951 resultados para Full factorial design
Resumo:
Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA.
Resumo:
Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA.
Resumo:
Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA.
Resumo:
We show how certain N-dimensional dynamical systems are able to exploit the full instability capabilities of their fixed points to do Hopf bifurcations and how such a behavior produces complex time evolutions based on the nonlinear combination of the oscillation modes that emerged from these bifurcations. For really different oscillation frequencies, the evolutions describe robust wave form structures, usually periodic, in which selfsimilarity with respect to both the time scale and system dimension is clearly appreciated. For closer frequencies, the evolution signals usually appear irregular but are still based on the repetition of complex wave form structures. The study is developed by considering vector fields with a scalar-valued nonlinear function of a single variable that is a linear combination of the N dynamical variables. In this case, the linear stability analysis can be used to design N-dimensional systems in which the fixed points of a saddle-node pair experience up to N21 Hopf bifurcations with preselected oscillation frequencies. The secondary processes occurring in the phase region where the variety of limit cycles appear may be rather complex and difficult to characterize, but they produce the nonlinear mixing of oscillation modes with relatively generic features
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On this instrumental study we intend to analyse the factorial structure of the Screen for Child Anxiety Related Emotional Disorders (SCARED) in a Spanish sample using exploratory and confirmatory factorial analysis. As a second objective we intend to develop a short form of it for rapid screening and, finally, to analyze the reliabilities of both questionnaires. The SCARED was administered to a community sample of 1,508 children aged between 8 and 12 years. The sample was randomly split using half for the exploratory analysis and the other half for the confirmatory study. Furthermore a reduced version of the SCARED was developed using the SchmidLeiman procedure. Exploratory Factor Analysis yielded a four factor structure comprised of Somatic/panic, Generalized anxiety, Separation anxiety and Social phobia factors This structure was confirmed using Confirmatory Factor Analysis. The four factors, the full scale and the short scale showed good reliabilities. The results obtained seem to indicate that the Spanish version of the SCARED has good internal consistency, and along with other recent results, has a structure of four related factors that replicates the dimensions proposed for anxiety disorders by the DSM-IV-TR
Resumo:
Multiprocessing is a promising solution to meet the requirements of near future applications. To get full benefit from parallel processing, a manycore system needs efficient, on-chip communication architecture. Networkon- Chip (NoC) is a general purpose communication concept that offers highthroughput, reduced power consumption, and keeps complexity in check by a regular composition of basic building blocks. This thesis presents power efficient communication approaches for networked many-core systems. We address a range of issues being important for designing power-efficient manycore systems at two different levels: the network-level and the router-level. From the network-level point of view, exploiting state-of-the-art concepts such as Globally Asynchronous Locally Synchronous (GALS), Voltage/ Frequency Island (VFI), and 3D Networks-on-Chip approaches may be a solution to the excessive power consumption demanded by today’s and future many-core systems. To this end, a low-cost 3D NoC architecture, based on high-speed GALS-based vertical channels, is proposed to mitigate high peak temperatures, power densities, and area footprints of vertical interconnects in 3D ICs. To further exploit the beneficial feature of a negligible inter-layer distance of 3D ICs, we propose a novel hybridization scheme for inter-layer communication. In addition, an efficient adaptive routing algorithm is presented which enables congestion-aware and reliable communication for the hybridized NoC architecture. An integrated monitoring and management platform on top of this architecture is also developed in order to implement more scalable power optimization techniques. From the router-level perspective, four design styles for implementing power-efficient reconfigurable interfaces in VFI-based NoC systems are proposed. To enhance the utilization of virtual channel buffers and to manage their power consumption, a partial virtual channel sharing method for NoC routers is devised and implemented. Extensive experiments with synthetic and real benchmarks show significant power savings and mitigated hotspots with similar performance compared to latest NoC architectures. The thesis concludes that careful codesigned elements from different network levels enable considerable power savings for many-core systems.
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Weeds compete with field crops mainly for water, light and nutrients, and the degree of competition is affected by the weed density and the intrinsic competitive ability of each plant species in coexistence. The objective of this research was to compare the competitiveness of alexandergrass (Brachiaria plantaginea) or Bengal dayflower (Commelina benghalensis) in coexistence with soybean, cv. M-Soy 8045. A factorial experiment (2 x 5) with two weed species and five competition proportions was carried out in a completely randomized design with four replicates. Proportions were based on a replacement series competition design, always maintaining the total density of four plants per 10 L plastic pots, which corresponded to 60 plants m ². The weed-crop proportions were: 0:4; 1:3; 2:2; 3:1; 4:0; that corresponded to the proportion of 100, 75, 50, 25 and 0% of soybean plants and the opposite for weeds, B. plantaginea or C. benghalensis plants. Leaf area, shoot dry mass of the weeds and soybean and number of soybean trifoliate leaves were evaluated when the soybean reached the phenologic stage of full flowering. B. plantaginea was a better competitor than soybean plants. Otherwise, C. benghalensis revealed a similar competitive ability that of the soybean. In both cases, there were evidences that intraspecific competition was more important.
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In this thesis, the main point of interest is the robust control of a DC/DC converter. The use of reactive components in the power conversion gives rise to dynamical effects in DC/DC converters and the dynamical effects of the converter mandates the use of active control. Active control uses measurements from the converter to correct errors present in the converter’s output. The controller needs to be able to perform in the presence of varying component values and different kinds of disturbances in loading and noises in measurements. Such a feature in control design is referred as robustness. This thesis also contains survey of general properties of DC/DC converters and their effects on control design. In this thesis, a linear robust control design method is studied. A robust controller is then designed and applied to the current control of a phase shifted full bridge converter. The experimental results are shown to match simulations.
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The design process of direct-driven permanent magnet synchronous machines (PMSMs) for a full electric 4 ´ 4 sports car is presented. The rotor structure of the machine consists of two permanent magnet layers embedded inside the rotor laminations thus resulting in some inverse saliency, where the q-axis inductance is larger than the d-axis one. An integer slot stator winding was selected to fully take advantage of the additional reluctance torque. The performance characteristics of the designed PMSMs were calculated by applying a twodimensional finite element method. Cross-saturation between the d- and q-axes was taken into account in the calculation of the synchronous inductances. The calculation results are validated by measurements.
Resumo:
A looming attrition rate, a steady increase in the number of women in administration, and a lack of Canadian research all provided the rationale for this study. The problem in this study was to investigate the needs and challenges of new female administrators and to examine the role that mentors play in addressing these issues. This study also explored the perceived benefits of having a mentor. This study examined the inductive year of 33 female administrators from 3 Ontario school boards. It was a qualitative and quantitative design, using questionnaire and interview data. It was found that the majority felt that they struggled with biases and expectations that were gender specific. The challenges that were perceived to be most prevalent were categorized into 4 thematic areas: Maintaining Balance, Feeling Pressured, The Perceptions of Others, and Being Challenged by Others. Regarding the benefits of mentoring, the participants perceived mentoring to be most beneficial in terms of professional growth, followed by learning how to run a school, and then career advancement. The significance of this study was threefold: it had theoretical implications as well as implications for practice and future research. Suggestions included: facilitating longitudinal relationships, having the board become more actively involved in facilitating the relationship, and implementing an internship program. This study attempted to extend the current literature by theorizing that a mentorship is cyclical in nature. Future research could include program design and implementation, as well as providing consistent and accessible mentoring opportunities for all.
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The purpose of this qualitative study was to explore the full-time graduate students' perceptions of teacher effectiveness at the graduate school level, to identify how graduate students perceive effective and ineffective teachers, and specifically to discover the main dimensions of teacher effectiveness that graduate students perceive as most significant. This topic was investigated because, although the teacher has been deemed as a crucial component in the teaching process, there is no common agreement on the definition and measure of teacher effectiveness. Graduate students' perceptions of teacher effectiveness have not been given much attention. The research design was based on a ground theory approach. It utilized qualitative data through interviews, field notes, andjournals. The findings ofthis study revealed that teacher effectiveness is markedly influential to graduate students. There is no universally consented definition or measure of teacher effectiveness due to the multidimensionality of teaching and learning. Nevertheless, several major dimensions ofteacher effectiveness were discovered and highlighted in this study. Such dimensions include good command of subject matter, presentation skills, challenging and motivating students, rapport with students, learning environment, course demands, as well as assessment and feedback. It was hoped that the study would move towards developing a theory that contributes to the knowledge base of graduate students' perceptions of teacher effectiveness. It was anticipated that the results would provide first-hand information for the instructor to improve teaching; for the administrator to promote the effective educational experiences and student achievements. It was intended that the findings would lay a theoretical and empirical groundwork for future research.
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Two classes of building blocks have been prepared and characterized and their coordination chemistry explored working towards the preparation of new molecule-based magnetic materials. In the first project, the amine functionality of 3,3'-diamino-2,2'- bipyridine was exploited for the preparation of a new family of ligands (H2L 1)-(H2L 4). The molecular structures of three ligands have been fully characterized by X-ray crystallography. [molecular structure diagram will not copy here, but is available in full pdf.] The coordination chemistry of these ligands with divalent first row transition metal ions was investigated. For ligand (H2L1), the molecular structures of four coordination complexes with stoichiometries [Zn2(Ll)(OAc)(MeO)]2 (I), [Cu2(L1)(OAc)2 (II), [Li(L1)]3 (III), and [Ni(L1)]3 (IV) were determined by X-ray crystallography. For ligand (H2L2), a Cu(II) complex of stoichiometry [Cu3(L2)(OAc)3MeO] (V) was determined by X-ray crystallography. The magnetic properties of complexes (II), (III), and (V) have been fully elucidated. In project two, synthetic strategies for the preparation of porphyrin molecules bearing triol substituents is presented. Following this approach, three new porphyrin derivatives have been prepared and characterized [Zn(HPTPP-CH2C(CH20H)3)] (VI), [P(TPP)(OCH2C(CH2)H)3)2]+CL- (VII), and [P(OEP)(C6H5)(OCH2C(CH2OH)3)]+Cl- (VIII). Attempts to exchange the labile methoxide bridges of a tetraironIIl single molecule magnet of stoichiometry [Fe4(OMe)6(dpm)6] (Hdpm = dipivaloylmethane) with the triol appended porphyrins will be discussed. [molecular structure diagram will not copy here, but is available in full pdf.]
Resumo:
An experimental design that included both between-group and within-group designs was used to assess media influence on perceptions of sport leadership. Participants were recruited and randomly assigned to three groups, where each group completed two separate survey sessions regarding leader personality traits and behaviours. During the second survey session, experimental Groups 1 and 2 watched a video on a separate, respective sport leader prior to filling out the survey. There were a total of 104 participants (N = 104) for the first session, and 99 (N = 99) participants completed the second session. One-way ANOVA, factorial repeated measures ANOVA, and ANCOVA were used for data analysis. Results indicate a significant change in Group 2’s results after watching the video clip, thus rejecting the null hypotheses. Results and implications are discussed, highlighting their relationships to sport and media related theories and sport management practice.
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The goal of this research is to develop the prototype of a tactile sensing platform for anthropomorphic manipulation research. We investigate this problem through the fabrication and simple control of a planar 2-DOF robotic finger inspired by anatomic consistency, self-containment, and adaptability. The robot is equipped with a tactile sensor array based on optical transducer technology whereby localized changes in light intensity within an illuminated foam substrate correspond to the distribution and magnitude of forces applied to the sensor surface plane. The integration of tactile perception is a key component in realizing robotic systems which organically interact with the world. Such natural behavior is characterized by compliant performance that can initiate internal, and respond to external, force application in a dynamic environment. However, most of the current manipulators that support some form of haptic feedback either solely derive proprioceptive sensation or only limit tactile sensors to the mechanical fingertips. These constraints are due to the technological challenges involved in high resolution, multi-point tactile perception. In this work, however, we take the opposite approach, emphasizing the role of full-finger tactile feedback in the refinement of manual capabilities. To this end, we propose and implement a control framework for sensorimotor coordination analogous to infant-level grasping and fixturing reflexes. This thesis details the mechanisms used to achieve these sensory, actuation, and control objectives, along with the design philosophies and biological influences behind them. The results of behavioral experiments with a simple tactilely-modulated control scheme are also described. The hope is to integrate the modular finger into an %engineered analog of the human hand with a complete haptic system.
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Caches are known to consume up to half of all system power in embedded processors. Co-optimizing performance and power of the cache subsystems is therefore an important step in the design of embedded systems, especially those employing application specific instruction processors. In this project, we propose an analytical cache model that succinctly captures the miss performance of an application over the entire cache parameter space. Unlike exhaustive trace driven simulation, our model requires that the program be simulated once so that a few key characteristics can be obtained. Using these application-dependent characteristics, the model can span the entire cache parameter space consisting of cache sizes, associativity and cache block sizes. In our unified model, we are able to cater for direct-mapped, set and fully associative instruction, data and unified caches. Validation against full trace-driven simulations shows that our model has a high degree of fidelity. Finally, we show how the model can be coupled with a power model for caches such that one can very quickly decide on pareto-optimal performance-power design points for rapid design space exploration.