Modelling time of day substitution using the second moments of demand

Time of day (TOD) rates are a commonly used method for peak load pricing of many services. Such services as; electricity, communications, transportation, shared computer facilities, and computer networks (i.e. the Internet), either use, or will use, some form of TOD pricing. However, TOD rates do not ensure a movement towards economic efficiency unless the patterns of TOD substitution are known. The model presented here provedes a method for estimating TOD substitution without the need for rate experiments that have proven to be both costly and limited by sample selection bias problems. This model employs the estimated second moment of demand to estimate a matrix of relative own- and cross-price elasticities and it can estimate elasticities even when there is no apparent TOD price variation. The low level of computations required for the estimates allows the application of a bootstrap procedure to estimate the covariance matrix of the elasticities. Two applications of this model are presented: a case of aggregate demand for computer services and a case of an individual household's electricity demand.     

基于灰色聚类的工程项目满意度评价

对工程项目利益相关者满意度进行综合评价,是衡量项目价值的重要标准之一。在定性分析的基础上,从定量的角度评价各利益相关者对工程项目的满意度水平,能够更加客观地认识不同项目的优劣,同时为项目的成功提供科学依据。针对利益相关者满意度评价的多目标、多层次等特点,构建了较全面的评价指标体系,在此基础上,综合运用灰色系统理论和模糊一致矩阵,建立基于灰色聚类分析的工程项目利益相关者满意度评价模型。实例结果表明,该模型计算过程简单,评价结果客观可靠,便于计算机编程,是一种评价工程项目利益相关者满意度的行之有效的方法。     

Generation dynamics in computer-integrated manufacturing systems

The application of generation dynamics, a methodology for technological forecasting, is widespread in computer-integrated manufacturing systems (CIMS). Experts' opinions about the past and future generations of technology are summarized for computer hardware, computer software, industrial robots, computer vision, computer-aided process planning, and the entire automated factory. The concept of generation dynamics has also been applied to products to be produced by CIMS and to the industrial environment of CIMS. Although experts in the same area do not completely agree with one another, their acceptance of experts' opinions on generation dynamics in other areas to be integrated by CIMS helps the forecasts to be mutually reinforcing and self-fulfilling. On the other hand, such relatively unquestioned acceptance, if and when experts' opinions in other areas become outdated, leads to assumption drag in forecasting.     

Developing an introductory curriculum in system modeling and simulation: The system dynamics approach

Under a grant from the Office of Education, a set of self-teaching, introductory materials in system dynamics has just been completed. The curriculum consists of six student learning packages which integrate text material, completely worked through examples, and open-ended exercises. The packages take students from initial problem conceptualization to building a mathematical model of the problem under study, and simulating the model over time with the aid of a computer. The curriculum also includes an extensive teacher's manual and comprehensive answer books. These materials have been and are being pilot-tested at the high school, undergraduate, and graduate school levels. Initial trial results indicate the materials do succeed in introducing computer simulation as a problem-solving tool to these audiences.     

Modeling as a communication process: Computer conferencing offers new perspectives

Model building is currently one of the most expensive and difficult applications of computer technology. It is expensive both as a conceptual activity, because building a model requires an abstract understanding of a complex process, and as a computational activity, because it demands massive amounts of data and many operations. Furthermore, under conventional approaches one cannot start using the full power of the computer in modeling until all the components have been identified and all the relationships are established. This article introduces an alternative approach in which the computer is used during the earliest stages of model construction. This approach is actually an extension of current technology for computer-based teleconferencing. It incorporates nonhuman “participants” – modules, data bases, or parts of programs-in the modeling process. The advantages of this approach include (1) the opportunity for human participants to test alternative model structures and (2) the capability of the computer to monitor and feed information about the process back to the model director.     

成长战略导向的大型建筑企业项目群管理优势分析

面对日益激烈的国内外建筑市场竞争,大型建筑企业需要以项目群管理的方式实现企业整体效益优化。从建筑企业角度定义了项目群管理,并指出其与单项目管理的不同点。通过数形结合的方法,对比分析了项目群管理 “量”的优势,并应用系统动力学方法建立流图进行了仿真计算。结果表明,与单项目管理相比,项目群管理在“质”的优势方面产生的剩余优势显著。两个维度对比分析表明,项目群管理方式比单项目管理优势更大。     

基于关联数字矩阵的科技创新政策传导路径研究

科技创新政策传导系统是一个动态复杂性反馈系统，基于关联数字矩阵对政策传导系统路径进行量化研究，综合考虑政策输入变量—政策过程变量—政策输出变量的整个过程，建立科技创新政策传导模型，结合关联数字矩阵反馈复杂性、系统动力学和政策科学，构建科技创新政策传导系统因果关系图，并根据政策工具的划分解析人才、税收、研发、政府采购、服务外包5类政策的作用路径。研究发现：①科技创新政策传导系统存在87条正反馈环，无负反馈环，其中主导反馈环45条；②通过关联数字矩阵最终得到14条政策独立主导传导路径并明确各个路径的数量、长度和极性，其中，8条路径都存在延迟效应；③人才激励在政策调控促进创新和发展中占比较大，具有重要地位，服务外包政策紧随其后，两类政策工具对政策调控效果具有直接显著作用，而研发补贴政策对目标的调控最缺乏活力。     

从文献计量分析看1981—2011年全球系统动力学研究

系统动力学作为一个研究复杂反馈系统的研究领域,在20世纪80年代以后得到了较为广泛的传播和较快发展。以美国科学引文索引数据库扩展版(SCI-Expanded)和社会科学引文索引数据库(SSCI)收录发表于1981—2011年间的976篇系统动力学论文为研究对象,对这些论文的产出规模、地域分布、学科分布、知识基础等方面进行了计量分析。结果显示,30余年来,全球系统动力学成果产出逐渐丰富,理论研究与应用研究得到积极推进,与众多学科联系紧密,各国科研投入力量在不断加强,同时也反映出,美国系统动力学研究在全球一枝独秀。     

基于智慧专业化理论的东营国家创新型城市建设研究

为进一步推动东营国家创新型城市建设,促进城市绿色、可持续发展,本文借鉴欧盟智慧专业化相关研究,从科学、技术和经济三个维度构建指标体系,在各指标下将东营分别与领先创新型城市和同类创新型城市进行标杆对比,并构建SWOT矩阵,分析东营创新型城市建设过程中的优势、劣势、机遇和挑战。结果发现:东营国家创新型城市建设取得一定成就,R&D投入强度与每万名就业人员中研发人员指标具有一定的优势,战略性新兴产业与高新技术企业是短板,仍需加大培育力度。对此基于SWOT分析提出有关引才引智、创新主体培育、战略性新兴产业发展的相关政策建议。     

Assimilation of aggregated inputs into Delphi forecasts: A regression analysis

To examine the manner in which the individual assessments of a panel of delphi experts are combined into a delphi forecast, the supporting reasons they gave for their forecasts of 40 computer applications were coded into categories of assessed “technical feasibility,” “cost of initiating,” and “benefits or needs provided.” Even though different sets of experts provided these statements in support of their individual forecasts, with some experts emphasizing one aspect and others another, it was found that the median forecast of the entire panel was significantly related to the average proportion of reasons in each category which favored bringing about the development. That is, the delphi forecasts of computer applications suggest that the computer application is forecasted to occur sooner to the extent it was judged to be technically feasible, beneficial to users or society, and not costly to develop. The results indicate further that delphi forecasting among a group of experts has logical validity, and that individual contributions are integrated into a group outcome.     

Causality: Its characterization in system dynamics and KSIM models of socioeconomic systems

Two methodologies—Kane's KSIM and Forrester's system dynamics—for modeling socioeconomic systems are compared and contrasted with regard to the manner in which each characterizes and classifies casuality in socioeconomic systems. The equivalence of the so-called casual diagram used in system dynamics to the cross-impact matrix used in KSIM is indicated. Each method identifies exactly two classes of casual links—the similarity between the classes distinguished in system dynamics with those employed in KSIM is suggested. Then the assumptions regarding the nature of causality that are implicit within the two methodologies are compared. In this context techniques for translating linear system-dynamics models to KSIM-like models (and vice versa) are provided. Examples are provided to illustrate the notions discussed in the article.     

Using the functional analysis to understand the emergence of biomaterials within an existing biotechnology system: observations from a case study in Turkey

ABSTRACT

The paper applies a functional approach to the analysis of an emerging technology within an innovation system (IS) in a developing country. By doing so, the paper identifies the advantages and drawbacks of the approach through a dynamic analysis and highlights the life cycle of an IS within which a new technology is emerging. This is done empirically by analysing the emergence of biosimilars within the infant Turkish biotechnology system mainly from the perspective of firms. Our analysis of the Turkish case illustrates how the tool of functional approach could be valuable in understanding the dynamics of a technology in a developing country context. Policy suggestions and implications of the study are presented as concluding remarks.     

中国高考录取与博士生录取的机制设计

学校录取机制问题是一个教育界广泛讨论的话题。本文探讨了目前高考录取平行志愿制度的优点和缺陷,提出降低投档比例、打通不同院校之间的专业志愿和增加志愿个数可以改进学生的效用损失。而博士生录取是另外一种类型的非统一录取学校录取机制问题,本文设计了一种偏好顺序机制,并证明了这种机制是满足公平、无浪费、个人理性、抗策略且帕累托最优的,最后提出在现实中运用该机制的具体措施。     

公司控制权与剩余索取权计量模型的选择:基于鲁能集团的案例分析

公司控制权与剩余索取权的计量是财务学与公司治理研究的基础性问题。从线性模型出发,探讨矩阵模型对复杂股权网络的计量,并通过具体案例剖析两类模型的优缺点。研究结果表明:矩阵模型可以更好地计量复杂股权网络,股权网络复杂度和透明度等指标可以进一步推进相关领域的实证研究。同时,案例分析也进一步揭示了国家监管部门和投资者等利益相关者在现行信息披露制度下,难以获得真实的股权结构信息,应利用矩阵模型对现行制度进行改良。     

Market penetration of new products in segmented populations: A system dynamics simulation with fuzzy sets

The application of system dynamics methodology to the study of market penetration (diffusion) of new products offers considerable flexibility. The differential equations representing total (cumulative) sales need not be that restrictive as in those instances where solely mathematical tools are applied for their solutions. This paper first develops a mathematical formulation of “dynamic diffusion phenomena,” where the target population is not assumed to be constant in time. Besides incorporating the “marketing efforts” of the producer as an explicit variable, the model also gives due importance to the population characteristics affecting the diffusion phenomena. This is achieved by representing all variables and parameters in the differential equations as higher dimensional arrays. Then some basic properties of “fuzzy sets” are exploited to assign numerical values to the parameters. At the end, the problem is cast in a system dynamics setup for its solution. A computer solution with the help of a DYNAMO compiler for a hypothetical case is added to demonstrate the applicability of the ideas developed.     

A comparison of clustering dynamics in the US and UK computer industries

This paper compares the dynamics of the process by which geographical clusters emerge in the US and UK computer industries, by modelling the evolution of firm growth and entry. In both countries, new companies are attracted by industry strength in particular sub-sectors in a particular region. Moreover, incumbent firms located in a cluster that is strong in their own sub-sector of the industry tend to grow faster than average. While there are some second order differences between the models estimated for the US and the UK, it appears that the dynamics of clustering are similar. In particular, there is no evidence that clustering effects are weaker in the UK than in the US.     

Can Non-point Phosphorus Emissions from Agriculture be Regulated Efficiently Using Input-Output Taxes?

In many parts of Europe and North America, phosphorus loss from cultivated fields is threatening natural ecosystems. Though there are similarities to other non-point agricultural emissions like nitrogen that have been studied extensively, phosphorus is often characterized by the presence of large stocking capacities for phosphorus in farm soils and long time-lags between applications and emission. This makes it important to understand the dynamics of the phosphorus emission problem when designing regulatory systems. Using a model that reflects these dynamics, we evaluate alternative regulatory systems. Depending on the proportions of different types of farms in the agricultural sector, we find that an input-output tax system can be the core element of a close to efficient regulatory policy.     

Determining reverse salient types and evolutionary dynamics of technology systems with performance disparities

Technological system evolution is marked by the uneven evolution of constituent sub-systems. Subsequently, system evolution is hampered by the resulting state of unevenness, or reverse salience, which results from the presence of the sub-system that delivers the lowest level of performance with respect to other sub-systems, namely, the reverse salient. In this paper, we develop absolute and proportional performance gap measures of reverse salience and, in turn, derive a typology of reverse salients that distinguishes alternative dynamics of change in the evolving system. We subsequently demonstrate the applicability of the measures and the typology through an illustrative empirical study of the PC (personal computer) technological system that functions as a gaming platform. Our empirical analysis demonstrates that patterns of temporal dynamics can be distinguished with the measurement of reverse salience, and that distinct paths of technological system evolution can be identified as different types of reverse salients emerge over time.     

INTELLECTUAL PROPERTY RIGHTS IN A KNOWLEDGE-BASED ECONOMY: A NEW FRAME-OF-ANALYSIS

The debate on software intellectual property rights (IPRs) has not only highlighted fundamental issues regarding the scheme of protection that software enjoys, it has also pointed out major gaps in the representation of computer programs as economic goods. In this respect, various interpretations of software propose a limited outlook by referring only to particular aspects of computer programs.

The paper discusses the economic nature of software and computational processes and how they should be properly represented as commodities by focusing on software IPR legislation in the US. It elaborates the similarities and differences between software applications and machines on the basis of historical evidence from the evolution of information technologies and computer science. Further, we discuss whether computer programs should enjoy IPR protection (like their physical equivalents) and which legal regime would induce the maximal degree of societal benefits, while satisfying private and public interests.

The paper also elaborates the essential issues of the distinction between ideas and expressions and the ways they are treated as intellectual property. It highlights major aspects in the debate over protection of software applications by both patents and copyrights and analyses the economic impact of the joint regime.

By highlighting the dissimilarities in the economic nature and market behaviour of ideas and expressions we point out the difficulties in drawing parallels between software and physical equivalents. Finally, we provide alternative ways to establish coherent juridical basis and legal policy of software IPRs that aim at stimulating innovation and developing the technological landscape in information technologies.     

技术资源优势、系统集成能力与“低端锁定”突破的实证研究

发展中国家通过比较优势进入国际化分工,在实现自身快速发展的同时,也陷入价值链"低端锁定"陷阱。基于模块再集成视角,将企业技术资源优势分为技术潜能和创新资源,将系统集成能力作为中介变量,将"低端锁定"突破路径分为同种模块再集成和异种模块再集成,研究技术资源优势、系统集成能力对"低端锁定"突破路径的影响。实证结果表明,技术资源优势,即技术潜能与创新资源优势,对突破路径选择发挥正向影响作用;系统集成能力对突破路径选择发挥正向影响作用;技术资源优势对系统集成能力发挥正向影响作用。由此,企业应通过整合及运用技术资源提高自身系统集成能力,利用模块再集成路径突破"低端锁定"。