Generalizing the OLS and Grid Estimators

The vast majority of market valuations employ either some formal estimator such as ordinary least squares (OLS) or rely upon an informal set of rules defining the grid adjustment estimator. The success of the grid adjustment estimator suggests the data do not obey the ideal assumptions underlying OLS. However, the grid adjustment estimator's lack of a formal statistical foundation makes it difficult to use for inference and other purposes. This article demonstrates how to generalize the grid estimator and OLS to potentially obtain the best features of both. Interestingly, the generalization defines a spatial autoregression. On an empirical example the spatial autoregression outperforms the grid estimator which in turn outperforms OLS.     

Occupational Licensing and the Earnings Premium in the United States: Updated Evidence from the Current Population Survey

Using survey data from 2015 to 2018, this article analyses the occupational licensing wage premium in the United States. The estimates show a robust 4–6 per cent wage differential for licensed workers. This premium is robust to careful control for location/local labour market effects and occupation effects. The premium is also positive for the majority of individual occupations and groups of occupations estimated. Similar results are found using additional techniques, including a matching estimator and an analysis of border metropolitan statistical areas.     

An Empirical Analysis of Hedonic Regression and Grid-Adjustment Techniques in Real Estate Appraisal

Multiple regression analysis has become increasingly popular when appraising residential properties for tax purposes. Alternatively, most fee appraisers and real estate brokers use the traditional sales comparison approach. This study combines the two techniques and uses multiple regression to generate the adjustment coefficients used in the grid adjustment method. The study compares the combined grid-regression method with ordinary regression and defines the market conditions under which each method is likely to be more effective. The grid-regression method is found to be more accurate for relatively homogeneous housing markets, and the multiplicative percentage adjustment method (MPAM) the preferred approach.     

车轮外流场的数值网格生成技术的研究

有机结合代数法和椭圆方程法,采用分块结构化网格,针对轮胎地面接触区域网格生成质量不合格的问题,提出并讨论了车轮外流场网格划分的3种拓扑结构,确定了其中的最佳方案；然后应用该方案进行某国产轿车及其车轮的外流场数值网格的划分,成功的生成了高质量的网格单元,验证了所选网格拓扑方案的有效性。     

梯度法对输出颜色渐变平滑度的量化

为了使用客观测量值对颜色渐变中平滑程度的感知进行量化,本文建立了一个计算硬拷贝中颜色渐变平滑度的模型。这种基于梯度的方法可以由95%阶调跳跃评价值二阶导数和5%阶调失真评价值一阶导数共同决定。从心理物理学角度分析了模型的性能和早期提出的方法,而且对其预测精准性进行了相互比较。模型对于相应的视觉数据表现出了较强的皮尔森相关性,皮尔森相关系数值达到了0.87。通过方差分析验证模型的显著性。将记忆色的变化（蓝天、绿草和白种人肤色）制作成渐变梯级当做测试样品。     

基于以太网的闭环网络控制系统设计

概述了以太网用于工业现场的必要性。介绍了基于以太网的闭环网络控制系统的系统模型。在系统中设计了观测器和预估器以解决不确定变化的网络延时问题,保持了系统的稳定性并改善了系统的动态特性。仿真研究表明了该方法的有效性。     

基于模态应变能密度理论的网架结构损伤识别方法

为了研究网架结构的损伤检测方法,根据应变能密度理论,提出采用单元模态应变能密度差值作为网架结构损伤识别指标的方法,以损伤单元模态应变能密度差值的大小初步确定单元的损伤程度。分析了5种具有代表性的损伤工况,并在数值计算结果中引入了白噪声。结果显示,在一阶模态下,针对单损伤、多损伤和轻微损伤、严重损伤等不同损伤工况,损伤杆件的模态应变能密度差值均为高值。因此,该方法可以有效识别出网架结构的损伤位置,根据损伤单元的模态应变能密度差值大小初步确定单元的损伤程度,且在一定的噪声水平下具有较强的鲁棒性,对网架结构损伤识别具有参考价值。     

西班牙风电发展的经验与启示

西班牙近年来通过实施风电溢价制度、调整电源结构、强化系统调峰能力、应用风力预测技术、建立可再生能源电力控制中心、加强电网建设规划等手段,在推动风电快速发展的同时,保障了电网的稳定运行。对西班牙风电发展情况、电源结构和电网特点进行了介绍,分析了其在促进风电消纳和保障电网安全运行方面的举措,提出了推动我国风电与电力系统协调发展的启示和建议。     

输电线路差异化设计分析

基于重大自然灾害对电网的损害,指出要提高电网设防标准,并对输电线路进行差异化设计。对线路差异化设计的思路和原则进行了阐述,从自然灾害影响因素、保证负荷预测、重要线路选取、最小骨干网架形成以及投资估算等几个方面对线路差异化设计的方法进行描述并针对区域电网举例说明。     

Housing Renovations and the Quantile Repeat-Sales Price Index

A median-based quantile estimator suffers less bias from positive outliers, such as unobserved renovations, than a standard mean-based estimator. Quantile repeat-sales estimates for single-family homes in the city of Chicago show nominal price appreciation of 68.9% between 1993 and 2002, substantially smaller than the standard approach's estimate of 77.8%. Omitting observations with building permits reduces the mean and median-based estimates by 4.4 and 1.6 percentage points. The results imply that quality improvements account for much of the rapid rise in house prices, and that a median-based quantile estimator produces a more accurate view of the price performance of a typical house.     

网格供应链——基于时间Petri网的供应链协同管理优化

为了使当前供应链协同管理货物流程面临的时间效率得以提高,提出了一种将网格技术和供应链协同管理相结合的货物流程触发时间求解方式。在该求解方式中,为获得供应链货物流程的触发时间值,利用基于时间Petri网的可达性分析算法模型进行仿真计算,以在从订货、发货到收货的流程中,得到每个流程相对应的最早、最晚触发时间值,进而通过在网格环境下改善后的流程触发时间与相应的传统供应链流程触发时间值进行对比,明显的减少了时间上的浪费,提高了货物流程的时间效率,体现了将网格技术应用于供应链协同管理的优势。     

电网企业成本管理与控制改革研究

通过对电网企业成本管理的现状分析,提出了加强电网企业建设、融资、生产全过程成本管理与控制,改革电网企业内部治理和成本管理体制,建立新型成本预算、控制、考核方法的设想.     

关于输配电价几个重要问题的探讨

我国电力企业将要由传统的垂直垄断的模式转变为网厂分开、竞价上网的模式。电网公司作为一个独立的经营实体分离开来,有着独立的收益需求。在市场运营过程中,通过输配电价取得收益就成了电网公司取得收益的主要手段。在输配电价的制订过程之中,管制方式、输配电成本、输电定价方法、价格水平及电网投资、输配电价价区、电网提供的辅助服务等六个问题十分重要。文中就这六个问题的解决作了一些有价值的探讨。     

Repeat Sales as a Matching Estimator

The most common approaches for constructing house price indices—hedonic price functions and the repeat sales estimator—focus on changes over time in mean prices. Though the hedonic approach is less wasteful of data than the repeat sales estimator, it relies on an accurate specification of the underlying econometric model. I suggest using a matching estimator as an alternative to the hedonic and repeat sales approaches. Like the repeat sales approach, a matching estimator uses pairs of sales from different dates to estimate the mean difference in sales prices over time. The matching approach preserves much larger sample sizes than the repeat sales estimator while requiring less preimposed structure than the hedonic approach. The matching approach makes it easy to characterize changes in the full distribution of house prices.     

基于模块化与网格技术的价值网格——以“浙商”为例的组织超越发展的建构论观点

价值创造网络的核心命题,在于价值模块的动态配置绩效。本文借鉴计算机网格技术中客户化异构资源动态配置的思想及其对价值创造网络的隐喻,提出价值网格的概念,阐述了价值网格的系统动态模型及其系统功能创新,并从经济学、组织理论等角度分析论证了价值网格的创新点和科学性。文章运用价值网格理论,分析了转型背景中的“浙商”组织寻求超越发展,构建价值网格的战略导向和具体路径。价值网格理论及方法是组织间理论研究思路的跨学科拓展与创新,对“浙商”乃至中国企业组织的超越发展具有前瞻性和指导意义。     

智能化发展给电网带来的风险与防控对策

智能电网相对于传统电网有着明显的优势,各国都在致力于发展智能电网。然而,智能电网新技术在带来效益的同时,对电网公司而言同样也带来了风险因素。通过对智能电网电力流各环节的风险因素识别,提出了针对性的风险防控措施,对更深层次地认识智能电网、指导智能电网规划、防范智能电网发展风险等有着积极的参考价值。     

Evaluation method of benefits and efficiency of grid investment in China: A case study

The existing evaluation system for power grid investment in China has not combined measures of the investment benefits and investment efficiency very well and it lacks practical reference value. This article proposes an improved evaluation index system of the benefits and efficiency of power grid investment projects. The system divides the evaluation method into indexes. This includes the basic indexes, modification indexes, and appraisal indexes that evaluate the economic and environmental benefits of the investment projects comprehensively. It considers the overall efficiency in terms of the economy, technology, and society. It combines an absolute efficiency evaluation model with a data envelope analysis relative efficiency evaluation model. Finally, the benefits and efficiency of investment of an actual power grid project are evaluated through a case study. The results show the practical value of the proposed efficiency evaluation method for evaluating investment projects in a power grid.     

输电网扩容投资与电网可靠性的协调优化研究

给出了一种对输电网投资与电网可靠性进行协调优化的分析评估方法,推导了能够反映随着输电约束限值变化,输电约束附加成本如何变化的成本函数,并建立了输电网全年最优可靠性分析数学模型,通过一个实例进行了验证.还研究了进行输电网扩容项目投融资的市场机制的建立问题,并给出了相应的方案建议.     

The Analytical Foundations of Adjustment Grid Methods

Within the market data approach to real estate appraisal, two basic types of analysis generally are used: (1) regression analysis; and (2) adjustment grid methods. The focus of this paper is on the adjustment grid methods. Three such methods are identified in the appraisal literature, but their analytical foundations are not clearly presented. The primary objective of this paper is to clarify the analytical foundations of each method. In addition, various ways to estimate the adjustment factors needed to apply the grid methods and a weighting scheme for reconciliation of indicated values are presented. Also, the possible advantage of grid-based over purely regression-based predictions is identified.     

美国智能电网发展模式的系统分析

在全球金融危机的大背景下,智能电网作为奥巴马能源新政的一项核心内容加以提出,得到经济刺激计划大力支持,在全球掀起了建设智能电网的热潮。在系统回顾关国智能电网发展战略的孕育、成熟以及实施整个过程基础上指出,发展智能电网并非是美国政府在全球金融危机背景下的应急策略,而是经过数年的深思熟虑,依次经历了战略研究与规划、立法保障、政府主导推进3个阶段,是一个典型的美国国家发展战略推进过程,该过程具备延续性、完整性、系统性的特点,对我国当前推进智能电网建设具有一定借鉴意义。