Testing Seasonal Unit Roots in Data at Any Frequency, an HEGY approach

This paper generalizes the HEGY-type test to detect seasonal unit roots in data at any frequency, based on the seasonal unit root tests in univariate time series by Hylleberg, Engle, Granger and Yoo (1990). We introduce the seasonal unit roots at first, and then derive the mechanism of the HEGY-type test for data with any frequency. Thereafter we provide the asymptotic distributions of our test statistics when different test regressions are employed. We find that the F-statistics for testing conjugation unit roots have the same asymptotic distributions. Then we compute the finite-sample and asymptotic critical values for daily and hourly data by a Monte Carlo method. The power and size properties of our test for hourly data is investigated, and we find that including lag augmentations in auxiliary regression without lag elimination have the smallest size distortion and tests with seasonal dummies included in auxiliary regression have more power than the tests without seasonal dummies. At last we apply the our test to hourly wind power production data in Sweden and shows there are no seasonal unit roots in the series.

Managerial leadership for research use in nursing and allied health care professions : a narrative synthesis protocol

BACKGROUND: Nurses and allied health care professionals (physiotherapists, occupational therapists, speech and language pathologists, dietitians) form more than half of the clinical health care workforce and play a central role in health service delivery. There is a potential to improve the quality of health care if these professionals routinely use research evidence to guide their clinical practice. However, the use of research evidence remains unpredictable and inconsistent. Leadership is consistently described in implementation research as critical to enhancing research use by health care professionals. However, this important literature has not yet been synthesized and there is a lack of clarity on what constitutes effective leadership for research use, or what kinds of intervention effectively develop leadership for the purpose of enabling and enhancing research use in clinical practice. We propose to synthesize the evidence on leadership behaviours amongst front line and senior managers that are associated with research evidence by nurses and allied health care professionals, and then determine the effectiveness of interventions that promote these behaviours.Methods/design: Using an integrated knowledge translation approach that supports a partnership between researchers and knowledge users throughout the research process, we will follow principles of knowledge synthesis using a systematic method to synthesize different types of evidence involving: searching the literature, study selection, data extraction and quality assessment, and analysis. A narrative synthesis will be conducted to explore relationships within and across studies and meta-analysis will be performed if sufficient homogeneity exists across studies employing experimental randomized control trial designs. DISCUSSION: With the engagement of knowledge users in leadership and practice, we will synthesize the research from a broad range of disciplines to understand the key elements of leadership that supports and enables research use by health care practitioners, and how to develop leadership for the purpose of enhancing research use in clinical practice.

A data driven approach for automating vehicle activated signs

Vehicle activated signs (VAS) display a warning message when drivers exceed a particular threshold. VAS are often installed on local roads to display a warning message depending on the speed of the approaching vehicles. VAS are usually powered by electricity; however, battery and solar powered VAS are also commonplace. This thesis investigated devel-opment of an automatic trigger speed of vehicle activated signs in order to influence driver behaviour, the effect of which has been measured in terms of reduced mean speed and low standard deviation. A comprehen-sive understanding of the effectiveness of the trigger speed of the VAS on driver behaviour was established by systematically collecting data. Specif-ically, data on time of day, speed, length and direction of the vehicle have been collected for the purpose, using Doppler radar installed at the road. A data driven calibration method for the radar used in the experiment has also been developed and evaluated. Results indicate that trigger speed of the VAS had variable effect on driv-ers’ speed at different sites and at different times of the day. It is evident that the optimal trigger speed should be set near the 85th percentile speed, to be able to lower the standard deviation. In the case of battery and solar powered VAS, trigger speeds between the 50th and 85th per-centile offered the best compromise between safety and power consump-tion. Results also indicate that different classes of vehicles report differ-ences in mean speed and standard deviation; on a highway, the mean speed of cars differs slightly from the mean speed of trucks, whereas a significant difference was observed between the classes of vehicles on lo-cal roads. A differential trigger speed was therefore investigated for the sake of completion. A data driven approach using Random forest was found to be appropriate in predicting trigger speeds respective to types of vehicles and traffic conditions. The fact that the predicted trigger speed was found to be consistently around the 85th percentile speed justifies the choice of the automatic model.

A Model of Normative Power

A power describes the ability of an agent to act in some way. While this notion of power is critical in the context of organisational dynamics, and has been studied by others in this light, it must be constrained so as to be useful in any practical application. In particular, we are concerned with how power may be used by agents to govern the imposition and management of norms, and how agents may dynamically assign norms to other agents within a multi-agent system. We approach the problem by defining a syntax and semantics for powers governing the creation, deletion, or modification of norms within a system, which we refer to as normative powers. We then extend this basic model to accommodate more general powers that can modify other powers within the system, and describe how agents playing certain roles are able to apply powers, changing the system’s norms, and also the powers themselves. We examine how the powers found within a system may change as the status of norms change, and show how standard norm modification operations — such as the derogation, annulment and modification of norms— may be represented within our system.

A produção de subjetividades em organizações contemporâneas: práticas discursivas e políticas da empregabilidade

The research aimed at analysing the political and discursive practices of the metanarrative of employability in the contemporary organizational field, heading for the understanding of the social and micropolitical devices which happen to produce some especific kinds of subjectivities within organizations. From a post-modern epistemological perspective (Weltanshauung), the research focused on the issues concerning the production of subjectivities in the existing organizational society beyond the traditional theoretical standpoints whose common assumptions are due to the modernist approaches of organizational analysis. A deconstructive theoretical approach was emphasized across the whole text and it was mainly inspired and intellectually based upon Michel Foucault's genealogical démarche. His original conceptualization of power-knowledge relations informed the development of a methodology so as to analyse the discursive practices which determine many of the human resources policies concerning employability. The main thesis presented employability as a grand-device of micropolitical control towards the production of subjectivities whose main operation technologies are: an economic modernizing rhetoric, a moralistic dietetics and an instrumental education. Several discursive fragments from different academicists, journalists and some authors from the managerial litterature were taken into account so as to carefully deconstruct their speeches. This analysis revealed the mechanisms of production of pasteurized, mercantile and erratic subjectivities. Some inquietudes of heuristic nature are featured in the domain of organizational, psychological, sociological and political perspectives heading for new studies.

Estudo da validade de generalização das práticas de governança corporativa ao ambiente dos fundos de pensão: uma análise segundo as teorias da agência e institucional

Este estudo investiga as possibilidades de generalização das práticas de governança corporativa a organizações operando em ambientes não mercantilistas. Os limites da teoria da agência, referencial teórico predominante no desenvolvimento dessas práticas, são analisados no ambiente dos fundos de pensão brasileiros a partir da verificação da aplicação dos mecanismos de monitoramento, controle e incentivos, previstos por essa teoria, por patrocinadores e participantes, e a percepção dos gestores quanto à importância desses mecanismos na conformação de seu comportamento. Alternativamente, é examinada a extensão da busca de legitimidade pelos gestores, segundo o referencial da teoria institucional. São comparados os resultados obtidos para fundos com perfis diversos quanto a variáveis como tipo de plano, origem do patrocinador e maturidade. Os resultados indicam uma diferença no uso e percepção daqueles mecanismos, em virtude principalmente da natureza do patrocinador, volume de ativos de investimento, tempo de existência e maturidade do fundo. Não foram obtidas diferenças estatísticas significativas para a percepção dos fatores institucionais, sugerindo a existência de elevada coesão no campo organizacional constituído pelos fundos de pensão.

The BoP approach and its links to main related research fields: sense-making of the current discussion

A Base-da-Pirâmide (Base ofthePyramid- BoP) é referida na literatura como sendo o segmento sócio-econômico mais baixo em termos de paridade do poder de compra. Esse segmento encontrase geralmente excluído do sistema capitalista global. Esta tese analisa o tema BoP e discute dentro de um contexto sócio-econômico, como essa abordagem se relaciona com outras áreas de pesquisa, assim como a teoria do desenvolvimento internacional e a teoria de negócios internacionais. Estas duas teorias são identificadas como tendo uma relação mais forte com BoP. No que se segue, a abordagem BoP é incorporada nessas duas teorias com o objetivo de tornar este conceito mais claro e abrangente. Seguindo este raciocínio a abordagem BoP vem identificar contribuições no tocante a cada uma dessas abordagens teóricas. O argumento principal da tese é que a abordagem BoP é capaz de ligar essas duas teorias (teoria do desenvolvimento internacional e a teoria de negócios internacionais) em um só modelo teórico, mostrando assim que essas duas abordagens teóricas distintas podem na realidade serem complementares.

Board of directors and top management team: a study on CEO relative power and financial return

Best corporate governance practices published in the primers of Brazilian Securities and Exchange Commission and the Brazilian Corporate Governance Institute promote board independence as much as possible, as a way to increase the effectiveness of governance mechanism (Sanzovo, 2010). Therefore, this paper aims at understanding if what the managerial literature portraits as being self-evident - stricter governance, better performance - can be observed in actual evidence. The question answered is: do companies with a stricter control and monitoring system perform better than others? The method applied in this paper consists on comparing 116 companies in respect to the their independence level between top management team and board directors– being that measured by four parameters, namely, the percentage of independent outsiders in the board, the separation of CEO and chairman, the adoption of contingent compensation and the percentage of institutional investors in the ownership structure – and their financial return measured in terms return on assets (ROA) from the latest Quarterly Earnings release of 2012. From the 534 companies listed in the Stock Exchange of Sao Paulo – Bovespa – 116 were selected due to their level of corporate governance. The title “Novo Mercado” refers to the superior level of governance level within companies listed in Bovespa, as they have to follow specific criteria to assure shareholders ´protection (BM&F, 2011). Regression analyses were conducted in order to reveal the correlation level between two selected variables. The results from the regression analysis were the following: the correlation between each parameter and ROA was 10.26%; the second regression analysis conducted measured the correlation between the independence level of top management team vis-à-vis board directors – namely, CEO relative power - and ROA, leading to a multiple R of 5.45%. Understanding that the scale is a simplification of the reality, the second part of the analysis transforms all the four parameters into dummy variables, excluding what could be called as an arbitrary scale. The ultimate result from this paper led to a multiple R of 28.44%, which implies that the combination of the variables are still not enough to translate the complex reality of organizations. Nonetheless, an important finding can be taken from this paper: two variables (percentage of outside directors and percentage of institutional investor ownership) are significant in the regression, with p-value lower than 10% and with negative coefficients. In other words, counter affirming what the literature very often portraits as being self-evident – stricter governance leads to higher performance – this paper has provided evidences to believe that the increase in the formal governance structure trough outside directors in the board and ownership by institutional investor might actually lead to worse performance. The section limitations and suggestions for future researches presents some reasons explaining why, although supported by strong theoretical background, this paper faced some challenging methodological assumptions, precluding categorical statements about the level of governance – measured by four selected parameters – and the financial return in terms of financial on assets.

The gay subject in business and its discursive formation: an exploration on power, knowledge and sexuality

Issues related to the reality of lesbian, gay, bisexual and transgender (LGBT) individuals are being incorporated into institutional and social discourses, and show the challenges that must be overcome towards citizenship. The inclusion of gay rights in the domain of institutions like the United Nations and the Brazilian Secretariat of Human Rights are a response to broader movements that places the gay subject as an important topic of debate in the social-political sphere. In this scenario, some institutions deserve close attention from researchers related to gay issues, the business environment being a good example. In this domain, diversity has become an important topic of debate between scholars, where the question of sexual identity in most cases does not appear. The literature that actually focuses on the theme is explored through approaches that are not able to break with universalisms and a normatized vocabulary. Therefore, this research explores discursive structures related to sexuality and examines the meanings construed throughout these structures as described by gay individuals working in business. Furthermore, it investigates patterns of discursive normative structures and consequential challenges faced by gay people in the working environment, and also complements the current debate both in the socio-political sphere and in academic reality on LGBT challenges. The Foucauldian notions of discourse, knowledge and power, and the main concepts of queer theory are incorporated to the analysis, as well as concepts related to the politics of post-colonial sexuality, subordination, and hegemonic forces, together with role of reflexivity in modernity and its impacts on secularized mental structures. The research design takes a phenomenological approach and bases its knowledge claim on a participatory perspective, where the sample chosen for data collection consisted of gay individuals working in the business environment, aiming at generate categories of meanings through the description of their experiences.

Assessing competition in banking industry: a multiproduct approach

This paper aims to investigate the competition aspects of banking multiproduct operation. Based on an extension of Panzar and Rosse (1987)’s test to the case of a multiproduct banking firm, we take advantage of a new dataset constructed to Brazilian banking conglomerates to infer the impact of conglomeration on market power. We find that banks offering classic (i.e., loans and credit cards) and other bank products (i.e., brokerage services, insurance and capitalization bonds) have substantially higher market power than the ones which offer only classic products. Results suggest a positive bias on the traditional estimates of competition in which the multioutput actions are not taken into account.

Assessing competition in the banking industry: a multi-product approach

This paper investigates the competitive aspects of multi-product banking operations. Extending Panzar and Rosse (1987)’s model to the case of a multi-product banking firm, we show that the higher the economies of scope in multi-product banking are, the lower Panzar-Rosse’s measure of competition in the banking sector is. To test this empirical implication and determine the impact of multi-production/conglomeration on market power, we use a new dataset on Brazilian banking conglomerates. Consistent with our theoretical prediction, we find that banks offering classic banking products (i.e., loans and credit cards) and other banking products (i.e., brokerage services, insurance and capitalization bonds) have substantially higher market power than banks that offer only classic products. These results suggest a positive bias in the traditional estimates of competition in which multi-output actions are not considered.

Market coupling in the power markets

The thesis analyses the European Unions’ effort to create an integrated pan-European electricity market based on “market coupling” as the proposed allocation mechanism for interconnector transfer capacity. Thus, the thesis’ main focus is if market coupling leads to a price convergence in interlinked markets and how it affects the behavior of electricity price data. The applied research methods are a qualitative, structured literature review and a quantitative analysis of electricity price data. The quantitative analysis relies on descriptive statistics of absolute price differentials and on a Cointegration analysis according to Engle & Granger (1987)’s two step approach. Main findings are that implicit auction mechanisms such as market coupling are more efficient than explicit auctions. Especially the method of price coupling leads to a price convergence in involved markets, to social welfare gains and reduces market power of producers, as shown on the example of the TLC market coupling. The market coupling initiative between Germany and Denmark, on the other hand, is evaluated as less successful and illustrates the complexity and difficulties of implementing market coupling initiatives. The cointegration analysis shows that the time series were already before the coupling date cointegrated, but the statistical significance increased. The thesis suggests that market coupling leads to a price convergence of involved markets and thus functions as method to create a single, integrated European electricity market.

Elasticity of substitution between capital and labor: a panel data approach

This paper estimates the elasticity of substitution of an aggregate production function. The estimating equation is derived from the steady state of a neoclassical growth model. The data comes from the PWT in which different countries face different relative prices of the investment good and exhibit different investment-output ratios. Then, using this variation we estimate the elasticity of substitution. The novelty of our approach is that we use dynamic panel data techniques, which allow us to distinguish between the short and the long run elasticity and handle a host of econometric and substantive issues. In particular we accommodate the possibility that different countries have different total factor productivities and other country specific effects and that such effects are correlated with the regressors. We also accommodate the possibility that the regressors are correlated with the error terms and that shocks to regressors are manifested in future periods. Taking all this into account our estimation resuIts suggest that the Iong run eIasticity of substitution is 0.7, which is Iower than the eIasticity that had been used in previous macro-deveIopment exercises. We show that this lower eIasticity reinforces the power of the neoclassical mo deI to expIain income differences across countries as coming from differential distortions.

Development of a novel microextraction by packed sorbent-based approach followed by ultrahigh pressure liquid chromatography as a powerful technique for quantification phenolic constituents of biological interest in wines

A novel analytical approach, based on a miniaturized extraction technique, the microextraction by packed sorbent (MEPS), followed by ultrahigh pressure liquid chromatography (UHPLC) separation combined with a photodiode array (PDA) detection, has been developed and validated for the quantitative determination of sixteen biologically active phenolic constituents of wine. In addition to performing routine experiments to establish the validity of the assay to internationally accepted criteria (linearity, sensitivity, selectivity, precision, accuracy), experiments are included to assess the effect of the important experimental parameters on the MEPS performance such as the type of sorbent material (C2, C8, C18, SIL, and M1), number of extraction cycles (extract-discard), elution volume, sample volume, and ethanol content, were studied. The optimal conditions of MEPS extraction were obtained using C8 sorbent and small sample volumes (250 μL) in five extraction cycle and in a short time period (about 5 min for the entire sample preparation step). The wine bioactive phenolics were eluted by 250 μL of the mixture containing 95% methanol and 5% water, and the separation was carried out on a HSS T3 analytical column (100 mm × 2.1 mm, 1.8 μm particle size) using a binary mobile phase composed of aqueous 0.1% formic acid (eluent A) and methanol (eluent B) in the gradient elution mode (10 min of total analysis). The method gave satisfactory results in terms of linearity with r2-values > 0.9986 within the established concentration range. The LOD varied from 85 ng mL−1 (ferulic acid) to 0.32 μg mL−1 ((+)-catechin), whereas the LOQ values from 0.028 μg mL−1 (ferulic acid) to 1.08 μg mL−1 ((+)-catechin). Typical recoveries ranged between 81.1 and 99.6% for red wines and between 77.1 and 99.3% for white wines, with relative standard deviations (RSD) no larger than 10%. The extraction yields of the MEPSC8/UHPLC–PDA methodology were found between 78.1 (syringic acid) and 99.6% (o-coumaric acid) for red wines and between 76.2 and 99.1% for white wines. The inter-day precision, expressed as the relative standard deviation (RSD%), varied between 0.2% (p-coumaric and o-coumaric acids) and 7.5% (gentisic acid) while the intra-day precision between 0.2% (o-coumaric and cinnamic acids) and 4.7% (gallic acid and (−)-epicatechin). On the basis of analytical validation, it is shown that the MEPSC8/UHPLC–PDA methodology proves to be an improved, reliable, and ultra-fast approach for wine bioactive phenolics analysis, because of its capability for determining simultaneously in a single chromatographic run several bioactive metabolites with high sensitivity, selectivity and resolving power within only 10 min. Preliminary studies have been carried out on 34 real whole wine samples, in order to assess the performance of the described procedure. The new approach offers decreased sample preparation and analysis time, and moreover is cheaper, more environmentally friendly and easier to perform as compared to traditional methodologies.

A New Approach for Nontechnical Losses Detection Based on Optimum-Path Forest

Nowadays, fraud detection is important to avoid nontechnical energy losses. Various electric companies around the world have been faced with such losses, mainly from industrial and commercial consumers. This problem has traditionally been dealt with using artificial intelligence techniques, although their use can result in difficulties such as a high computational burden in the training phase and problems with parameter optimization. A recently-developed pattern recognition technique called optimum-path forest (OPF), however, has been shown to be superior to state-of-the-art artificial intelligence techniques. In this paper, we proposed to use OPF for nontechnical losses detection, as well as to apply its learning and pruning algorithms to this purpose. Comparisons against neural networks and other techniques demonstrated the robustness of the OPF with respect to commercial losses automatic identification.