基于灰色线性回归组合模型的航班起降架次预测研究

基于线性回归模型和灰色预测模型的优缺点,将两种模型相结合,采用灰色线性回归组合模型结合历年的航班起降架次,对未来航班起降架次进行预测.通过对预测结果及实际数据的对比分析,2020年的航班起降架次预测结果与实际数据相比误差较大,其余年份预测结果与实际值误差均小于5％,考虑到疫情对民航的影响,该模型总体上能够较好的对航班起降架次进行预测,预测结果较准确.     

关于正确使用虚拟变量的探讨

虚拟变量是表示属性的变量,使用到经济计量模型中,应该表示重要的属性。但是在我国目前的一些宏观经济模型中,虚拟变量被使用得太多了。我国处于改革开放的过程中,不时会有一些特殊原因对经济变量产生正面或负面影响,因此,模型作者很容易为其被解释变量中的离群数据找到理由,在解释变量中加入相应的虚拟变量,拟合出精度很高的模型。但是,这样构造的模型,拟合精度越高,预测精度也就越差,因为我们不知道未来会有甚么“特殊原     

航班计划优化研究概述

从航班计划优化的不同时间阶段分析,可以将航班计划优化分为航班计划静态编排优化、基于航班延误预测的航班计划动态反馈优化和基于机场协同决策(A-CDM)的航班计划动态调整角度三类;进而从航班时刻、机型指派、航班频率等编制环节分析了航班计划静态编排优化;随后利用延误波及预测与数据挖掘预测的优化方法分析了基于航班延误预测的航班计划动态反馈优化的相关研究。最后,根据航班计划优化复杂性分析,给出了航班计划优化的发展趋势和未来研究方向。     

一个新的U-MIDAS-Mlogit模型及应用

研究目标:解决响应变量与解释变量存在混频观测时的多分类分析问题,扩展多项选择Logit(Multinomial Logit, Mlogit)模型到混频数据环境下,使之能够处理混频数据并实现多分类预测。研究方法:将无约束混频数据抽样(U-MIDAS)技术引入Mlogit模型中,构建U-MIDAS-Mlogit模型,给出其极大似然估计。研究发现:新建的U-MIDAS-Mlogit模型,不但能够高频预测响应变量的多分类结果,而且具有比传统Mlogit模型更高的分类精度。研究创新:提出了一个新的U-MIDAS-Mlogit模型,能够直接对原始混频数据进行建模,克服了传统Mlogit模型需要进行数据同频化处理的局限,提升了Mlogit模型的功能,提高了多分类预测效果。研究价值:U-MIDAS-Mlogit模型具有广阔的应用前景,能够解决一类混频数据环境下的多分类分析问题,本文从数值模拟与模型应用两个层面进行了证实。     

混合数据抽样波动模型

混合数据抽样(MIDAS)模型能处理不同频率变量间的动态关系。本文比较了MIDAS波动模型和ABDL模型,发现我国股市对数实现波动呈长期记忆性。在预测波动方面,ABDL模型优于MIDAS模型;利用MIDAS波动模型预测实现波动水平,日绝对值报酬是最好的回归项;利用MIDAS模型预测未来波动,至少应采用一个月的历史数据。     

居民存款增量影响因素地区差异的实证分析

本文在现代储蓄理论的基础上，结合中国华南三省的实际情况，修改假设、增减变量，利用官方数据做出了各省居民存款的计量模型，比较分析了收入等变量对经济发展程度不同地区居民存款的不同影响，得出了几个主要结论；用灰色系统方法对各省的居民存款做了预测。     

文化休闲景区游客满意度测评

本文通过对国际上认可度较高的顾客满意度指数模型进行改进,在此基础上构建了文化休闲景区顾客满意度指数的模型。通过对大雁塔文化休闲景区进行大量的调查,通用统计分析软件对调查数据进行处理分析,再分析探究模型中观测变量是否对文化休闲景区具有显著影响,模型的变量之间系数与假设是否一致,从而验证模型拟合的良好性,验证模型的合理性和普遍适用性,以期望对文化休闲景区游客满意度研究提供建议和对策。     

基于粗糙集和神经网络的数据挖掘应用

本论文就是根据电信行业需求,针对电信企业拥有大量详实而且丰富的数据,但是可用有效数据提取困难这一问题。首先利用粗糙集理论中的差别矩阵方法对电信客户数据进行属性约简,之后采用BP(Back Propagation)神经网络建立基于粗糙集和神经网络的数据挖掘模型,实现对电信业务系统的客户数据信息进行有效分析和高效提取,并通过matlab实现了仿真模拟。所建立的模型,减少神经网络的输入层个数、简化了运算次数、缩短了训练时间并提高数据预测的准确度。     

基于灰色预测国内航班延误模型研究

本文从动态演化的视角,研究了有关航班延误的国内外文献,认为影响我国航班延误因素有以下几点:航空公司自身原因、流量控制、天气原因和其他不确定因素。了解到航班延误程度与航班总量成正比。基于灰色预测模型,建立了我国航班延误总量和航班延误因素的时间数列GM(1,1)模型,经检验模型的预测精度可靠,依据所求模型,计算出了2014-2018年的航班总量,预测该时间内航班延误因素的比重,用于预防航班延误等突发状况,从而减少航空公司的损失和旅客们因等待而浪费的时间。     

基于GM(1,1)模型的湖南文化创意产业的发展预测

本文采用灰色模型对湖南省文化创意产业的发展状况做预测,对缺失的数据利用牛顿插值法补全,使之符合模型要求。将模型得到的数据与实际数据做对比,发现二者符合良好。利用该模型预测了2016到2020年湖南省文化创意产业总产出额,预测结果对未来湖南省文化创意产业政策效果的评估有一定的参考价值。     

Development in Information and Communications Technology (ICT) Statistics at the Australian Bureau of Statistics

This paper outlines the ICT statistical developments that the ABS has undertaken over recent years. These developments have been on both the supply side (ICT industry) and the demand side (use of IT by sector). The content of ABS ICT surveys has changed significantly over the last few years and are expected to develop further in line with industry changes and emerging policy needs.
Recent developments in household collections have been the inclusion of IT use questions in the 2001 Census of Population and Housing and in various ABS social surveys such as Children's Participation in Culture and Leisure Activities. Annual business IT use surveys are now conducted and include topics such as Internet commerce and IT security. Biennial ICT industry surveys are conducted to provide data on ICT production, imports and exports, ICT industry employment, performance and structure information. An Internet activity survey is run every six months and provides regional Internet access details and infrastructure details on Internet service providers.
A major development for 2002–03 will be the compilation of an ICT satellite account. ABS intends to produce an ICT Information Development Plan to guide its future statistical development work in the ICT field.     

Value at Risk in the Suburbs: Eminent Domain and the Geographical Politics of the US Foreclosure Crisis

Several US counties and local governments have recently considered a novel solution to the foreclosure crisis. They plan to use eminent domain to compel the owners of mortgage debt—and specifically of private‐label mortgage‐backed securities—to sell the debt to the government at a price reflecting the loan's market value. The government would then restructure the debt and resell it to new investors. The plans are striking because—in contrast to both development‐driven eminent domain and the federal subprime bank bailout—they would force investors to assume asset devaluation and increased long‐term risk. Notably, the plans have emerged as an instance of financialization‐focused politics in suburbs and suburban cities of color, specifically majority‐black and ‐Latino/a suburbs. Local support for the plans, we argue, is rooted in the long‐term disinvestment of these ‘suburbs of exception', which became targets of subprime lending and eventually sites where the ‘financial exception' has been localized. But these demographic shifts, fragmentation and fiscal pressures have at the same time created a suburban political terrain in which the plans have gained their strongest political support.     

Towards a Theory of Serendipity: A Systematic Review and Conceptualization

Serendipity – the notion of making surprising and valuable discoveries – plays a major role in the success of individuals and organizations alike. Previous research has established the importance of serendipity and identified important individual- and organizational-level antecedents. However, the literature has been dispersed and the boundaries of the concept have been blurry, leading to a lack of conceptual clarity and structure, and thus limiting validity and managerial actionability. Based on a systematic literature review, I synthesize existing management-related research on serendipity and explicate the emergence and composition of serendipity in the organizational context. I first identify three necessary conditions that differentiate serendipity from related concepts such as luck or targeted innovation: agency, surprise, and value. Then, I draw from the literature on sensemaking, event-based theorizing, and quantum-based approaches to management to conceptualize the process of cultivating serendipity in the organizational context as a process of enabling potentiality and materialization, and develop a multi-level theory of (cultivating) serendipity. This conceptualization contributes to our collective understanding of how, why, and when (i.e., under what conditions) organizations can leverage the value in the unexpected, which opens up fruitful avenues for further research.     

Accountability of NGOs in Bangladesh A critical overview

NGOs in Bangladesh have been recognized as effective change agents in the socio-economic arena throughout the world. Their contributions in micro credit, non-formal education and primary health care are widely known. NGOs play a significant role in society. NGO accountability, as a result, has become a critical issue. NGO accountability in Bangladesh has been examined here in relation to patrons, clients and themselves. Of the three relationships only accountability to patrons is in a near satisfactory state. Accountability to clients is handicapped by lack of opportunities of beneficiaries to participate meaningfully in NGO policy making. Accountability to themselves is adversely affected due to the adherence to a strictly hierarchical system and the influence of founding and charismatic NGO leaders.     

Towards an Asian model of human resource management? A comparative analysis of China,Japan and South Korea

There has been much discussion regarding the possible decline and weakening of national systems of human resource management (HRM). Yet, culture and institutions are often cited as the major stumbling blocks to this outcome. Such constraints may dissipate in the analysis, particularly if ‘regional clusters’ are considered where geographic and cultural closeness and ‘openness’ to similar economic pressures exist. In such cases, it might be postulated that convergence in HRM will occur. We argue that China, Japan and South Korea represent such a cluster. This article examines these countries, to see if a degree of convergence is taking place and if it is towards an identifiable ‘Asian’ model of HRM. A model of change is presented that distinguishes between levels of occurrence and acceptance. Details of the development and practice of HRM in each country are then set out. The article ends with a discussion and implications section and a brief conclusion.     

The Creation of the Office for National Statistics

A new Office for National Statistics was created in the United Kingdom in 1996 following a series of developments designed to strengthen the relevance and integrity of statistics. This paper describes these fundamental changes and sets out a blueprint for future progress. It also sets current developments in the United Kingdom in an historical and international context.     

What helps? Women engineers' accounts of staying on

We have considerable understanding of the obstacles that women engineers encounter and the reasons that they leave the field, but we know less about what enables them to remain. Adopting an interpretivist approach, this article examines how a group of British women engineers in two FTSE 100 companies account for “staying on” in their male‐dominated work settings. We delineate four specific forms of help that facilitate women's retention in the field. We argue that exposure to help leads to women developing a habitus that enables them to continue working in engineering. To conclude, we draw on our findings to outline HR practices that will facilitate supportive relationships in the workplace and pave the way towards developing more positive organisational climates.     

论现代物流企业的发展观

物流业经过诸多年的发展目前已经成为最热门的行业之一,物流企业的注册数量也与日俱增,达到前所未有的规模。毋庸置疑,任何企业都希望自己迅速做强做大,并成为真正现代物流企业的典型代表,要实现这一目标一个首要问题就是要解决现代物流企业的发展观问题。     

浅谈大体积混凝土裂缝的控制

大体积混凝土的裂缝问题是实际工程中长期困扰工程技术人员的问题,其控制技术的研究是混凝土结构研究的热点问题,具有重大的学术价值和潜伏的工程背景。     

Supply Chain Strategies in the UK Fashion Industry—The Rhetoric of Partnership and Realities of Power

This paper focuses on the fashion industry, one characterised by issues such as dramatic shifts in the scale and power of major retail buyers in the market, the advent of retailer own brands, and the nature of sourcing and supply chain decisions, issues that are increasingly global in nature. The aim of this research is to explore the nature of relationships between UK high street multiple fashion retailers and their contracted suppliers, many of whom are entrepreneurial firms by most definitions of the term. Four core themes emerge from the literature and provide a framework for the research, namely, power, process, partnership, and people. The research approach was qualitative, and conducted over a period of twelve months. The paper ends with an agenda for future research.