Queensland University of Technology

About: Queensland University of Technology is a education organization based out in Brisbane, Queensland, Australia. It is known for research contribution in the topics: Population & Poison control. The organization has 14188 authors who have published 55022 publications receiving 1496237 citations. The organization is also known as: QUT.

Useful estimation procedures for critical gaps

Abstract: Many different methods for the estimation of crtical gaps at unsignalized intersections have been published in the international literature. This paper gives an overview of some of the more important methods. These methods are described by their characteristic properties. For comparison purposes a set of quality criteria has been formulated by which the usefulness of the different methods can be assessed. Among these one aspect seems to be of primary importance. This is the objective that the results of the estimation process should not depend on the traffic volume on the major street during the time of observation. Only if this condition is fulfilled can the estimation be applied under all undersaturated traffic conditions at unsignalized intersections. To test the qualification of some of the estimation methods under this aspect, a series of comprehensive simulations has been performed. As a result, the maximum likelihood procedure and the method developed by Hewitt can be recommended for practical application.

Emergence of Liquid Metals in Nanotechnology

Abstract: Bulk liquid metals have prospective applications as soft and fluid electrical and thermal conductors in electronic and optical devices, composites, microfluidics, robotics, and metallurgy with unique opportunities for processing, chemistry, and function. Yet liquid metals' great potential in nanotechnology remains in its infancy. Although work to date focuses primarily on Ga, Hg, and their alloys, to expand the field, we define "liquid metals" as metals and alloys with melting points (mp) up to 330 °C, readily accessible and processable even using household kitchen appliances. Such a definition encompasses a family of metals - including the majority of post-transition metals and Zn group elements (excluding Zn itself) - with remarkable versatility in chemistry, physics, and engineering. These liquid alloys can create metallic compounds of different morphologies, compositions, and properties, thereby enabling control over nanoscale phenomena. In addition, the presence of electronic and ionic "pools" within the bulk of liquid metals, as well as deviation from classical metallurgy on the surfaces of liquid metals, provides opportunities for gaining new capabilities in nanotechnology. For example, the bulk and surfaces of liquid metals can be used as reaction media for creating and manipulating nanomaterials, promoting reactions, or controlling crystallization of dissolved species. Interestingly, liquid metals have enormous surface tensions, yet the tension can be tuned electrically over a wide range or modified via surface species, such as the native oxides. The ability to control the interfacial tension allows these liquids to be readily reduced in size to the nanoscale. The liquid nature of such nanoparticles enables shape-reconfigurable structures, the creation of soft metallic nanocomposites, and the dissolution or dispersion of other materials within (or on) the metal to produce multiphasic or heterostructure particles. This Perspective highlights the salient features of these materials and seeks to raise awareness of future opportunities to understand and to utilize liquid metals for nanotechnology.

Understanding Conceptual Schemas: Exploring the Role of Application and IS Domain Knowledge

Abstract: Although information systems (IS) problem solving involves knowledge of both the IS and application domains, little attention has been paid to the role of application domain knowledge. In this study, which is set in the context of conceptual modeling, we examine the effects of both IS and application domain knowledge on different types of schema understanding tasks: syntactic and semantic comprehension tasks and schema-based problem-solving tasks. Our thesis was that while IS domain knowledge is important in solving all such tasks, the role of application domain knowledge is contingent upon the type of understanding task under investigation. We use the theory of cognitive fit to establish theoretical differences in the role of application domain knowledge among the different types of schema understanding tasks. We hypothesize that application domain knowledge does not influence the solution of syntactic and semantic comprehension tasks for which cognitive fit exists, but does influence the solution of schema-based problem-solving tasks for which cognitive fit does not exist. To assess performance on different types of conceptual schema understanding tasks, we conducted a laboratory experiment in which participants with high- and low-IS domain knowledge responded to two equivalent conceptual schemas that represented high and low levels of application knowledge (familiar and unfamiliar application domains). As expected, we found that IS domain knowledge is important in the solution of all types of conceptual schema understanding tasks in both familiar and unfamiliar applications domains, and that the effect of application domain knowledge is contingent on task type. Our findings for the EER model were similar to those for the ER model. Given the differential effects of application domain knowledge on different types of tasks, this study highlights the importance of considering more than one application domain in designing future studies on conceptual modeling.