Capping computation time and storage requirements for appearance-based localization with CAT-SLAM

Appearance-based localization is increasingly used for loop closure detection in metric SLAM systems. Since it relies only upon the appearance-based similarity between images from two locations, it can perform loop closure regardless of accumulated metric error. However, the computation time and memory requirements of current appearance-based methods scale linearly not only with the size of the environment but also with the operation time of the platform. These properties impose severe restrictions on longterm autonomy for mobile robots, as loop closure performance will inevitably degrade with increased operation time. We present a set of improvements to the appearance-based SLAM algorithm CAT-SLAM to constrain computation scaling and memory usage with minimal degradation in performance over time. The appearance-based comparison stage is accelerated by exploiting properties of the particle observation update, and nodes in the continuous trajectory map are removed according to minimal information loss criteria. We demonstrate constant time and space loop closure detection in a large urban environment with recall performance exceeding FAB-MAP by a factor of 3 at 100% precision, and investigate the minimum computational and memory requirements for maintaining mapping performance.

Separation/Divorce Sexual Assault: The Current State of Social Scientific Knowledge

Many contend that the logical solution to woman abuse in marriage/cohabitation is for women to exit through legal separation, divorce, or other means. However, a growing body of empirical work shows that separation or divorce does not necessarily solve the problem of woman abuse. For example, in addition to experiencing lethal or nonlethal forms of physical violence and psychological abuse, many women who try to leave, or who have left their male partners, are sexually assaulted. The main objective of this paper is to critically review the extant empirical and theoretical work on separation/divorcesexual assault. Suggestions for future research and theorizing are also provided.

Developing key concepts in physics : Is it more effective to teach using scientific visualizations?

A quantitative, quasi-experimental study of the effectiveness of computer-based scientific visualizations for concept learning on the part of Year 11 physics students (n=80) was conducted in six Queensland high school classrooms. Students’ gender and academic ability were also considered as factors in relation to the effectiveness of teaching with visualizations. Learning with visualizations was found to be equally effective as learning without them for all students, with no statistically significant difference in outcomes being observed for the group as a whole or on the academic ability dimension. Male students were found to learn significantly better with visualizations than without, while no such effect was observed for female students. This may give rise to some concern for the equity issues raised by introducing visualizations. Given that other research shows that students enjoy learning with visualizations and that their engagement with learning is enhanced, the finding that the learning outcomes are the same as for teaching without visualizations supports teachers’ use of visualizations.

Scientific Research in Information Systems : A Beginner's Guide

- ​Covers entire research process from start to end - Places particular emphasis on motivational components, modes of inquiry in scholarly conduct, theorizing and planning research - Includes aspects such as publication and ethical challenges This book is designed to introduce doctoral and other higher-degree research students to the process of scientific research in the fields of Information Systems as well as fields of Information Technology, Business Process Management and other related disciplines within the social sciences. It guides research students in their process of learning the life of a researcher. In doing so, it provides an understanding of the essential elements, concepts and challenges of the journey into research studies. It also provides a gateway for the student to inquire deeper about each element covered​. Comprehensive and broad but also succinct and compact, the book is focusing on the key principles and challenges for a novice doctoral student.

A human-simulated immune evolutionary computation approach

Premature convergence to local optimal solutions is one of the main difficulties when using evolutionary algorithms in real-world optimization problems. To prevent premature convergence and degeneration phenomenon, this paper proposes a new optimization computation approach, human-simulated immune evolutionary algorithm (HSIEA). Considering that the premature convergence problem is due to the lack of diversity in the population, the HSIEA employs the clonal selection principle of artificial immune system theory to preserve the diversity of solutions for the search process. Mathematical descriptions and procedures of the HSIEA are given, and four new evolutionary operators are formulated which are clone, variation, recombination, and selection. Two benchmark optimization functions are investigated to demonstrate the effectiveness of the proposed HSIEA.

Hybridized writing for scientific literacy : pedagogy and evidence

Disengagement of students in science and the scientific literacy of young adults are interrelated international concerns. One way to address these concerns is to engage students imaginatively in activities designed to improve their scientific literacy. Our ongoing program of research has focused on the effects of a sequence of activities that require students to transform scientific information on important issues for their communities from government websites into narrative text suitable for a lay reader. These hybridized stories we call BioStories. Students upload their stories for peer review to a dedicated website. Peer reviews are intended to help students refine their stories. Reviewing BioStories also gives students access to a wider range of scientific topics and writing styles. We have conducted separate studies with students from Grade 6, Grade 9 and Grade 12, involving case study and quasi-experimental designs. The results from the 6th grade study support the argument that writing the sequence of stories helped the students become more familiar with the scientific issue, develop a deeper understanding of related biological concepts, and improve their interest in science. Unlike the Grade 6 study, it was not possible to include a control group for the study conducted across eight 9th grade classes. Nevertheless, these results suggest that hybridized writing developed more positive attitudes toward science and science learning, particularly in terms of the students’ interest and enjoyment. In the most recent case study with Grade 12 students, we found that pride, strength, determination, interest and alertness were among the positive emotions most strongly elicited by the writing project. Furthermore, the students expressed enhanced feelings of self-efficacy in successfully writing hybridized scientific narratives in science. In this chapter, we describe the pedagogy of hybridized writing in science, overview the evidence to support this approach, and identify future developments.

Notes towards the scientific study of public communication on Twitter

Twitter is now well-established as an important platform for real-time public communication. Twitter research continues to lag behind these developments, with many studies remaining focused on individual case studies and utilizing home-grown, idiosyncratic, non-repeatable, and non-verifiable research methodologies. While the development of a full-blown “science of Twitter” may remain illusory, it is nonetheless necessary to move beyond such individual scholarship and toward the development of more comprehensive, transferable, and rigorous tools and methods for the study of Twitter on a large scale and in close to real time.

Does teaching sequence matter when teaching high school chemistry with scientific visualisations?

Five Canadian high school Chemistry classes in one school, taught by three different teachers, studied the concepts of dynamic chemical equilibria and Le Chatelier’s Principle. Some students received traditional teacher-led explanations of the concept first and used an interactive scientific visualisation second, while others worked with the visualisation first and received the teacher-led explanation second. Students completed a test of their conceptual understanding of the relevant concepts prior to instruction, after the first instructional session and at the end of instruction. Data on students’ academic achievement (highest, middle or lowest third of the class on the mid-term exam) and gender were also collected to explore the relationship between these factors, conceptual development and instructional sequencing. Results show, within this context at least, that teaching sequence is not important in terms of students’ conceptual learning gains.

An evolutionary computation approach to three-dimensional path planning for unmanned aerial vehicles with tactical and kinematic constraints

This paper presents a novel evolutionary computation approach to three-dimensional path planning for unmanned aerial vehicles (UAVs) with tactical and kinematic constraints. A genetic algorithm (GA) is modified and extended for path planning. Two GAs are seeded at the initial and final positions with a common objective to minimise their distance apart under given UAV constraints. This is accomplished by the synchronous optimisation of subsequent control vectors. The proposed evolutionary computation approach is called synchronous genetic algorithm (SGA). The sequence of control vectors generated by the SGA constitutes to a near-optimal path plan. The resulting path plan exhibits no discontinuity when transitioning from curve to straight trajectories. Experiments and results show that the paths generated by the SGA are within 2% of the optimal solution. Such a path planner when implemented on a hardware accelerator, such as field programmable gate array chips, can be used in the UAV as on-board replanner, as well as in ground station systems for assisting in high precision planning and modelling of mission scenarios.

Calculation of engine parameters using reconfigurable hardware

The feasibility of real-time calculation of parameters for an internal combustion engine via reconfigurable hardware implementation is investigated as an alternative to software computation. A detailed in-hardware field programmable gate array (FPGA)-based design is developed and evaluated using input crank angle and in-cylinder pressure data from fully instrumented diesel engines in the QUT Biofuel Engine Research Facility (BERF). Results indicate the feasibility of employing a hardware-based implementation for real-time processing for speeds comparable to the data sampling rate currently used in the facility, with acceptably low level of discrepancies between hardware and software-based calculation of key engine parameters.

Improving the efficiency of RFID authentication with pre-computation

Security of RFID authentication protocols has received considerable interest recently. However, an important aspect of such protocols that has not received as much attention is the efficiency of their communication. In this paper we investigate the efficiency benefits of pre-computation for time-constrained applications in small to medium RFID networks. We also outline a protocol utilizing this mechanism in order to demonstrate the benefits and drawbacks of using thisapproach. The proposed protocol shows promising results as it is able to offer the security of untraceableprotocols whilst only requiring the time comparable to that of more efficient but traceable protocols.

Preparing citizens for a complex world : the grand challenge of teaching socio-scientific issues in science education

The dawn of the twenty-first century encouraged a number of scientific and technological organisations to identify what they saw as ‘Grand Challenges and Opportunities’. Issues of environment and health featured very prominently in these quite short lists, as can be seen from a sample of these challenges in Table 1. Indeed, the first two lists of challenges in Table 1 were identified as for the environment and for health, respectively.

Linking scientific evidence and decision making : A case study of hand hygiene interventions

We consider how data from scientific research should be used for decision making in health services. Whether a hand hygiene intervention to reduce risk of nosocomial infection should be widely adopted is the case study. Improving hand hygiene has been described as the most important measure to prevent nosocomial infection. 1 Transmission of microorganisms is reduced, and fewer infections arise, which leads to a reduction in mortality2 and cost savings.3 Implementing a hand hygiene program is itself costly, so the extra investment should be tested for cost-effectiveness.4,5 The first part of our commentary is about cost-effectiveness models and how they inform decision making for health services. The second part is about how data on the effectiveness of hand hygiene programs arising from scientific studies are used, and 2 points are made: the threshold for statistical inference of .05 used to judge effectiveness studies is not important for decision making,6,7 and potentially valuable evidence about effectiveness might be excluded by decision makers because it is deemed low quality.8 The ideas put forward will help researchers and health services decision makers to appraise scientific evidence in a more powerful way.