Search results for "TF"
showing 10 items of 1652 documents
Ostfront von Kurland bis Konstantinopel
1915
"Mit rund 160 photographischen Aufnahmen"
A cross-country study of skills and unemployment flows
2021
AbstractUsing an international survey that directly assesses the cognitive skills of the adult population, I study the relation between skills and unemployment flows across 37 countries. Depending on the specifically assessed domain, I document that skills have an unconditional correlation with the log-risk-ratio of exiting to entering unemployment of 0.65–0.68 across the advanced and skill-abundant countries in the sample. The relation is remarkably robust and it is unlikely to be due to reverse causality. I do not find evidence that this positive relation extends to the seven relatively less advanced and less skill-abundant countries in the sample: Peru, Ecuador, Indonesia, Mexico, Chile,…
When do Improved Covariance Matrix Estimators Enhance Portfolio Optimization? An Empirical Comparative Study of Nine Estimators
2010
The use of improved covariance matrix estimators as an alternative to the sample estimator is considered an important approach for enhancing portfolio optimization. Here we empirically compare the performance of 9 improved covariance estimation procedures by using daily returns of 90 highly capitalized US stocks for the period 1997-2007. We find that the usefulness of covariance matrix estimators strongly depends on the ratio between estimation period T and number of stocks N, on the presence or absence of short selling, and on the performance metric considered. When short selling is allowed, several estimation methods achieve a realized risk that is significantly smaller than the one obtai…
Block Bootstrap Methods and the Choice of Stocks for the Long Run
2011
Financial advisors commonly recommend that the investment horizon should be rather long in order to benefit from the "time diversification". In this case, in order to choose the optimal portfolio, it is necessary to estimate the risk and reward of several alternative portfolios over a long-run given a sample of observations over a short-run. Two interrelated obstacles in these estimations are lack of sufficient data and the uncertainty in the nature of the return generating process. To overcome these obstacles researchers rely heavily on block bootstrap methods. In this paper we demonstrate that the estimates provided by a block bootstrap method are generally biased and we propose two metho…
Labor productivity and firm-level TFP with technology-specific production functions
2020
Abstract We investigate the technological dimension of productivity, presenting an empirical methodology based on mixture models to disentangle the labor productivity differences associated with the firm's choice of technology (BTFP) and those related to the firm's ability to exploit the adopted technology (WTFP). The estimation endogenously determines the number of technologies (in the sector) and degree of technology sharing across firms (i.e., for each firm, the probability of using a given technology). By using comparable data for about 35,000 firms worldwide distributed across 22 (two-digit) sectors, we show BTFP to be at least as important as WTFP in explaining the labor productivity …
Blockchain tehnoloģijā balstītu sistēmu izveide ar Ethereum
2016
Darba mērķis ir Ethereum decentralizētas programmatūras platformas pētīšana. Darbā tiek pētītas tehnoloģijas uz kurām balstās decentralizētās programmatūras platforma, programmatūras izstrādes process tajā un platformas stiprās un vājās puses. Darba praktiskajā daļā, tiek izveidots decentralizētas kopfinansēšanas sistēmas prototips Ethereum platformā.
Viedo līgumu izstrādes platformu salīdzinājums
2018
Viedie līgumi ir jauna tehnoloģija, kurai ir liels potenciāls nākotnē tik plaši izmantotai. To pirmā izstrādes platforma bija Ethereum, taču laika gaitā tai ir parādījušies spēcīgi konkurenti, kuri nav tikuši sīkāk pētīti. Darbā tiek veikta populārāko viedo līgumu izstrādes platformu Ethereum, NEO un EOS projektējuma filozofijas, darbības principu un īpašību pētīšana un, balstoties uz tā, tiek veidots atšķirību salīdzinājums. Pētījuma rezultātā ir iegūta tabula, kurā redzamas platformu būtiskākās atšķirības. Pētījumā secinātas apskatīto platformu projektējuma filozofijas, darbības principu un īpašību atšķirības un kompromisi, uz kuriem platformām jāiziet, lai sasniegtu savus projektējuma mē…
Bruk av dyr i vitenskapelige eksperimenter : en filosofisk undersøkelse
2004
I dette arbeidet behandles filosofiske og etiske spørsmål som oppstår i forbindelse med bruk av dyr i vitenskapelige eksperimenter. Med vitenskapelige eksperimenter menes eksperimenter innenfor all slags medisinsk og veterinærmessig forskning og innenfor arbeid som tar sikte på å utvikle og prøve medikamenter. Det tenkes altså både på anvendt forskning og på grunnforskning. Forfatteren kommer ikke inn på bruk av dyr i kosmetikkindustrien, i matvareproduksjonen eller i kontrollen av matvarer. Det gås heller ikke inn på bruk av dyr som kjæledyr eller som følgedyr.
European Universities: Forthem e la mobilità virtuale
2022
Il contributo introduce dapprima il programma European Universities e i vari progetti finanziati con la partecipazione di università italiane, con particolare attenzione sulla mobilità virtuale. Successivamente la presentazione esamina la Digital Academy, la piattaforma online per la mobilità virtuale, la collaborazione e il networking per studenti e membri del personale accademico ed amministrativo sviluppato nel Progetto Forthem, di cui l’Università di Palermo è Università partner. Verrà illustrato il modello di apprendimento e insegnamento che ne deriva. The paper deals with the European Universities program and the various projects funded with the participation of Italian universities. …
Evaluación de la calidad pedagógica de los MOOC
2014
Los MOOC han irrumpido de forma acelerada en el ámbito de la educación. Las principales universidades estadounidenses primero y, posteriormente, muchas otras –entre ellas, algunas españolas— están desarrollando a través de diversas plataformas en Internet, cursos bajo este formato. Al encontrarnos en una situación inicial de desarrollo de MOOC, son escasos los estudios sobre su evaluación. Por ello, el presente estudio ha realizado 129 evaluaciones a 52 MOOC ofertados por 10 plataformas. Se han analizado sus características pedagógicas a partir del Cuestionario de evaluación de la calidad de cursos virtuales (Arias, 2007). Del mismo modo se aborda la hipótesis de la existencia de diferencia…