Constraining the Location of Microlensing Objects by using the Finite Source Effect in EAGLE events

We propose a new method to constrain the location of microlensing objects using EAGLE (Extremely Amplified Gravitational LEnsing) events. We have estimated the rate of EAGLE events by taking the finite-source effect in to account. We found that the EAGLE event rate for using a 1-m class telescope w hose limiting magnitude is $V \sim 21$ is the same as or higher than that of the ordinary microlensing events which have been found to date. We have also found that the fraction of transit EAGLE events is large enough to detect: between $4 \sim 80$ depending on the lens location. Since the lens proper motion can be measured for a transit event, one can distinguish whether the lens is a MACHO (MAssive Compact Halo Object) in our hal o or one of the known stars in the Large Magellanic Cloud (LMC) from the proper motion measurement for each transit EAGLE event. Moreover, we show that the fraction of transit EAGLEs in all EAGLE events signif icantly depends on the lensing locations: the transit EAGLE fraction for the sel f-lensing case is $2 \sim 15$ times larger than that for halo MACHOs. Thus, one can constrain the location of lens objects by the statistics of the tr ansit events fraction. We show that we can reasonably expect $0 \sim 6$ transit events out of 21 EAGLE events in 3 years. We can also constrain the lens population properties at a gre ater than 99% confidence level depending on the number of transit events de tected. We also present the duration of EAGLE events, and show how an hourly ob servational mode is more suitable for an EAGLE event search program.Comment: 18 pages, 4 figures, accepted for publication in Ap

Public sector debt dynamics in Brazil

1. INTRODUCTION 2. POLICY MIX AND THE PUBLIC-SECTOR NET DEBT 3. SKELETONS IN THE CLOSET, PRIVATIZATION PROCEEDS AND SEIGNIORAGE 4. SIMULATING DEBT DYNAMICS 5. SENSITIVITY ANALYSIS 6. CONCLUDING REMARKS APPENDIX: THE SIMULATION MODEL

O genero "Cheilanthes" Swartz em Portugal

A A. estudou minuciosamente os espécimes de Cheilanthes spp. existentes nos principais herbários portugueses (COI, LISI, LISU e PO) e concluiu que grande parte dos espécimes em tempos identificados como Ch. pteridioides ou Ch. fragrans não pertenecen de facto a esta espécie mas sim ás afins Ch. guanchica C. Bolle, Ch. maderensis Lowe e Ch. tinaei Tod. São apresentadas chaves de identificação para as espécies portuguesas, bem como listas dos exemplares estudados e respectivos mapas de distribuição.Hemos estudiado minuciosamente las especies de Cheilanthes ssp. existentes en los principales herbarios portugueses (COI, LISI, LISU e PO), concluyendo que la mayor parte de estas, identificadas anteriormente como Ch. pteridioides o Ch. fragrans, no pertenecen de hecho a esta especie sino a aquellas afines, Ch. guanchica C. Bolle, Ch. maderensis Lowe e Ch. tinaei Tod. Se presentan unas claves de identificación para las especies portuguesas, así como listas de los ejemplares estudiados y los correspondientes mapas de distribución

Online sales and business model innovation in art markets: a case study

Every year online sales represent a higher percentage of the sales total in nearly all sectors of the economy, and the art markets are no exception. However, there are few empirical studies showing how online sales and digital technologies are transforming the art markets at a micro-level. This study is based on the detailed examination of the financial performance of one of the two largest Portuguese auction houses, Cabral Moncada Leilões (CML), over a period of twelve years (2007-2018), complemented with interviews with its top-managers. It analyses a set of financial indicators (e.g., EBIT, ROA, EQUITY, sales volume, net results, etc.), along with some markers that are specific to the auction sector (e.g., average lot value, number of auctions per year, etc.). From this analysis it is possible to conclude that the deterioration of this company's financial performance was the driving force that led it to explore the potential of digital economy. In the process, its business model changed dramatically, leading the company to a different market position and to the enlargement of its national and international customer base.info:eu-repo/semantics/publishedVersio

Key success factors and conditions for quality management implementation in micro-enterprises: A case study

Purpose: The purpose of this paper is to examine if quality management can be implemented in a micro-enterprise. Indeed, very few studies have been found in literature analysing quality management in micro-enterprises. Additionally, this paper explores the key success factors for quality management implementation that are most likely found, and seeks also to identify the conditions linked to quality management implementation in a micro-enterprise setting. Methodology: This investigation covers one micro-enterprise in Portugal (H3D is the name of the organisation). It operates in the hospitality and catering industry – equipment manufacturing and assemblage, and services provided. A qualitative methodology was used to conduct the research, supported on a case study. Data were collected from tape-recorded interviews and from written documentation provided by the company. Findings: It was found that it is possible to implement a quality management system in a micro- enterprise, even being difficult to put in place. However, an actor is needed to trigger the process. Moreover, several key success factors identified in literature (particularly the Oakland revised model) were clearly seen in the organisation. Additionally, some quality management practices were found being deeply rooted in the company. Research Implication: This paper shows that micro-enterprises can also implement quality management systems (visualized in key success factors), in an intuitive way, when an institutional entrepreneur acts. This conclusion is very important for academics and for practitioners. Originality/Value: There is a gap in the literature regarding the implementation of quality management in micro-enterprises. Very little research has been conducted on this subject. This paper shows that micro-enterprises can also implement successfully quality management, under some specific conditions.info:eu-repo/semantics/publishedVersio

On the Determination of Star Formation Rates in Evolving Galaxy Populations

The redshift dependence of the luminosity density in certain wavebands (e.g. UV and H-alpha) can be used to infer the history of star formation in the populations of galaxies producing this luminosity. This history is a useful datum in studies of galaxy evolution. It is therefore important to understand the errors that attend the inference of star formation rate densities from luminosity densities. This paper explores the self-consistency of star formation rate diagnostics by reproducing commonly used observational procedures in a model with known galaxy populations, evolutionary histories and spectral emission properties. The study reveals a number of potential sources of error in the diagnostic processes arising from the differential evolution of different galaxy types. We argue that multi-wavelength observations can help to reduce these errors.Comment: 13 pages (including 5 encapsulated postscript figures), aastex, accepted for publication in Ap

The Phoenix Deep Survey: The 1.4 GHz microJansky catalogue

The initial Phoenix Deep Survey (PDS) observations with the Australia Telescope Compact Array have been supplemented by additional 1.4 GHz observations over the past few years. Here we present details of the construction of a new mosaic image covering an area of 4.56 square degrees, an investigation of the reliability of the source measurements, and the 1.4 GHz source counts for the compiled radio catalogue. The mosaic achieves a 1-sigma rms noise of 12 microJy at its most sensitive, and a homogeneous radio-selected catalogue of over 2000 sources reaching flux densities as faint as 60 microJy has been compiled. The source parameter measurements are found to be consistent with the expected uncertainties from the image noise levels and the Gaussian source fitting procedure. A radio-selected sample avoids the complications of obscuration associated with optically-selected samples, and by utilising complementary PDS observations including multicolour optical, near-infrared and spectroscopic data, this radio catalogue will be used in a detailed investigation of the evolution in star-formation spanning the redshift range 0 < z < 1. The homogeneity of the catalogue ensures a consistent picture of galaxy evolution can be developed over the full cosmologically significant redshift range of interest. The 1.4 GHz mosaic image and the source catalogue are available on the web at http://www.atnf.csiro.au/~ahopkins/phoenix/ or from the authors by request.Comment: 16 pages, 11 figures, 4 tables. Accepted for publication by A

Development and test of an intra-vehicular network based on bluetooth low energy

This paper presents the development and test of an intra-vehicular system, based on Bluetooth Low Energy (BLE), designed to present to the driver, in real-time, information collected from multiple sensors distributed inside of the car, using an Android smartphone. The architecture of the implemented BLE network is composed by the smartphone, which has the role of central station, and two BLE modules (peripheral stations) based on the CC2540 system-on-chip, which collect relevant sensor information from the battery system and the traction system of an electric car. Results based on an experimental performance evaluation of the wireless network show that the network is able to satisfy the application requirements, as long as the network parameters are properly configured taking into account the peculiarities of the BLE data transfer modes and the limitations of the BLE platform.This work is supported by FCT with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01-0145-FEDER-006941.info:eu-repo/semantics/publishedVersio

Bidirectional power converters for EV battery chargers

[Excerpt] The introduction of electric mobility into the transport sector has significantly contributed to the mitigation of environmental issues [...]This work has been supported by FCT—Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020. This work has been supported by the MEGASOLAR Project POCI-01-0247-FEDER-047220