Knowledge integration via the fusion of the data models used in automotive production systems

ABSTRACT

In this paper a novel information model that can be used in Manufacturing Execution Systems is presented. The model is based on the fusion of ISA95, AML and OPC UA. ISA95 is used to define, unify and describe the details of a product and production technology. It also enables communication with ERP systems. The AML standard allows information about the production facilities to be presented. The OPC UA address space represents different parts of an information model while the OPC communication protocol enables it to be linked to actual production systems. The proposed concept is illustrated using an actual example of a production line for electronic devices.     

Macroeconomic forecasting using structural factor analysis

The use of a small number of underlying factors to summarize the information from a much larger set of information variables is one of the new frontiers in forecasting. In prior work, the estimated factors have not usually had a structural interpretation and the factors have not been chosen on a theoretical basis. In this paper we propose several variants of a general structural factor forecasting model, and use these to forecast certain key macroeconomic variables. We make the choice of factors more structurally meaningful by estimating factors from subsets of information variables, where these variables can be assigned to subsets on the basis of economic theory. We compare the forecasting performance of the structural factor forecasting model with that of a univariate AR model, a standard VAR model, and some non-structural factor forecasting models. The results suggest that our structural factor forecasting model performs significantly better in forecasting real activity variables, especially at short horizons.     

我国物流经营模式的归类、评价与选择

首先 ,对我国发展物流业过程中的各种经营模式进行了总结和归类 ;其次 ,对归类后的物流经营模式进行了分析与评价 ,指出了不符合我国国情的、在现实经营中不宜采用的一些物流经营模式 ;第三 ,对适合我国现阶段经济运行要求的物流经营模式 ,从提高经营管理水平的角度进行了分析和探讨。     

Can oil shocks explain asymmetries in the US Business Cycle?

We consider whether oil prices can account for business cycle asymmetries. We test for asymmetries based on the Markov switching autoregressive model popularized by Hamilton (1989), using the tests devised by Clements and Krolzig (2000). We find evidence against the conventional wisdom that recessions are more violent than expansions: while some part of the downturn in economic activity that characterises recessionary periods can be attributed to dramatic changes in the price of oil, post-War US economic growth is characterized by the steepness of expansions. First Version Received: December 2000/Final Version Received: September 2001     

World Oil Depletion Models: Price effects compared with strategic or technological interventions

World oil depletion, including natural gas liquids, was modelled in the past by many authors. Recently, Guseo and Dalla Valle have introduced and Guidolin has applied a new approach following perturbed life-cycle diffusion models. Here we examine joint effects of economic and strategic or technological interventions using a Generalized Bass Model (GBM). Statistical analysis takes into account three different hierarchical levels: natural diffusion, long memory interventions and stochastic components. The main results confirm the statistical significance of historical 1970s shocks and highlight a strong long memory effect due to an increase in oil production after World War II. The estimated peak-date, 2007, and the 90% depletion time, 2019, are determined under an equilibrium intervention hypothesis.     

Business models for material efficiency services: Conceptualization and application

Despite the abundant research on material flows and the growing recognition of the need to dematerialize the economy, business enterprises are still not making the best possible use of the many opportunities for material efficiency improvements. This article proposes one possible solution: material efficiency services provided by outside suppliers. It also introduces a conceptual framework for the analysis of different business models for eco-efficient services and applies the framework to material efficiency services. Four business models are outlined and their feasibility is studied from an empirical vantage point. In contrast to much of the previous research, special emphasis is laid on the financial aspects. It appears that the most promising business models are ‘material efficiency as additional service’ and ‘material flow management service’. Depending on the business model, prominent material efficiency service providers differ from large companies that offer multiple products and/or services to smaller, specialized providers. Potential clients (users) typically lack the resources (expertise, management's time or initial funds) to conduct material efficiency improvements themselves. Customers are more likely to use material efficiency services that relate to support materials or side-streams rather than those that are at the core of production. Potential client organizations with a strategy of outsourcing support activities and with experience of outsourcing are more keen to use material efficiency services.     

The Legislator as Political Entrepreneur: Investment in Political Capital

This paper applies the standard Austrian theory of capital investment to the standard interest group model of legislator behavior. Distinguishing between reputational capital and representative capital as interdependent forms of political capital, I argue that legislator behavior (specifically roll call voting) can be explained as entrepreneurial investment in political capital under uncertainty. I discuss several examples in which this approach can potentially add predictive power regarding legislative voting.     

The British low-wage sector and the employment prospects of the unemployed

Are low wages a way for the unemployed to switch to higher-paying jobs? Using data from the British Household Panel Survey, the labour market dynamics of unemployed, low-paid and higher-paid employed men are analysed. Moreover, the respective (un)employment duration and occupational skill level are accounted for. Results show that in general low wages significantly reduce the risk of future unemployment and increase the chances of ascending the salary ladder, especially in the case of long-term unemployment (>360 days). Furthermore, the occupational skill level has a substantial influence on the upward mobility of low-paid jobs: individuals working in the initial period in a low-paid and higher-skilled occupation have on average an 11 percentage points higher probability of entering higher pay compared to when working in a low-paid and low-skilled occupation.     

INTEREG: A Twenty-region Input–Output Model for Italy

Since the regional scale turns out to be the scale at which fiscal devolution is likely to be accomplished in Italy, and that at which trade and growth interdependencies as well as regional convergence can be most conveniently investigated, a new 20-region input–output model for Italy seems to be a useful tool of analysis. Although various regional and interregional models have been constructed since the 1950s, none has been implemented for the whole system of 20 Italian administrative regions considered in their tight mutual dependence; also, the pool approach has not been greatly favoured, even in situations where direct information on regional trade is lacking. The main purpose of this paper is to report on the structure of the model, the rather complex procedure used in the model construction and the adopted solution technique. Some space is devoted to the problems encountered in handling regional trade endogenously in an input–output setting and to a comparison between the pool approach, used in the Italian model, and other current techniques. The paper also reports on some preliminary results regarding the regional impact of fiscal policy.     

Illicit drug markets and economic irregularities

Markets for illicit drugs present an interesting case study for economics, combining non-standard characteristics such as addiction and product illegality. One response has been to argue the generality of economic principles by suggesting that they apply even in the extreme case of markets for addictive substances, e.g., by showing that demand for illicit goods is responsive to price [1] [Reframing health behavior change with behavioral economics. Hillsdale, NJ:Lawrence Earlbaum Associates; 2000. p. 89-111.] and even by modeling addiction as rational [2] [J Political Econ 1988;96:675-700]. This paper sketches examples of an alternative reaction, focusing on idiosyncrasies of drug markets that might plausibly create counter-intuitive effects, including supply curves that slope downward because of enforcement swamping and/or a good serving as the only available store of wealth for its producer, demand reduction programs that increase demand, and consumption by “jugglers” possibly increasing rather than decreasing as prices rise. This analysis yields non-obvious policy recommendations; for example, source country control programs should concentrate on growing regions with a healthy banking sector.