578 resultados para learning effect
Resumo:
Most information retrieval (IR) models treat the presence of a term within a document as an indication that the document is somehow "about" that term, they do not take into account when a term might be explicitly negated. Medical data, by its nature, contains a high frequency of negated terms - e.g. "review of systems showed no chest pain or shortness of breath". This papers presents a study of the effects of negation on information retrieval. We present a number of experiments to determine whether negation has a significant negative affect on IR performance and whether language models that take negation into account might improve performance. We use a collection of real medical records as our test corpus. Our findings are that negation has some affect on system performance, but this will likely be confined to domains such as medical data where negation is prevalent.
Resumo:
The rapid growth of mobile telephone use, satellite services, and now the wireless Internet and WLANs are generating tremendous changes in telecommunication and networking. As indoor wireless communications become more prevalent, modeling indoor radio wave propagation in populated environments is a topic of significant interest. Wireless MIMO communication exploits phenomena such as multipath propagation to increase data throughput and range, or reduce bit error rates, rather than attempting to eliminate effects of multipath propagation as traditional SISO communication systems seek to do. The MIMO approach can yield significant gains for both link and network capacities, with no additional transmitting power or bandwidth consumption when compared to conventional single-array diversity methods. When MIMO and OFDM systems are combined and deployed in a suitable rich scattering environment such as indoors, a significant capacity gain can be observed due to the assurance of multipath propagation. Channel variations can occur as a result of movement of personnel, industrial machinery, vehicles and other equipment moving within the indoor environment. The time-varying effects on the propagation channel in populated indoor environments depend on the different pedestrian traffic conditions and the particular type of environment considered. A systematic measurement campaign to study pedestrian movement effects in indoor MIMO-OFDM channels has not yet been fully undertaken. Measuring channel variations caused by the relative positioning of pedestrians is essential in the study of indoor MIMO-OFDM broadband wireless networks. Theoretically, due to high multipath scattering, an increase in MIMO-OFDM channel capacity is expected when pedestrians are present. However, measurements indicate that some reductions in channel capacity could be observed as the number of pedestrians approaches 10 due to a reduction in multipath conditions as more human bodies absorb the wireless signals. This dissertation presents a systematic characterization of the effects of pedestrians in indoor MIMO-OFDM channels. Measurement results, using the MIMO-OFDM channel sounder developed at the CSIRO ICT Centre, have been validated by a customized Geometric Optics-based ray tracing simulation. Based on measured and simulated MIMO-OFDM channel capacity and MIMO-OFDM capacity dynamic range, an improved deterministic model for MIMO-OFDM channels in indoor populated environments is presented. The model can be used for the design and analysis of future WLAN to be deployed in indoor environments. The results obtained show that, in both Fixed SNR and Fixed Tx for deterministic condition, the channel capacity dynamic range rose with the number of pedestrians as well as with the number of antenna combinations. In random scenarios with 10 pedestrians, an increment in channel capacity of up to 0.89 bits/sec/Hz in Fixed SNR and up to 1.52 bits/sec/Hz in Fixed Tx has been recorded compared to the one pedestrian scenario. In addition, from the results a maximum increase in average channel capacity of 49% has been measured while 4 antenna elements are used, compared with 2 antenna elements. The highest measured average capacity, 11.75 bits/sec/Hz, corresponds to the 4x4 array with 10 pedestrians moving randomly. Moreover, Additionally, the spread between the highest and lowest value of the the dynamic range is larger for Fixed Tx, predicted 5.5 bits/sec/Hz and measured 1.5 bits/sec/Hz, in comparison with Fixed SNR criteria, predicted 1.5 bits/sec/Hz and measured 0.7 bits/sec/Hz. This has been confirmed by both measurements and simulations ranging from 1 to 5, 7 and 10 pedestrians.
Resumo:
In professions such as teaching, health sciences (medicine, nursing, allied health), and built environment (engineering), significant work-based learning through practica is an essential element before graduation. However, there is no such requirement in Accountancy. This thesis reports the findings of a qualitative case study of the development and implementation of a Workplace Learning Experience Program in Accountancy at the Queensland University of Technology (QUT) in Australia. The case study of this intervention, based on sociocultural learning theory, provides the grounds for the development of a new model of teaching and learning for accounting education. The survey and interview-based study documents the responses of two cohorts of university students and a group of employers to a work placement program. The study demonstrates that a 100 hour work placement in Accountancy has elements that enhance student learning. It demonstrates the potential value of the application of sociocultural theories of learning, especially the concept of situated learning involving legitimate peripheral participation (Lave & Wenger, 1991). This research establishes the theoretical base for a paradigm shift for the Accountancy profession to acknowledge work placements prior to graduation as a major element of learning. It is argued that the current model of accounting education requires reform to better align university and workplace learning.
Resumo:
Along with their essential role in electricity transmission and distribution, some powerlines also generate large concentrations of corona ions. This study aimed at comprehensive investigation of corona ions, vertical dc e-field, ambient aerosol particle charge and particle number concentration levels in the proximity of some high/sub-transmission voltage powerlines. The influence of meteorology on the instantaneous value of these parameters, and the possible existence of links or associations between the parameters measured were also statistically investigated. The presence of positive and negative polarities of corona ions was associated with variation in the mean vertical dc e-field, ambient ion and particle charge concentration level. Though these variations increased with wind speed, their values also decreased with distance from the powerlines. Predominately positive polarities of ions were recorded up to a distance of 150 m (with the maximum values recorded 50 m downwind of the powerlines). At 200 m from the source, negative ions predominated. Particle number concentration levels however remained relatively constant (103 particle cm-3) irrespective of the sampling site and distance from the powerlines. Meteorological factors of temperature, humidity and wind direction showed no influence on the electrical parameters measured. The study also discovered that e-field measurements were not necessarily a true representation of the ground-level ambient ion/particle charge concentrations.
Resumo:
We alternately measured on-road and in-vehicle ultrafine (<100 nm) particle (UFP) concentration for 5 passenger vehicles that comprised an age range of 18 years. A range of cabin ventilation settings were assessed during 301 trips through a 4 km road tunnel in Sydney, Australia. Outdoor airflow(ventilation) rates under these settings were quantified on open roads using tracer gas techniques. Significant variability in tunnel trip average median in-cabin/on-road (I/O) UFP ratios was observed (0.08 to ∼1.0). Based on data spanning all test automobiles and ventilation settings, a positive linear relationship was found between outdoor air flow rate and I/O ratio, with the former accounting for a substantial proportion of variation in the latter (R2 ) 0.81). UFP concentrations recorded in cabin during tunnel travel were significantly higher than those reported by comparable studies performed on open roadways. A simple mathematical model afforded the ability to predict tunnel trip average in-cabin UFP concentrations with good accuracy. Our data indicate that under certain conditions, in-cabin UFP exposures incurred during tunnel travel may contribute significantly to daily exposure. The UFP exposure of automobile occupants appears strongly related to their choice of ventilation setting and vehicle.
Resumo:
Current guidelines on clear zone selection and roadside hazard management adopt the US approach based on the likelihood of roadside encroachment by drivers. This approach is based on the available research conducted in the 1960s and 70s. Over time, questions have been raised regarding the robustness and applicability of this research in Australasia in 2010 and in the Safe System context. This paper presents a review of the fundamental research relating to selection of clear zones. Results of extensive rural highway statistical data modelling suggest that a significant proportion of run-off-road to the left casualty crashes occurs in clear zones exceeding 13 m. They also show that the risk of run-off-road to the left casualty crashes was 21% lower where clear zones exceeded 8 m when compared with clear zones in the 4 – 8 m range. The paper discusses a possible approach to selection of clear zones based on managing crash outcomes, rather than on the likelihood of roadside encroachment which is the basis for the current practice. It is expected that this approach would encourage selection of clear zones wider than 8 m when the combination of other road features suggests higher than average casualty crash risk.
Resumo:
In this paper we discuss an advanced, 3D groundwater visualisation and animation system that allows scientists, government agencies and community groups to better understand the groundwater processes that effect community planning and decision-making. The system is unique in that it has been designed to optimise community engagement. Although it incorporates a powerful visualisation engine, this open-source system can be freely distributed and boasts a simple user interface allowing individuals to run and investigate the models on their own PCs and gain intimate knowledge of the groundwater systems. The initial version of the Groundwater Visualisation System (GVS v1.0), was developed from a coastal delta setting (Bundaberg, QLD), and then applied to a basalt catchment area (Obi Obi Creek, Maleny, QLD). Several major enhancements have been developed to produce higher quality visualisations, including display of more types of data, support for larger models and improved user interaction. The graphics and animation capabilities have also been enhanced, notably the display of boreholes, depth logs and time-series water level surfaces. The GVS software remains under continual development and improvement
Informed learning: a pedagogical construct attending simultaneously to information use and learning.
Resumo:
The idea of informed learning, applicable in academic, workplace and community settings, has been derived largely from a program of phenomenographic research in the field of information literacy, which has illuminated the experience of using information to learn. Informed learning is about simultaneous attention to information use and learning, where both information and learning are considered to be relational; and is built upon a series of key concepts such as second–order perspective, simultaneity, awareness, and relationality. Informed learning also relies heavily on reflection as a strategy for bringing about learning. As a pedagogical construct, informed learning supports inclusive curriculum design and implementation. This paper reports aspects of the informed learning research agenda which are currently being pursued at the Queensland University of Technology (QUT). The first part elaborates the idea of informed learning, examines the key concepts underpinning this pedagogical construct, and explains its emergence from the research base of the QUT Information Studies research team. The second presents a case, which demonstrates the ongoing development of informed learning theory and practice, through the development of inclusive informed learning for a culturally diverse higher education context.
Resumo:
The power to influence others in ever-expanding social networks in the new knowledge economy is tied to capabilities with digital media production that require increased technological knowledge. This article draws on research in elementary classrooms to examine the repertoires of cross-disciplinary knowledge that literacy learners need to produce innovative digital media via the “social web”. The article builds on Learning by Design and the Knowledge Processes to describe “how” learning occurs, while presenting a model to theorise “what” students know – the Knowledge Assets – when learners produce digital and multimodal texts.
Resumo:
There is a need for educational frameworks for computer ethics education. This discussion paper presents an approach to developing students’ moral sensitivity, an awareness of morally relevant issues, in project-based learning (PjBL). The proposed approach is based on a study of IT professionals’ levels of awareness of ethics. These levels are labelled My world, The corporate world, A shared world, The client’s world and The wider world. We give recommendations for how instructors may stimulate students’ thinking with the levels and how the levels may be taken into account in managing a project course and in an IS department. Limitations of the recommendations are assessed and issues for discussion are raised.
Resumo:
Increasingly, celebrities appear not only as endorsers for products but are apparently engaged in entrepreneurial roles as initiators, owners and perhaps even managers in the ventures that market the products they promote. Despite being extensively referred to in popular media, scholars have been slow to recognise the importance of this new phenomenon. This thesis argues theoretically and shows empirically that celebrity entrepreneurs are more effective communicators than typical celebrity endorsers because of their increased engagement with ventures. I theorise that greater engagement increases the celebrity‘s emotional involvement as perceived by consumers. This is an endorser quality thus far neglected in the marketing communications literature. In turn, emotional involvement, much like the empirically established dimensions trustworthiness, expertise and attractiveness, should affect traditional outcome variables such as attitude towards the advertisement and brand. On the downside, increases in celebrity engagement may lead to relatively stronger and worsening changes in attitudes towards the brand if and when negative information about the celebrity is revealed. A series of eight experiments was conducted on 781 Swedish and Baltic students and 151 Swedish retirees. Though there were nuanced differences and additional complexities in each experiment, participants‘ reactions to advertisements containing a celebrity portrayed as a typical endorser or entrepreneur were recorded. The overall results of these experiments suggest that emotional involvement can be successfully operationalised as distinct from variables previously known to influence communication effectiveness. In addition, emotional involvement has positive effects on attitudes toward the advertisement and brand that are as strong as the predictors traditionally applied in the marketing communications literature. Moreover, the celebrity entrepreneur condition in the experimental manipulation consistently led to an increase in emotional involvement and to a lesser extent trustworthiness, but not expertise and attractiveness. Finally, negative celebrity information led to a change in participants‘ attitudes towards the brand which were more strongly negative for celebrity entrepreneurs than celebrity endorsers. In addition, the effect of negative celebrity information on a company‘s brand is worse when they support the celebrity rather than fire them. However, this effect did not appear to interact with the celebrity‘s purported engagement.
Resumo:
Multidisciplinary learning, interdisciplinary learning and transdisciplinary learning are often used with a similar meaning, but the misunderstanding of these terms may cause a failure of defining learner needs and developing high quality learning design. In this article, the three terms are reviewed in line with learner engagement and are conceptualised according to different types and levels of interactivity. An undergraduate course, named Creative Industries: Making Connections, was designed to deliver various learning modules to over 1200 students from 11 different disciplines in a blended learning mode. A visual communication learning module in the course, in particular, challenges students as well as academic staff to experience transdisciplinary learning. A survey was conducted to evaluate students' learning experience in the visual communication learning module. The results of the survey bring up meaningful implications for the realisation of transdisciplinary learning.
Resumo:
Background: Many studies have illustrated that ambient air pollution negatively impacts on health. However, little evidence is available for the effects of air pollution on cardiovascular mortality (CVM) in Tianjin, China. Also, no study has examined which strata length for the time-stratified case–crossover analysis gives estimates that most closely match the estimates from time series analysis. Objectives: The purpose of this study was to estimate the effects of air pollutants on CVM in Tianjin, China, and compare time-stratified case–crossover and time series analyses. Method: A time-stratified case–crossover and generalized additive model (time series) were applied to examine the impact of air pollution on CVM from 2005 to 2007. Four time-stratified case–crossover analyses were used by varying the stratum length (Calendar month, 28, 21 or 14 days). Jackknifing was used to compare the methods. Residual analysis was used to check whether the models fitted well. Results: Both case–crossover and time series analyses show that air pollutants (PM10, SO2 and NO2) were positively associated with CVM. The estimates from the time-stratified case–crossover varied greatly with changing strata length. The estimates from the time series analyses varied slightly with changing degrees of freedom per year for time. The residuals from the time series analyses had less autocorrelation than those from the case–crossover analyses indicating a better fit. Conclusion: Air pollution was associated with an increased risk of CVM in Tianjin, China. Time series analyses performed better than the time-stratified case–crossover analyses in terms of residual checking.
Resumo:
The role of particular third sector organisations, Social Clubs, in supporting gambling through the use of EGMs in venues presents as a difficult social issue. Social Clubs gain revenue from gambling activities; but also contribute to social well-being through the provision of services to communities. The revenues derived from gambling in specific geographic locales has been seen by government as a way to increase economic development particularly in deprived areas. However there are also concerns about accessibility of low-income citizens to Electronic Gaming Machines (EGMS) and the high level of gambling overall in these deprived areas. We argue that social capital can be viewed as a guard against deleterious effects of unconstrained use of EGM gambling in communities. However, it is contended that social capital may also be destroyed by gambling activity if commercial business actors are able to use EGMs without community obligations to service provision. This paper examines access to gambling through EGMs and its relationship to social capital and the consequent effect on community resilience, via an Australian case study. The results highlight the potential two-way relationship between gambling and volunteering, such that volunteering (and social capital more generally) may help protect against problems of gambling, but also that volunteering as an activity may be damaged by increased gambling activity. This suggests that, regardless of the direction of causation, it is necessary to build up social capital via volunteering and other social capital activities in areas where EGMS are concentrated. The study concludes that Social Clubs using EGMs to derive funds are uniquely positioned within the community to develop programs that foster social capital creation and build community resilience in deprived areas.
Resumo:
Background: Thirst and dry mouth are common among hemodialysis (HD) patients. This paper reports a study to evaluate the impact of an acupressure program on HD patients’ thirst and salivary flow rates. Methods: The acupressure program included placebo, followed by true acupressure each applied for 4 weeks. Twenty-eight patients (mean age 57.6, SD = 16.13 years) first received a sticker as placebo acupressure at two acupoints CV23 and TE17 three times a week for 4 weeks, and then received true acupressure in the same area for the next 4 weeks. Salivary flow rate and thirst intensity were measured at baseline, during and after treatment completion for both the placebo and true acupressure program. Results: The true acupressure program was associated with significantly increased salivary flow rate (0.09 ± 0.08 ml/min at baseline to 0.12 ± 0.08 ml/min after treatments completion, p = 0.04). The mean thirst intensity also improved from 4.21 ± 2.66 at baseline to 2.43 ± 2.32 (p = 0.008) after treatment completion in HD patients. There was no statistically significant difference in pre-post program salivary flow rate; however, significant improvement in thirst intensity scores was observed (p = 0.009) in the placebo acupressure program. Conclusion: This study provides preliminary evidence that acupressure may be effective in improving salivary flow rates and thirst intensity.