496 resultados para multiple measurements
Resumo:
It has been 21 years since the decision in Rogers v Whitaker and the legal principles concerning informed consent and liability for negligence are still strongly grounded in this landmark High Court decision. This paper considers more recent developments in the law concerning the failure to disclose inherent risks in medical procedures, focusing on the decision in Wallace v Kam [2013] HCA 19. In this case, the appellant underwent a surgical procedure that carried a number of risks. The surgery itself was not performed in a sub-standard way, but the surgeon failed to disclose two risks to the patient, a failure that constituted a breach of the surgeon’s duty of care in negligence. One of the undisclosed risks was considered to be less serious than the other, and this lesser risk eventuated causing injury to the appellant. The more serious risk did not eventuate, but the appellant argued that if the more serious risk had been disclosed, he would have avoided his injuries completely because he would have refused to undergo the procedure. Liability was disputed by the surgeon, with particular reference to causation principles. The High Court of Australia held that the appellant should not be compensated for harm that resulted from a risk he would have been willing to run. We examine the policy reasons underpinning the law of negligence in this specific context and consider some of the issues raised by this unusual case. We question whether some of the judicial reasoning adopted in this case, represents a significant shift in traditional causation principles.
Resumo:
A unique high temporal frequency dataset from an irrigated cotton-wheat rotation was used to test the agroecosystem model DayCent to simulate daily N2O emissions from sub-tropical vertisols under different irrigation intensities. DayCent was able to simulate the effect of different irrigation intensities on N2O fluxes and yield, although it tended to overestimate seasonal fluxes during the cotton season. DayCent accurately predicted soil moisture dynamics and the timing and magnitude of high fluxes associated with fertilizer additions and irrigation events. At the daily scale we found a good correlation of predicted vs. measured N2O fluxes (r2 = 0.52), confirming that DayCent can be used to test agricultural practices for mitigating N2O emission from irrigated cropping systems. A 25 year scenario analysis indicated that N2O losses from irrigated cotton-wheat rotations on black vertisols in Australia can be substantially reduced by an optimized fertilizer and irrigation management system (i.e. frequent irrigation, avoidance of excessive fertiliser application), while sustaining maximum yield potentials.
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Voltage rise is the main issue which limits the capacity of Low Voltage (LV) network to accommodate more Renewable Energy (RE) sources. In addition, voltage drop at peak load period is a significant power quality concern. This paper proposes a new robust voltage support strategy based on distributed coordination of multiple distribution static synchronous compensators (DSTATCOMs). The study focuses on LV networks with PV as the RE source for customers. The proposed approach applied to a typical LV network and its advantages are shown comparing with other voltage control strategies.
Resumo:
OBJECTIVE To compare the physical activity levels of overweight and non overweight 3- to 5-y-old children while attending preschool. A secondary aim was to evaluate weight-related differences in hypothesized parental determinants of child physical activity behavior. DESIGN Cross-sectional study. SUBJECTS A total of 245, 3- to 5-y-olds ( 127 girls, 118 boys) and their parent(s) ( 242 mothers, 173 fathers) recruited from nine preschools. Overweight status determined using the age- and sex-specific 85th percentile for body mass index (BMI) from CDC Growth Charts. MEASUREMENTS Physical activity during the preschool day was assessed on multiple days via two independent objective measures-direct observation using the observation system for recording activity in preschools (OSRAP) and real-time accelerometry using the MTI/CSA 7164 accelerometer. Parents completed a take-home survey assessing sociodemographic information, parental height and weight, modeling of physical activity, support for physical activity, active toys and sporting equipment at home, child's television watching, frequency of park visitation, and perceptions of child competence. RESULTS Overweight boys were significantly less active than their nonoverweight peers during the preschool day. No significant differences were observed in girls. Despite a strong association between childhood overweight status and parental obesity, no significant differences were observed for the hypothesized parental influences on physical activity behavior. CONCLUSIONS Our results suggest that a significant proportion of overweight children may be at increased risk for further gains in adiposity because of low levels of physical activity during the preschool day.
Resumo:
This paper addresses the topic of real-time decision making for autonomous city vehicles, i.e., the autonomous vehicles' ability to make appropriate driving decisions in city road traffic situations. The paper explains the overall controls system architecture, the decision making task decomposition, and focuses on how Multiple Criteria Decision Making (MCDM) is used in the process of selecting the most appropriate driving maneuver from the set of feasible ones. Experimental tests show that MCDM is suitable for this new application area.
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This paper presents a method to enable a mobile robot working in non-stationary environments to plan its path and localize within multiple map hypotheses simultaneously. The maps are generated using a long-term and short-term memory mechanism that ensures only persistent configurations in the environment are selected to create the maps. In order to evaluate the proposed method, experimentation is conducted in an office environment. Compared to navigation systems that use only one map, our system produces superior path planning and navigation in a non-stationary environment where paths can be blocked periodically, a common scenario which poses significant challenges for typical planners.
Resumo:
OBJECTIVE To compare the physical activity levels of overweight and non overweight 3- to 5-y-old children while attending preschool. A secondary aim was to evaluate weight-related differences in hypothesized parental determinants of child physical activity behavior. DESIGN Cross-sectional study. SUBJECTS A total of 245, 3- to 5-y-olds (127 girls, 118 boys) and their parent(s) (242 mothers, 173 fathers) recruited from nine preschools. Overweight status determined using the age- and sex-specific 85th percentile for body mass index (BMI) from CDC Growth Charts. MEASUREMENTS Physical activity during the preschool day was assessed on multiple days via two independent objective measures direct observation using the observation system for recording activity in preschools (OSRAP) and real-time accelerometry using the MTI/CSA 7164 accelerometer. Parents completed a take-home survey assessing sociodemographic information, parental height and weight, modeling of physical activity, support for physical activity, active toys and sporting equipment at home, child’s television watching, frequency of park visitation, and perceptions of child competence. RESULTS Overweight boys were significantly less active than their nonoverweight peers during the preschool day. No significant differences were observed in girls. Despite a strong association between childhood overweight status and parental obesity, no significant differences were observed for the hypothesized parental influences on physical activity behavior. CONCLUSIONS Our results suggest that a significant proportion of overweight children may be at increased risk for further gains in adiposity because of low levels of physical activity during the preschool day.
Resumo:
OBJECTIVE To compare the physical activity levels of overweight and non overweight 3- to 5-y-old children while attending preschool. A secondary aim was to evaluate weight-related differences in hypothesized parental determinants of child physical activity behavior. DESIGN: Cross-sectional study. SUBJECTS A total of 245, 3- to 5-y-olds (127 girls, 118 boys) and their parent(s) (242 mothers, 173 fathers) recruited from nine preschools. Overweight status determined using the age- and sex-specific 85th percentile for body mass index (BMI) from CDC Growth Charts. MEASUREMENTS Physical activity during the preschool day was assessed on multiple days via two independent objective measuresFdirect observation using the observation system for recording activity in preschools (OSRAP) and real-time accelerometry using the MTI/CSA 7164 accelerometer. Parents completed a take-home survey assessing sociodemographic information, parental height and weight, modeling of physical activity, support for physical activity, active toys and sporting equipment at home, child’s television watching, frequency of park visitation, and perceptions of child competence. RESULTS Overweight boys were significantly less active than their nonoverweight peers during the preschool day. No significant differences were observed in girls. Despite a strong association between childhood overweight status and parental obesity, no significant differences were observed for the hypothesized parental influences on physical activity behavior. CONCLUSIONS Our results suggest that a significant proportion of overweight children may be at increased risk for further gains in adiposity because of low levels of physical activity during the preschool day.
Resumo:
The use of Wireless Sensor Networks (WSNs) for vibration-based Structural Health Monitoring (SHM) has become a promising approach due to many advantages such as low cost, fast and flexible deployment. However, inherent technical issues such as data asynchronicity and data loss have prevented these distinct systems from being extensively used. Recently, several SHM-oriented WSNs have been proposed and believed to be able to overcome a large number of technical uncertainties. Nevertheless, there is limited research verifying the applicability of those WSNs with respect to demanding SHM applications like modal analysis and damage identification. Based on a brief review, this paper first reveals that Data Synchronization Error (DSE) is the most inherent factor amongst uncertainties of SHM-oriented WSNs. Effects of this factor are then investigated on outcomes and performance of the most robust Output-only Modal Analysis (OMA) techniques when merging data from multiple sensor setups. The two OMA families selected for this investigation are Frequency Domain Decomposition (FDD) and data-driven Stochastic Subspace Identification (SSI-data) due to the fact that they both have been widely applied in the past decade. Accelerations collected by a wired sensory system on a large-scale laboratory bridge model are initially used as benchmark data after being added with a certain level of noise to account for the higher presence of this factor in SHM-oriented WSNs. From this source, a large number of simulations have been made to generate multiple DSE-corrupted datasets to facilitate statistical analyses. The results of this study show the robustness of FDD and the precautions needed for SSI-data family when dealing with DSE at a relaxed level. Finally, the combination of preferred OMA techniques and the use of the channel projection for the time-domain OMA technique to cope with DSE are recommended.
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This paper introduces a straightforward method to asymptotically solve a variety of initial and boundary value problems for singularly perturbed ordinary differential equations whose solution structure can be anticipated. The approach is simpler than conventional methods, including those based on asymptotic matching or on eliminating secular terms. © 2010 by the Massachusetts Institute of Technology.
SWIRLnet : portable anemometer network for wind speed measurements of land-falling tropical cyclones
Resumo:
Wind speed measurement systems are sparse in the tropical regions of Australia. Tropical cyclone wind speeds impacting communities are often ‘guestimated’ from analyzing damaged structures. A re-locatable anemometer system is required to enable measurements of wind speeds. This paper discusses design criteria of the tripods and tie down system, proposed deployment of the anemometers, instrumentation, and data logging. Preliminary assessment of the anemometer response indicates a reliable system for 1 second response, however, it is noted that the Australian building code and wind loading standard uses a moving average time of approximately 0.2 seconds for its wind speed design criteria.
Resumo:
Wind speed measurement systems are sparse in the tropical regions of Australia. Given this, tropical cyclone wind speeds impacting communities are seldom measured and often only ‘guestimated’ by analysing the extent of damage to structures. In an attempt to overcome this dearth of data, a re-locatable network of anemometers to be deployed prior to tropical cyclone landfall is currently being developed. This paper discusses design criteria of the network’s tripods and tie down system, proposed deployment of the anemometers, instrumentation and data logging. Preliminary assessment of the anemometer response indicates a reliable system for measuring the spectral component of wind with frequencies of approximately 1 Hz. This system limitation highlights an important difference between the capabilities of modern instrumentation and that of the Dines anemometer (around 0.2 seconds) that was used to develop much of the design criteria within the Australian building code and wind loading standard.
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NLS is a stream cipher which was submitted to the eSTREAM project. A linear distinguishing attack against NLS was presented by Cho and Pieprzyk, which was called Crossword Puzzle (CP) attack. NLSv2 is a tweak version of NLS which aims mainly at avoiding the CP attack. In this paper, a new distinguishing attack against NLSv2 is presented. The attack exploits high correlation amongst neighboring bits of the cipher. The paper first shows that the modular addition preserves pairwise correlations as demonstrated by existence of linear approximations with large biases. Next, it shows how to combine these results with the existence of high correlation between bits 29 and 30 of the S-box to obtain a distinguisher whose bias is around 2^−37. Consequently, we claim that NLSv2 is distinguishable from a random cipher after observing around 2^74 keystream words.
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The value of information technology (IT) is often realized when continuously being used after users’ initial acceptance. However, previous research on continuing IT usage is limited for dismissing the importance of mental goals in directing users’ behaviors and for inadequately accommodating the group context of users. This in-progress paper offers a synthesis of several literature to conceptualize continuing IT usage as multilevel constructs and to view IT usage behavior as directed and energized by a set of mental goals. Drawing from the self-regulation theory in the social psychology, this paper proposes a process model, positioning continuing IT usage as multiple-goal pursuit. An agent-based modeling approach is suggested to further explore causal and analytical implications of the proposed process model.
Resumo:
The ability to build high-fidelity 3D representations of the environment from sensor data is critical for autonomous robots. Multi-sensor data fusion allows for more complete and accurate representations. Furthermore, using distinct sensing modalities (i.e. sensors using a different physical process and/or operating at different electromagnetic frequencies) usually leads to more reliable perception, especially in challenging environments, as modalities may complement each other. However, they may react differently to certain materials or environmental conditions, leading to catastrophic fusion. In this paper, we propose a new method to reliably fuse data from multiple sensing modalities, including in situations where they detect different targets. We first compute distinct continuous surface representations for each sensing modality, with uncertainty, using Gaussian Process Implicit Surfaces (GPIS). Second, we perform a local consistency test between these representations, to separate consistent data (i.e. data corresponding to the detection of the same target by the sensors) from inconsistent data. The consistent data can then be fused together, using another GPIS process, and the rest of the data can be combined as appropriate. The approach is first validated using synthetic data. We then demonstrate its benefit using a mobile robot, equipped with a laser scanner and a radar, which operates in an outdoor environment in the presence of large clouds of airborne dust and smoke.