Search results for "Control variable"
showing 10 items of 17 documents
The influence of organizational factors on road transport safety
2018
Road transport safety is a major concern across Europe due to the human and socio-economic costs associated with work-related traffic accidents. Traditional approaches have adopted regulatory and technical measures to prevent road accidents leaving aside the organizational factors that might contribute to road transport safety. However, contemporary sociotechnical systems theory acknowledges the need to take into account organizational factors. This study adopts a sociotechnical approach and it examines the relationship between a number of organizational factors (organizational learning and training) and road traffic accidents in the organizations under study. Our sample was composed of 107…
Variable selection in the analysis of energy consumption-growth nexus
2015
There is abundant empirical literature that focuses on whether energy consumption is a critical driver of economic growth. The evolution of this literature has largely consisted of attempts to solve the problems and answer the criticisms arising from earlier studies. One of the most common criticisms is that previous work concentrates on the bivariate relationship, energy consumption–economic growth. Many authors try to overcome this critique using control variables. However, the choice of these variables has been ad hoc, made according to the subjective economic rationale of the authors. Our contribution to this literature is to apply a robust probabilistic model to select the explanatory …
Job Mobility and Sorting: Theory and Evidence
2019
Abstract Motivated by the canonical (random) on-the-job search model, I measure a person’s ability to sort into higher ranked jobs by the risk ratio of job-to-job transitions to transitions into unemployment. I show that this measure possesses various desirable features. Making use of the Survey of Income and Program Participation (SIPP), I study the relation between human capital and the risk ratio of job-to-job transitions to transitions into unemployment. Formal education tends to be positively associated with this risk ratio. General experience and occupational tenure have a pronounced negative correlation with both job-to-job transitions and transitions into unemployment, leaving the r…
Environmental expenditure interactions among OECD countries, 1995-2017
2021
International audience; How do countries respond to other countries when setting the level of their environmental expenditures? Using data from 1995-2017 on a sample of 28 OECD countries, we examine the nature and extent of strategic interactions in environmental expenditures among OECD countries using a spatial Durbin model including economic and political control variables and both economic and spatial weight matrices reflecting several interaction mechanisms. The results show the existence of significant positive spatial dependence in environmental spending suggesting that OECD countries consider their neighbors' behavior when making policy choices related to environmental expenditures. …
A systematic approach for fine-tuning of fuzzy controllers applied to WWTPs
2010
A systematic approach for fine-tuning fuzzy controllers has been developed and evaluated for an aeration control system implemented in a WWTP. The challenge with the application of fuzzy controllers to WWTPs is simply that they contain many parameters, which need to be adjusted for different WWTP applications. To this end, a methodology based on model simulations is used that employs three statistical methods: (i) Monte-Carlo procedure: to find proper initial conditions, (ii) Identifiability analysis: to find an identifiable parameter subset of the fuzzy controller and (iii) minimization algorithm: to fine-tune the identifiable parameter subset of the controller. Indeed, the initial locatio…
Energy efficient operation in smart grids: optimal management of shiftable loads and storage systems
2012
In this paper, the authors analyze the impact of the participation of customers to the sustainable implementation of energy rational strategies in microgrids. The management of shiftable loads is compared to the control of real and reactive storage systems in smart grids. An optimization algorithm is used as analysis tool to assess the impact of such control variables in different conditions. The results clearly indicate that if shiftable loads are of suitable size, they have a more promising as tools to both reduce losses and to flatten the peak load through the HV/MV bus. Many tests have been carried out on a real experimental MV system in the area of Rome Italy.
Power tracking with maximum efficiency for wireless charging of E-bikes
2014
Wireless charging techniques, based on Inductive Power Transfer (IPT), are attractive for Electric Vehicles (EV), due to benefits such as convenience and safety. An accurate valuation of the maximum achievable efficiency in an IPT system is extremely unlikely due to the high sensitivity to parasitic elements variations. Therefore, an “on site” procedure of power efficiency characterization is useful to get a precise description of the efficiency curve and obtain the actual maximum efficiency. In this paper, a power tracking algorithm aiming at efficiency maximization is proposed for a Wireless Charging system. The algorithm aims at finding the maximum power transfer efficiency with respect …
The Effect of Public Education Expenditure on Shadow Economy: A Cross-Country Analysis
2015
AbstractThis paper empirically examines whether devoting more resources to education can reduce the size of the shadow economy on a cross-section of countries. The findings show a negative relationship between public education expenditure and the size of the shadow economy, which is robust to the inclusion of different proxies for the control variables, a large set of policy variables, regional differences and endogeneity. The findings also emphasize the role of education, suggesting that public policies devoted to higher education level imply a decreasing effect on the shadow economy.
Country size and business cycle volatility: Scale really matters
2007
Abstract In a recent study Andrew Rose found that country size does not matter for several economic outcomes [Rose, A.K., 2006. Size really doesn't matter: In search of a national scale effect. J. Japanese Int. Economies 4, 482–507]. However, he did not consider the effect that country size may have on business-cycle volatility. To investigate the empirical relationship between business cycle volatility and country size, we use a panel data set that includes 167 countries from 1960 to 2000. The results suggest very strongly that the relationship between country size and business cycle volatility is negative and statistically significant. This implies that smaller countries are subject to mo…
Effect of Software on CSP Performance
2009
In order to verify how (if at all) CSP's investments in software affect their business performance, the relationship between (i) CSP's spending on software and (ii) its key performance indicators (KPIs) is considered below. The investments in software are represented by internal, external, and total software spending a year or two years prior to the KPI values, while the KPIs include average revenue per user (ARPU), revenue, net income, EBIDTA, and change in revenue (as an indicator of company growth). Besides, Opex and Capex along with R&D expenses are used as control variables. We use the data collected for the years 2004–2007 (revenue, net income, EBITDA, market capitalization, R&D, CAPE…