830 research outputs found
Capital-Skill Complimentarity: Evidence from Manufacturing Industries in Ghana
Using U.S. manufacturing data, Griliches (1969) found evidence suggesting that capital equipment was more substitutable for unskilled than skilled labor. Griliches formulated this finding as the capital-skill complementarity hypothesis. The purpose of this study is to determine whether the capital-skill complementarity framework holds for Ghana manufacturing plants in industry and aggregate level. We use an unbalanced panel of plant-level data for manufacturing firms in Ghana during the 1991 and 1997 in four industries (food-bakery, textiles-garments, wood-furniture and metal-machinery). Our findings suggest that capital-skill complimentarity holds in aggregate level and wood-furniture sector in Ghana. However, we reject the capital-skill complementarity hypothesis for food-bakery, textile-garment and metal-machinery sectors.capital-skill complementarity, elasticity of substitution, translog cost function
Finite element analysis of transonic flows in cascades: Importance of computational grids in improving accuracy and convergence
The finite element method is applied for the solution of transonic potential flows through a cascade of airfoils. Convergence characteristics of the solution scheme are discussed. Accuracy of the numerical solutions is investigated for various flow regions in the transonic flow configuration. The design of an efficient finite element computational grid is discussed for improving accuracy and convergence
Capital-skill complementarity: evidence from manufacturing industries in Ghana
Using U.S. manufacturing data, Griliches (1969) found evidence suggesting that capital equipment was more substitutable for unskilled than skilled labor. Griliches formulated this finding as the capital-skill complementarity hypothesis. The purpose of this study is to determine whether the capital-skill complementarity framework holds for Ghana manufacturing plants in industry and aggregate level. We use an unbalanced panel of plant-level data for manufacturing firms in Ghana during the 1991 and 1997 in four industries (food-bakery, textiles-garments, wood-furniture and metal-machinery). Our findings suggest that capital-skill complementarity holds in aggregate level and wood-furniture sector in Ghana. However, we reject the capital-skill complementarity hypothesis for food-bakery, textile-garment and metal-machinery sectors
Back to Bentham, Should We? Large-Scale Comparison of Experienced versus Decision Utility
Subjective well-being (SWB) data is increasingly used to perform welfare analyses. In- terpreted as 'experienced utility', SWB has recently been compared to 'decision utility' using specific experiments, most often based on stated preferences. Results point to an overall congruence between these two types of welfare measures. We question whether these findings hold in the more general framework of non-experimental and large-scale data, i.e. the setting commonly used for policy analysis. For individuals in the British household panel, we compare the ordinal preferences either "revealed" from their labor supply decisions or elicited from their reported SWB. The results show striking similari- ties on average, reflecting the fact that a majority of individuals made decisions that are consistent with SWB maximization. DiĀ¤erences between the two welfare measures arise for particular subgroups, lending themselves to intuitive explanations that we illustrate for specific factors (health and labor market constraints, 'focusing illusion', aspirations)
KoriÅ”tenje GIS tehnika za modeliranje Å”irenja antropogene buke koju stvara motorna pila prilikom sjeÄe Å”uma
Noise is an environmental pollution that negatively affects human health and reduces the performance of employees. Forest harvesting activities are one of the working environments where noise effect is intense. The most common equipment used in forest operations is chainsaw whose noise affects not only the operator but also the wildlife in the territory. The noise maps showing noise propagation can be effectively used in evaluating and controlling the noise effects. In this study, it was aimed to measure the anthropogenic noise levels ​​resulting from the chainsaw used in tree felling and to map its noise propagation with SPreAD-GIS (System for Prediction of Acoustic Detectability) which is a GIS (Geographical Information Systems) based noise prediction software. The study was conducted in Karacabey Flooded Forest within the city of Bursa in TĆ¼rkiye. The results indicated that the average noise level from the chainsaw was above the danger limit (90 dBA) that causes increased physiological reactions and headache on the workers. According to the noise propagation map, the noise exposure of the employees exceeded the warning limit (85 dBA) and the maximum noise level was 95.96 dBA during the harvesting activity. In some parts of the study area, the noise level was 45 dBA or above, causing negative effects on bird species. It can be concluded that the noise maps can be effectively used to determine noise propagation generated by a chainsaw and evaluate the noise effects on the operators and as well as on the bird species in the perimeter.Buka je oneÄiÅ”Äenje okoliÅ”a koje negativno utjeÄe na zdravlje ljudi i smanjuje uÄinak zaposlenika. Aktivnosti sjeÄe Å”uma jedno su od radnih okruženja u kojima je buka intenzivna. NajÄeÅ”Äa oprema koja se koristi u Å”umarstvu je motorna pila, Äija buka utjeÄe ne samo na operatera, veÄ i na divlje životinje na teritoriju. Karte buke koje prikazuju Å”irenje buke mogu se uÄinkovito koristiti za procjenu i kontrolu uÄinaka buke. U ovome radu cilj je bio izmjeriti razine antropogene buke nastale radom motorne pile koja se koristi pri sjeÄi stabala i mapirati Å”irenje buke pomoÄu SPreAD-GIS programa (Sustav za predviÄanje akustiÄne detektabilnosti) Äija se procjena Å”irenja buke temelji na GIS-u (Geografski informacijski sustav). Istraživanje je provedeno u poplavnoj Å”umi Karacabey na podruÄju grada Bursa u Turskoj. Rezultati su pokazali da je prosjeÄna razina buke motorne pile iznad granice opasnosti (90 dBA), Å”to uzrokuje pojaÄane fizioloÅ”ke reakcije i glavobolju radnika. Prema karti Å”irenja buke, izloženost zaposlenika buci preÅ”la je granicu upozorenja (85 dBA), a maksimalna razina buke tijekom rada iznosila je 95,96 dBA. U nekim dijelovima istraživanog podruÄja razina buke iznosila je 45 dBA ili viÅ”e, Å”to je uzrokovalo negativan utjecaj na vrste ptica. Može se zakljuÄiti da se karte buke mogu uÄinkovito koristiti za odreÄivanje Å”irenja buke koju stvara motorna pila i procjenu uÄinaka buke na operatere, kao i na vrste ptica u okruženju
Model validation for a noninvasive arterial stenosis detection problem
Copyright @ 2013 American Institute of Mathematical SciencesA current thrust in medical research is the development of a non-invasive method for detection, localization, and characterization of an arterial stenosis (a blockage or partial blockage in an artery). A method has been proposed to detect shear waves in the chest cavity which have been generated by disturbances in the blood flow resulting from a stenosis. In order to develop this methodology further, we use both one-dimensional pressure and shear wave experimental data from novel acoustic phantoms to validate corresponding viscoelastic mathematical models, which were developed in a concept paper [8] and refined herein. We estimate model parameters which give a good fit (in a sense to be precisely defined) to the experimental data, and use asymptotic error theory to provide confidence intervals for parameter estimates. Finally, since a robust error model is necessary for accurate parameter estimates and confidence analysis, we include a comparison of absolute and relative models for measurement error.The National Institute of Allergy and Infectious Diseases, the Air Force Office of Scientific Research, the Deopartment of Education and the Engineering and Physical Sciences Research Council (EPSRC)
Review of Linac-Ring Type Collider Proposals
There are three possibly types of particle colliders schemes: familiar (well
known) ring-ring colliders, less familiar however sufficiently advanced linear
colliders and less familiar and less advanced linac-ring type colliders. The
aim of this paper is two-fold: to present possibly complete list of papers on
linac-ring type collider proposals and to emphasize the role of linac-ring type
machines for future HEP research.Comment: quality of figures is improved, some misprints are correcte
application of surface transformation films and nanosphere lithography
Photoelectrochemical (PEC) cells offer the possibility of carbon-neutral solar fuel production through artificial photosynthesis. The pursued design involves technologically advanced IIIāV semiconductor absorbers coupled via an interfacial film to an electrocatalyst layer. These systems have been prepared by in situ surface transformations in electrochemical environments. High activity nanostructured electrocatalysts are required for an efficiently operating cell, optimized in their optical and electrical properties. We demonstrate that shadow nanosphere lithography (SNL) is an auspicious tool to systematically create three-dimensional electrocatalyst nanostructures on the semiconductor photoelectrode through controlling their morphology and optical properties. First results are demonstrated by means of the photoelectrochemical production of hydrogen on p-type InP photocathodes where hitherto applied photoelectrodeposition and SNL-deposited Rh electrocatalysts are compared based on their JāV and spectroscopic behavior. We show that smaller polystyrene particle masks achieve higher defect nanostructures of rhodium on the photoelectrode which leads to a higher catalytic activity and larger short circuit currents. Structural analyses including HRSEM and the analysis of the photoelectrode surface composition by using photoelectron spectroscopy support and complement the photoelectrochemical observations. The optical performance is further compared to theoretical models of the nanostructured photoelectrodes on light scattering and propagation
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