A radial basis function network classifier to maximise leave-one-out mutual information

tWe develop an orthogonal forward selection (OFS) approach to construct radial basis function (RBF)network classifiers for two-class problems. Our approach integrates several concepts in probabilisticmodelling, including cross validation, mutual information and Bayesian hyperparameter fitting. At eachstage of the OFS procedure, one model term is selected by maximising the leave-one-out mutual infor-mation (LOOMI) between the classifier’s predicted class labels and the true class labels. We derive theformula of LOOMI within the OFS framework so that the LOOMI can be evaluated efficiently for modelterm selection. Furthermore, a Bayesian procedure of hyperparameter fitting is also integrated into theeach stage of the OFS to infer the l2-norm based local regularisation parameter from the data. Since eachforward stage is effectively fitting of a one-variable model, this task is very fast. The classifier construc-tion procedure is automatically terminated without the need of using additional stopping criterion toyield very sparse RBF classifiers with excellent classification generalisation performance, which is par-ticular useful for the noisy data sets with highly overlapping class distribution. A number of benchmarkexamples are employed to demonstrate the effectiveness of our proposed approach.

The blended approach to real estate allocations: performance implications of combining an exposure to German Spezialfonds with Global Listed Real Estate Securities

This paper seeks to increase the understanding of the performance implications for investors who choose to combine an unlisted real estate portfolio (in this case German Spezialfonds) with a (global) listed real estate element. We call this a “blended” approach to real estate allocations. For the avoidance of doubt, in this paper we are dealing purely with real estate equity (listed and unlisted) allocations, and do not incorporate real estate debt (listed or unlisted) or direct property into the process. A previous paper (Moss and Farrelly 2014) showed the benefits of the blended approach as it applied to UK Defined Contribution Pension Schemes. The catalyst for this paper has been the recent attention focused on German pension fund allocations, which have a relatively low (real estate) equity content, and a high bond content. We have used the MSCI Spezialfonds Index as a proxy for domestic German institutional real estate allocations, and the EPRA Global Developed Index as a proxy for a global listed real estate allocation. We also examine whether a rules based trading strategy, in this case Trend Following, can improve the risk adjusted returns above those of a simple buy and hold strategy for our sample period 2004-2015. Our findings are that by blending a 30% global listed portfolio with a 70% allocation (as opposed to a typical 100% weighting) to Spezialfonds, the real estate allocation returns increase from 2.88% p.a. to 5.42% pa. Volatility increases, but only to 6.53%., but there is a noticeable impact on maximum drawdown which increases to 19.4%. By using a Trend Following strategy raw returns are improved from 2.88% to 6.94% p.a. , The Sharpe Ratio increases from 1.05 to 1.49 and the Maximum Drawdown ratio is now only 1.83% compared to 19.4% using a buy and hold strategy . Finally, adding this (9%) real estate allocation to a mixed asset portfolio allocation typical for German pension funds there is an improvement in both the raw return (from 7.66% to 8.28%) and the Sharpe Ratio (from 0.91 to 0.98).

Texture, realism, performance: exploring the intersection of transtexts and the contemporary sitcom

Contemporary US sitcom is at an interesting crossroads: it has received an increasing amount of scholarly attention (e.g. Mills 2009; Butler 2010; Newman and Levine 2012; Vermeulen and Whitfield 2013), which largely understands it as shifting towards the aesthetically and narratively complex. At the same time, in the post-broadcasting era, US networks are particularly struggling for their audience share. With the days of blockbuster successes like Must See TV’s Friends (NBC 1994-2004) a distant dream, recent US sitcoms are instead turning towards smaller, engaged audiences. Here, a cult sensibility of intertextual in-jokes, temporal and narrational experimentation (e.g. flashbacks and alternate realities) and self-reflexive performance styles have marked shows including Community (NBC 2009-2015), How I Met Your Mother (CBS 2005-2014), New Girl (Fox 2011-present) and 30 Rock (NBC 2006-2013). However, not much critical attention has so far been paid to how these developments in textual sensibility in contemporary US sitcom may be influenced by, and influencing, the use of transmedia storytelling practices, an increasingly significant industrial concern and rising scholarly field of enquiry (e.g. Jenkins 2006; Mittell 2015; Richards 2010; Scott 2010; Jenkins, Ford and Green 2013). This chapter investigates this mutual influence between sitcom and transmedia by taking as its case studies two network shows that encourage invested viewership through their use of transtexts, namely How I Met Your Mother (hereafter HIMHM) and New Girl (hereafter NG). As such, it will pay particular attention to the most transtextually visible character/actor from each show: HIMYM’s Barney Stinson, played by Neil Patrick Harris, and NG’s Schmidt, played by Max Greenfield. This chapter argues that these sitcoms do not simply have their particular textual sensibility and also (happen to) engage with transmedia practices, but that the two are mutually informing and defining. This chapter explores the relationships and interplay between sitcom aesthetics, narratives and transmedia storytelling (or industrial transtexts), focusing on the use of multiple delivery channels in order to disperse “integral elements of a fiction” (Jenkins, 2006 95-6), by official entities such as the broadcasting channels. The chapter pays due attention to the specific production contexts of both shows and how these inform their approaches to transtexts. This chapter’s conceptual framework will be particularly concerned with how issues of texture, the reality envelope and accepted imaginative realism, as well as performance and the actor’s input inform and illuminate contemporary sitcoms and transtexts, and will be the first scholarly research to do so. It will seek out points of connections between two (thus far) separate strands of scholarship and will move discussions on transtexts beyond the usual genre studied (i.e. science-fiction and fantasy), as well as make a contribution to the growing scholarship on contemporary sitcom by approaching it from a new critical angle. On the basis that transmedia scholarship stands to benefit from widening its customary genre choice (i.e. telefantasy) for its case studies and from making more use of in-depth close analysis in its engagement with transtexts, the chapter argues that notions of texture, accepted imaginative realism and the reality envelope, as well as performance and the actor’s input deserve to be paid more attention to within transtext-related scholarship.

Análise de persistência de performance de investimento: há evidências de persistências em fundos ativos de ibovespa para clientes do varejo?

Este trabalho tem como objetivo analisar o desempenho de quinze fundos de ações de varejo tendo como características a gestão ativa e como objetivo de mercado superar o índice Ibovespa, para o período compreendido entre janeiro de 1999 e junho de 2003. A análise pretende verificar a existência de persistência de desempenho neste grupo de fundos através dos métodos de análises de desempenho mais utilizados no mercado de fundos de ações, separando-os em três grupos de desempenho. O trabalho tem como segundo objetivo analisar a possibilidade de fundos certificados por metodologias qualitativas apresentarem desempenho superior aos fundos não certificados, dentro da amostra deste estudo. As conclusões demonstraram que há evidências de persistência de desempenho deste grupo de fundos, tanto em períodos de um ano como em dois anos. Foram encontradas evidências de que os fundos certificados tendem a apresentar melhores resultados que os demais fundos ativos de Ibovespa selecionados para este estudo.

Um estudo sobre a persistência de performance positiva dos fundos IBOVESPA ativos

O objetivo desta dissertação é identificar se persistência de performance positiva um fenômeno presente entre os fundos de investimento ativos em relação ao índice da bolsa de valores de São Paulo (IBOVESPA). Para tanto, foram utilizadas informações em bases diárias, para período de janeiro de 1997 dezembro de 2001, de 191 fundos que tiveram para cada ano sua performance calculada. Em cada ano sob estudo definiu-se, pelo menos, dois grupos: um em que se alinhavam os fundos que apresentavam os melhores indicadores outro em que estavam presentes aqueles cujos desempenhos foram considerados piores. Os fundos que lograram sucesso em permanecer no primeiro grupo em pares de anos consecutivos foram denominados persistentes. Para que se pudesse medir significância dos resultados apurados, fez-se uso do instrumental de testes estatísticos, testes de hipóteses, que buscaram identificar se as proporções de fundos persistentes forneciam evidências suficientes para que se garantisse ocorrência do fenômeno no mercado brasileiro para período pesquisado.

Persistência na performance de fundos de investimento imobiliário brasileiros entre 2008 e 2012

O objetivo deste trabalho é avaliar a persistência na performance de fundos de investimento imobiliário. Para isso, adotamos metodologia semelhante à de Carhart (1997): analisamos o desempenho, ao longo do tempo, de carteiras de fundos selecionados segundo seus percentis de retorno. Posteriormente, a performance desses fundos foi avaliada através de modelos multifatores. Para determinação desses modelos, foram criados índices baseados nas informações das ações do mercado brasileiro e do IBOVESPA. Os resultados sugerem que fundos de investimento imobiliário de retorno superior apresentam persistência em seus desempenhos. No caso dos modelos multifatores, conclui-se que os dados utilizados do mercado acionário não representam de forma satisfatória fundos de investimento imobiliário. No entanto, quando a modelagem é feita utilizando-se o IFIX, nota-se alfa positivo para os fundos mais rentáveis.

O desempenho dos hedge funds brasileiros a partir da não normalidade de seus retornos

Devido à utilização de estratégias distintas de investimento dos hedge funds brasileiros caracterizadas pelo uso de derivativos, operações alavancadas e vendas a descoberto, esses fundos apresentam significante não normalidade dos retornos gerados. Portanto, as medidas usuais de avaliação de performance são incapazes de fornecer resultados consistentes com o verdadeiro desempenho dos portfólios de hedge fund. Este trabalho irá utilizar duas metodologias não tradicionais para analisar a performance dos hedge funds brasileiros e determinar qual estratégia supera o mercado acionário. Serão utilizadas duas medidas não paramétricas, Almost Stochastic Dominância (ASD) e Manipulation-Proof Performance Measure (MPPM). Os resultados demonstram que os hedge funds brasileiros não superam os benckmaks utilizados na dominância de primeira ordem, mas quando analisada a dominância de segunda ordem sete estratégias apresentaram desempenho superior ao Índice Ibovespa.

The impact of corruption on the performance of state-owned companies: case of Petrobras Brasil

As empresas estatais são freqüentemente consideradas como componentes cruciais da economia de um país. Eles são responsáveis pela criação de vários postos de trabalho e proveem serviços essenciais que exigem um grande investimento de capital. Porém, em países com instituições fracas, onde a responsabilidade dos políticos é limitada e a gestão dos recursos financeiros das empresas estatais sofre pouco controle, os funcionários são muitas vezes tentados pela corrupção. Enormes quantidades de fundos públicos são facilmente desviados, e dinheiro que deveria ter sido investido nas despesas de capital, no pagamento de dívida da empresa ou no aumento do retorno para os acionistas, é usado para aumentar a riqueza privada de indivíduos ou para financiar ilegalmente partidos políticos. O desempenho da empresa sofre com essas alienações visto que parte dos lucros da empresa não são reinvestidos na empresa e dado que incentivos dos gestores estão desalinhados com os interesses dos acionistas. Petrobras, a maior empresa da América Latina em termos de ativos e receitas anuais, sofreu em 2014 e 2015 um escândalo de corrupção imenso, cujo impacto económico foi considerável, levando ao enfraquecimento da confiança de muitos investidores no Brasil após o evento. O escândalo expôs um extenso esquema de corrupção através do qual os contratantes foram conspirando para aumentar os preços de contratos de construção, com a aprovação da administração da Petrobras que pediu em troca ganhos pessoais ou fundos para o Partido dos Trabalhadores (PT). A exposição do escândalo na imprensa brasileira teve um grande impacto sobre a credibilidade da Petrobras: as contas da empresa estavam escondendo imensas irregularidades dado que a empresa tinha pago demais para os contratos de construção que não foram precificados no valor do mercado. Ao longo deste estudo, usamos o exemplo da Petrobras para ilustrar como a corrupção dentro empresas estatais prejudica o desempenho da empresa e como ela afeta as várias partes interessadas da empresa.

A performance do suicídio em Ariel, de Sylvia Plath

This dissertation aims at investigating the book Ariel (1965), written by Sylvia Plath, as a kind of performative and ritual poetry that fragments and reconstructs the personal experience, manipulating the memory of the autobiographical body as a way to rehearse and restore subjectivity. We propose that, in Ariel, the hyperbolic, transcendent and parodic transfiguration of real episodes, used as literary substance, corrupts and subverts the specular idea of a confessional truth usually related to the writer s work. Our objective is to examine signs of confluence between Sylvia Plath s poetry and performance art, departing from de idea that the spectacularization of the self, the exhibition of private rituals, the theatricalization of autobiographical circumstances and the undressing of one s craziness and vulnerability are mutual procedures to the poet and the perfomer. Simultaneously unfolding between the inside and the outside of the poem, Sylvia Plath s real suicide and the death and rebirth rituals performed in the literary text appear as symbolic elements that might reveal the performer s liminal space, where reality and representation coexist, and where the performative testimony does not frame only the real subject s body but also his/her infinite possibilities of being restored through art.

The impact of exchange-rate and trade policy on export performance in the 1980s

Includes bibliography

Road maintenance, funds and fund management

This edition of the Bulletin deals with road maintenance, funds and fund management. Among other things, it emphasizes, the need to manage road funds in accordance with clear performance rules which seek to minimize maintenance costs and ensure that the road network is maintained in an appropriate condition.

Mechanical Performance of Cylindrical and Dual-Core Pedicle Screws After Repeated Insertion

Study Design. Ex vivo study of the mechanical performance of cylindrical and dual-core pedicle screws after insertion, removal, and reinsertion in the same hole. Objective. To evaluate the effect of repeated use of same screw hole on the insertion torque and the retentive strength of the cylindrical and dual-core screws. Summary of Background Data. Insertion and removal of pedicle screws is sometimes necessary during surgical procedure to assess the integrity of the pilot-hole wall. However, this maneuver may compromise the implant-holding capacity. Methods. Sixty thoracolombar vertebrae (T13-L5), harvested from 10 healthy calves, were used to insert 2 different designs of pedicle screws: cylindrical (5.0-mm outer diameter) and dual-core screws (5.2-mm outer diameter). Three experimental groups were created on the basis of the number of insertions of the screws and 2 subgroups were established according to the core pedicle screw design (dual-core and cylindrical). The insertion torque was measured during initial insertion, second insertion, and third insertion. Pullout screw tests were performed using a universal testing machine to evaluate the pullout strength after initial insertion, second insertion, and third insertion. Results. Significant reductions of 38% in mean insertion torque and 30% in mean pullout strength of dual-core screw were observed between the initial insertion and the third insertion. The cylindrical screw observed significant reductions of 52.5% in mean insertion torque and 42.3% in mean pullout strength between the initial insertion and the third insertion. A reduction of mean insertion torque and pullout strength between the first insertion and the second insertion but without significance was also observed for both types of screws. Conclusion. Insertions and reinsertion of either cylindrical or dual-core pedicle screws have compromised insertion torque and pullout strength of the implants as measured by mechanical tests.

EVALUATING THE INSTALLATION AND PERFORMANCE OF MANUALLY DRILLED WELLS IN NORTH-EASTERN MADAGASCAR

Manual drilling is a popular solution for programs seeking to increase drinking water supply in rural Madagascar. Lightweight, affordable and locally produced drilling equipment allows rapid implementation where access is problematic and funds are limited. This report will look at the practical implications of using manual drilling as a one-step solution to potable water in rural development. The main benefits of using these techniques are time and cost savings. The author uses his experience managing a drilling campaign in northeastern Madagascar to explore the benefits and limitations of one particular drilling methodology – BushProof’s Madrill technique. Just under 200 wells were drilled using this method in the course of one fiscal year (September 2011-September 2012). The paper explores what compromises must be considered in the quest for cost-effective boreholes and whether everybody - from the implementers to project managers to clients and lawmakers - are in agreement about the consequences of such compromises. The paper also discusses water quality issues encountered when drilling in shallow aquifers.

Mutual Information for Testing Gene-Environment Interaction

Despite current enthusiasm for investigation of gene-gene interactions and gene-environment interactions, the essential issue of how to define and detect gene-environment interactions remains unresolved. In this report, we define gene-environment interactions as a stochastic dependence in the context of the effects of the genetic and environmental risk factors on the cause of phenotypic variation among individuals. We use mutual information that is widely used in communication and complex system analysis to measure gene-environment interactions. We investigate how gene-environment interactions generate the large difference in the information measure of gene-environment interactions between the general population and a diseased population, which motives us to develop mutual information-based statistics for testing gene-environment interactions. We validated the null distribution and calculated the type 1 error rates for the mutual information-based statistics to test gene-environment interactions using extensive simulation studies. We found that the new test statistics were more powerful than the traditional logistic regression under several disease models. Finally, in order to further evaluate the performance of our new method, we applied the mutual information-based statistics to three real examples. Our results showed that P-values for the mutual information-based statistics were much smaller than that obtained by other approaches including logistic regression models.

HEALTH MAINTENANCE ORGANIZATION ENVIRONMENT: AN EMPIRICAL STUDY OF THE RELATIONSHIP OF EXTERNAL CONTEXT AND PERFORMANCE

The research project is an extension of a series of administrative science and health care research projects evaluating the influence of external context, organizational strategy, and organizational structure upon organizational success or performance. The research will rely on the assumption that there is not one single best approach to the management of organizations (the contingency theory). As organizational effectiveness is dependent on an appropriate mix of factors, organizations may be equally effective based on differing combinations of factors. The external context of the organization is expected to influence internal organizational strategy and structure and in turn the internal measures affect performance (discriminant theory). The research considers the relationship of external context and organization performance.^ The unit of study for the research will be the health maintenance organization (HMO); an organization the accepts in exchange for a fixed, advance capitation payment, contractual responsibility to assure the delivery of a stated range of health sevices to a voluntary enrolled population. With the current Federal resurgence of interest in the Health Maintenance Organization (HMO) as a major component in the health care system, attention must be directed at maximizing development of HMOs from the limited resources available. Increased skills are needed in both Federal and private evaluation of HMO feasibility in order to prevent resource investment and in projects that will fail while concurrently identifying potentially successful projects that will not be considered using current standards.^ The research considers 192 factors measuring contextual milieu (social, educational, economic, legal, demographic, health and technological factors). Through intercorrelation and principle components data reduction techniques this was reduced to 12 variables. Two measures of HMO performance were identified, they are (1) HMO status (operational or defunct), and (2) a principle components factor score considering eight measures of performance. The relationship between HMO context and performance was analysed using correlation and stepwise multiple regression methods. In each case it has been concluded that the external contextual variables are not predictive of success or failure of study Health Maintenance Organizations. This suggests that performance of an HMO may rely on internal organizational factors. These findings have policy implications as contextual measures are used as a major determinant in HMO feasibility analysis, and as a factor in the allocation of limited Federal funds. ^