Towards training-free appearance-based localization : probabilistic models for whole-image descriptors

Whole image descriptors have recently been shown to be remarkably robust to perceptual change especially compared to local features. However, whole-image-based localization systems typically rely on heuristic methods for determining appropriate matching thresholds in a particular environment. These environment-specific tuning requirements and the lack of a meaningful interpretation of these arbitrary thresholds limits the general applicability of these systems. In this paper we present a Bayesian model of probability for whole-image descriptors that can be seamlessly integrated into localization systems designed for probabilistic visual input. We demonstrate this method using CAT-Graph, an appearance-based visual localization system originally designed for a FAB-MAP-style probabilistic input. We show that using whole-image descriptors as visual input extends CAT-Graph’s functionality to environments that experience a greater amount of perceptual change. We also present a method of estimating whole-image probability models in an online manner, removing the need for a prior training phase. We show that this online, automated training method can perform comparably to pre-trained, manually tuned local descriptor methods.

Transforming morning to afternoon using linear regression techniques

Visual localization in outdoor environments is often hampered by the natural variation in appearance caused by such things as weather phenomena, diurnal fluctuations in lighting, and seasonal changes. Such changes are global across an environment and, in the case of global light changes and seasonal variation, the change in appearance occurs in a regular, cyclic manner. Visual localization could be greatly improved if it were possible to predict the appearance of a particular location at a particular time, based on the appearance of the location in the past and knowledge of the nature of appearance change over time. In this paper, we investigate whether global appearance changes in an environment can be learned sufficiently to improve visual localization performance. We use time of day as a test case, and generate transformations between morning and afternoon using sample images from a training set. We demonstrate the learned transformation can be generalized from training data and show the resulting visual localization on a test set is improved relative to raw image comparison. The improvement in localization remains when the area is revisited several weeks later.

Voltammetric, spectroscopic, and microscopic investigations of electrocrystallized forms of semiconducting AgTCNQ (TCNQ=7,7,8,8-tetracyanoquinodimethane) exhibiting different morphologies and colors

Chemically synthesized AgTCNQ exists in two forms that differ in their morphologies (needles and microcrystals) and colors (red and blue). It is now shown that both forms exhibit essentially indistinguishable X-ray diffraction, spectroscopic, and thermochemical data, implying that they are not separate phases, as implied in some literature. Electrochemical reduction of TCNQ((MeCN)) in the presence of Ag+((MeCN)) generates both red and blue AgTCNQ. On glassy carbon, platinum, or indium tin oxide electrodes and at relatively positive deposition potentials, slow growth of high aspect ratio, red needle AgTCNQ crystals occurs. After longer times and at more negative deposition potentials, blue microcrystalline AgTCNQ thin films are favored. Blue AgTCNQ is postulated to be generated via reduction of a Ag+\[(TCNQ(center dot-))(TCNQ)]((MeCN)) intermediate. At even more negative potentials, Ag-(metal) formation inhibits further growth of AgTCNQ. On a gold electrode, Ag-(metal)) deposition occurs at more positive potentials than on the other electrode materials examined. However, surface plasmon resonance data indicate (hat a small potential region is available between the stripping of Ag-(metal)) and the oxidation of TCNQ(center dot-)(MeCN) back to TCNQ(MeCN) where AgTCNQ may form. AgTCNQ in both the red and blue forms also can be prepared electrochemically on a TCNQ((s)) modified electrode in -0.1 M AgNO3(aq) where deposition of Ag(m,,,I) onto the TCNQ((s)) crystals allows a charge transfer process to occur. However, the morphology formed in this solid-solid phase transformation is more difficult to control.

How relevant are science curricula for rural and remote students?

This paper reports findings from the Choosing Science study (Lyons & Quinn, 2010) indicating that Australian Year 10 students in small rural or remote areas tend to regard their science lessons as less relevant than do students in larger towns and cities. Specifically, those in small rural or remote schools were significantly more inclined than their city peers to disagree that what they learned in science classes 'helped them make sense of the world'. They were also significantly more likely to strongly agree that they found science lessons boring, and to strongly disagree that science was one of the most interesting subjects. Potential explanations discussed include a mismatch between science curriculum content and the everyday experiences of students in these regions, the relative shortage of experienced specialist science teachers in rural or remote areas and a lack of opportunities to demonstrate the relevance of school science, among others. The paper considers the implications of these findings in relation to the Australian Science Curriculum and whether it is likely to better address the needs of rural and remote students.

Rural high school students' attitudes towards school science

This paper reports findings from an Australian survey of Year 10 students (N=3759) indicating that those in small rural and remote areas tend to enjoy school science significantly less than their peers in larger towns and cities (Lyons & Quinn, 2010). The study also found that rural and remote students were less inclined than those in other locations to enjoy science relative to other subjects. Such a result has not previously been recorded in the science education literature and raises a number of questions about the relevance and quality of the science education experienced by rural and remote students. It also raises timely questions about the applicability to rural and remote students of an Australian Science Curriculum. The paper explores these issues and their implications for policy and research.

Participation in science and technology : young people's achievement-related choices in late modern societies

Young people’s participation in science, technology, engineering and mathematics (STEM) is a matter of international concern. Studies and careers that require physical sciences and advanced mathematics are most affected by the problem and women in particular are under-represented in many STEM fields. This article views international research about young people’s relationships to, and participation in, STEM subjects and careers through the lens of an expectancy value model of achievement-related choices. In addition it draws on sociological theories of late-modernity and identity, which situate decision-making in a cultural context. The article examines how these frameworks are useful in explaining the decisions of young people – and young women in particular – about participating in STEM and proposes possible strategies for removing barriers to participation.

High school students' perceptions of school science and science careers : a critical look at a critical issue

Disproportionate representation of males and females in science courses and careers continues to be of concern. This article explores gender differences in Australian high school students’ perceptions of school science and their intentions to study university science courses. Nearly 3800 15-year-old students responded to a range of 5-point Likert items relating to intentions to study science at university, perceptions of career-related instrumental issues such as remuneration and job security, self-rated science ability and enjoyment of school science. Australian boys and girls reported enjoying science to a similar extent, however boys reported enjoying it more in relation to other subjects than did girls, and rated their ability in science compared to others in their class more highly than did girls. There was no significant difference between the mean responses of girls and boys to the item “It is likely I will choose a science-related university course when I leave school” and the strongest predictors of responses to this item were items relating to students’ liking for school science and awareness from school science of new and exciting jobs, followed by their perceived self-ability. These results are discussed in relation to socio-scientific values that interact with identity and career choices, employment prospects in science, and implications for science education.

The influence of school science teachers : the differential importance attributed by males and females to encouragement from science teachers

Research on the achievement and retention of female students in science and mathematics is located within a context of falling levels of participation in physical science and mathematics courses in Australian schools, and underrepresentation of females in some science, technology, engineering and mathematics (STEM) courses. The Interests and Recruitment in Science (IRIS) project is an international project that aims to contribute to understanding and improving recruitment, retention and gender equity in STEM higher education. Nearly 3500 first year students in 30 Australian universities responded to the IRIS survey of 5-point Likert items and open responses. This paper explores gender differences in first year university students’ responses to three questions about important influences on their course choice. The IRIS study found good teachers were rated highly by both males and females as influential in choosing STEM courses, and significantly higher numbers of females rated personal encouragement from senior high school science teacher as very important. In suggestions for addressing sex disparities in male-dominated STEM courses, more females indicated the importance of good teaching/encouragement and more females said (unspecified) encouragement. This study relates to the influence of school science teachers and results are discussed in relation to implications for science education.

The influence of teachers on students' decisions about choosing science : comparing student and teacher perceptions

This paper reports results from a study comparing teachers’ and students’ perceptions about the relative degree of influence parents, teachers, friends, older students and careers advisors have on students’ decisions about enrolling in non-compulsory high school science subjects. The comparison was carried out as part of the Choosing Science project - a large-scale Australian study of 15 year-old students’ experiences of school science and intentions regarding further participation. The study found that students considered their science teachers to have had the greatest influence, followed by parents and then friends. In contrast, however, science teachers believed their students to be most influenced in their decisions by friends and peers, followed by older students and siblings and parents, with teachers themselves having relatively little influence. Both groups believed that advice from careers advisors was of little influence. The findings are unique in the science education literature in providing an insight into differences and similarities in the perceptions of students and their teachers. In particular they indicate that teachers play a far greater role in students’ decisions about enrolling in science than they believe. This has important implications for science teachers and teacher educators in terms of appreciating their influence and applying it in ways that encourage participation in science courses.

Islamic contributions to the International Organization for Science and Technology Education (IOSTE)

This presentation introduces the International Organization for Science and Technology Education (IOSTE), outlining its history, structure, principles and activities. It discusses the role of IOSTE as a values-oriented STE research organization established in response to cold war ideologies with the aim of encouraging dialogue and academic exchange. The presentation then highlights the recent engagement of IOSTE with STE in predominantly Muslim countries. It examines quantitatively and qualitatively the increasing contributions from researchers in these countries, and outlines possible future engagements which could lead to closer research collaborations and relationships between STE academics in Muslim and non-Muslim countries.

Looking back : students' perceptions of the relative enjoyment of primary and secondary school science

This paper reports and discusses a contentious result from an Australia-wide study of the influences on students' decisions about taking senior science subjects. As part of the Choosing Science study (Lyons and Quinn 2010) 3759 Year 10 students were asked to indicate which stage of their schooling (lower primary, upper primary, lower secondary, middle secondary) they had most enjoyed learning science. Crosstabulations of responses revealed that around 78% of students indicated that they had enjoyed learning science more in secondary than in primary school, and 55% enjoyed it the most during Years 9 and 10. The perception that school science was more enjoyable in high school was also found among students who did not intend taking science in Year 11, though to a lesser extent. These findings are unexpected and significant, challenging the prevailing view that enjoyment of school science steadily declines after primary school. The paper elaborates on the findings and suggests that the different conclusions arrived at by studies in this field may be due to the different methodologies employed.

Gender differences in Australian students' relationships with school science

This paper explores issues of gender in Year 10 Australian students‘ experiences of science at school, their self-reported ability in science and their perceptions of science as a subject choice for senior secondary school. A sample of 3759 Year 10 students from across Australia responded to Likert-style questions related to these issues, with findings showing gender differences in perceptions of science, self-rated ability, and reasons for choosing not to study further science. Moreover, interesting contrasts were revealed in patterns of difference of self-rated ability for boys and girls across single-sex and co-educational schools.

Starting out in STEM : a study of young men and women in first year science, technology, engineering and mathematics courses

In late 2011, first year university students in science, technology, engineering and mathematics (STEM) courses across Australia were invited to participate in the international Interests and Recruitment in Science (IRIS) study. IRIS investigates the influences on young people's decisions to choose university STEM courses and their subsequent experiences of these courses. The study also has a particular focus on the motivations and experiences of young women in courses such as physics, IT and engineering given the low rates of female participation in these fields. Around 3500 students from 30 Australian universities contributed their views on the relative importance of various school and non-school influences on their decisions, as well as insights into their experiences of university STEM courses so far. It is hoped that their contributions will help improve recruitment, retention and gender equity in STEM higher education and careers.