Search results for "ESTIMATION"
showing 10 items of 924 documents
Skill Biased Technical Change and Misallocation: A Unified Framework
2019
Due to strict reliance on competitive labor markets, standard approaches which measure skill biased technical change (SBTC) conflate labor market distortions which prevent firms from choosing the efficient ratio between skilled and unskilled labor and `true' SBTC. This contrasts with recent evidence on decoupling between wages and productivity. To overcome this limitation, we present a unified framework to estimate SBTC which accounts for factor accumulation (FA) effects, and quantifies the discrepancy (i.e., relative misallocation) between the wage ratio (skilled to unskilled) and the marginal rate of technical substitution (MRTS). The suggested methodology takes advantage of recent develo…
Innovation at the workplace: Do professional competencies matter?
2014
Abstract This paper analyzes individuals' propensity to innovate in professional environments, by focusing on the specific competency profile of individuals who play a role in the incorporation of product, technological, and knowledge innovations at work. The analysis draws on economic and managerial literature on innovation, innovative behavior, and competencies to gain a better understanding of the relationships between the process of competency development and innovative behavior in working environments. Using data from REFLEX, a European survey on the transition from higher education to labor markets, the empirical component of this study estimates discrete response models to explain th…
The effect of choice complexity on perception of time spent choosing: When choice takes longer but feels shorter
2009
Two studies examine the effect of the complexity of the choice environment on the perceived duration of the time spent choosing. The experiments demonstrate that the estimation of the time spent making a decision is affected by the number of options available in the choice set. In Experiment 1, participants having to choose 1 of 24 mobile phones tended to underestimate the time spent whereas participants confronted with the choice of 6 mobile phones tended to overestimate the actual time spent. Experiment 2 corroborates this finding, in the presence of varying degrees of attribute correlation. We conclude with theoretical and practical implications for marketers. © 2009 Wiley Periodicals, I…
Evaluating temporary retail price discounts using semiparametric regression
2009
PurposeTo analyze the impact of temporary retail price discount on a consumer goods product category using semiparametric regression and considering different promotional price discount characteristics as well as brand characteristics.Design/methodology/approachA semiparametric regression model using Support Vector Machines, which aim to evaluate retailers' decisions about temporary price discounts, has been developed. The model is derived from the analysis of historical sales data, which provide precise evaluation of previous temporary price discounts periods. The model is also consistent with ample empirical evidence showing that historical retail sales data can be used to evaluate the im…
Physics-Aware Gaussian Processes for Earth Observation
2017
Earth observation from satellite sensory data pose challenging problems, where machine learning is currently a key player. In recent years, Gaussian Process (GP) regression and other kernel methods have excelled in biophysical parameter estimation tasks from space. GP regression is based on solid Bayesian statistics, and generally yield efficient and accurate parameter estimates. However, GPs are typically used for inverse modeling based on concurrent observations and in situ measurements only. Very often a forward model encoding the well-understood physical relations is available though. In this work, we review three GP models that respect and learn the physics of the underlying processes …
Design av en offshore gangbru i fiberarmert polymer
2018
Masteroppgave bygg BYG508 - Universitetet i Agder 2018 Innovation and development are essential for a market in demand of faster, lighter and stronger solutions. As a material with high strength to weight ratio, and good possibilities of being premade, fiber reinforced polymers can meet those requirements. However, it has yet to challenge concrete, steel and aluminum as a structural material. This is the underlying challenge for the problem statement of this assignment, to construct an offshore gangway using fiber reinforced polymers. The design concept is based on existing steel and aluminum constructions within the size range of 25- 30m fully extended. To solve the problem and answer the …
Series resistance determination and further characterization of c-Si PV modules
2012
Abstract This paper presents a new algorithm for determination of the series resistance of crystalline-Si PV modules from individual illuminated I–V curves. The ideality factor and the reverse saturation current are then extracted in the classic way. The approach is applied to in-situ measured data from modules based on two types of mc-Si feedstock. The results indicate that the method yields physically meaningful parameters. An improved definition of local ideality factor is suggested, resulting in m-V plots unaffected by the series resistance. In addition, m-I plots are introduced for the first time. The novel differential techniques reveal an unexpected rise of the ideality factor at ope…
Modeling and parameter identification of crystalline silicon photovoltaic devices
2011
In this paper the physical correctness of the standard single-exponential (one-diode) model of crystalline-Si photovoltaic devices is examined. In particular, we focus on the shunt current. I-V curves of in situ illuminated polycrystalline-Si photovoltaic modules are measured, and based on these measurements, we extract the shunt current. There is a certain voltage range in which the shunt current shows an Ohmic-like behavior, but the value of the resistance varies with irradiance and the quality of illumination. In addition, the Ohmic behavior takes place at voltages well below the maximum-power point (MPP). At higher voltages, the shunt current drops to negligible values. We conclude that…
The additive dose method for dose estimation in irradiated oregano by thermoluminescence technique
2009
The ionizing radiation treatment of food is nowadays a worldwide recognized tool for food preservation, provided that proper and validated identification methods are available and used. The thermoluminescence (TL) technique is one of the physical methods recommended by the European Committee for Standardization to distinguish irradiated from not irradiated samples, for food containing silicate minerals as contaminants, such as spices and aromatic herbs, which are among the most frequently irradiated foods. The experimental results presented in this work show that, at least up to the highest tested doses (2 kGy), it is possible to set up a procedure to estimate the actual dose in the irradia…
Nonlocal Third Order Boundary Value Problems with Solutions that Change Sign
2014
We investigate the existence and the number of solutions for a third order boundary value problem with nonlocal boundary conditions in connection with the oscillatory behavior of solutions. The combination of the shooting method and scaling method is used in the proofs of our main results. Examples are included to illustrate the results.