总体变化趋势以及社会经济发展用水现状,详细分析了GM(1,1)、Logistic模型理论和参数特征后将上述2种模型有效结合构建了组合预测模型,对辽宁省水资源需求量进行预测分析并对预测结果采用ARIMA模型进行了一级修正;然后根据辽宁省综合节水潜力和节水规划总体目标对预测结果进行二级修正。研究表明:水资源需求量二级修正预测结果能够更加准确、客观地反映区域水资源需求现状,模型表现出较高的准确度与可靠性。     

高频视角下创业板市场的非对称尾部风险度量

创业板汇集了大批高成长性的科技企业,面临着高度不确定的市场风险。本文考虑创业板市场的非对称性和厚尾性,在偏t分布下利用5分钟高频数据构建已实现GARCH模型衡量其波动率,同时考虑到微观结构噪声影响,在RV的基础上引入对噪声稳健的BPV已实现测度,从而提升高频VaR模型的预测准确性。对创业板指和深证成指的实证结果表明,已实现GARCH模型在参数显著性和模型预测准确性方面均优于低频下的ARMA-fGARCH-VaR模型;基于RV和BPV的已实现模型没有显著差异;相比于深市主板,创业板面临的尾部风险更大。同时,为更好地监测与管控创业板市场风险,从政府和创业企业两个层面提出对策建议。     

基于ARIMA-SVM的煤炭价格预测及实证研究

煤炭价格是煤炭市场最重要的风向标,预测煤炭价格对我国煤炭行业及相关产业发展具有重要意义,为提高煤炭价格预测的准确度,提出了基于ARIMA-SVM的煤炭价格预测方法。ARI-MA-SVM考虑了煤炭价格时间序列自身特性和对煤炭价格的多种影响因素,采用平均加权的方式将ARIMA和SVM的预测结果进行结合,以期得精度较高、误差水平低的预测结果。对环渤海动力煤价格进行了预测实证分析,实验结果表明,与分别采用ARIMA或SVM的预测结果相比,ARI-MA-SVM方法可以对煤炭价格进行精度更高的预测。     

基于ARIMA模型的全国煤层气产量预测研究

我国煤层气产业发展迅速,煤层气地面开发取得重大进展,勘探开发利用规模也呈逐年增长趋势。对未来煤层气产量进行预测,对煤层气产业发展成为新型能源产业提供政策起到了,通过构建ARIMA (1,0,5)模型,预测了我国2019—2025年全国煤层气地面产量,预测结果表明未来5年煤层气产量持续增长,且增长速度持续加快。建议不断增强煤层气开发技术,深化煤层气体制改革,加强煤层气产业的创新驱动力,从而更好的将煤层气产业发展成为我国重要的新型能源产业。     

基于ARIMA模型的电网线路工程造价预测分析

正本文以国网北京市电力公司2009～2016年的架空和电缆8年的工程数据为基础,运用ARIMA模型的预测方法,对历史工程数据进行训练和测试,可以预测出2017年架空和电缆线路的单位长度造价,实现工程总体指标的预测,并使误差在合理范围内,有效控制工程造价,为公司投资管理决策提供有力支撑。     

目标企业产品销量的预测模型与分析

本文主要应用时间序列模型中的ARIMA模型、疏系数ARIMA模型和自回归、残差自回归几种模型,对目标空调企业1996—2007年的全国空调总销售量月度变化进行建模。通过比较和分析各模型的数据拟合情况和所得的特征统计量,评价各模型的优劣,得到拟合该空调企业销量变化的最优模型,并利用所得模型计算出该企业空调未来十个月总销量的预测值,供该企业生产、营销部门参考。     

GARCH型过程控制图在汇率市场预警监控中的应用

金融数据常被用来进行金融市场预测和决策,本文从控制图角度出发,对汇率市场收益率采用AR、MA、ARMA和GARCH四类模型比较研究,最终使用异方差模型建立控制限随时间变动控制图.文中数据来源于2000～2008年美元兑日元汇率共2731个日收盘价,利用对数收益率方法,建立GARCH(1,1)型休哈特控制图.具体解释2008年超出控制限的时点所体现的宏观经济、政治等事件影响以及微观个人行为因素,此类控制图较好的监测出宏微观因素所致的汇率市场波动性.     

Comparing FTTH access networks based on P2P and PMP fibre topologies

There is an ongoing discussion in the market which Next Generation Access (NGA) architecture best suits future needs and which investment and cost differences exist. The discussion can be subsumed as P2P vs. GPON, which is somewhat misleading as this article reveals. The discussion is driven by the fact that the high capital cost and the long asset life time of fibre mean that the technology choices made today will dominate the opportunities for telecommunication business of all market players, incumbents, competitors, content providers and business and residential users for many years in the future.The paper analyzes the cost and other differences between Fibre-to-the-Home (FTTH) access network architectures and their related different wholesale approaches by using the well-known and understood steady state approach applied in other NGA analyses in the past. In addition to the steady state analysis a dynamic cost evaluation is included taking into account the different investment behaviour of the FTTH architectures over time. The results describe investment and cost differences between architectures, incumbents and wholesale based competitive operators. The analysis has been performed for different geotypes (clusters) of decreasing population density in a representative European settlement structure.     

Divergent patterns of engagement in Internet standardization: Japan,Korea and China

This article analyzes the engagement of Japanese, Korean and Chinese participants in the development of Internet standards at IETF on the basis of four quantitative metrics: attendance, patenting, authorship and leadership. The results are strikingly divergent. Japanese involvement in Internet standardization began early and Japan was, for many years, second only to the U.S. in terms of IETF participation. Though Japanese participation has declined since the early 2000s, Japan remains a major contributor to IETF standardization. Korean involvement in IETF has always been significant, but below the levels of Japan and major European countries. Korean participation in IETF has also declined over the past decade, and has been dominated by one firm, Samsung. Though meaningful Chinese involvement in IETF did not begin until the mid-2000s, it has rapidly expanded in recent years. Today, China is a major player in numerous areas of Internet standardization in terms of three metrics (participation, patenting and leadership), and is rapidly gaining in terms of document authorship as well. Most of China׳s recent IETF involvement can be attributed to Huawei, though other Chinese firms have recently begun to increase their participation in the organization. Thus, contrary to some views that China׳s engagement with standardization is primarily one of indigenous innovation and “catching up”, China׳s experience with IETF demonstrates deliberate and effective engagement with a major Western standards-development organization on its own terms.     

快速成形技术的应用及热点分析

基于快速成形技术的原理,展示了快速成形技术在快速模具制造、金属零件直接成形、反求工程等领域的广泛应用,总结了快速成形制造技术研究的热点,即研发新材料和新设备、提高成形精度、建立RPM的反求工程系统、建立成形技术的统一标准和扩大成形技术的应用领域。     

Whose Image is it Anyway?: Some Considerations of the Curricular Importance of Subject Image in Secondary School Design and Technology Education

This paper explores the idea that a sense of school subject image is a necessary feature of curriculum management and a potent force for change. The discussion centres on the view that all school subjects have an image and that if those intimately involved with the subject do not control the image then someone else does! In such circumstances the image is the product of past encounters and old euphemisms and is unlikely to hold the changed realities.The UK developments in Design and Technology education (the term Design and Technology is used to denote the school subject defined under this heading by the UK National Curriculum, 1995) have created something of an image problem which has interesting international parallels. Some of these problems are due to clearly discernible internal tensions and an ambiguous relationship with other subject areas.Through greater attention to subject image internal controversies might be acknowledged and resolved, relationships with other subject areas can be more meaningfully understood and practitioners can be helped to make sense of curriculum change.     

Indigenous peoples’ nutrition transition in a right to food perspective

In indigenous communities the nutrition transition characterized by a rapid westernization of diet and lifestyle is associated with rising prevalence of chronic disease. Field work and literature reviews from two different policy environments, Argentina (Jujuy) and Canada (Nunavut), identified factors that add to indigenous peoples’ disease risk. The analytical framework was the emerging human right to adequate food approach to policies and programmes. Indigenous peoples’ chronic disease risk tends to increase as a result of government policies that infringe on indigenous peoples’ livelihoods and territories, undermining their economic system, values and solidarity networks. Policies intended to increase food security, including food aid, may also fuel the nutrition transition. There is a need to explore further the connection between well-intended policies towards indigenous peoples and the development of chronic diseases, and to broaden the understanding of the role that different forms of discrimination play in the westernization of their lifestyles, values and food habits. Food policies that take due account of indigenous peoples’ human rights, including their right to enjoy their culture, may counteract the growth of chronic disease in these communities.     

HSE走进中国石油

企业管理水平的好坏直接影响着企业的经济效益,运用HSE管理能提高企业管理水平,HSE管理模式将健康,安全,环境三者视为一个有机的整体。HSE管理认为人的安全是第一位的,人是创造财富的原动力,是企业的最大财产,HSE管理体系强调的是“蝴蝶效应”。     

A strategic skill based model of supplier integration and its effect on supply management performance

Supplier integration is a tool to help organizations gain competitive advantage. Strategic supply management skills and the supply management function's perceived status are hypothesized as antecedents to supplier integration leading to supply management performance. The sample for this study includes 152 executive level supply management professionals. The empirical results suggest that strategic skills and perceived status are essential antecedents to supplier integration and subsequent performance. Further, the relationship between strategic skills and performance is mediated by supplier integration. Results of a dominance analysis also suggest which strategic skills are most likely to explain status integration, and performance. These findings have significant implications for supply management theory and practice.     

Cost allocation of WCDMA and wholesale pricing for mVoIP and data services

This study estimates cost-based prices for wholesale voice and data services provided to 3G (WCDMA) MVNOs according to their distinct types. For estimation, 3G MVNOs are classified into different types, and the overall cost of WCDMA facilities are separated into voice and data components based on their subscriber rates, actual traffic rates, as well as efficiency consideration of traffic rates. The study then calculates cost-based wholesale prices of voice and data services for each of the 3G MVNO types. The result of this study shows that a cost-plus pricing scheme can help achieve the policy goals of the regulator, namely, lowering telecommunications tariffs and facilitating the introduction of new convergent-type services, far more effectively than the current retail-minus pricing scheme. The findings of this study may assist firms in developing business models based on 3G networks and telecom regulators in designing policies related to interconnection, mVoIP, prepaid calls, wholesale services, and network neutrality.     

Collectivism,individualism, and outgroup cooperation in a segmented China

A consistent theme in cross-cultural management research is that collectivists are more cooperative than individualists. We use Hofstede's measure for individualism–collectivism and combine it with an experimental measure of cooperation to test this relationship in China. In contrast to the established paradigm, we find that groups with higher individualistic scores are more cooperative than those groups with higher collectivistic scores. We attribute these results to groups being composed of outgroup members. In addition, we find that subjects from the more developed coastal area are more individualistic and cooperative than are subjects from inland China.

Material power and normative conflict in global and local agrifood governance: The lessons of ‘Golden Rice’ in India

This special section aims to investigate the interaction of global and local forces in shaping agrifood governance. It starts from the recognition that a multitude of actors and norms shape today’s agrifood system. The resulting opaqueness of the systems makes it extremely difficult to understand and explain processes and outcomes of agrifood governance. Given the sustainability challenges facing the agrifood system, improvements in our understanding of what the interaction of global and local actors and norms means on the ground are urgently needed, however. The section, therefore, analyses agrifood governance in India across a selected group of cases. It does so by employing a systematic framework emphasizing the material and ideational dimensions of power and their interaction. The section has chosen India as the setting in which to analyze this interaction due to the crucial role the food demand and supply of this rising power plays in today’s agrifood system. This article provides the special sections’ analytical framework, which uses the interplay of material and ideational dimensions of power as a focal lens. In addition, the article applies this framework to an empirical study of the political conflict around GMO foods in India, specifically the case of ‘Golden Rice’.