How well does the Friends-of-Friends algorithm recover group properties from galaxy catalogs limited in both distance and luminosity?

We test the Friends-of-Friends (FoF) grouping algorithm, which depends on two linking lengths (LLs), plane-of-sky and line-of-sight (LOS), normalized to the mean nearest neighbor separation of field galaxies. We argue, on theoretical grounds, that LLs should be $b_\perp \simeq 0.11$, and $b_\parallel \simeq 1.3$ to recover 95% of all galaxies with projected radii within the virial radius $r_{200}$ and 95% of the galaxies along the LOS. We then predict that 80 to 90% of the galaxies in FoF groups should lie within their parent real-space groups (RSGs), defined within their virial spheres. We test the FoF extraction for 16x16 pairs of LLs, using subsamples of galaxies, doubly complete in distance and luminosity, of a flux-limited mock SDSS galaxy catalog. We find that massive RSGs are more prone to fragmentation, while the fragments typically have low estimated mass, with typically 30% of groups of low and intermediate estimated mass being fragments. Group merging rises drastically with estimated mass. For groups of 3 or more galaxies, galaxy completeness and reliability are both typically better than 80% (after discarding the fragments). Estimated masses of extracted groups are biased low, by up to a factor 4 at low richness, while the inefficiency of mass estimation improves from 0.85 dex to 0.2 dex when moving from low to high multiplicity groups. The optimal LLs depend on the scientific goal for the group catalog. We propose $b_\perp \simeq 0.07$, with $b_\parallel \simeq 1.1$ for studies of environmental effects, $b_\parallel \simeq 2.5$ for cosmographic studies and $b_\parallel \simeq 5$ for followups of individual groups.Comment: Revised version resubmitted to MNRAS. 16 pages. Smaller optimal linking lengths. Two extra figures. Comments welcome

Sertularia marginata (Cnidaria: Hydrozoa) in the Mediterranean: an alien species in expansion?

Mature and dense populations of the tropical hydroid species Sertularia marginata were detected in the Alboran Sea (Western Mediterranean) and along the Atlantic coast of the Strait of Gibraltar. Until now, it had only been recorded in the eastern basin of the Mediterranean Sea. This species has previously been recorded in estuaries and anthropogenic habitats but, in the area studied here, we only found it in natural zones. These observations could indicate early expansion and naturalization in the Mediterranean Sea. Due to its limited dispersion capacity and the history of its records, the observations provided here support the hypothesis of an arrival and a spread by anthropogenic vectors. A pathway of arrival and dispersion of alien species into the Mediterranean Sea is proposed for future monitoring: from Macaronesia (particularly Canary Islands) to the Atlantic coast of the Strait of Gibraltar and from there to the Mediterranean.Financiado por el Ministerio de Economía y Competitividad, proyecto CTM2010-16363. Cofinanciación con fondos FEDER

Reducing Procrastination while Improving Performance: A Wiki-powered Experiment with Students

© 2019 Copyright held by the owner/author(s). Publication rights licensed to ACM.Students in higher education are traditionally requested to produce various pieces of written work during the courses they undertake. When students' work is submitted online as a whole, both the ethically questionable act of procrastinating and late submissions afect performance. The objective of this paper is to assess the performance of students from a control group, with that of students from an experimental group. The control group produced work as a unique deliverable to be submitted at the end of the course. On the other hand, the experimental group worked on each part for a week, and their work was managed by a wiki environment and monitored by a speciically developed software. Positive efects were noticed in the experimental group, as both students' time management skills and performance increased. Replications of this experiment can and should be performed, in order to compare results in coursework submission.Final Accepted Versio

Privacy-Preserving Reengineering of Model-View-Controller Application Architectures Using Linked Data

When a legacy system’s software architecture cannot be redesigned, implementing additional privacy requirements is often complex, unreliable and costly to maintain. This paper presents a privacy-by-design approach to reengineer web applications as linked data-enabled and implement access control and privacy preservation properties. The method is based on the knowledge of the application architecture, which for the Web of data is commonly designed on the basis of a model-view-controller pattern. Whereas wrapping techniques commonly used to link data of web applications duplicate the security source code, the new approach allows for the controlled disclosure of an application’s data, while preserving non-functional properties such as privacy preservation. The solution has been implemented and compared with existing linked data frameworks in terms of reliability, maintainability and complexity

a aplicação de uma estratégia baseada em Inbound Marketing inserida no mercado de recrutamento e Outsourcing

No âmbito do Mestrado em Marketing Digital da Universidade Europeia, foi proposto aos alunos no terceiro semestre, a realização de um Projeto Final sendo as opções da realização deste projeto: relatório de estágio, dissertação ou projeto aplicado. Este relatório, redigido por Manuel Duarte Mendes, foi realizado no âmbito de Estágio Curricular. O objetivo do mesmo foi a inserção do aluno no mundo empresarial de forma a integrar os conhecimentos adquiridos ao longo do percurso do mestrado de Marketing Digital. O relatório irá relatar o estágio que realizei durante o período de 16 de novembro de 2015 até 31 de dezembro de 2015, na empresa RUPEAL, sobre a marca KWAN. A escolha da empresa foi efetuada através de um apelo prévio à empresa de forma a ingressar nos painéis de marketing da mesma. A RUPEAL é uma média empresa com dois negócios distintos sendo esses a criação de software através da marca SWAT (Special Web and Apps Tactics) e recrutamento e outsourcing através da marca KWAN, marca essa ao qual fui atribuído. Este estágio permitiu-me utilizar o conhecimento adquirido de diversas formas e baseou-se fortemente numa estratégia de Inbound Marketing.The following report concerns the tasks I have performed during the time I worked for RUPEAL under the KWAN brand. Its structure is both based on a pratical and theoretical approach, in order to best explain the tasks and their purpose. This approach relied on the knowledge I obtained during my masters in digital marketing and the knowledge obtained whilst working at RUPEAL. The report’s objective, apart from describing my experience at KWAN, is to display the connection between the brand’s marketing goals and how these goals interacted with digital marketing

Air budJets: A VTOL virtual operator company in Portugal

The aeronautical industry is evolving very rapidly mainly due to the development of technology. These technological advances have allowed the Man to develop projects that are very ambitious as is the case of "flying cars". This concept has been developed since the '80s, but only now have arisen prototypes capable of satisfying this dream. With this, the appearance of VTOL aircraft, aircraft capable of taking off and landing vertically, without needing any runways to do so. For this project, helicopters are not considered as VTOL aircraft because they are not very energy efficient. Many companies have developed VTOL aircraft, with design and consequently characteristics very different from each other, but having in common being hybrid or fully electric aircraft. For this study, a "fictitious" airline company was created using VTOL aircraft. The service characterization was then carried out, where using localization algorithms and trajectory optimization, we were able to elaborate an application (software) that treats the data of the flights to the marked ones by clients to optimize the routes/trajectories of the flights. Then the elaboration of a model and a business plan was made, and it is possible to observe the viability of the economic-financial results of the new (fictitious) company.A indústria aeronáutica está a evoluir muito rapidamente sobretudo devido ao desenvolvimento da tecnologia. Estes avanços tecnológicos têm permitido ao Homem desenvolver projetos há muito ambicionados como é o caso dos “carros voadores”. Este conceito tem vindo a ser desenvolvido desde os anos 80, mas só agora surgiram protótipos capazes de satisfazer este sonho. Com isto o aparecimento de aeronaves VTOL, aeronaves capazes de descolar e aterrar na vertical sem necessitar de quaisquer pistas para o fazer. Para este projeto não são considerados aeronaves VTOL os helicópteros pois estes são pouco eficientes energeticamente. Muitas empresas têm desenvolvido aeronaves VTOL, com design e consequentemente características muito diferentes entre si, mas que tendo em comum serem aeronaves híbridas ou totalmente elétricas. Para este estudo foi então criada uma empresa “fictícia” de transporte aéreo que utiliza aeronaves VTOL. Foi então feita a caracterização do serviço, onde utilizando algoritmos de localização e de otimização de trajetórias, fomos capazes de elaborar uma aplicação (software) que faz o tratamento dos dados dos voos já marcados por clientes para otimizar as rotas/trajetórias desses voos. Depois a elaboração de um modelo e de um plano de negócios foi possível observar a viabilidade dos resultados económico-financeiros da nova empresa (fictícia)

Learning roadmaps for Higher Education

An integrated platform for the support of teaching activities as been developed and deployed at the Aveiro Norte Polytechnic School of the University of Aveiro. In this paper we present an approach to Learning Roadmaps for Higher Education based on this platform. The aprend.e platform – Electronic Integrated System for Learning and Training - has at its core a Learning Management System with a number of plugins. It represents a new challenge for the University of Aveiro for higher education and is already being at its core is the concept of learning roadmaps that act upon two fundamental axes: education and learning. For the teachers, it aims at becoming a self-supporting tool that stimulates the organization and management of the course materials (lectures, presentations, multimedia content, and evaluation materials, amongst others). For the students, the learning roadmap aims at promoting self-study and supervised study, endowing the pupil with the capabilities to find the relevant information and to capture the concepts in the study materials. The outcome will be a stimulating learning process together with an organized management of those materials