The Dwarf Spheroidal Companions to M31: WFPC2 Observations of Andromeda I

Images have been obtained with the Hubble Space Telescope WFPC2 camera of Andromeda I, a dwarf spheroidal (dSph) galaxy that lies in the outer halo of M31. The resulting color-magnitude diagrams reveal for the first time the morphology of the horizontal branch in this system. We find that, in a similar fashion to many of the galactic dSph companions, the horizontal branch (HB) of And~I is predominantly red. Combined with the metal abundance of this dSph, this red HB morphology indicates that And I can be classified as a ``second parameter'' system in the outer halo of M31. This result then supports the hypothesis that the outer halo of M31 formed in the same extended chaotic manner as is postulated for the outer halo of the Galaxy.Comment: 26 pages using aas2pp4.sty, including 2 tables and 7 figures, to be published in AJ. Figure 1 is in gif form. To include in main ps file, use xv to create a ps file called Da_Costa.fig1.ps and uncomment appropriate lines in .tex fil

Essays on information asymmetry and financial institutions

The thesis consists of three chapters that investigate informational asymmetry mechanisms surrounding financial institutions. In the first chapter, my co-authors and I develop a theoretical model to analyse the effect of competition on the conflict of interest arising from the issuer pay compensation model of the credit rating industry. We find that relative to monopoly, rating agencies are more likely to inflate ratings under competition, resulting in lower expected welfare. These results do not depend on the presence of ratings shopping, but instead focus on the trade-off between maintaining reputation (to increase profits in the future) and inflating ratings today (to increase current profits). In the second chapter, I document a direct link between stock mispricing, as proxied by mutual fund flow-driven price pressure, and corporate investment. One standard deviation increase in stock price pressure leads to an increase of 1.3 percent in investment. High price pressure firms with high investments have lower future stock returns and lower future operational performance than high price pressure firms with low investments. Investment sensitivity to price pressure is stronger for firms that are less financially constrained, firms with high churn rates (shorter horizon) and firms with high R&D intensity (with more opaque assets). Finally, investment sensitivity to price pressure remains positive and significant for firms that do not engage in seasoned equity offerings around the investment period, suggesting there is a channel between stock price pressure and corporate investment that is independent of external financing. The third chapter documents a pronounced market timing ability of institutional investors when it comes to selling individual stocks. Based on more than 8 million institutional trades over the period 1999 to 2009, my co-authors and I document that (i) large (block) sales of institutional investors correlate with future negative excess returns, while stock purchases do not predict positive excess returns at the stock level,(ii) the one-sided successful market timing of block liquidations is more pronounced if the block represents a larger share of the investor portfolio or/and the stock capitalization, (iii) international investors have a weaker one-sided timing ability for block liquidations. The evidence strongly supports the hypothesis that proximity of block holding investors to management provides important inside information advantages

Database-Based IP Network Routing

The Software-Defined Networking (SDN) approach has the goal of simplifying network management. SDN uses a logically centralized approach to enable simpler network programmability and simplify the network architecture. SDN is in general associated with the OpenFlow protocol, which standardizes communication between a controller and network devices. Alternatively, a database approach could be used to tackle data exchange between controller and network devices. This solution requires the installation of a database server inside each switch, and replicas of those local switches databases, in the controller. The database approach offers several potential advantages over OpenFlow such as higher level of abstraction, flexibility and the use of mature implementations of standardised database protocols to propagate information events and commands. The purpose of this work is to apply a Database-Based Control Plane (DBCP) for SDN networks on a wide area environment. The objective is to implement a replacement of the control plane of a wide area network, currently achieved using a link-state protocol such as OSPF or IS-IS, by an SDN approach based on similar techniques as the ones used in [4]. We conducted an experiment, which we called IP-DBCP, that consisted of the definition of data models and the construction of an SDN network with database replication as the means of communication between one controller and multiple switches. To this end, a switch was developed, using OpenSwitch software as a logical hardware layer, that is capable of executing a MySQL database management system, load it with its characteristics and collect data related to its network neighbourhood. A controller was also developed that executes a MySQL database management system with the replicated databases of all switches. The controller uses those replicated databases to construct routing rules, using a shortest-path algorithm. Ultimately we tested the correct functioning of the solution and evaluated the convergence time by performing network state changes and compared the results with the ones found in traditional link state protocols

Total factor productivity of national innovation systems in the European Union

Innovation is important for economic growth. In this research, we analyze the productivity and efficiency of the National Innovation Systems (NIS) of the European Union 28 (EU-28) Member States, in the period 2006–2012. The data come from the Innovation Union Scoreboard 2014 report and Eurostat. Based on the Battese and Coelli (1995) time-varying inefficiency model, a Cobb– Douglas stochastic frontier is estimated as well as the effects of macroeconomic environmental variables on inefficiency. Innovation growth is decomposed into total factor productivity (TFP) changes, accumulation of inputs, and an unexplained residual component. Using an extension of the Kumbhakar and Lovell (2000) decomposition, TFP changes are computed as the sum of technological changes, changes in technical efficiency, and scale effects. Results show decreasing returns to scale in innovation production. Concerning the effects of macroeconomic environmental variables, technical inefficiency decreases with higher standards of living, the rate of economic growth, the reduction of economic inequality, and the control of inflation and unemployment. Excessive financial liquidity and political decentralization increase technical inefficiency. Growth in the innovation production of the EU- 28 Member States is due to TFP changes, to the accumulation of inputs, and to a residual non-explained component. Positive TFP changes resulted exclusively from the improvement in technical efficiency.info:eu-repo/semantics/publishedVersio

The political and economic dependence of the press in Macao under Portuguese and Chinese rule: continuity and change

The article analyses the media system in Macao, a special administrative region of China that transitioned from Portuguese to Chinese sovereignty in 1999, becoming one of cities in the world with the largest number of published newspapers per capita. Combining historical research with the analysis of contemporary empirical data collected through interviews with journalists working on the ground, the research demonstrates how there is a long tradition of state control that goes back to the colonial era and that has assumed different forms, ranging from outright censorship to physical intimidation of journalists and economic dependence on the government. Limitations and control strategies imposed on news reporting during the Portuguese administration continue to be practiced today by the Chinese authorities. Even so, journalists operating on the Macao media market tend to overstate the level of freedom they are given, which can be attributed to media outlets being economically dependent on the state. Nevertheless, the level of freedom attributed to the press is today higher than it had been during the colonial period with some critical voices being allowed to reach the media. This needs to be understood in the context of what has been defined as the Chinese safety valve strategy.info:eu-repo/semantics/publishedVersio

Experimental investigation of the residual behaviour of damaged masonry arch structures

New masonry arch bridges are rarely constructed as part of modern transport networks, however they continue to remain an integral part of modern civil infrastructure due to their overall resilience. This resilience has led to extremely long service lives which in turn has led to the majority of those bridges still in service being either distorted or damaged. Interest in the bridge owners community is directed towards prolonging the service life of these structures rather than replacement with new bridges. The aim of this paper is to explore whether the residual strength and the service life can be reliably established, and whether load limits must be imposed based on condition-based assessment, and/or retrofit the masonry arch system to prolong the life span of these important structures.To investigate residual strength and safe working loads, large scale,soil-backfilled masonry arches were constructed and subsequently subjected to a range of loading scenarios in controlled laboratory environments. Post-failure, these structures were further tested using both cyclic and quasi-static loadings. Results shows that: repeated cyclic loading at safe working load levels do not significantly alter the ultimate load carrying capacity of virgin masonry arch structures; the residual strength of distorted and/or damaged arch structures can be significant; distorted and/or damaged bridges are to some extent able to heal when subjected to repeated cyclic loading at safe working load levels, which is not the case with a virgin arch. Based on these findings, it can be concluded that the safe working load and life span of distorted and/or damaged masonry arch structures must be established in conjunction with the current state of the masonry arch structur

MEREC - Guarda: An Energy and Resource Efficiency Process undermined by the early stages of a democratic setting.

This article focuses on the historical background which lead to the implementation of an EUA programme in a European country; a programme designed for developing countries. To that end, we seek to discern, how 1980's Managing Energy and Resource Efficient Cities (MEREC) methodology has perpetuated in urban planning and architecture practice as well as in the discourses of its stakeholders. Guarda is a medieval border town (1050m) in the hinterland of Portugal, far away from the impact of metropolitan areas, such as Lisbon or Porto. Guarda kept a balanced urban growth over the years, but demography and key sectors of the economy changed profoundly after the Portuguese democratic revolution (1974). Serving as an early experience towards city resilience and sustained development, MEREC was a programme developed by the United States Agency for International Development (USAID). Inspired by the work of Richard Meier (1974), MEREC answered to the growing concerns triggered by the 1970s energy crisis and its consequences. Amid a rapid urbanisation and population growth, increased energy costs and pressure on natural resources, MEREC targeted cities in developing countries which could adopt preventive approaches towards resource efficiency. However, instead of concentrating its efforts on metropolitan areas, MEREC aimed at the development of secondary cities, where most of the growth had yet to come.From 1983 to 1985, MEREC established a comprehensive planning process, involving Guarda Municipality, central and regional agencies and the know-how of Portuguese universities and private consultants. MEREC identified the city's problems in water supply, urban waste, urban management, changes in local building materials used and scattered urbanisation. Several of these problems had been overcome with the project's completion, the development of Guarda's master plan, research technology, and awareness campaigns.USAID-MEREC advisors considered the results achieved in Guarda as rewarding. Architect Maria Castro (1989) points out the clarity achieved in the decision-making processes for urban planning and management during the MEREC programme. However, as she notes, discourses and institutional support changed after MEREC. MEREC’s methodology was somehow thrown away, suggesting a lack of planning culture among local political powers, unwilling to redirect resources. MEREC happened ten years after Portugal's dictatorship had ended, when the country was committed to the world as a democratic country, facing political and economical instability until its accession to the European Economic Union (EEC), as well as, undergoing deep socio-cultural transformations and striving for development. From 1986 onwards, MEREC programme was hampered by a democratic setting that aimed for development in more immediate ways, regardless of the resource-efficiency strategy proposed