486 resultados para slifetime-based garbage collection


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The PISA assessment instruments for students’ scientific literacy in 2000, 2003 and 2006 have each consisted of units made up of a real world context involving Science and Technology, about which students are asked a number of cognitive and affective questions. This paper discusses a number of issues from this use of S&T contexts in PISA and the implications they have for the current renewed interest in context-based science education. Suitably chosen contexts can engage both boys and girls. Secondary analyses of the students’ responses using the contextual sets of items as the unit of analysis provides new information about the levels of performance in PISA 2006 Science. .Embedding affective items in the achievement test did not lead to gender/context interactions of significance, and context interactions were less than competency ones. A number of implications for context-based science teaching and learning are outlined and the PISA 2006 Science test is suggested as a model for its assessment.

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In this paper we discuss our current efforts to develop and implement an exploratory, discovery mode assessment item into the total learning and assessment profile for a target group of about 100 second level engineering mathematics students. The assessment item under development is composed of 2 parts, namely, a set of "pre-lab" homework problems (which focus on relevant prior mathematical knowledge, concepts and skills), and complementary computing laboratory exercises which are undertaken within a fixed (1 hour) time frame. In particular, the computing exercises exploit the algebraic manipulation and visualisation capabilities of the symbolic algebra package MAPLE, with the aim of promoting understanding of certain mathematical concepts and skills via visual and intuitive reasoning, rather than a formal or rigorous approach. The assessment task we are developing is aimed at providing students with a significant learning experience, in addition to providing feedback on their individual knowledge and skills. To this end, a noteworthy feature of the scheme is that marks awarded for the laboratory work are primarily based on the extent to which reflective, critical thinking is demonstrated, rather than the amount of CBE-style tasks completed by the student within the allowed time. With regard to student learning outcomes, a novel and potentially critical feature of our scheme is that the assessment task is designed to be intimately linked to the overall course content, in that it aims to introduce important concepts and skills (via individual student exploration) which will be revisited somewhat later in the pedagogically more restrictive formal lecture component of the course (typically a large group plenary format). Furthermore, the time delay involved, or "incubation period", is also a deliberate design feature: it is intended to allow students the opportunity to undergo potentially important internal re-adjustments in their understanding, before being exposed to lectures on related course content which are invariably delivered in a more condensed, formal and mathematically rigorous manner. In our presentation, we will discuss in more detail our motivation and rationale for trailing such a scheme for the targeted student group. Some of the advantages and disadvantages of our approach (as we perceived them at the initial stages) will also be enumerated. In a companion paper, the theoretical framework for our approach will be more fully elaborated, and measures of student learning outcomes (as obtained from eg. student provided feedback) will be discussed.

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This paper proposes a new prognosis model based on the technique for health state estimation of machines for accurate assessment of the remnant life. For the evaluation of health stages of machines, the Support Vector Machine (SVM) classifier was employed to obtain the probability of each health state. Two case studies involving bearing failures were used to validate the proposed model. Simulated bearing failure data and experimental data from an accelerated bearing test rig were used to train and test the model. The result obtained is very encouraging and shows that the proposed prognostic model produces promising results and has the potential to be used as an estimation tool for machine remnant life prediction.

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A bioactive and bioresorbable scaffold fabricated from medical grade poly (epsilon-caprolactone) and incorporating 20% beta-tricalcium phosphate (mPCL–TCP) was recently developed for bone regeneration at load bearing sites. In the present study, we aimed to evaluate bone ingrowth into mPCL–TCP in a large animal model of lumbar interbody fusion. Six pigs underwent a 2-level (L3/4; L5/6) anterior lumbar interbody fusion (ALIF) implanted with mPCL–TCP þ 0.6 mg rhBMP-2 as treatment group while four other pigs implanted with autogenous bone graft served as control. Computed tomographic scanning and histology revealed complete defect bridging in all (100%) specimen from the treatment group as early as 3 months. Histological evidence of continuing bone remodeling and maturation was observed at 6 months. In the control group, only partial bridging was observed at 3 months and only 50% of segments in this group showed complete defect bridging at 6 months. Furthermore, 25% of segments in the control group showed evidence of graft fracture, resorption and pseudoarthrosis. In contrast, no evidence of graft fractures, pseudoarthrosis or foreign body reaction was observed in the treatment group. These results reveal that mPCL–TCP scaffolds could act as bone graft substitutes by providing a suitable environment for bone regeneration in a dynamic load bearing setting such as in a porcine model of interbody spine fusion.

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Building Information Modelling (BIM) is an information technology [IT] enabled approach to managing design data in the AEC/FM (Architecture, Engineering and Construction/ Facilities Management) industry. BIM enables improved interdisciplinary collaboration across distributed teams, intelligent documentation and information retrieval, greater consistency in building data, better conflict detection and enhanced facilities management. Despite the apparent benefits the adoption of BIM in practice has been slow. Workshops with industry focus groups were conducted to identify the industry needs, concerns and expectations from participants who had implemented BIM or were BIM “ready”. Factors inhibiting BIM adoption include lack of training, low business incentives, perception of lack of rewards, technological concerns, industry fragmentation related to uneven ICT adoption practices, contractual matters and resistance to changing current work practice. Successful BIM usage depends on collective adoption of BIM across the different disciplines and support by the client. The relationship of current work practices to future BIM scenarios was identified as an important strategy as the participants believed that BIM cannot be efficiently used with traditional practices and methods. The key to successful implementation is to explore the extent to which current work practices must change. Currently there is a perception that all work practices and processes must adopt and change for effective usage of BIM. It is acknowledged that new roles and responsibilities are emerging and that different parties will lead BIM on different projects. A contingency based approach to the problem of implementation was taken which relies upon integration of BIM project champion, procurement strategy, team capability analysis, commercial software availability/applicability and phase decision making and event analysis. Organizations need to understand: (a) their own work processes and requirements; (b) the range of BIM applications available in the market and their capabilities (c) the potential benefits of different BIM applications and their roles in different phases of the project lifecycle, and (d) collective supply chain adoption capabilities. A framework is proposed to support organizations selection of BIM usage strategies that meet their project requirements. Case studies are being conducted to develop the framework. The results of the preliminary design management case study is presented for contractor led BIM specific to the design and construct procurement strategy.

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The Resource Based View (RBV) of strategic management has been criticized for relying on inconsistent assumptions of rationality, and mutually inconsistent underlying hypotheses. In this paper, I outline how these critiques can be addressed by re-building RBV on a sense-making foundation. The core notions from sense-making of bounded cognition, retrospective sense-making, incrementalism, loose coupling, causal maps and organizational paradigm are introduced. These are then used to propose a re-construction of key RBV constructs, extending some conceptual discussions, and providing for a conceptually consistent formulation. Implications for the use of RBV as a theory and future research are discussed.

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The aim of this paper is to provide a contemporary summary of statistical and non-statistical meta-analytic procedures that have relevance to the type of experimental designs often used by sport scientists when examining differences/change in dependent measure(s) as a result of one or more independent manipulation(s). Using worked examples from studies on observational learning in the motor behaviour literature, we adopt a random effects model and give a detailed explanation of the statistical procedures for the three types of raw score difference-based analyses applicable to between-participant, within-participant, and mixed-participant designs. Major merits and concerns associated with these quantitative procedures are identified and agreed methods are reported for minimizing biased outcomes, such as those for dealing with multiple dependent measures from single studies, design variation across studies, different metrics (i.e. raw scores and difference scores), and variations in sample size. To complement the worked examples, we summarize the general considerations required when conducting and reporting a meta-analysis, including how to deal with publication bias, what information to present regarding the primary studies, and approaches for dealing with outliers. By bringing together these statistical and non-statistical meta-analytic procedures, we provide the tools required to clarify understanding of key concepts and principles.

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Synthetic polymers have attracted much attention in tissue engineering due to their ability to modulate biomechanical properties. This study investigated the feasibility of processing poly(varepsilon-caprolactone) (PCL) homopolymer, PCL-poly(ethylene glycol) (PEG) diblock, and PCL-PEG-PCL triblock copolymers into three-dimensional porous scaffolds. Properties of the various polymers were investigated by dynamic thermal analysis. The scaffolds were manufactured using the desktop robot-based rapid prototyping technique. Gross morphology and internal three-dimensional structure of scaffolds were identified by scanning electron microscopy and micro-computed tomography, which showed excellent fusion at the filament junctions, high uniformity, and complete interconnectivity of pore networks. The influences of process parameters on scaffolds' morphological and mechanical characteristics were studied. Data confirmed that the process parameters directly influenced the pore size, porosity, and, consequently, the mechanical properties of the scaffolds. The in vitro cell culture study was performed to investigate the influence of polymer nature and scaffold architecture on the adhesion of the cells onto the scaffolds using rabbit smooth muscle cells. Light, scanning electron, and confocal laser microscopy showed cell adhesion, proliferation, and extracellular matrix formation on the surface as well as inside the structure of both scaffold groups. The completely interconnected and highly regular honeycomb-like pore morphology supported bridging of the pores via cell-to-cell contact as well as production of extracellular matrix at later time points. The results indicated that the incorporation of hydrophilic PEG into hydrophobic PCL enhanced the overall hydrophilicity and cell culture performance of PCL-PEG copolymer. However, the scaffold architecture did not significantly influence the cell culture performance in this study.

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The Safety Effectiveness Indicators (SEI) Project has used extensive research to determine what safety effectiveness measures can be developed by industry, for industry use to improve its safety performance. These indicators can measure how effectively the 13 safety management tasks1 (SMTs) selected for this workbook are undertaken. Currently, positive performance indicators (PPIs) are only able to measure the number of activities undertaken. They do not provide information on whether each activity is being undertaken effectively, and therefore do not provide data which can be used by industry to target areas of focus and improvement. The initial workbook contained six SMTs, and was piloted on various construction sites during August 2008. The workbook was refined through feedback from the pilot, and 13 SMTs were used in a field trial during the months of October, November and December 2008. The project team also carried out 12 focus groups in Brisbane, Canberra, Sydney and Melbourne during April, May and June 2008, and developed an initial format of this workbook through these groups and team workshops. Simplification of the language was a recurring theme, and we have attempted to do this throughout the project. The challenge has been to ensure we keep the descriptions short, to the point and relevant to all companies, without making them too specific. The majority of the construction industry participants also requested an alteration to the scale used, so a ‘Yes’/‘No’/’Not applicable’ format is used in this workbook. This workbook, based on industry feedback, is for use on site by various construction companies and contains 13 SMTs. However, you are invited to personalise the SEI tools to better suit your individual company and workplaces.

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Cohen (1977) reviewed the then current research on occupational safety and stated that both strong company commitment to safety, and communication between all levels of a company are the most influential factors to improving safety. Other relevant factors included careful selection of staff, and early and continuous training throughout the lifetime with the company. These continue to be important factors in OHS today. There has been a continued decrease in the injury rates since Cohen’s review within the Australian construction industry, however, the construction industry has far more injuries and ill-health than the Australian average, with one fatality occurring on average per week in the Australian Construction Industry. The Fatality rate in the building and construction industry remains three times higher than the national average, and 15% of all industry fatalities are in the building and construction industry. In addition the construction industry pays one of the highest workers’ compensation premium rates – in 2001 alone approximately 0.5% ($267 million) of revenue would have to be allocated to the direct cost of 1998/99 compensations (Office of the Federal Safety Commissioner, 2006). Based on these statistics there is a need to measure and improve safety performance within the construction industry.

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Effective knowledge transfer can prevent the reinvention of systems and ideas as well as the repetition of errors. Doing so will save substantial time, as well as contribute to better performance of projects and project-based organisations (PBOs). Despite the importance of knowledge, PBOs face serious barriers to the effective transfer of knowledge, while their characteristics, such as unique and innovative approaches taken during every project, mean they have much to gain from knowledge transfer. As each new project starts, there is the strong potential to reinvent the process, rather than utilise learning from previous projects. In fact, rework is one of the primary factors contributing to construction industry's poor performance and productivity. Current literature has identified several barriers to knowledge transfer in organisational settings in general, and not specifically PBOs. However, PBOs significantly differ from other types of organisations. PBOs operate mainly on temporary projects, where time is a crucial factor and people are more mobile than in other organisational settings. The aim of this research is to identify the key barriers that prevent effective knowledge transfer for PBOs, exclusively. Interviews with project managers and senior managers of PBOs complement the analysis of the literature and provide professional expertise. This research is crucial to gaining a better understanding of obstacles that hinder knowledge transfer in projects. The main contribution of this research is exclusive for PBO, list of key barriers that organisation and project managers need to consider to ensure effective knowledge transfer and better project management.

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Evidence-based Practice (EBP) has recently emerged as a topic of discussion amongst professionals within the library and information services (LIS) industry. Simply stated, EBP is the process of using formal research skills and methods to assist in decision making and establishing best practice. The emerging interest in EBP within the library context serves to remind the library profession that research skills and methods can help ensure that the library industry remains current and relevant in changing times. The LIS sector faces ongoing challenges in terms of the expectation that financial and human resources will be managed efficiently, particularly if library budgets are reduced and accountability to the principal stakeholders is increased. Library managers are charged with the responsibility to deliver relevant and cost effective services, in an environment characterised by rapidly changing models of information provision, information access and user behaviours. Consequently they are called upon not only to justify the services they provide, or plan to introduce, but also to measure the effectiveness of these services and to evaluate the impact on the communities they serve. The imperative for innovation in and enhancements to library practice is accompanied by the need for a strong understanding of the processes of review, measurement, assessment and evaluation. In 2001 the Centre for Information Research was commissioned by the Chartered Institute of Library and Information Professionals (CILIP) in the UK to conduct an examination into the research landscape for library and information science. The examination concluded that research is “important for the LIS [library and information science] domain in a number of ways” (McNicol & Nankivell, 2001, p.77). At the professional level, research can inform practice, assist in the future planning of the profession, raise the profile of the discipline, and indeed the reputation and standing of the library and information service itself. At the personal level, research can “broaden horizons and offer individuals development opportunities” (McNicol & Nankivell, 2001, p.77). The study recommended that “research should be promoted as a valuable professional activity for practitioners to engage in” (McNicol & Nankivell, 2001, p.82). This chapter will consider the role of EBP within the library profession. A brief review of key literature in the area is provided. The review considers issues of definition and terminology, highlights the importance of research in professional practice and outlines the research approaches that underpin EBP. The chapter concludes with a consideration of the specific application of EBP within the dynamic and evolving field of information literacy (IL).

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Evidence based practice (EBP) is recognised as a way of improving the quality of professional practice in many disciplines however its adoption within library and information sciences (LIS) has been gradual. The term was first introduced into the library and information profession‟s vocabulary a decade ago but an impediment to its uptake is the lack of clear understanding regarding how LIS practitioners understand the concept. Partridge, Thorpe, Edwards and Hallam (2007) identified the need to understand how LIS professionals experience or understand evidence based practice and proposed a model of four categories of experience to describe how LIS professionals experience EBP. This paper extends that framework by refining the different conceptions of evidence based practice and identifying relationships which exist between the categories of experience to provide a rich description of the EBP phenomenon. The paper also argues that the phrase “evidence based librarianship” and its variations be abandoned as practitioners do not see a distinction between EBP as applied to librarianship and information practice and industry specific jargon like “evidence based library and information practice”. This research will help current and future LIS practitioners, leaders and educators engage more actively in the establishment of an evidence based culture to improve library and information practice in Australia and internationally.

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The enhanced accessibility, affordability and capability of the Internet has created enormous possibilities in terms of designing, developing and implementing innovative teaching methods in the classroom. As existing pedagogies are revamped and new ones are added, there is a need to assess the effectiveness of these approaches from the students’ perspective. For more than three decades, proven qualitative and quantitative research methods associated with learning environments research have yielded productive results for educators. This article presents the findings of a study in which Getsmart, a teacher-designed website, was blended into science and physics lessons at an Australian high school. Students’ perceptions of this environment were investigated, together with differences in the perceptions of students in junior and senior years of schooling. The article also explores the impact of teachers in such an environment. The investigation undertaken in this study also gave an indication of how effective Getsmart was as a teaching model in such environments.

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A surface plasmon resonance-based solution affinity assay is described for measuring the Kd of binding of heparin/heparan sulfate-binding proteins with a variety of ligands. The assay involves the passage of a pre-equilibrated solution of protein and ligand over a sensor chip onto which heparin has been immobilised. Heparin sensor chips prepared by four different methods, including biotin–streptavidin affinity capture and direct covalent attachment to the chip surface, were successfully used in the assay and gave similar Kd values. The assay is applicable to a wide variety of heparin/HS-binding proteins of diverse structure and function (e.g., FGF-1, FGF-2, VEGF, IL-8, MCP-2, ATIII, PF4) and to ligands of varying molecular weight and degree of sulfation (e.g., heparin, PI-88, sucrose octasulfate, naphthalene trisulfonate) and is thus well suited for the rapid screening of ligands in drug discovery applications.