The dust environment of comet 67P/Churyumov-Gerasimenko from Rosetta OSIRIS and VLT observations in the 4.5 to 2.9 au heliocentric distance range inbound

Context. The ESA Rosetta spacecraft, currently orbiting around comet 67P/Churyumov-Gerasimenko, has already provided in situ measurements of the dust grain properties from several instruments,particularly OSIRIS and GIADA. We propose adding value to those measurements by combining them with ground-based observations of the dust tail to monitor the overall, time-dependent dust-production rate and size distribution.
Aims. To constrain the dust grain properties, we take Rosetta OSIRIS and GIADA results into account, and combine OSIRIS data during the approach phase (from late April to early June 2014) with a large data set of ground-based images that were acquired with the ESO Very Large Telescope (VLT) from February to November 2014.
Methods. A Monte Carlo dust tail code, which has already been used to characterise the dust environments of several comets and active asteroids, has been applied to retrieve the dust parameters. Key properties of the grains (density, velocity, and size distribution) were obtained from Rosetta observations: these parameters were used as input of the code to considerably reduce the number of free parameters. In this way, the overall dust mass-loss rate and its dependence on the heliocentric distance could be obtained accurately.
Results. The dust parameters derived from the inner coma measurements by OSIRIS and GIADA and from distant imaging using VLT data are consistent, except for the power index of the size-distribution function, which is α = −3, instead of α = −2, for grains smaller than 1 mm. This is possibly linked to the presence of fluffy aggregates in the coma. The onset of cometary activity occurs at approximately 4.3 AU, with a dust production rate of 0.5 kg/s, increasing up to 15 kg/s at 2.9 AU. This implies a dust-to-gas mass ratio varying between 3.8 and 6.5 for the best-fit model when combined with water-production rates from the MIRO experiment.

Punishment, youth justice and cultural contingency: Towards a balanced approach

Reflecting developments in the broader penological realm, accounts have been advanced over the last number of decades about a ‘punitive turn’ in the youth justice systems of Western democracies. Against the background of this work, this project seeks to identify convergent and divergent trends in the youth justice systems of England, the Republic of Ireland and Northern Ireland as well as the rationalities and discourses animating these. The results lend support to research emphasising the continued salience of national, regional and local factors on penal outcomes but also suggest the need to steer an analytical path somewhere between nomothetic (convergent) and idiographic (divergent) accounts.

Is Longer-Distance Migration Slowing? An Analysis of the Annual Record for England and Wales since the 1970s

This paper is prompted by the widespread acceptance that the rates of inter-county and inter-state migration have been falling in the USA and sets itself the task of examining whether this decline in migration intensities is also the case in the UK. It uses annual inter-area migration matrices available for England and Wales since the 1970s by broad age group. The main methodological challenge, arising from changes in the geography of health areas for which the inter-area flows are given, is addressed by adopting the lowest common denominator of 80 areas. Care is also taken to allow for the effect of economic cycles in producing short-term fluctuations on migration rates and to isolate the effect of a sharp rise in rates for 16-24 year olds in the 1990s, which is presumed to be related to the expansion of higher education. The findings suggest that, unlike for the USA, there has not been a substantial decline in the intensity of internal migration between the first two decades of the study period and the second two. If there has been any major decline in the intensity of address changing in England and Wales, it can only be for the within-area moves that this time series does not cover. This latter possibility is examined in a companion paper using a very different data set (Champion and Shuttleworth, 2016).

Are People Changing Address Less? An Analysis of Migration within England and Wales, 1971–2011, by Distance of Move

Expectations of migration and mobility steadily increasing in the longer term, which have a long currency in migration theory and related social science, are at odds with the latest US research showing a marked decline in internal migration rates. This paper reports the results of research that investigates whether England and Wales have experienced any similar change in recent decades. Using the Office for National Statistics Longitudinal Study (ONS-LS) of linked census records, it examines the evidence provided by its 10-year migration indicator, with particular attention to a comparison of the first and latest decades available, 1971-1981 and 2001-2011. This suggests that, as in the USA, there has been a marked reduction in the level of shorter-distance (less than 10km) moving that has involved almost all types of people. In contrast to this and to US experience, however, the propensity of people to make longer-distance address changes between decennial censuses has declined much less, largely corroborating the results of a companion study tracking the annual trend in rates of between-area migration since the 1970s (Champion and Shuttleworth, 2016).

Comet 322P/SOHO 1: An asteroid with the smallest perihelion distance?

We observed comet 322P/SOHO 1 (P/1999 R1) from the ground and with the Spitzer Space Telescope when it was between 2.2 and 1.2 AU from the Sun. These are the first observations of any SOHO-discovered periodic comet by a non-solar observatory, and allow us to investigate its behavior under typical cometary circumstances. 322P appeared inactive in all images. Its lightcurve suggests a rotation period of 2.8+/-0.3 hr and has an amplitude greater than ~0.3 mag, implying a density of at least 1000 kg m$^{-3}$, considerably higher than that of any known comet. It has average colors of g'-r' = 0.52+/-0.04 and r'-i' = 0.04+/-0.09. We converted these to Johnson colors and found that the V-R color is consistent with average cometary colors, but R-I is somewhat bluer; these colors are most similar to V- and Q-type asteroids. Modeling of the optical and IR photometry suggests it has a diameter of 150-320 m and a geometric albedo of 0.09-0.42, with diameter and albedo inversely related. Our upper limits to any undetected coma are still consistent with a sublimation lifetime shorter than the typical dynamical lifetimes for Jupiter Family Comets. These results suggest that it may be of asteroidal origin and only active in the SOHO fields of view via processes different from the volatile-driven activity of traditional comets. If so, it has the smallest perihelion distance of any known asteroid.

O balanced scorecard e a administração local:aplicação à divisão financeira do município de Vila Franca de Xira

Dissertação, Mestrado, Contabilidade e Finanças, Instituto Politécnico de Santarém, Escola Superior de Gestão e Tecnologia, 2014

O balanced scorecard:estudo de caso da empresa Hidromethos, Lda.

Dissertação, Mestrado, Contabilidade e Finanças, Instituto Politécnico de Santarém, Escola Superior de Gestão e Tecnologia, 2015

A generalization of the Hoffman-Lovász upper bound on the independence number of a regular graph

A family of quadratic programming problems whose optimal values are upper bounds on the independence number of a graph is introduced. Among this family, the quadratic programming problem which gives the best upper bound is identified. Also the proof that the upper bound introduced by Hoffman and Lovász for regular graphs is a particular case of this family is given. In addition, some new results characterizing the class of graphs for which the independence number attains the optimal value of the above best upper bound are given. Finally a polynomial-time algorithm for approximating the size of the maximum independent set of an arbitrary graph is described and the computational experiments carried out on 36 DIMACS clique benchmark instances are reported.

Necessary and sufficient conditions for a Hamiltonian graph

A graph is singular if the zero eigenvalue is in the spectrum of its 0-1 adjacency matrix A. If an eigenvector belonging to the zero eigenspace of A has no zero entries, then the singular graph is said to be a core graph. A ( k,t)-regular set is a subset of the vertices inducing a k -regular subgraph such that every vertex not in the subset has t neighbours in it. We consider the case when k=t which relates to the eigenvalue zero under certain conditions. We show that if a regular graph has a ( k,k )-regular set, then it is a core graph. By considering the walk matrix we develop an algorithm to extract ( k,k )-regular sets and formulate a necessary and sufficient condition for a graph to be Hamiltonian.

Spectra of graphs obtained by a generalization of the join graph operation

Taking a Fiedler’s result on the spectrum of a matrix formed from two symmetric matrices as a motivation, a more general result is deduced and applied to the determination of adjacency and Laplacian spectra of graphs obtained by a generalized join graph operation on families of graphs (regular in the case of adjacency spectra and arbitrary in the case of Laplacian spectra). Some additional consequences are explored, namely regarding the largest eigenvalue and algebraic connectivity.

Wissensmanagement und Balanced Scorecard

Die Arbeit befasst sich allgemein mit Wissensmanagement und der Balanced Scorecard (BSC). Ziel der Arbeit war es, darzustellen, welche Systeme auf BSC-Basis das Controlling von Wissensmanagement-Aktivitäten ermöglichen.

Die Balanced Scorecard als Führungsinstrument zur Herbarbeleg-Digitalisierung

Neben circa 22.000 verschiedenen kultivierten Pflanzenarten besitzt die Zentraleinrichtung Botanischer Garten und Botanische Museum Berlin-Dahlem (BGBM) ca. 3,8 Millionen konservierter Pflanzenbelege aus aller Welt in seinem Herbarium. Diese Herbarbelege dienen als Grundlage wissenschaftlicher Forschung. Über die Erstellung digitaler Kopien kann das Versenden des empfindlichen Materials verhindert und der Zugang für Forscher erheblich erleichtert werden. Die Prozesse und Methoden der Digitalisierung werden in Herbar Digital untersucht, um eine Senkung der Kosten zu ermöglichen. In dem vorliegenden Arbeitspapier wird der Einsatz einer Balanced Scorecard als Steuerungsinstrument der Herbarbeleg-Digitalisierung untersucht. Das Instrument misst die Zielerreichung und unterstützt so Entscheidungen der Führung. Vision und Strategie der Unternehmung werden in mehreren Perspektiven operationalisiert. Für jedes Ziel sind Indikatoren, Sollwerte, Istwerte und Maßnahmen zu definieren. Die Istwerte werden zu den Indikatoren und Zeitpunkten verdichtet und zeigen so den Zielerreichungsgrad an. In einem individuellen Dashboard werden die Ziele, Indikatoren, Zielwerte, Maßnahmen und weitere Informationen angezeigt und können kommentiert werden. Die Planwerte sind die Basis für den operativen Planungsprozess. Die Struktur sieht vor, dass die Ziel-Dashboards aller Organisationseinheiten einer Hochschule schließlich zu Sub- und Teil-Balanced Scorecards miteinander verknüpft werden können. Es ergibt sich je nach Sachverhalt eine Übersicht über die Ziele und korrespondierenden Indikatoren sowie deren Entwicklung und Maßnahmen. Dies wird am Beispiel der Herbarbeleg-Digitalisierung verdeutlicht.

Robust handling of out-of-vocabulary words in deep language processing

Tese de doutoramento, Informática (Ciências da Computação), Universidade de Lisboa, Faculdade de Ciências, 2014