Non-invasive method for detecting changes in soil moisture using wireless sensor networks

There are several popular soil moisture measurement methods today such as time domain reflectometry, electromagnetic (EM) wave, electrical and acoustic methods. Significant studies have been dedicated in developing method of measurements using those concepts, especially to achieve the characteristics of noninvasiveness. EM wave method provides an advantage because it is non-invasive to the soil and does not need to utilise probes to penetrate or bury in the soil. But some EM methods are also too complex, expensive, and not portable for the application of Wireless Sensor Networks; for example satellites or UAV (Unmanned Aerial Vehicle) based sensors. This research proposes a method in detecting changes in soil moisture using soil-reflected electromagnetic (SREM) wave from Wireless Sensor Networks (WSNs). Studies have shown that different levels of soil moisture will affects soil’s dielectric properties, such as relative permittivity and conductivity, and in turns change its reflection coefficients. The SREM wave method uses a transmitter adjacent to a WSNs node with purpose exclusively to transmit wireless signals that will be reflected by the soil. The strength from the reflected signal that is determined by the soil’s reflection coefficients is used to differentiate the level of soil moisture. The novel nature of this method comes from using WSNs communication signals to perform soil moisture estimation without the need of external sensors or invasive equipment. This innovative method is non-invasive, low cost and simple to set up. There are three locations at Brisbane, Australia chosen as the experiment’s location. The soil type in these locations contains 10–20% clay according to the Australian Soil Resource Information System. Six approximate levels of soil moisture (8, 10, 13, 15, 18 and 20%) are measured at each location; with each measurement consisting of 200 data. In total 3600 measurements are completed in this research, which is sufficient to achieve the research objective, assessing and proving the concept of SREM wave method. These results are compared with reference data from similar soil type to prove the concept. A fourth degree polynomial analysis is used to generate an equation to estimate soil moisture from received signal strength as recorded by using the SREM wave method.

Projecting change through construction innovation

In projecting change for the critical Australian construction industry, the CRC for Construction Innovation envisions a culture of self improvement through applied research and technology transfer. Construction Innovation is driving research outcomes into business practice in areas such as innovativeness, sustainability, procurement, project diagnostics and site safety. The group has also led the formation of an international alliance to ensure its activities are hitting the mark nationally and internationally. Through initiatives like these, the CRC for Construction Innovation is already providing a potent vehicle for change.

HMM triangle relative entropy concepts in sequential change detection applied to vision-based dim target manoeuvre detection

The quick detection of abrupt (unknown) parameter changes in an observed hidden Markov model (HMM) is important in several applications. Motivated by the recent application of relative entropy concepts in the robust sequential change detection problem (and the related model selection problem), this paper proposes a sequential unknown change detection algorithm based on a relative entropy based HMM parameter estimator. Our proposed approach is able to overcome the lack of knowledge of post-change parameters, and is illustrated to have similar performance to the popular cumulative sum (CUSUM) algorithm (which requires knowledge of the post-change parameter values) when examined, on both simulated and real data, in a vision-based aircraft manoeuvre detection problem.

Dealing with unfinished business : preparing pre-service social education teachers for curriculum change

Pre-service teacher education is unfinished business. New social education teachers face the challenge of fluid policy environments in which curriculum content and pedagogy are continually changing. The evolving Australian curriculum is the most recent example of such fluidity with its emphasis on shifting the educational agenda to a focus on discipline-based approaches. This paper addresses the concerns of final year pre-service and early career social education teachers, in terms of their professional development needs, by drawing on the findings of a pilot study with students and recent graduates from a university in south-east Queensland. It concludes that social education curriculum units which embed links to professional practice and professional development in teaching, learning and assessment may provide the way forward for enhancing the transition to practice for beginning teachers and assist them in navigating constant change.