Diversity-Weighted Portfolios with Negative Parameter

We analyze a negative-parameter variant of the diversity-weighted portfolio studied by Fernholz, Karatzas, and Kardaras (Finance Stoch 9(1):1-27, 2005), which invests in each company a fraction of wealth inversely proportional to the company's market weight (the ratio of its capitalization to that of the entire market). We show that this strategy outperforms the market with probability one, under a non-degeneracy assumption on the volatility structure and the assumption that the market weights admit a positive lower bound. Several modifications of this portfolio, which outperform the market under milder versions of this "no-failure" condition, are put forward, one of which is rank-based. An empirical study suggests that such strategies as studied here have indeed the potential to outperform the market and to be preferable investment opportunities, even under realistic proportional transaction costs.Comment: 25 page

A influência dos estereótipos de gênero no processamento de informações sobre candidatos homens e mulheres

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciência Política, 2017.Eleições recentes têm visto uma onda de candidatas mulheres concorrendo a cargos políticos locais, estaduais e nacionais. No entanto, a sub-representação política das mulheres persiste no mundo todo. Os estudos que tentam compreender os motivos da dificuldade da entrada das mulheres na política são numerosos, porém seus achados costumam ser contraditórios e ainda não conseguiram fornecer explicações suficientes sobre a desigualdade nos níveis de representação política entre homens e mulheres. Uma das explicações possíveis para essa dificuldade seria a existência de estereótipos de gênero pelos quais os indivíduos julgam as candidatas mulheres. Entre os achados mais persistentes está a ideia de que os eleitores esperam que mulheres e homens candidatos possuam competências políticas diferentes. Espera-se que mulheres sejam melhores em políticas que lidam com a compaixão e com o cuidado de outras pessoas, como educação, saúde e redução da pobreza e que homens sejam melhores em políticas que necessitam de força e assertividade, como crime, violência e política externa. O presente trabalho faz o teste dessas hipóteses no contexto eleitoral brasileiro. Os resultados mostram que a relação entre os estereótipos de gênero e as candidatas mulheres é bastante complexa e que não segue o caminho proposto por parte da literatura. Apesar das mulheres candidatas serem, a primeira vista, percebidas como melhores em questões políticas que envolvem compaixão, esse fato não parece influenciar as decisões eleitorais. O mesmo ocorre com os candidatos homens. É possível que os estereótipos utilizados na compreensão das mulheres "comuns" não sejam os mesmos para as mulheres da vida pública e cargos de liderança.Recent elections have seen a surge of female candidates running for office at the local, state, and national level. However, women’s political underrepresentation persists all over the world. Studies that try to understand the reasons for the difficulty of women entering politics are numerous, but their findings are often contradictory and have not yet been able to provide sufficient explanations for the inequality in the levels of political representation between men and women. One of the possible explanations for this difficulty would be the existence of gender stereotypes by which individuals judge women candidates. Among the more persistent findings is the idea that voters expect women and men candidates to have different political competencies. Women are expected to be better at policies that deal with compassion and caring for others, such as education, health, and poverty, and for men to be better at policies that require strength and assertiveness, such as crime, violence, and foreign policy.This paper tests these hypotheses in the Brazilian electoral context. The results show that the relationship between gender stereotypes and female candidates is quite complex and does not follow the path proposed by the literature. Although women candidates are, at first glance, perceived as better at political issues involving compassion, this fact does not seem to influence electoral decisions. The same goes for male candidates. It is possible that the stereotypes used in understanding "ordinary" women are not the same for women in politics and leadership positions

Modeling Business Process Variability

This master thesis presents research findings on business process variability modeling. Its main goal is to analyze inherent problems of business process variability and solve them simply, innovatively and effectively. To achieve this goal, process variability is defined by analyzing scientific literature, its main problems identified and is illustrated using a healthcare running example: process variability is classified into process variability within the domain space and over time. These two forms of process variability respectively lead to process variability modeling and process model evolution problems. After defining the main problems inherent to process variability, the focus of this research project is defined: solving process variability modeling problems. First current business process modeling languages are evaluated to assess the effectiveness of their respective modeling concepts when modeling process variability, using a newly created set of evaluation criteria and the healthcare running example. The following business process modeling languages are evaluated: Event driven process chains (EPC), the Business Process Modeling Notation (BPMN) and Configurable EPC (C-EPC). Business process variability modeling and Software product line engineering have similar problems. Therefore the variability modeling concepts developed by software product line engineering are analyzed. Feature diagrams and software configuration management are the main variability management concepts provided by software product line engineering. To apply these variability management concepts to model process variability meant combining them with existing business modeling languages. Riebisch feature diagrams are combined with C-EPC to form Feature-EPC. Applying software configuration management, meant merging Change Oriented Versioning with basic EPC to create COV-EPC, and merging the Proteus Configuration Language with basic EPC to design PCL-EPC. Finally these newly created business process modeling languages are also evaluated using the newly designed evaluation criteria and the healthcare running example. EPC or BPMN are not suited to model business process variability within the domain space. C-EPC provide explicit means to model business process variability, however the process models tend to get big very fast. Furthermore the syntax, the contextual constraints and the semantics of the configuration requirements and guidelines used to configure the C-EPC process models are unclear. Feature-EPC improve C-EPC with domain modeling capability and clearly defined configuration rules: their syntax, contextual constraints and semantics have been clearly defined using a context free grammar in Backus-Naur form. Furthermore, consistent combinations of features and configuration rules are ensured using respectively constraints and a conflict resolution algorithm. However, Feature-EPC and C-EPC suffer from the same weakness: large configurable process models. In COV-EPC and PCL-EPC the problem of large configurable process models is solved. COV-EPC ensures consistent combinations of options and configuration rules using respectively validities and a conflict resolution algorithm. PCL-EPC guarantees consistent combinations of process fragments by means of a PCL specification