410 resultados para Haar transform
Resumo:
The ninth release of the Toolbox, represents over fifteen years of development and a substantial level of maturity. This version captures a large number of changes and extensions generated over the last two years which support my new book “Robotics, Vision & Control”. The Toolbox has always provided many functions that are useful for the study and simulation of classical arm-type robotics, for example such things as kinematics, dynamics, and trajectory generation. The Toolbox is based on a very general method of representing the kinematics and dynamics of serial-link manipulators. These parameters are encapsulated in MATLAB ® objects - robot objects can be created by the user for any serial-link manipulator and a number of examples are provided for well know robots such as the Puma 560 and the Stanford arm amongst others. The Toolbox also provides functions for manipulating and converting between datatypes such as vectors, homogeneous transformations and unit-quaternions which are necessary to represent 3-dimensional position and orientation. This ninth release of the Toolbox has been significantly extended to support mobile robots. For ground robots the Toolbox includes standard path planning algorithms (bug, distance transform, D*, PRM), kinodynamic planning (RRT), localization (EKF, particle filter), map building (EKF) and simultaneous localization and mapping (EKF), and a Simulink model a of non-holonomic vehicle. The Toolbox also including a detailed Simulink model for a quadcopter flying robot.
Resumo:
Serving as a powerful tool for extracting localized variations in non-stationary signals, applications of wavelet transforms (WTs) in traffic engineering have been introduced; however, lacking in some important theoretical fundamentals. In particular, there is little guidance provided on selecting an appropriate WT across potential transport applications. This research described in this paper contributes uniquely to the literature by first describing a numerical experiment to demonstrate the shortcomings of commonly-used data processing techniques in traffic engineering (i.e., averaging, moving averaging, second-order difference, oblique cumulative curve, and short-time Fourier transform). It then mathematically describes WT’s ability to detect singularities in traffic data. Next, selecting a suitable WT for a particular research topic in traffic engineering is discussed in detail by objectively and quantitatively comparing candidate wavelets’ performances using a numerical experiment. Finally, based on several case studies using both loop detector data and vehicle trajectories, it is shown that selecting a suitable wavelet largely depends on the specific research topic, and that the Mexican hat wavelet generally gives a satisfactory performance in detecting singularities in traffic and vehicular data.
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The pervasive use of IT is prominent amongst organizations in developing economies. However, there is growing evidence that these economies fail to capitalize on their IT investment to transform their organizations to be competitive both locally and globally. IT-related benefits are possible with appropriate governance of the IT-related resources, and we need to broaden our understanding on the IT governance mechanics suitable for organizations in the developing economies. In this study, we adopted an initial interpretive design to obtain a deeper understanding of the IT governance (ITG) environment and conceptions of the stakeholders on effective IT governance structures for the developing economies. We found that the presence of an IT Strategic Planning Committee, Multiple level of authority, and a Forum for informal discussions as the crucial components of an ITG structure in developing economies.
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The aim of this study was to prepare and characterise composites of Soluble potato starch or hydroxypropylated maize starch with milled sugar cane fibre (i.e., bagasse). Prior to the preparation of the starch-fibre composites, the ‘cast’ and the ‘hot-pressed’ methods were investigated for the preparation of starch films in order to select the preferred preparation method. The physicochemical and mechanical properties of films conditioned at different relative humidities (RHs) were determined through moisture uptake, crystallinity, glass transition temperature (Tg), thermal properties, molecular structure and tensile tests. Hot-pressed starch films have ~5.5% less moisture, twice the crystallinity (~59%), higher Tg and Young’s modulus than cast starch films. The VH-type starch polymorph was observed to be present in the hot-pressed films. The addition of bagasse fibre to both starch types, prepared by hot-pressing, reduced the moisture uptake by up to 30% (cf., cast film) at 58% RH. The addition of 5 wt% fibre increased the tensile strength and Young’s modulus by 16% and 24% respectively. It significantly decreased the tensile strain by ~53%. Fourier Transform infrared (FT-IR) spectroscopy revealed differences in hydrogen bonding capacity between the films with fibre and those without fibre. The results have been explained on the basis of the intrinsic properties of starch and bagasse fibres.
Resumo:
This paper focuses on the turning point experiences that worked to transform the researcher during a preliminary consultation process to seek permission to conduct of a small pilot project on one Torres Strait Island. The project aimed to learn from parents how they support their children in their mathematics learning. Drawing on a community research design, a consultative meeting was held with one Torres Strait Islander community to discuss the possibility of piloting a small project that focused on working with parents and children to learn about early mathematics processes. Preliminary data indicated that parents use networks in their community. It highlighted the funds of knowledge of mathematics that exist in the community and which are used to teach their children. Such knowledges are situated within a community’s unique histories, culture and the voices of the people. “Omei” tree means the Tree of Wisdom in the Island community.
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In the field of process mining, the use of event logs for the purpose of root cause analysis is increasingly studied. In such an analysis, the availability of attributes/features that may explain the root cause of some phenomena is crucial. Currently, the process of obtaining these attributes from raw event logs is performed more or less on a case-by-case basis: there is still a lack of generalized systematic approach that captures this process. This paper proposes a systematic approach to enrich and transform event logs in order to obtain the required attributes for root cause analysis using classical data mining techniques, the classification techniques. This approach is formalized and its applicability has been validated using both self-generated and publicly-available logs.
Resumo:
Over the last decade, Ionic Liquids (ILs) have been used for the dissolution and derivatization of isolated cellulose. This ability of ILs is now sought for their application in the selective dissolution of cellulose from lignocellulosic biomass, for the manufacture of cellulosic ethanol. However, there are significant knowledge gaps in the understanding of the chemistry of the interaction of biomass and ILs. While imidazolium ILs have been used successfully to dissolve both isolated crystalline cellulose and components of lignocellulosic biomass, phosphonium ILs have not been sufficiently explored for the use in dissolution of lignocellulosic biomass. This thesis reports on the study of the chemistry of sugarcane bagasse with phosphonium ILs. Qualitative and quantitative measurements of biomass components dissolved in the phosphonium ionic liquids (ILs), trihexyltetradecylphosphonium chloride ([P66614]Cl) and tributylmethylphosphonium methylsulphate ([P4441]MeSO4) are obtained using attenuated total reflectance-Fourier Transform Infra Red (FTIR). Absorption bands related to cellulose, hemicelluloses and lignin dissolution monitored in situ in biomass-IL mixtures indicate lignin dissolution in both ILs and some holocellulose dissolution in the hydrophilic [P4441]MeSO4. The kinetics of lignin dissolution reported here indicate that while dissolution in the hydrophobic IL [P66614]Cl appears to follow an accepted mechanism of acid catalysed β-aryl ether cleavage, dissolution in the hydrophilic IL [P4441]MeSO4 does not appear to follow this mechanism and may not be followed by condensation reactions (initiated by reactive ketones). The quantitative measurement of lignin dissolution in phosphonium ILs based on absorbance at 1510 cm-1 has demonstrated utility and greater precision than the conventional Klason lignin method. The cleavage of lignin β-aryl ether bonds in sugarcane bagasse by the ionic liquid [P66614]Cl, in the presence of catalytic amounts of mineral acid. (ca. 0.4 %). The delignification process of bagasse is studied over a range of temperatures (120 °C to 150 °C) by monitoring the production of β-ketones (indicative of cleavage of β-aryl ethers) using FTIR spectroscopy and by compositional analysis of the undissolved fractions. Maximum delignification is obtained at 150 °C, with 52 % of lignin removed from the original lignin content of bagasse. No delignification is observed in the absence of acid which suggests that the reaction is acid catalysed with the IL solubilising the lignin fragments. The rate of delignification was significantly higher at 150 °C, suggesting that crossing the glass transition temperature of lignin effects greater freedom of rotation about the propanoid carbon-carbon bonds and leads to increased cleavage of β-aryl ethers. An attempt has been made to propose a probable mechanism of delignifcation of bagasse with the phosphonuim IL. All polymeric components of bagasse, a lignocellulosic biomass, dissolve in the hydrophilic ionic liquid (IL) tributylmethylphosphonium methylsulfate ([P4441]MeSO4) with and without a catalytic amount of acid (H2SO4, ca. 0.4 %). The presence of acid significantly increases the extent of dissolution of bagasse in [P4441]MeSO4 (by ca. 2.5 times under conditions used here). The dissolved fractions can be partially recovered by the addition of an antisolvent (water) and are significantly enriched in lignin. Unlike acid catalysed dissolution in the hydrophobic IL tetradecyltrihexylphosphonium chloride there is little evidence of cleavage of β-aryl ether bonds of lignin dissolving in [P4441]MeSO4 (with and without acid), but this mechanism may play some role in the acid catalysed dissolution. The XRD of the undissolved fractions suggests that the IL may selectively dissolve the amorphous cellulose component, leaving behind crystalline material.
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Successful firms use business model innovation to rethink the way they do business and transform industries. However, current research on business model innovation is lacking theoretical underpinnings and is in need of new insights. This objective of this paper is to advance our understanding of both the business model concept and business model innovation based on service logic as foundation for customer value and value creation. We present and discuss a rationale for business models based on ‘service logic’ with service as a value-supporting process and compared it with a business model based on ‘goods logic’ with goods as value-supporting resources. The implications for each of the business model dimensions: customer, value proposition, organizational architecture and revenue model, are described and discussed in detail.
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Blends of lignin and poly(hydroxybutyrate) (PHB) were obtained by melt extrusion. They were buried in a garden soil for up to 12 months, and the extent and mechanism of degradation were investigated by gravimetric analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and Fourier transform infra-red spectroscopy (FTIR) over the entire range of compositions. The PHB films were disintegrated and lost 45 wt% of mass within 12 months. This value dropped to 12 wt% of mass when only 10 wt% of lignin was present, suggesting that lignin both inhibited and slowed down the rate of PHB degradation. TGA and DSC indicated structural changes, within the lignin/PHB matrix, with burial time, while FTIR results confirmed the fragmentation of the PHB polymer. XPS revealed an accumulation of biofilms on the surface of buried samples, providing evidence of a biodegradation mechanism. Significant surface roughness was observed with PHB films due to microbial attack caused by both loosely and strongly associated micro-organisms. The presence of lignin in the blends may have inhibited the colonisation of the micro-organisms and caused the blends to be more resistant to microbial attack. Analysis suggested that lignin formed strong hydrogen bonds with PHB in the buried samples and it is likely that the rate of breakdown of PHB is reduced, preventing rapid degradation of the blends.
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Denaturation of tissues can provide a unique biological environment for regenerative medicine application only if minimal disruption of their microarchitecture is achieved during the decellularization process. The goal is to keep the structural integrity of such a construct as functional as the tissues from which they were derived. In this work, cartilage-on-bone laminates were decellularized through enzymatic, non-ionic and ionic protocols. This work investigated the effects of decellularization process on the microarchitecture of cartiligous extracellular matrix; determining the extent of how each process deteriorated the structural organization of the network. High resolution microscopy was used to capture cross-sectional images of samples prior to and after treatment. The variation of the microarchitecture was then analysed using a well defined fast Fourier image processing algorithm. Statistical analysis of the results revealed how significant the alternations among aforementioned protocols were (p < 0.05). Ranking the treatments by their effectiveness in disrupting the ECM integrity, they were ordered as: Trypsin> SDS> Triton X-100.
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The development of the Learning and Teaching Academic Standards Statement for Architecture (the Statement) centred on requirements for the Master of Architecture and proceeded alongside similar developments in the building and construction discipline under the guidance and support of the Australian Deans of Built Environment and Design (ADBED). Through their representation of Australian architecture programs, ADBED have provided high-level leadership for the Learning and Teaching Academic Standards Project in Architecture (LTAS Architecture). The threshold learning outcomes (TLOs), the description of the nature and extent of the discipline, and accompanying notes were developed through wide consultation with the discipline and profession nationally. They have been considered and debated by ADBED on a number of occasions and have, in their fi nal form, been strongly endorsed by the Deans. ADBED formed the core of the Architecture Reference Group (chaired by an ADBED member) that drew together representatives of every peak organisation for the profession and discipline in Australia. The views of the architectural education community and profession have been provided both through individual submissions and the voices of a number of peak bodies. Over two hundred individuals from the practising profession, the academic workforce and the student cohort have worked together to build consensus about the capabilities expected of a graduate of an Australian Master of Architecture degree. It was critical from the outset that the Statement should embrace the wisdom of the greater ‘tribe’, should ensure that graduates of the Australian Master of Architecture were eligible for professional registration and, at the same time, should allow for scope and diversity in the shape of Australian architectural education. A consultation strategy adopted by the Discipline Scholar involved meetings and workshops in Perth, Melbourne, Sydney, Canberra and Brisbane. Stakeholders from all jurisdictions and most universities participated in the early phases of consultation through a series of workshops that concluded late in October 2010. The Draft Architecture Standards Statement was formed from these early meetings and consultation in respect of that document continued through early 2011. This publication represents the outcomes of work to establish an agreed standards statement for the Master of Architecture. Significant further work remains to ensure the alignment of professional accreditation and recognition procedures with emerging regulatory frameworks cascading from the establishment of the Tertiary Education Quality and Standards Agency (TEQSA). The Australian architecture community hopes that mechanisms can be found to integrate TEQSA’s quality assurance purpose with well-established and understood systems of professional accreditation to ensure the good standing of Australian architectural education into the future. The work to build renewed and integrated quality assurance processes and to foster the interests of this project will continue, for at least the next eighteen months, under the auspices of Australian Learning and Teaching Council (ALTC)-funded Architecture Discipline Network (ADN), led by ADBED and Queensland University of Technology. The Discipline Scholar gratefully acknowledges the generous contributions given by those in stakeholder communities to the formulation of the Statement. Professional and academic colleagues have travelled and gathered to shape the Standards Statement. Debate has been vigorous and spirited and the Statement is rich with the purpose, critical thinking and good judgement of the Australian architectural education community. The commitments made to the processes that have produced this Statement reflect a deep and abiding interest by the constituency in architectural education. This commitment bodes well for the vibrancy and productivity of the emergent Architecture Discipline Network (ADN). Endorsement, in writing, was received from the Australian Institute of Architects National Education Committee (AIA NEC): The National Education Committee (NEC) of the Australian Institute of Architects thank you for your work thus far in developing the Learning and Teaching Academic Standards for Architecture In particular, we acknowledge your close consultation with the NEC on the project along with a comprehensive cross-section of the professional and academic communities in architecture. The TLOs with the nuanced levels of capacities – to identify, develop, explain, demonstrate etc – are described at an appropriate level to be understood as minimum expectations for a Master of Architecture graduate. The Architects Accreditation Council of Australia (AACA) has noted: There is a clear correlation between the current processes for accreditation and what may be the procedures in the future following the current review. The requirement of the outcomes as outlined in the draft paper to demonstrate capability is an appropriate way of expressing the measure of whether the learning outcomes have been achieved. The measure of capability as described in the outcome statements is enhanced with explanatory descriptions in the accompanying notes.
Resumo:
There has been a renaissance in Australian genre cinema in recent years. Indeed, not since the 1980s have Australian genre movies across action, adventure, horror, and science-fiction among others, experienced such prominence within production, policy discourse, and industry debate. Genre movies, typically associated with commercial filmmaking and entertainment, have been identified as a strategy to improve the box-office performance of Australian feature films and to attract larger audiences. Much of this conversation has revolved around the question of whether or not genre can deliver on these high expectations and transform the unpredictable local film industry into a popular and profitable commercial production sector. However, this debate for the most part has been disconnected from analysis of Australia’s genre movie heritage in terms of their position within Australian cinema and their reception with domestic audiences, and how this correlates to contemporary trends. As this chapter argues, genre production is not a silver bullet which will single handedly improve the Australian feature film industry’s commercial performance. Genre movies have occupied, and continue to occupy, a difficult position within Australian cinema and face numerous challenges in terms of reception with national audiences, limited production scale and enterprise structures, and ongoing tensions between culture and commerce.
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Successful organizational transformation typically requires transformed leadership; that is, fundamental changes in the implicit leadership schema that underpin observed organizational leadership practice. The purpose of this study is to elaborate leadership schema change theory by investigating a case study in which the CEO of a public infrastructure organization sought to transform traditional organizational leadership to facilitate wider organization transformation. Data were generated through focus groups and semi-structured interviews at four points over a three-year period. Our findings suggest that (a) change leader initiatives do not necessarily activate the cognitive processing required to achieve leadership schema change, (b) collective schema change, defined in terms of the system of beliefs and values underlying the new leading-managing schema did not occur, however, (c) sub-schema change did occur. The research contributes to existing literature on implicit leadership schema change in three main ways. First, we provide a schema change framework to guide current and future research on schema change. Second, we highlight the role that both change leader initiatives and individual and social processing play in schema change. Finally, we stress the role of teleological processes in leadership schema change.
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The complex design process of airport terminal needs to support a wide range of changes in operational facilities for both usual and unusual/emergency events. Process model describes how activities within a process are connected and also states logical information flow of the various activities. The traditional design process overlooks the necessity of information flow from the process model to the actual building design, which needs to be considered as a integral part of building design. The current research introduced a generic method to obtain design related information from process model to incorporate with the design process. Appropriate integration of the process model prior to the design process uncovers the relationship exist between spaces and their relevant functions, which could be missed in the traditional design approach. The current paper examines the available Business Process Model (BPM) and generates modified Business Process Model(mBPM) of check-in facilities of Brisbane International airport. The information adopted from mBPM then transform into possible physical layout utilizing graph theory.
Resumo:
Structural health monitoring (SHM) refers to the procedure used to assess the condition of structures so that their performance can be monitored and any damage can be detected early. Early detection of damage and appropriate retrofitting will aid in preventing failure of the structure and save money spent on maintenance or replacement and ensure the structure operates safely and efficiently during its whole intended life. Though visual inspection and other techniques such as vibration based ones are available for SHM of structures such as bridges, the use of acoustic emission (AE) technique is an attractive option and is increasing in use. AE waves are high frequency stress waves generated by rapid release of energy from localised sources within a material, such as crack initiation and growth. AE technique involves recording these waves by means of sensors attached on the surface and then analysing the signals to extract information about the nature of the source. High sensitivity to crack growth, ability to locate source, passive nature (no need to supply energy from outside, but energy from damage source itself is utilised) and possibility to perform real time monitoring (detecting crack as it occurs or grows) are some of the attractive features of AE technique. In spite of these advantages, challenges still exist in using AE technique for monitoring applications, especially in the area of analysis of recorded AE data, as large volumes of data are usually generated during monitoring. The need for effective data analysis can be linked with three main aims of monitoring: (a) accurately locating the source of damage; (b) identifying and discriminating signals from different sources of acoustic emission and (c) quantifying the level of damage of AE source for severity assessment. In AE technique, the location of the emission source is usually calculated using the times of arrival and velocities of the AE signals recorded by a number of sensors. But complications arise as AE waves can travel in a structure in a number of different modes that have different velocities and frequencies. Hence, to accurately locate a source it is necessary to identify the modes recorded by the sensors. This study has proposed and tested the use of time-frequency analysis tools such as short time Fourier transform to identify the modes and the use of the velocities of these modes to achieve very accurate results. Further, this study has explored the possibility of reducing the number of sensors needed for data capture by using the velocities of modes captured by a single sensor for source localization. A major problem in practical use of AE technique is the presence of sources of AE other than crack related, such as rubbing and impacts between different components of a structure. These spurious AE signals often mask the signals from the crack activity; hence discrimination of signals to identify the sources is very important. This work developed a model that uses different signal processing tools such as cross-correlation, magnitude squared coherence and energy distribution in different frequency bands as well as modal analysis (comparing amplitudes of identified modes) for accurately differentiating signals from different simulated AE sources. Quantification tools to assess the severity of the damage sources are highly desirable in practical applications. Though different damage quantification methods have been proposed in AE technique, not all have achieved universal approval or have been approved as suitable for all situations. The b-value analysis, which involves the study of distribution of amplitudes of AE signals, and its modified form (known as improved b-value analysis), was investigated for suitability for damage quantification purposes in ductile materials such as steel. This was found to give encouraging results for analysis of data from laboratory, thereby extending the possibility of its use for real life structures. By addressing these primary issues, it is believed that this thesis has helped improve the effectiveness of AE technique for structural health monitoring of civil infrastructures such as bridges.