Miracle-dz/UniFAR-FTUs huggingface dataset:
Transmitting craft knowledge : designing interactive media to support tacit skills learning

This research has used a practice-led approach to explore, from the perspective of an interactive media designer, the problem of how to understand and transmit the practical knowledge of skilled craft practitioners. It has involved two practical research projects, each exploring the skills of both expert and novice craft practitioners in the fields of traditional bowl turning and clog making. In the first project I experimentally used a systems-orientated approach to explore the tacit knowledge within the practice of an experienced traditional bowl turning practitioner. This involved eliciting craft knowledge from the expert, using a low-fidelity prototype learning resource as a means of representing that knowledge, and observing learners applying the knowledge through using the resource to support their learning. In the second project I undertook a series of video-recordings with a traditional clog maker, during which I developed a less intrusive elicitation technique based on increasingly focussed observation and interviewing. This overcame the defensiveness encountered with the first practitioner with whom I used an elicitation approach based on his descriptions of his practice. In the light of the outcomes from the practical work, I reconsidered the current context for craft knowledge and developed a framework to understand craft learning. Drawing on three important theorists: Michael Polanyi and his theory of tacit knowledge, John Dewey and his theory of experiential learning, and Donald Schon and his theory of reflection, I reassessed the learning I had previously observed and proposed a new model of how craft knowledge is learned. I propose that the guidance offered by the expert can be seen as a series of bridges that provide the novice with a means of accessing the personal knowledge of the expert. These bridges are not necessarily the way to undertake a task, but a way that the expert feels to be helpful at that time. As a novice increasingly learns from the feedback from their own actions, they can progress their skill by moving through different modes of reflection. This research makes three specific contributions to knowledge. In the field of multimedia design it establishes a methodology for transmitting craft knowledge, refining principles previously published through my MA research, and it establishes techniques for eliciting craft knowledge which are interwoven with the process of developing the transmission resource. In the field of learning and pedagogy it establishes a framework for understanding craft skills learning drawing on recognised theory and validated through appraisal of the practical work undertaken.
Radiation pattern of spherical array of rectangular microstrip patches

A program for calculating the radiation pattern of spherical arrays consisting of quasi-rectangular patches is presented. The problem is solved in the spectral domain, i.e. for each value of spectral variable only a one-dimensional problem has to be solved. A general algorithm for calculating Green's functions is used in the program, therefore the patches can be printed on or embedded in a multilayer spherical structure. Two different types of array grids are investigated: icosahedron grid and quasi-rectangular grid.
Modeling and nonlinear control of shunt active power filter in the synchronous reference frame

This paper presents a modeling and a nonlinear control of three-phase voltage source shunt active filter. The modeling is based on the abc/dq transformation of the AC system variables. The currents injected by the active filter are controlled in the synchronous orthogonal dq frame using a decoupled nonlinear control strategy. The reference harmonic components are extracted from the sensed nonlinear load currents by applying the synchronous reference frame method, where a three-phase thyristor bridge rectifier with R-L load is taken as the nonlinear load. The voltage level of the DC side is regulated using a linearizing feedback control. The reference current needed to maintain a regulated DC voltage is added to the current loop reference. The transfer functions of the two loops are developed and synthesized to obtain the desired stability and dynamic response. Simulation results confirm the performances considered theoretically for the shunt active filter topology.
Current-controlled negative resistance (CCNR) in SiC P-i-N rectifiers

This paper presents an experimental demonstration of a current-controlled negative resistance (CCNR) in the forward characteristics of 6H-SiC P-i-N rectifiers. These forward characteristics indicate that the poor electrical performance of SiC diodes arises because conductivity modulation is not yet established. The cause of this behaviour appears to be high defect densities and low minority carrier lifetime in the lightly doped drift region. N/sup +/P junctions exhibit excellent forward characteristics with forward drop of 2.8 V at 100 A/cm/sup 2/ and 3.9 V at 1000 A/cm/sup 2/ without entering the CCNR mode when traps have been filled prior to the measurement.
Stock Price Forecasting: Review and Experiment on Time Series Data Processing

Stock price forecasting may present a huge benefit for economy sector as the ability to predict future stock prices may help related parties prepare for the predicted or forecasted condition. Many artificial intelligence-related approaches have been proposed, and this paper provides reviews of time series processing in general and stock price forecasting progresses for newcomers to get acquainted with. In addition, experimentation of stock price forecasting on several existing approaches from time series processing in general are provided to gain insight on which approach may perform better and which may merit further research on stock price forecasting task.
Breeding for coffee quality

In line with the focus on specialty coffee, we will concentrate on the breeding of Coffea arabica. Contrary to what many may believe, breeding for coffee quality is a relatively new initiative. The challenges and opportunities that breeders face when selecting varieties for high quality are discussed. In the coffee production sector, when talking about varieties, most people will mention Robusta and Arabica. This confusion between species, Coffea canephora and C. Arabica respectively, and varieties is typical of a pure commodity sector where only the largest and most obvious differences are recognized. According to the International Union for the Protection of New Varieties of Plants, a variety is "a plant grouping within a single botanical taxon of the lowest known rank, which grouping" can be: "i) defined by the expression of the characteristics resulting from a given genotype or combination of genotypes, ii) distinguished from any other plant grouping by the expression of at least one of the said characteristics and iii) considered as a unit with regard to its suitability for being propagated unchanged". One would argue that Bourbon or Tipica are Arabica coffee varieties and it is true that most coffee people would be able to roughly describe the phenotype of each. However, referring to the definition of a variety: exactly what are the characteristics expressed by Bourbon or Tipica? Are they distinguishable from other Arabica plants? Further adding to the complexity is the recognition by the International Coffee Organization (ICO) of three Arabica coffee categories: Colombian milds, other milds and Brazilian natural. Historically, the mainstream coffee market has been based largely on this classification and the reputation of quality coffee tends to be associated with geographic origin irrespective of the variety or botanical type. In this chapter, the concept of coffee variety and its relation to market demand are discussed. The current knowledge of coffee genetics and quality are also discussed, along with the gaps in knowledge that still remain. Breeding strategies are then proposed, stressing the need for new high throughput phenotyping of selection criteria linked to quality. Finally, some thoughts are offered about how producers might take advantage of new advances in genetics and selection methodologies. (Resume d'auteur)
Analysis and design of high frequency three-phase boost rectifiers

Analysis and design of high switching frequency, high efficiency, three-phase boost rectifiers are presented. A novel PWM scheme is developed to reduce switch conduction loss, switching loss, and input current ripple. An average method is proposed to calculate switch currents and input current ripple, allowing accurate prediction of switch loss, EMI emissions, and inductor loss. Soft switching, control and system interaction issues are also discussed. A 9 kW, 50 kHz ZVT boost rectifier is designed with high efficiency and light weight.
Effectively Managing the Air Force Enterprise Architecture

Abstract : The Air Force is developing and implementing an enterprise architecture to meet the Clinger-Cohen Act's requirement that all federal agencies use an architecture to guide their information technology (IT) investments. However, this act does not provide guidance on how to effectively manage an enterprise architecture. Prior research applied maturity models and competency stages to manage an enterprise architecture by defining layers of enterprise architecture management maturity. However, these efforts tend to view enterprise architecture development as a one-time planning process rather than an iterative progression. Enterprise architecture is not a one-time exercise, but rather it is an on-going effort within the organization to rationalize, integrate, and optimize the IT capability within an organization across many projects and business units. Hence, the critical success factors to effectively manage an enterprise architecture must be identified to ensure the structure, processes, and governing mechanisms are established within the organization for maintaining an enterprise architecture. This research draws from existing academic, professional, and government literature to identify the key issues affecting the Air Force's ability to manage its enterprise architecture effectively. Once identified, a quantitative analysis will assist in interpreting the qualitative findings in hopes of determining the underlying factors driving these issues.
Application of the intellectual decision making system for vessel traffic control

This paper presents an intellectual decision making system for the vessel traffic service (VTS). Its aim is to increase the safety and efficiency of the traffic and the effectiveness of VTS. In general, the navigational decision making process in a traffic control system is based on radar and navigation information although other systems, such as automatic identification systems, GPS can be used with good effect. The application of an intellectual component during a decision making process increases safety and economic effects of the shipping as well as reduces the operator's workload.
Methodological issues arising from research into the emergence of enterprise in the creative industries

In the digital economy, the creative industries revolve around dynamic, innovative and often unorthodox collaborations between individuals and organisations. Large, small and micro-businesses often come together for the duration of a project, then disband and form new partnerships for the next project. During such projects, novelty emerges in the form of new products, services, business models or patterns of consumer/producer behaviour. The structure of novelty-creating practices, i.e. the interactions within one-off dynamic project groups is not well understood. Firstly, it spans multiple levels of analysis (individuals, groups, organisations, society); secondly, creativity in the digital domain often has unpredictable outcomes as the availability and potential of technology changes so rapidly. This presents a challenge for research design. Latterly, we have undertaken a stream of research that utilises the theoretical field of entrepreneurship to study the emergence of novelty. Here we extend that work by presenting a conceptual framework that we suggest can capture how novelty emerges over time. Methodologically, we suggest that the framework has analytical potential too, in that it could be used to support effectively the collection of data: ordering and categorising empirical observations concerning how different phenomena emerge over time across multiple levels of analysis and contexts.
Modular scale-free architecture of Colombian financial networks: Evidence and challenges with financial stability in view

Scale-free (inhomogeneous) connective structures with modular (highly clustered) hierarchies are ubiquitous in real–world networks. Evidence from the main Colombian payment and settlement systems verifies that local financial networks have self-organized into a modular scale-free architecture that favors everyday robustness and performance in exchange for rare episodes of fragility but rapid evolution. Results provide new elements for understanding and modeling the formation and structure of financial networks, and suggest new insights and challenges for authorities contributing to their stability. For instance, (i) the observed architecture suggests that financial systems are complex adaptive systems; (ii) complex adaptive features invalidate traditional reductionist assumptions for modeling financial systems (e.g. homogeneity, normality, static equilibrium, linearity); (iii) the observed modular scale-free architecture tends to limit cascades and isolate feedbacks; and (iv) with financial stability in view, authorities should understand and take advantage of the existing architecture by means of designing and implementing macro-prudential regulation and system-calibrated requirements. Yet, the quest for discovering, explaining and handling the emerging structure of financial systems is an enduring task.
Peer support for people with severe mental illness versus usual care: study protocol for a pragmatic multicentre randomised controlled trial (UPSIDES-RCT)

Background: Peer support is an established intervention involving a person in recovery from mental illness being engaged to offering support to others with mental illness. Peers are an under-used resource in global mental health. Building upon comprehensive formative research, this study will rigorously evaluate the impact of peer support at the levels of service users (psychosocial and clinical outcomes), peer support workers (work role, empowerment), services (cost-effectiveness, return on investment), and implementation (adoption, sustainability, organisational change). Methods: UPSIDES-RCT is a pragmatic parallel-group multi-centre randomised controlled trial assessing the effectiveness of UPSIDES at four measurement points over one year (baseline, 4-, 8-, and 12-month follow-up), and embedded process evaluation and cost-effectiveness analysis. Research will take place in a range of high-, middle- and low-income countries (Germany, United Kingdom, Israel, Uganda, Tanzania, India). The primary outcome is social inclusion of service users with severe mental illness (N= 558; N = 93 per site) at 8-month follow-up, measured with the Social Inclusion Scale. Secondary outcomes include empowerment (Empowerment Scale), hope (HOPE scale), recovery (Stages of Recovery), and health and social functioning (Health of the Nations Outcome Scales). Mixed-methods process evaluation will investigate mediators and moderators of effect, and implementation experiences of four UPSIDES stakeholder groups (service users, peer support workers, mental health workers, and policy makers). A cost-effectiveness analysis examining cost-utility and health budget impact will estimate the value for money of UPSIDES peer support. Discussion: By implementing and evaluating a manualized peer support intervention for people with severe mental illness across low-, middle-, and high-income countries, this study will contribute to harmonising core elements of peer support across different cultural and organisational dimensions. The UPSIDES-RCT will explore the essential components necessary to create a peer support model in mental health care, while providing the evidence required to sustain and eventually scale-up the intervention. Performance of mental health services will be maximised by actively involving and empowering service users, generating system changes towards user-centeredness, recovery orientation, community participation, and realising mental health as a human right. Trail registration: ISRCTN, ISRCTN26008944. Registered 30 October 2019, http://www.isrctn. com/ISRCTN26008944.
Chaotic Modeling Of Radar Backscatper From An Ocean Surface

Radar backscatter from an ocean surface, commonly referred to as sea clutter, has a long history of being modeled as a stochastic process. In this paper, we take a fundamentally different viewpoint in describing sea clutter. In particular, we demonstrate that the random nature of sea clutter is indeed the result of a chaotic phenomenon. Using different realizations of actual sea clutter, we use the correlation dimension analysis to show that sea clutter can indeed *be embedded as a chaotic attractor in a finite dimensional space. This observation provides a reliable indication for the existence of a chaotic behavior. The result of correlation dimension analysis is used to construct a neural network model for sea clutter to reconstruct the dynamics of sea clutter. The model is in the form of a radial basis function (RBF) network. The deterministic model for sea clutter so obtained is shown to be capable of predicting the evolution of sea clutter as a function of time in a reasonable manner.
Asynchronous multi-sensor tracking in clutter with uncertain sensor locations using Bayesian sequential Monte Carlo methods

This paper presents the development of a tracking algorithm for multi-sensor single target tracking in the presence of asynchronous or missing measurements and high clutter levels. The algorithm is based upon the random sample representation of state PDFs and uses sequential Monte Carlo or "particle" filtering methods to perform prediction and update. The performance of the algorithm is illustrated on the challenging problem of naval subsurface target tracking using multiple drifting sonobuoys of the DIFAR type. Good performance was demonstrated on simulated scenarios with a high level of uncertainty represented by unknown sensor location, 20% missing measurements and 70% clutter.
Design of an Accurately Regulated Multiple Output ZVS DC/DC Converter

Design method for an Accurately Regulated multiple output ZVS dc/dc converter is proposed. The converter is composed of three outputs altogether. The 1 st and 3 rd outputs are regulated through the duty cycle control of two asymmetrical half bridge converters, while the 2 nd output is regulated through the phase shift of the two asymmetrical half bridge converters. The characteristic of the proposed multiple output dc/dc converter is analyzed and the design process is investigated. ZVS is easily realized for all the main switches. Therefore this multiple output converter can operate with high efficiency at high switching frequency. A 400V input, 48V/10A, 12V/5A, 5V/20A outputs prototype has been built to verify its advantage.
Speciation, clustering and other genetic algorithm improvements for structural topology optimization

Genetic algorithms are used to search for optimal structural topologies. Modifications to basic genetic algorithm techniques are implemented to increase computational efficiency, avoid premature convergence to a single solution, and solve new categories of problems. GA's are a search and optimization tool based on the principles of evolution and survival of the fittest. Potential designs are represented by chromosomes, each of which receives a fitness score based on the quality of the design it represents. As in nature, the more fit a chromosome is, the more likely it is to survive and "reproduce," combining with another "parent" chromosome to produce new "child" chromosomes. As this process of evaluation, selection, and reproduction is iterated, the population of chromosomes "evolves," and new and improved designs are generated. In this study, an allowable design domain is discretized into several binary, material/void elements, yielding a combinatorial search space. One chromosome represents one design, which can be evaluated using finite element analysis or analytical techniques. Extending previous efforts with the same basic representation and search technique, this research proposes several methods for improving genetic algorithm performance. New population initialization and parent selection methods are implemented to reduce run-times and decrease the number of poor intermediate designs generated and evaluated by the algorithm. Fitness sharing and speciation are used to distribute subsets of the evolving population over many local optima, preventing premature convergence to a single solution when multiple, equally good solutions exist. The resulting distribution of sub-populations is analogous to different species exploiting different niches in an ecosystem. Statistical cluster analysis techniques are used to divide the population into sub-species and to quantify the extent to which a population is speciated. Additionally, this cluster analysis is used to discourage the mating of dissimilar designs (designs from different clusters). Results show that these modifications to basic genetic algorithm techniques result in shorter run-times and greater diversity of solutions. Finally, a hybrid GA / simulated annealing method is introduced for topology design of adaptive structures. Thesis Supervisor: Mark J. Jakiela Title: Associate Professor, Mechanical Engineering
Overcoming distance in virtual teams : effects of communication media, experience, and time pressure on distributed teamwork

Een virtueel team is een team waarvan de leden elkaar niet of zelden in levenden lijve ontmoeten, bijvoorbeeld omdat de teamleden verschillende werktijden hebben of op verschillende vestigingen van een organisatie werken. Anders dan reguliere teams zijn virtuele teams in grote mate afhankelijk van informatie- en communicatietechnologie. Een voorbeeld van een virtueel team is een ontwerpteam dat binnen een multinationaal bedrijf een nieuwe productlijn ontwikkelt vanaf verschillende locaties door gebruik te maken van e-mail en videovergaderingen. Een belangrijke bijdrage van het huidige onderzoek is dat het laat zien dat de beperkingen van gedistribueerd samenwerken die de wijdverbreide toepassing van virtuele teams hinderen, zijn te overkomen. Door een combinatie van relevante groupware en ervaring met samenwerken op afstand, kunnen virtuele teams werk produceren dat qua kwaliteit en hoeveelheid vergelijkbaar is met het werk van face-to-face teams. Het lijkt er dan ook op dat virtuele teams geen modeverschijnsel zijn. Virtuele teams zijn de toekomst.
Phase-locked semiconductor laser diode arrays

Phase-locked semiconductor diode laser arrays are capable of emitting light at high power in low divergence beams. Moreover, because of their small size and high electrical-to-optical conversion efficiency, these devices have many applications. The presentation begins with a review of semiconductor diode lasers and the principles of phased arrays. Various experiments relating to the lasers themselves and to their operation in external cavities are reviewed and the theory of their operation and conditions needed to favor lasing in a desired array mode (supermode) is discussed. The talk concludes with recent results concerning reliability.