973 resultados para pre-emphasis technique
Resumo:
This study presents a comprehensive mathematical formulation model for a short-term open-pit mine block sequencing problem, which considers nearly all relevant technical aspects in open-pit mining. The proposed model aims to obtain the optimum extraction sequences of the original-size (smallest) blocks over short time intervals and in the presence of real-life constraints, including precedence relationship, machine capacity, grade requirements, processing demands and stockpile management. A hybrid branch-and-bound and simulated annealing algorithm is developed to solve the problem. Computational experiments show that the proposed methodology is a promising way to provide quantitative recommendations for mine planning and scheduling engineers.
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Rae and Davidson have found a striking connection between the averaging method generalised by Kruskal and the diagram technique used by the Brussels school in statistical mechanics. They have considered conservative systems whose evolution is governed by the Liouville equation. In this paper we have considered a class of dissipative systems whose evolution is governed not by the Liouville equation but by the last-multiplier equation of Jacobi whose Fourier transform has been shown to be the Hopf equation. The application of the diagram technique to the interaction representation of the Jacobi equation reveals the presence of two kinds of interactions, namely the transition from one mode to another and the persistence of a mode. The first kind occurs in the treatment of conservative systems while the latter type is unique to dissipative fields and is precisely the one that determines the asymptotic Jacobi equation. The dynamical equations of motion equivalent to this limiting Jacobi equation have been shown to be the same as averaged equations.
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Highly purified fluorescent labelled anti-bicuculline antibodies were used to mark bicuculline binding sites in cerebral cortex of monkey brain. Specific binding of bicuculline could be demonstrated in the synaptosomal fraction, when bicuculline was added both Image and Image . Addition of γ-aminobutyric acid (GABA) to the bicucullinised membrane led to a decrease in fluorescence indicating same receptor loci and establishing GABA-bicuculline antagonism at a molecular level.
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Conventional methods for determining the refractive index demand specimens of optical quality, the preparation of which is often very difficult. An indirect determination by matching the refractive indices of specimen and immersion liquid is a practical alternative for photoelastic specimen of nonoptical quality. An experimental arrangement used for this technique and observations made while matching the refractive indices of three different specimens are presented.
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Early detection of (pre-)signs of ulceration on a diabetic foot is valuable for clinical practice. Hyperspectral imaging is a promising technique for detection and classification of such (pre-)signs. However, the number of the spectral bands should be limited to avoid overfitting, which is critical for pixel classification with hyperspectral image data. The goal was to design a detector/classifier based on spectral imaging (SI) with a small number of optical bandpass filters. The performance and stability of the design were also investigated. The selection of the bandpass filters boils down to a feature selection problem. A dataset was built, containing reflectance spectra of 227 skin spots from 64 patients, measured with a spectrometer. Each skin spot was annotated manually by clinicians as "healthy" or a specific (pre-)sign of ulceration. Statistical analysis on the data set showed the number of required filters is between 3 and 7, depending on additional constraints on the filter set. The stability analysis revealed that shot noise was the most critical factor affecting the classification performance. It indicated that this impact could be avoided in future SI systems with a camera sensor whose saturation level is higher than 106, or by postimage processing.
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Purification of drinking water is routinely achieved by use of conventional coagulants and disinfection procedures. However, there are instances such as flood events when the level of turbidity reaches extreme levels while NOM may be an issue throughout the year. Consequently, there is a need to develop technologies which can effectively treat water of high turbidity during flood events and natural organic matter (NOM) content year round. It was our hypothesis that pebble matrix filtration potentially offered a relatively cheap, simple and reliable means to clarify such challenging water samples. Therefore, a laboratory scale pebble matrix filter (PMF) column was used to evaluate the turbidity and natural organic matter (NOM) pre-treatment performance in relation to 2013 Brisbane River flood water. Since the high turbidity was only a seasonal and short term problem, the general applicability of pebble matrix filters for NOM removal was also investigated. A 1.0 m deep bed of pebbles (the matrix) partly in-filled with either sand or crushed glass was tested, upon which was situated a layer of granular activated carbon (GAC). Turbidity was measured as a surrogate for suspended solids (SS), whereas, total organic carbon (TOC) and UV Absorbance at 254 nm were measured as surrogate parameters for NOM. Experiments using natural flood water showed that without the addition of any chemical coagulants, PMF columns achieved at least 50% turbidity reduction when the source water contained moderate hardness levels. For harder water samples, above 85% turbidity reduction was obtained. The ability to remove 50% turbidity without chemical coagulants may represent significant cost savings to water treatment plants and added environmental benefits accrue due to less sludge formation. A TOC reduction of 35-47% and UV-254 nm reduction of 24-38% was also observed. In addition to turbidity removal during flood periods, the ability to remove NOM using the pebble matrix filter throughout the year may have the benefit of reducing disinfection by-products (DBP) formation potential and coagulant demand at water treatment plants. Final head losses were remarkably low, reaching only 11 cm at a filtration velocity of 0.70 m/h.
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In 2010 a group of teacher educators from four universities, experienced in rural and remote education, formed the Tertiary Educators Rural, Regional and Remote Network (TERRR Network). The collaborative goal was to improve the quality of graduates taking appointments beyond the metropolitan areas of Western Australia. The TERRR Network developed a research project to improve the capacity of universities to prepare teachers for employment in rural and remote locations. A range of outcomes emerged from the project, including: 1) the development of seven rural and remote-oriented curricula modules linked to the Australian Professional Standards for Teachers; 2) a cross-institutional field experience, and; 3) the development of a community of practice involving the Department of Education, universities and schools to address the logistical implications of placing pre-service students in rural and remote locations. This paper reports on the five phases of the project design, with a focus on learning in the field and concludes with reflections on the collaborative process used by the four universities in order to ensure that research evidence informs future policy and program development.
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This paper reports on outcomes of Phases One and Two of the ALTC Competitive Research and Development Project "Developing Strategies at the Pre-Service Level to Address Critical Teacher Attraction and Retention Issues in Australian Rural, Regional and Remote Schools." This project funded over two years aims to strengthen the capacity and credibility of universities to prepare rural, regional and remote educators, similar to the capacity and credibility that has been created in preparing Australia's rural, regional and remote health workers. There is a strong recognition of the fundamental importance of quality teaching experiences rural, regional and remote schools and throughout this project over 200 pre-service teachers have participated in a curriculum module/object and completed a survey that encourages them to consider teaching in regional Western Australia. The project has mapped current Western Australian rural, regional and remote pre-service teacher education curriculum and field experience model. This mapping completed a comparison of national information with the identification of rural, regional and remote education curriculum and/or field experience models used nationally and internationally. In particular results from Phase One and Two will be presented reporting on the findings of the first year of the project.
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Teacher education in Australia has a rich history of evolution from apprenticeships to university education. In this chapter the teacher education internship is examined. More specifically, the chapter outlines the Western Australian Combined Universities Training School (WACUTS) project, with its focus on reducing the gap between theory and practice through a collaborative and reflective approach. The successes and challenges faced in the first six months of implementation are presented
Resumo:
This study explores the EMU stand taken by the major Finnish political parties from 1994 to 1999. The starting point is the empirical evidence showing that party responses to European integration are shaped by a mix of national and cross-national factors, with national factors having more explanatory value. The study is the first to produce evidence that classified party documents such as protocols, manifestos and authoritative policy summaries may describe the EMU policy emphasis. In fact, as the literature review demonstrates, it has been unclear so far what kind of stand the three major Finnish political parties took during 1994–1999. Consequently, this study makes a substantive contribution to understanding the factors that shaped EMU party policies, and eventually, the national EMU policy during the 1990s. The research questions addressed are the following: What are the main factors that shaped partisan standpoints on EMU during 1994–1999? To what extent did the policy debate and themes change in the political parties? How far were the policies of the Social Democratic Party, the Centre Party and the National Coalition Party shaped by factors unique to their own national contexts? Furthermore, to what extent were they determined by cross-national influences from abroad, and especially from countries with which Finland has a special relationship, such as Sweden? The theoretical background of the study is in the area of party politics and approaches to EU policies, and party change, developed mainly by Kevin Featherstone, Peter Mair and Richard Katz. At the same time, it puts forward generic hypotheses that help to explain party standpoints on EMU. It incorporates a large quantity of classified new material based on primary research through content analysis and interviews. Quantitative and qualitative methods are used sequentially in order to overcome possible limitations. Established content-analysis techniques improve the reliability of the data. The coding frame is based on the salience theory of party competition. Interviews with eight party leaders and one independent expert civil servant provided additional insights and improve the validity of the data. Public-opinion surveys and media coverage are also used to complete the research path. Four major conclusions are drawn from the research findings. First, the quantitative and the interview data reveal the importance of the internal influences within the parties that most noticeably shaped their EMU policies during the 1990s. In contrast, international events play a minor role. The most striking feature turned out to be the strong emphasis by all of the parties on economic goals. However, it is important to note that the factors manifest differences between economic, democratic and international issues across the three major parties. Secondly, it seems that the parties have transformed into centralised and professional organisations in terms of their EMU policy-making. The weight and direction of party EMU strategy rests within the leadership and a few administrative elites. This could imply changes in their institutional environment. Eventually, parties may appear generally less differentiated and more standardised in their policy-making. Thirdly, the case of the Social Democratic Party shows that traditional organisational links continue to exist between the left and the trade unions in terms of their EMU policy-making. Hence, it could be that the parties have not yet moved beyond their conventional affiliate organisations. Fourthly, parties tend to neglect citizen opinion and demands with regard to EMU, which could imply conflict between the changes in their strategic environment. They seem to give more attention to the demands of political competition (party-party relationships) than to public attitudes (party-voter relationships), which would imply that they have had to learn to be more flexible and responsive. Finally, three suggestions for institutional reform are offered, which could contribute to the emergence of legitimised policy-making: measures to bring more party members and voter groups into the policy-making process; measures to adopt new technologies in order to open up the policy-formation process in the early phase; and measures to involve all interest groups in the policy-making process.
Resumo:
This paper reports on the outcomes of a two year ALTC Competitive Research and Development Project that aimed to "Develop Strategies at the Pre-Service Level to Address Critical Teacher Attraction and Retention Issues in Australian Rural, Regional and Remote Schools". As well as developing a ‘training framework’ and teaching guides to increase the capacity and credibility of four universities to prepare educators who might venture out of the metropolitan area to teach, data were gathered from pre-service and graduate teachers to analyse regional resilience. It was found that there was a strong likelihood to participate in a regional practicum and stay in a non-metropolitan community once they graduated from university if they had a positive attitude to regional Western Australia either through a family connection or previous experience. Recommendations from this study emphasise the importance of having pre-service students participate in positive regional experiences early in their university study.
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The quality of an online university degree is paramount to the student, the reputation of the university and most importantly, the profession that will be entered. At the School of Education within Curtin University, we aim to ensure that students within rural and remote areas are provided with high quality degrees equal to their city counterparts who access face-to-face classes on campus.In 2010, the School of Education moved to flexible delivery of a fully online Bachelor of Education degree for their rural students. In previous years, the degree had been delivered in physical locations around the state. Although this served the purpose for the time, it restricted the degree to only those rural students who were able to access the physical campus. The new model in 2010 allows access for students in any rural area who have a computer and an internet connection, regardless of their geographical location. As a result enrolments have seen a positive increase in new students. Academic staff had previously used an asynchronous environment to deliver learning modules housed within a learning management system (LMS). To enhance the learning environment and to provide high quality learning experiences to students learning at a distance, the adoption of synchronous software was introduced. This software is a real-time virtual classroom environment that allows for communication through Voice over Internet Protocol (VoIP) and videoconferencing, along with a large number of collaboration tools to engage learners. This research paper reports on the professional development of academic staff to integrate a live e-learning solution into their current LMS environment. It involved professional development, including technical orientation for teaching staff and course participants simultaneously. Further, pedagogical innovations were offered to engage the students in a collaborative learning environment. Data were collected from academic staff through semi-structured interviews and participant observation. The findings discuss the perceived value of the technology, problems encountered and solutions sought.
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The scope of the differential transformation technique, developed earlier for the study of non-linear, time invariant systems, has been extended to the domain of time-varying systems by modifications to the differential transformation laws proposed therein. Equivalence of a class of second-order, non-linear, non-autonomous systems with a linear autonomous model of second order is established through these transformation laws. The feasibility of application of this technique in obtaining the response of such non-linear time-varying systems is discussed.
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In this paper a strategy for controlling a group of agents to achieve positional consensus is presented. The proposed technique is based on the constraint that every agents must be given the same control input through a broadcast communication mechanism. Although the control command is computed using state information in a global framework, the control input is implemented by the agents in a local coordinate frame. We propose a novel linear programming formulation that is computationally less intensive than earlier proposed methods. Moreover, we introduce a random perturbation input in the control command that helps us to achieve perfect consensus even for a large number of agents, which was not possible with the existing strategy in the literature. Moreover, we extend the method to achieve positional consensus at a pre-specified location. The effectiveness of the approach is illustrated through simulation results.