Godement resolutions and sheaf homotopy theory

The Godement cosimplicial resolution is available for a wide range of categories of sheaves. In this paper we investigate under which conditions of the Grothendieck site and the category of coefficients it can be used to obtain fibrant models and hence to do sheaf homotopy theory. For instance, for which Grothendieck sites and coefficients we can define sheaf cohomology and derived functors through it.Comment: 33 pages. To appear in Collectanea Mathematica. The final publication is available at Springer via http://dx.doi.org/10.1007/s13348-014-0123-

Vertically coupled quantum dots in the local spin-density functional theory

We have investigated the structure of double quantum dots vertically coupled at zero magnetic field within local spin-density functional theory. The dots are identical and have a finite width, and the whole system is axially symmetric. We first discuss the effect of thickness on the addition spectrum of one single dot. Next, we describe the structure of coupled dots as a function of the interdot distance for different electron numbers. Addition spectra, Hund's rule and molecular-type configurations are discussed. It is shown that self-interaction corrections to the density functional results do not play a very important role in the calculated addition spectra.Comment: Typeset using Revtex, 14 pages and 12 Postscript figures, to be published in Phys. Rev.

Far-infrared spectroscopy of nanoscopic InAs rings

We have employed time-dependent local-spin density theory to analyze the far-infrared transmission spectrum of InAs self-assembled nano-rings recently reported [A. Lorke et al, cond-mat/9908263 (1999)]. The overall agreement between theory and experiment is good, which on the one hand confirms that the experimental peaks indeed reflect the ring-like structure of the sample, and on the other hand, asseses the suitability of the theoretical method to describe such small nanostructures. The addition energies of one- and two-electron rings are also reported and compared with the corresponding capacitance spectra.Comment: Typeset using Revtex, 7 pages and 8 Postscript figure

A Cartan-Eilenberg approach to Homotopical Algebra

In this paper we propose an approach to homotopical algebra where the basic ingredient is a category with two classes of distinguished morphisms: strong and weak equivalences. These data determine the cofibrant objects by an extension property analogous to the classical lifting property of projective modules. We define a Cartan-Eilenberg category as a category with strong and weak equivalences such that there is an equivalence between its localization with respect to weak equivalences and the localised category of cofibrant objets with respect to strong equivalences. This equivalence allows us to extend the classical theory of derived additive functors to this non additive setting. The main examples include Quillen model categories and functor categories with a triple, in the last case we find examples in which the class of strong equivalences is not determined by a homotopy relation. Among other applications, we prove the existence of filtered minimal models for \emph{cdg} algebras over a zero-characteristic field and we formulate an acyclic models theorem for non additive functors

Geographical determinants of the creation of manufacturing firms: The regions of Spain

The complexity of the mechanisms determining the entry and exit of firms increases when geographical differences in production structure, human capital and unemployment are considered. Inter-reginal variations in the rate of the new firms start-ups within each industrial activity persist through long periods of time, a circumstance that indicates that there are non-conjunctural determinants to the capacity of regions to create new industrial projects. This study is concerned with establishing the influence o geographical variables on the setting up of new manufacturing establishments. The manufacturing industries (NACE R-25) in the Spanish regions (NUTS-2) have been taken as the units of analysis for the period 1980-1992.spanish regions, industrial dynamics, geographical determinants, firm start-ups

MODAL SOSIAL LULUSAN SARJANA DALAM MENCARI PEKERJAAN (STUDI KASUS DI GAMPONG BLANG PUUK KULU, KEC. SEUNAGAN, KAB. NAGAN RAYA)

ABSTRAKPenelitian ini bertujuan untuk mengetahui modal sosial lulusan sarjana dalam mencari pekerjaan, keterkaitan modal sosial dengan hal mendapatkan pekerjaan, dan konstribusi modal sosial dalam meningkatkan pendapatan ekonomi lulusan sarjana. dalam mengkaji permasalahan tersebut peneliti menggunakan metode penelitian deskriptif kualitatif, dengan instrumen pengumpulan data berupa wawancara, observasi dan dokumentasi. Informan dalam penelitian ini berjumlah 5 (lima) orang yang terdiri dari lulusan sarjana yang berada di Gampong Blang Puuk Kulu. adapun teori yang digunakan dalam penelitian ini adalah teori modal sosial. hasil penelitian ini menunjukkan bahwa Modal sosial lulusan sarjana di gampong Blang Puuk Kulu terdiri dari relasi-relasi sosial atau jaringan sosial yang berupa hubungan-hubungan yang terjalin antara lulusan sarjana dengan aktor yang membantu mencarikan pekerjaan, trust atau kepercayaan yang berupa sikap saling percaya antara lulusan sarjana dengan aktor yang membantu mencari pekerjaan, pembalasan atau timbal balik yang terjadi antara lulusan sarjana dengan aktor yang membantu mencari pekerjaan sehingga memunculkan sikap saling tukar kebaikan, norma sosial lulusan sarjana di gampong Blang Puuk Kulu berupa aturan-aturan yang ada dalam keluarga lulusan sarjana itu sendiri atau kesepakatan yang terjalin antara lulusan sarjana dengan aktor yang membantu mencarikan pekerjaan. kesimpulan dari penelitian ini adalah dengan adanya modal sosial berupa hubungan-hubungan sosial, trust atau kepercayaan, timbal balik, dan norma sosial membuat lulusan sarjana jadi mudah mendapatkan pekerjaan. Karena modal sosial di Gampong Blang Puuk Kulu bersifat mengikat dimana ada ikatan antara lulusan sarjana dengan aktor dalam keluarga maupun dengan aktor diluar keluarga.Kata Kunci: Modal Sosial, Lulusan Sarjana, Pekerjaan ABSTRACTThis study was meant to find out social capital of graduate students in finding a job, and the correlation between social capital and finding a job, as well as the contribution of social capital in boosting up the income of graduate students. In terms of this matter, the writer employed descriptive qualitative method. The research instruments used to collect the data were interview, observation, and documentation. The informants selected in this study were 5 (five) people consisting graduate students from Gampong Blang Puuk Kulu. The theory applied in this study was social capital. The results of the study illustrated that the social capital of graduate students of Gampong Blang Puuk Kulu were social relations or social network between them and actors who can help them find a job, well-maintained trust between graduate students and the actor, mutual relationship which make them share mutual benefits, and social norms which consist of rules applied in their family and the deals agreed between them. In conclusion, social network, trust, mutual relationship, and social norms have enabled graduate students to more easily have a job. Such phenomena happened because the social capital in Gampong Blang Puuk Kulu was bound relationship between graduate students and actors in family or actors who did not belong to the same family.Keywords: Social Capital, Graduate Students, Jo