Search results for "Production function"

ESSAYS ON THE DRIVERS OF FIRM COMPETITIVENESS

2020

Determining Optimal Seasonal Irrigation Depth Based on Field Irrigation Uniformity and Economic Evaluations: Application for Onion Crop

2016

The crop water production function (WPF), representing the relationship between crop yield and seasonal irrigation water, is a useful tool for irrigation planning purposes. The objective of the paper is to propose a methodology to evaluate the optimal seasonal irrigation depth based on the crop production function, the field distribution uniformity, and economic considerations. An extended unpublished database experimentally obtained on the onion crop on the island of Kula, Hawaii, was initially used to assess the crop WPF. The combination between the crop WPF and the model representing the field distribution uniformity allowed determining the area subjected to underirrigation and overirrig…

Identifier et évaluer les compétences dans le système éducatif : quels apports pour la recherche en education ?

2007

07077 - 176 p.; Après un bref rappel sur la fonction de production scolaire, nous nous attacherons à montrer l'intérêt de mieux en spécifier les résultats, en termes de compétences développées par les élèves notamment. Nous reviendrons, pour cela, sur la recherche d'une éventuelle définition de la notion de compétence, pour s'attarder plus particulièrement sur les mesures de la compétence proposées par les acteurs du système à différents niveaux : local, national ou international (chapitre I). Ceci nous amènera à mettre en parallèle, d'un point de vue méthodologique, les outils dont dispose le praticien avec ceux mis à la disposition du chercheur, qui s'avèrent peut-être plus complets, mais…

FORECASTING THE LABOUR FORCE DEMAND AND SUPPLY IN LATVIA / LATVIJOS DARBO JĖGOS PAKLAUSOS IR PASIŪLOS MODELIAVIMAS

2008

The purpose of this paper is to analyse the problems of Latvian labour market and its possible development. An econometric model for labour force demand and supply forecasting is elaborated and it comprises 120 professions, 37 aggregated groups of professions and covers time period 2007–2030. The results of the quantitative and qualitative Employers’ Survey are analysed and taken into account. The novelty of this research study lies in the complex approach to the labour force demand and supply analyses and to the forecasts to the Latvian economy in general and for its 15 separate sectors. Santrauka Šio straipsnio tikslas – išanalizuoti Latvijos darbo rinkos problemas ir galimus pokyčius. Su…

Public capital, productive efficiency and convergence in the Spanish regions (1964-93)

1998

This paper analyses the behaviour of productive efficiency in the Spanish regions for the period 1964–93. From a growth accounting approach, it describes the regional evolution of total factor productivity (TFP'), based on a private inputs production function. A stricter measure of efficiency is then quantified, which is not equivalent to Solow's residual, since public capital is included in the production function and constant returns to scale are not imposed. Finally, on the basis of the measures of total factor productivity and efficiency, the study discusses the existence of technological convergence among Spanish regions and the role played in it by public capital. The renewed interest…

A micro-founded approach to regional innovation in Italy

2022

Recent regional studies have taken a micro-founded perspective to uncover the influence of the external environment on the firm-level innovative performance. Despite the marked spatial disparities, there is a general lack of recent evidence on Italian regional innovation from a micro perspective. This paper fills this gap in the evidence base by estimating regional Knowledge Production Functions using Italian micro-data collected in the Community Innovation Survey. In particular, here we focus on the regional differences in the relationship between innovative inputs and outputs and on the ability of firms to absorb external knowledge. This analysis allows us to outline different regional in…

About the Ghosh Model: Clarifications

2007

We examine the consistency of the Ghosh supply-d riven input-output model (SM) by respect to the traditional Leontief demand-drive n input-output model (LM); the variants considered are: primal and dual, quantity and value ; input prices are not considered. SM offers solutions of limited interest, being incapab le to separate quantities and prices or values and price indexes. Comparing the dual value SM to the primal of LM is wrong. Even if the agents are forced to buy inputs in SM, the interpre tation of SM as a centrally planned economy must be rejected but SM may serve for modeling interfirm relations or analyzing the structural interindustry change when the production function is not sp…

Chemical weathering of volcanic rocks at the island of Pantelleria, Italy: Information from soil profile and soil solution investigations

2007

Abstract Concentrations of major, minor and trace elements were determined in soil profiles and soil solutions from the island of Pantelleria, Sicily Channel, to evaluate the weathering extent of soils evolved on trachytic and pantelleritic rocks and the aqueous transport of elements by their soil solutions. The chemical index of alteration (CIA) indicates a low-to-moderate degree of weathering; consistently, the mineralogical and geochemical imprints of the parent rocks are generally preserved. The chemical weathering appears to be incongruent, owing to primary minerals and glass dissolving to a variable degree while secondary minerals have formed. Based on the calculated saturation state …

Over-estimation of efficiency of weathering in tropical “Red Soils”: its importance for geoecological problems

2000

Abstract Weathering and soil formation rates are regarded as the main criteria of a tolerable soil loss. The efficiency of weathering in the seasonal semiarid tropics has often been greatly over-estimated especially in the geomorphologic literature in which weathering is assumed to be as fast or even faster than surface erosion. Six selected “Red Soils” in two intramontane basins of hyperthermic SW Nepal near the border with India, with 1500–1750 mm annual rainfall (5 humid months), and a “Black Soil” near Baroda, Gujarat, India (3–4 humid months) were studied mineralogically. Two of the “Red Soils” have TL ages between 10 and 30 ka, the “Black Soil” has one of about 10 ka. The yellowish si…

Clay minerals, oxyhydroxide formation, element leaching and humus development in volcanic soils

2008

Aweathering sequence with soils developing on volcanic, trachy-basaltic parent materials with ages ranging from 100–115,000 years in the Etna region served as the basis to analyse and calculate the accumulation and stabilisation mechanisms of soil organic matter (SOM), the transformation of pedogenic Fe and Al, the formation and transformation of clay minerals, the weathering indices and, by means of mass-balance calculations, net losses of the main elements. Although the soils were influenced by ash depositions during their development and the soil on the oldest lava flow developed to a great extent under a different climate, leaching of elements and mineral formation and transformation co…