Statistical distributions obtained from the compression of monodisperse, soft and frictionless particles

The cyclic compression of several granular systems has been simulated with a molecular dynamics code. All the samples consisted of bidimensional, soft, frictionless and equal-sized particles that were initially arranged according to a squared lattice and were compressed by randomly generated irregular walls. The compression protocols can be described by some control variables (volume or external force acting on the walls) and by some dimensionless factors, that relate stiffness, density, diameter, damping ratio and water surface tension to the external forces, displacements and periods. Each protocol, that is associated to a dynamic process, results in an arrangement with its own macroscopic features: volume (or packing ratio), coordination number, and stress; and the differences between packings can be highly significant. The statistical distribution of the force-moment state of the particles (i.e. the equivalent average stress multiplied by the volume) is analyzed. In spite of the lack of a theoretical framework based on statistical mechanics specific for these protocols, it is shown how the obtained distributions of mean and relative deviatoric force-moment are. Then it is discussed on the nature of these distributions and on their relation to specific protocols.

Discrete (MD) and continuum (DD) simulations of void growth in single crystals.

Void growth in ductile materials is an important problem from the fundamental and technological viewpoint. Most of the models developed to quantify and understand the void growth process did not take into account two important factors: the anisotropic nature of plastic flow in single crystals and the size effects that appear when plastic flow is confined into very small regions.

Contribution to active multi-beam reconfigurable antennas for L and S bands

La presente tesis doctoral con título "Contribution to Active Multi-Beam Reconfigurable Antennas for L and S Bands" ha sido desarrollada por el investigador ingeniero de telecomunicación estudiante de doctorado Javier García-Gasco Trujillo en el Grupo de Radiación del Departamento de Señales, Sistemas y Radiocomunicaciones de la ETSI de Telecomunicación de la Universidad Politécnica de Madrid bajo la dirección de los doctores Manuel Sierra Pérez y José Manuel Fernández González. Durante décadas, el desarrollo de antenas de apuntamiento electrónico ha estado limitado al área militar. Su alto coste y su gran complejidad eran los mayores obstáculos que frenaban la introducción de esta tecnología en aplicaciones comerciales de gran escala. La reciente aparición de componentes de estado sólido prácticos, fiables, y de bajo coste ha roto la barrera del coste y ha reducido la complejidad, haciendo que las antenas reconfigurables de apuntamiento electrónico sean una opción viable en un futuro cercano. De esta manera, las antenas phased array podrían llegar a ser la joya de la corona que permitan alcanzar los futuros retos presentes en los sistemas de comunicaciones tanto civiles como militares. Así pues, ahora es el momento de investigar en el desarrollo de antenas de apuntamiento electrónico de bajo coste, donde los nuevos componentes de estado sólido comerciales forman el núcleo duro de la arquitectura. De esta forma, el estudio e implementación de estos arrays de antenas activas de apuntamiento electrónico capaces de controlar la fase y amplitud de las distintas señales implicadas es uno de los grandes retos de nuestro tiempo. Esta tesis se enfrenta a este desafío, proponiendo novedosas redes de apuntamiento electrónico e innovadores módulos de transmisión/recepción (T/R) utilizando componentes de estado sólido de bajo coste, que podrán integrar asequibles antenas activas reconfigurables multihaz en bandas L y S. En la primera parte de la tesis se realiza una descripción del estado del arte de las antenas phased array, incluyendo su base teórica y sus ventajas competitivas. Debido a que las contribuciones obtenidas en la presente tesis han sido realizadas dentro de distintos proyectos de investigación, donde se han manejada antenas de simple/doble polarización circular y simple/doble banda de trabajo, se describen detenidamente los dos proyectos más relevantes de la investigación: el radar de basura espacial de la Agencia Espacial Europea (ESA), Space Situational Awareness (SSA); y la estación base de seguimiento y control de satélites de órbita baja, GEOdesic Dome Array (GEODA). Sin lugar a dudas, los dispositivos desfasadores son uno de los componentes clave en el diseño de antenas phased arrays. Recientemente se ha observado una gran variación en el precio final de estos dispositivos, llegando en ocasiones a límites inasequibles. Así pues, se han propuesto distintas técnicas de conformación de haz alternativas a la utilización de componentes desfasadores comerciales: el desfasador de líneas conmutadas, la red de haz conmutado, y una novedosa red desfasadora divisora/combinadora de potencia. Para mostrar un uso práctico de las mismas, se ha propuesto el uso de las tres alternativas para el caso práctico del subarray de cinco elementos de la celda GEODA-SARAS. Tras dicho estudio se obtiene que la novedosa red desfasadora divisora/combinadora de potencia propuesta es la que mejor relación comportamiento/coste presenta. Para verificar su correcto funcionamiento se construye y mide los dos bloques principales de los que está compuesta la red total, comprobando que en efecto la red responde según lo esperado. La estructura más simple que permite realizar un barrido plano es el array triangular de tres elementos. Se ha realizado el diseño de una nueva red multihaz que es capaz de proporcionar tres haces ortogonales en un ángulo de elevación _0 y un haz adicional en la dirección broadside utilizando el mencionado array triangular de tres elementos como antena. En primer lugar se realizar una breve introducción al estado del arte de las redes clásicas multihaz. Así mismo se comentan innovadores diseños de redes multihaz sin pérdidas. El estudio da paso a las redes disipativas, de tal forma que se analiza su base matemática y se muestran distintas aplicaciones en arrays triangulares de tres elementos. Finalmente, la novedosa red básica propuesta se presenta, mostrando simulaciones y medidas de la misma para el caso prácticoo de GEODA. También se ha diseñado, construido y medido una red compuesta por dos redes básicas complementarias capaz de proporcionar seis haces cuasi-ortogonales en una dirección _0 con dos haces superpuestos en broadside. La red propuesta queda totalmente validada con la fabricación y medida de estos con prototipos. Las cadenas de RF de los módulos T/R de la nueva antena GEODA-SARAS no son algo trivial. Con el fin de mostrar el desarrollo de una cadena compleja con una gran densidad de componentes de estado sólido, se presenta una descripción detallada de los distintos componentes que integran las cadenas de RF tanto en transmisión como en recepción de la nueva antena GEODA-SARAS. Tras presentar las especificaciones de la antena GEODA-SARA y su diagrama de bloques esquemático se describen los dos bloques principales de las cadenas de RF: la celda de cinco elementos, y el módulo de conversión de panel. De la misma manera también se presentará el módulo de calibración integrado dentro de los dos bloques principales. Para comprobar que el funcionamiento esperado de la placa es el adecuado, se realizará un análisis que tratará entre otros datos: la potencia máxima en la entrada del transmisor (comprobando la saturación de la cadena), señal de recepción mínima y máxima (verificando el rango de sensibilidad requerido), y el factor G/T (cumpliendo la especificación necesaria). Así mismo se mostrará un breve estudio del efecto de la cuantificación de la fase en el conformado de haz de RF. Los estudios muestran que la composición de las cadenas de RF permite el cumplimiento de las especificaciones necesarias. Finalmente la tesis muestra las conclusiones globales del trabajo realizado y las líneas futuras a seguir para continuar con esta línea de investigación. ABSTRACT This PhD thesis named "Contribution to Active Multi-Beam Reconfigurable Antennas for L and S Bands", has been written by the Electrical Engineer MSc. researcher Javier García-Gasco Trujillo in the Grupo de Radiación of the Departamento de Señales, Sistemas y Radiocomunicaciones from the ETSI de Telecomunicación of the Universidad Politécnica de Madrid. For decades, the implementation of electronically steerable phased array antennas was confined to the military area. Their high cost and complexity were the major obstacles to introduce this technology in large scale commercial applications. The recent emergence of new practical, low-cost, and highly reliable solid state devices; breaks the barrier of cost and reduces the complexity, making active phased arrays a viable future option. Thus, phased array antennas could be the crown jewel that allow to meet the future challenges in military and civilian communication systems. Now is time to deploy low-cost phased array antennas, where newly commercial components form the core of the architecture. Therefore, the study and implementation of these novel low-cost and highly efficient solid state phased array blocks capable of controlling signal phase/amplitude accurately is one of the great challenges of our time. This thesis faces this challenge, proposing innovative electronic beam steering networks and transmitter/ receiver (T/R) modules using affordable solid state components, which could integrate fair reconfigurable phased array antennas working in L and S bands. In the first part of the thesis, a description of the state of art of phased array antennas, including their fundamentals and their competitive advantages, is presented. Since thesis contributions have been carried out for different research projects, where antennas with single/double circular polarization and single/double working frequency bands have been examined, frameworks of the two more important projects are detailed: the Space Situational Awareness (SSA) programme from the European Space Agency (ESA), and the GEOdesic Dome Array (GEODA) project from ISDEFE-INSA and the ESA. Undoubtedly, phase shifter devices are one of the key components of phased array antennas. Recent years have witnessed wide fluctuations in commercial phase shifter prices, which sometimes led to unaffordable limit. Several RF steering technique alternatives to the commercial phase shifters are proposed, summarized, and compared: the switched line phase shifter, the switched-beam network, and the novel phase shifter power splitter/combiner network. In order to show a practical use of the three different techniques, the five element GEODA-SARAS subarray is proposed as a real case of study. Finally, a practical study of a newly phase shifter power splitter/combiner network for a subarray of five radiating elements with triangular distribution is shown. Measurements of the two different phase shifter power splitter/combiner prototypes integrating the whole network are also depicted, demonstrating their proper performance. A triangular cell of three radiating elements is the simplest way to obtain a planar scanner. A new multibeam network configuration that provides three orthogonal beams in a desired _0 elevation angle and an extra one in the broadside steering direction for a triangular array of three radiating elements is introduced. Firstly, a short introduction to the state of art of classical multi-beam networks is presented. Lossless network analysis, including original lossless network designs, are also commented. General dissipative network theory as well as applications for array antennas of three radiating elements are depicted. The proposed final basic multi-beam network are simulated, built and measured to the GEODA cell practical case. A combined network that provides six orthogonal beams in a desired _0 elevation angle and a double seventh one in the broadside direction by using two complementary proposed basic networks will be shown. Measurements of the whole system will be also depicted, verifying the expected behavior. GEODA-SARAS T/R module RF chains are not a trivial design. A thorough description of all the components compounding GEODA-SARAS T/R module RF chains is presented. After presenting the general specifications of the GEODA-SARAS antenna and its block diagrams; two main blocks of the RF chains, the five element cell and the panel conversion module, are depicted and analyzed. Calibration module integrated within the two main blocks are also depicted. Signal flow throw the system analyzing critical situations such as maximum transmitted power (testing the chain unsaturation), minimum and maximum receiving signal (verifying sensitivity range), maximum receiver interference signals (assuring a proper reception), and G/T factor (fulfilling the technical specification) are evaluated. Phase quantization error effects are also listed. Finally, the manuscript contains the conclusions drawn of the present research and the future work.

Industry Professionals Who Attain Leadership in Energy and Environmental Design (LEED) Accreditation: An Examination of Motivations in Human Resource (HR) Training and Development

Despite the economy, the green building industry continues to grow and drive the demand for environmentally conscious, highly skilled professionals (USGBC 2009). LEED Accredited Professionals (APs) have the knowledge and skills to meet such demand; however, information is limited regarding LEED APs or their motivations and expectations toward prospective employers. The author surveyed a sample of LEED Accredited architects and found a combination of job and personal factors motivated them to attain accreditation. LEED APs value both a competitive salary and commitment to sustainability in prospective employers. To attract, retain, and utilize LEED APs, executives in this industry must reexamine corporate culture, their willingness to pay for credentialing, and the alignment of their reputation with the desires of potential applicants.

Complex learning: the role of knowledge, intelligence, motivation and learning strategies

This work presents the main theories and models formulated with the purpose of offering a global overview on the acquisition of knowledge and skills involved in the initial development of expert competence. Setting from this background, we developed an empirical work whose main purpose is to define those factors in a complex learning situation such as chapter-sized in a knowledge-rich domain. The results obtained in a sample of Master students reveal that the several variables intervening, such as the qualitative organization of knowledge, intellectual ability, motivation, the deliberate use of strategies, and a rich learning environment, contribute in an independent way to provide an explanation for the acquired knowledge.

Technology diffusion and its effects on social inequalities

We develop a dynamic general-equilibrium framework in which growth is driven by skill-biased technology diffusion. The model incorporates leisure–labor decisions and human capital accumulation through education. We are able to reproduce the trends in income inequality and labor and skills supplies observed in the United States between 1969 and 1996. The paper also provides an explanation for why more individuals invest in human capital when the investment premium is going down, and why the skill-premium goes up when the skills supply is increasing.

Mentors’ implication in clinical learning and assessment of nursing students

Nursing Education in Europe is regulated by law from 2005. Clinical learning comprises at least 50% of the total degree program in nursing. It is necessary rely on professionals nurses involved in the learning process and skills development assessment. The level of implication in learning processes of these professional nurses is very important to ensure good results.

SMEs and Level 2 BIM, the Way Forward

The UK construction industry comprises a very high proportion of SMEs that is companies employing up to 250. A Department for Business, Innovation and Skills research paper, found that SMEs had a 71.2% share of work in the construction industry. Micro and small firms (i.e. those employing up to 50) had a share of 46.7% of work (Ive and Murray 2013). The Government has high ambitions for UK construction. Having been found by successive government commissioned studies to be inefficient and highly fragmented, ambitious targets have been set for the industry to achieve 33% reduction in costs and 50% faster delivery by 2025. As a significant construction client, the Government has mandated the use of Level 2 BIM from 2016 on publicly funded projects over £5 million. The adoption of BIM plays a key role in the 2025 vision but a lack of clarity persists in the industry over BIM and significant barriers are perceived to its implementation, particularly amongst SMEs. However, industry wide transformation will be challenging without serious consideration of the capabilities of this large majority. Many larger firms, having implemented Level 2 BIM are now working towards Level 3 BIM while many of the smaller firms in the industry have not even heard of BIM. It would seem that fears of a ‘two tier’ industry are perhaps being realised. This paper builds on an earlier one (Mellon & Kouider 2014) and investigates, through field work, the level of Level 2 BIM implementation amongst SMEs compared to a large organisation. Challenges and innovative solutions identified through collected data are fully discussed and compared. It is suggested that where the SME perceives barriers towards adoption of the technologies which underpin BIM, they may consider collaborative methods of working as an interim step in order to work towards realising the efficiencies and benefits that these methods can yield. While the barriers to adoption of BIM are significant, it is suggested that they are not insurmountable for the SME and some recommendations for possible solutions are made.

Promoting interculturalism through art education : a case study Portugal and Latvia

This study examines art student’s awareness, understanding and practices of intercultural art education in higher institution of art. Specifically, the research focused on Art Academy of Latvia, Riga. The purpose was to promote “interculturalism’’ among students and to acquaint them with the knowledge and skills of developing and reflecting on their cultural values and that of others’. For 10 weeks, 7 students in the Art Academy of Latvia explored the Traditional African Ceramics. My research included data gathered from student questionnaires, class discussions, interviews, observations, student artwork and photographs from their personal activities. I likewise took note of the students’ practical works and their approach to African-based ceramics. First, in literature review, I discuss my purpose of study, why the study is important, limitations, statements of problem, and further research. Secondly, I examine culture and paradigms of cultures, comprehensive context of the African history and traditions of the African ceramics, the importance of intercultural art education. Then, I describe how the case study in Latvia was carried out among 7 participants’ who are students from 2nd year – masters’ level. The case study involved 7 students from the department of graphics, glass, ceramics and painting with the aim of promoting intercultural learning among art students. The case study reveals participants’ attitude towards intercultural education and reveal the importance of intercultural education in higher institutions of art as well as other institutions of learning. Although the participants were positive attitude towards other culture, the study reveals that creating awareness through intercultural art and exposing students to other culture enhances their creativity ability to explore other culture and they are more likely to be opened in sharing their experiences and their cultural perspective. Experiencing culture based- art create awareness of other cultures

Future of skills in Europe-Convergence or polarisation? CEPS Working Document No. 390, 27 February 2014

In this Working Paper, based on nearly 20 papers produced by the Centre for European Policy Studies, Slovak Governance Institute and the Conference Board Europe, we examine whether the current trends in the areas of education and skills are pushing the European Union, towards convergence or polarisation. We cover a wide range of questions related to this main issue. No easy answers, but several cross-cutting messages emerged from the research. We demonstrated that there is increasing complexity in what a ‘low-skilled’ person is and how well (or poorly) s/he fares in the labour market. There are undoubtedly powerful forces pushing for more polarisation, particularly in the labour market. Our research confirmed that early childhood education plays an important role, and it also appears to be increasingly uncontested as a policy prescription. However, the other frequently emphasised remedy to inequality – less selection in secondary education, particularly later division of children into separate tracks – is more problematic. Its effectiveness depends on the country in question and the target group, while education systems are extremely difficult to shift even on a long-term basis. A different, more-nuanced type of warning to policy-makers is delivered in our research on returns to higher education by field of study, which showed hidden rationality in how students choose their major.

Rethinking the Attractiveness of EU Labour Immigration Policies: Comparative perspectives on the EU, the US, Canada and beyond

Is Europe's immigration policy attractive? One of the priorities driving current EU debates on labour immigration policies is the perceived need to boost Europe's attractiveness vis-á-vis 'talented' and 'highly skilled' immigrants. The EU sees itself playing a role in persuading immigrants to choose Europe over other competing destinations, such as the US or Canada. This book critically examines the determinants and challenges characterising discussions focused on the attractiveness of labour migration policies in the EU as well as other international settings. It calls for re-thinking some of the most commonly held premises and assumptions underlying the narratives of ‘attractiveness’ and ‘global competition for talent’ in migration policy debates. How can an immigration policy, in fact, be made to be ‘attractive’ and what are the incentives at play (if any)? A multidisciplinary team of leading scholars and experts in migration studies address the main issues and challenges related to the role played by rights and discrimination, qualifications and skills, and matching demand and supply in needs-based migration policies. The experiences in other jurisdictions such as South America, Canada and the United States are also covered: Are these countries indeed so ‘attractive’ and ‘competitive’, and if so what makes them more attractive than the EU? On the basis of the discussions and findings presented across the various contributions, the book identifies a number of priorities for policy formulation and design in the next generation of EU labour migration policies. In particular, it highlights important initiatives that the new European Commission should focus on in the years to come.

Understanding professional practice: investigations before and after an educational programme

During preparation for professional practice, the professional skill being developed is typically measured in the form of specific knowledge and skills. This study proposes an alternative to such measures, drawing upon research which demonstrates that our understanding of professional practice is central to how we both perform and develop that practice. The study investigates understanding of medical practice prior to and following a pre-medical programme. On commencing the programme, students showed substantial variation in their understanding of medical practice. At the end of the programme much of this variation remained, indicating the students had developed varying forms of professional skill. The study calls into question the adequacy of a focus on detailed knowledge and skills as a base for professional practice. In line with previous research, an important implication of the study is that developing skilful practice requires focusing on understanding of that practice in and through its performance.

Imaginary relish and exquisite torture: The elaborated intrusion theory of desire

The authors argue that human desire involves conscious cognition that has strong affective connotation and is potentially involved in the determination of appetitive behavior rather than being epiphenomenal to it. Intrusive thoughts about appetitive targets are triggered automatically by external or physiological cues and by cognitive associates. When intrusions elicit significant pleasure or relief, cognitive elaboration usually ensues. Elaboration competes with concurrent cognitive tasks through retrieval of target-related information and its retention in working memory. Sensory images are especially important products of intrusion and elaboration because they simulate the sensory and emotional qualities of target acquisition. Desire images are momentarily rewarding but amplify awareness of somatic and emotional deficits. Effects of desires on behavior are moderated by competing incentives, target availability, and skills. The theory provides a coherent account of existing data and suggests new directions for research and treatment.

Unfreezing the frame: Functional fram analysis for journalists and journalism students

This paper presents two case studies that suggest, in different but complementary ways, that the critical tool of frame analysis (Entman, 2002) has a place not only in the analytical environments of critical media research and media studies classes, where it is commonly found, but also in the media-production oriented environments of skills-based journalism training and even the newsroom. The expectations and constraints of both the latter environments, however, necessitate forms of frame analysis that are quick and simple. While commercial pressures mean newsrooms and skills-based journalism-training environments are likely to allow only an oversimplified approach to frame analysis, we argue that even a simple understanding and analysis at the production end could help to shift framing in ways that not only improve the quality and depth of Australasian newspapers' news coverage, but increase reader satisfaction with media output.

Towards a profitable and sustainable future for grain growers: A professional development model for farm partners

Many Australian grain growers need to change their management approach to ensure their continued viability, but do not have the required knowledge and skills. Uptake of relevant education and training is poor, despite the positive correlation between learning, change and farm viability. As men are generally occupied with the operational aspects of the farm, much of the management role has been taken on by their partners, despite their lack of relevant formal qualifications. Professional development of farm partners therefore has the potential to improve the viability of grain growers. A model combining learning circles and action learning projects is proposed.