Contingent derivatives and regularization for noncoercive inverse problems

We study the inverse problem of parameter identification in non-coercive variational problems that commonly appear in applied models. We examine the differentiability of the set-valued parameter-to-solution map by using the first-order and the second-order contingent derivatives. We explore the inverse problem by using the output least-squares and the modified output least-squares objectives. By regularizing the non-coercive variational problem, we obtain a single-valued regularized parameter-to-solution map and investigate its smoothness and boundedness. We also consider optimization problems using the output least-squares and the modified output least-squares objectives for the regularized variational problem. We give a complete convergence analysis showing that for the output least-squares and the modified output least-squares, the regularized minimization problems approximate the original optimization problems suitably. We also provide the first-order and the second-order adjoint method for the computation of the first-order and the second-order derivatives of the output least-squares objective. We provide discrete formulas for the gradient and the Hessian calculation and present numerical results

Can a home country benefit from FDI? A theoretical analysis

The effects of outward FDI on home country’s growth remain an open question. The growth of outward FDI has renewed this attention. By allowing for endogenous decisions of firms on both whether to conduct FDI and whether to flow capital returns back to the home country, we have found several interesting results. First, as long as the probability of conducting FDI is positive, a higher proportion of entrepreneurs may harm economic growth of the home country in short-run and long-run. The ambiguous effects of transaction costs and MRS between domestic and foreign consumption on the home country’s economic growth result from the role of financial intermediaries. If the effect via inflow probability dominates, conducting FDI in a host country with a more liberalized capital account, or with a higher capital return rate may promote the home country’s economic growth rate. This is consistent with the findings in the outward FDI in European Union since 1970s

On iterated minimization in nonconvex optimization

In dynamic programming and decomposition methods one often applies an iterated minimization procedure. The problem variables are partitioned into several blocks, say x and y. Treating y as a parameter, the first phase consists of minimization with respect to the variable x. In a second phase the minimization of the resulting optimal value function depending on y is considered. In this paper we treat this basic idea on a local level. It turns out that strong stability (in the sense of Kojima) in the first phase is a natural assumption. In order to show that the iterated local minima of the parametric problem lead to a local minimum for the whole problem, we use a generalized version of a positive definiteness criterion of Fujiwara-Han-Mangasarian

Comparing anaphora resolution in early and late Brazilian Portuguese-European Portuguese bidialectal bilinguals

The present study examines anaphora resolution in two groups of speakers exposed to Brazilian and European Portuguese (BP and EP, respectively), considering the different null subject distribution in these languages. Our research question is whether late BP-EP bilinguals (age of EP onset: 29.1) and heritage BP speakers raised in Portugal (age of EP onset 5.6), tested in both dialects, will pattern like the native controls or display some effects of EP in their native BP or vice-versa. This is an interesting question in light of the Interface Hypothesis, which claims that external interfaces should be subject to general bilingualism effects irrespective of language pairing and age (Sorace, 2011). The results show that age has an effect, as the heritage speakers do not perform like the late learners, and that the high degree of typological proximity between the two languages rules out the possibility of late bidialectal acquisition

Berufsschulumfrage 2012. Einflussfaktoren auf die Berufswahl und Verbleibentscheidung von Auszubildenden im Landkreis Mecklenburgische Seenplatte

Berufswahlsentscheidung und die Frage nach dem Gehen oder Bleiben ist nicht nur für viele junge Menschen in ländlichen Regionen eine wichtige Frage, sondern auch für die im Übergang Schule-Beruf arbeitenden Menschen und Akteure der jeweiligen Kommune. Vor dem Hintergrund der Abwanderungstendenzen und der Optimierung der Übergänge Schule-Beruf hat die Stabsstelle Bildung des Landkreises Mecklenburgische Seenplatte repräsentativ 2800 Auszubildende des Landkreises befragt über die Einflussfaktoren für ihre Berufswahl und über ihre Entscheidung hier zu bleiben oder gehen befragt. Die z.T. überraschenden Ergebnisse werden in dieser Studie zusammen mit Handlungsempfehlungen dargestellt. (DIPF/Autor

Spectroscopic ellipsometry on thin films of conjugated polymers

This work presents results from spectroscopic ellipsometry measurements of thin films of conjugated polymers constructed by spin casting with rapid solvent evaporation. Accurate data for the optical functions of MEH-PPV, PF2/6am5, PPy and PmPy films are given for the first time in a broad spectral range. A uniaxial anisotropic character is present in these functions with the optical axis parallel to the surface normal. The amount of anisotropy is found to be fairly high even in polymer layers with less rigid rod molecule chains (PF2/6am5 and MEH-PPV) and very high for the highly 7r-stiff polymer PPy. The influence of an anisotropic and highly dispersive optical response on the efficiency of light emitting diodes made from PF2/6am4 is investigated. The out-coupling efficiency in such devices is found to be highly dependent on the emission wavelength. The results obtained are compared to the commonly used approximation n =const. = 2. The importance of a proper knowledge of the optical behavior of this material group when utilized in devices is shown by the significant difference between these methods. The ability of ellipsometry to monitor structural changes in conjugated polymers is demonstrated. The perfect rigid rod behavior of PPy and the loss of rigidity when forming a copolymer together with meta mPy is clearly visible in the ellipsometry data. The amount of anisotropy is dependent of the ratio of mPy and an isotropic respond is obtained for pure PmPy. Furthermore, the blue shifted absorption spectrum for higher ratios of PmPy validate breaks in the conjugation by the additional meta linkages in the chain

Null Subject Behavior in the Attrition of Brazilian Portuguese

The syntax of referential null subjects in Brazilian Portuguese (BP) is the topic of much recent work (Kato & Negrão 2000; Ferreira 2000, 2004; Martins & Nunes 2005, 2010; Modesto 2000; Rodrigues 2002, 2004). In light of the Interface Hypothesis (Tsimpli, Sorace 2006), uninterpretable features such as purely syntactical elements should not undergo attrition. This study tests whether this theory is valid in regard to the Null Subject behavior in the production of BP speakers under influence of L2 English. In order to do so, I conducted an experiment with monolingual BP speakers and bilingual (English/BP) speakers to establish a clear-cut comparison. The experiment consisted of an elicited production task and a grammaticality judgment task. The results of the data analysis show that BP speakers under influence of L2 English do seem to indicate attrition, thus encouraging further studies questioning the Interface Hypothesis