Greener and leaner : unleashing capacity of railroad concrete ties via limit states concept

New knowledge has raised a concern about the cost-ineffective design methods and the true performance of railroad prestressed concrete ties. Because of previous knowledge deficiencies, railway civil and track engineers have been aware of the conservative design methods for structural components in any railway track that rely on allowable stresses and material strength reductions. In particular, railway sleeper (or railroad tie) is an important component of railway tracks and is commonly made of prestressed concrete. The existing code for designing such components makes use of the permissible stress design concept, whereas the fiber stresses over cross sections at initial and final stages are limited by some empirical values. It is believed that the concrete ties complying with the permissible stress concept possess unduly untapped fracture toughness, based on a number of proven experiments and field data. Collaborative research run by the Australian Cooperative Research Centre for Railway Engineering and Technologies (Rail CRC) was initiated to ascertain the reserved capacity of Australian railway prestressed concrete ties that were designed using the existing design code. The findings have led to the development of a new limit-states design concept. This paper highlights the conventional and the new limit-states design philosophies and their implication to both the railway community and the public. © 2011 American Society of Civil Engineers.

Capacity-building workshops on the responsibility to protect (R2P) and the protection of civilians (POC) in armed conflict - Summary Report

In June 2011, a research project team from the Institute for Ethics, Governance and Law (IEGL), Queensland University of Technology, the United Nations University, and the Australian Government’s Asia Pacific Civil-Military Centre of Excellence (APCMCOE) held three Capacity-Building Workshops (the Workshops) on the Responsibility to Protect (R2P) and the Protection of Civilians (POC) in Armed Conflict in Manila, Kuala Lumpur, and Jakarta. The research project is funded by the Australian Responsibility to Protect Fund, with support from APCMCOE. Developments in Libya and Cote d’Ivoire and the actions of the United Nations Security Council have given new significance to the relationship between R2P and POC, providing impetus to the relevance and application of the POC principle recognised in numerous Security Council resolutions, and the R2P principle, which was recognised by the United Nations General Assembly in 2005 and, now, by the Security Council. The Workshops considered the relationship between R2P and POC. The project team presented the preliminary findings of their study and sought contributions and feedback from Workshop participants. Prior to the Workshops, members of the project team undertook interviews with UN offices and agencies, international organisations (IOs) and non-government organisations (NGOs) in Geneva and New York as part of the process of mapping the relationship between R2P and POC. Initial findings were considered at an Academic-Practitioner Workshop held at the University of Sydney in November 2010. In addition to an extensive literature review and a series of academic publications, the project team is preparing a practical guidance text (the Guide) on the relationship between R2P and POC to assist the United Nations, governments, regional bodies, IOs and NGOs in considering and applying appropriate protection strategies. It is intended that the Guide be presented to the United Nations Secretariat in New York in early 2012. The primary aim of the Workshops was to test the project’s initial findings among an audience of diplomats, military, police, civilian policy-makers, practitioners, researchers and experts from within the region. Through dialogue and discussion, the project team gathered feedback – comments, questions, critique and suggestions – to help shape the development of practical guidance about when, how and by whom R2P and POC might be implemented.

Optimising a coal rail network under capacity constraints

This research deals with an innovative methodology for optimising the coal train scheduling problem. Based on our previously published work, generic solution techniques are developed by utilising a “toolbox” of standard well-solved standard scheduling problems. According to our analysis, the coal train scheduling problem can be basically modelled a Blocking Parallel-Machine Job-Shop Scheduling (BPMJSS) problem with some minor constraints. To construct the feasible train schedules, an innovative constructive algorithm called the SLEK algorithm is proposed. To optimise the train schedule, a three-stage hybrid algorithm called the SLEK-BIH-TS algorithm is developed based on the definition of a sophisticated neighbourhood structure under the mechanism of the Best-Insertion-Heuristic (BIH) algorithm and Tabu Search (TS) metaheuristic algorithm. A case study is performed for optimising a complex real-world coal rail system in Australia. A method to calculate the lower bound of the makespan is proposed to evaluate results. The results indicate that the proposed methodology is promising to find the optimal or near-optimal feasible train timetables of a coal rail system under network and terminal capacity constraints.

Determinants of China’s regional innovation capacity

This paper investigates the determinants of China’s regional innovation capacity (RIC) and variations in these determinants between different types of regions. Based on the framework of national innovation capacity (NIC) and research on innovation system, this paper develops a framework of RIC in the Chinese context. Using panel data from 1991 to 2009, clustering analysis is first employed to classify regions according to their innovation development path. Panel data regressions with fixed effect model are conducted to explore the determinants of RIC and how these vary across the different regional clusters. We find that the 30 regions can be clustered into three groups, and there are considerable differences in the drivers of RIC between these different regional groups.

Numerical Modelling of LiteSteel Beams Subject to Shear

Abstract: LiteSteel beam (LSB) is a new cold-formed steel hollow flange channel beam produced using a patented manufacturing process involving simultaneous cold-forming and dual electric resistance welding. It has the beneficial characteristics of torsionally rigid closed rectangular flanges combined with economical fabrication processes from a single strip of high strength steel. Although the LSB sections are commonly used as flexural members, no research has been undertaken on the shear behaviour of LSBs. Therefore experimental and numerical studies were undertaken to investigate the shear behaviour and strength of LSBs. In this research finite element models of LSBs were developed to investigate their nonlinear shear behaviour including their buckling characteristics and ultimate shear strength. They were validated by comparing their results with available experimental results. The models provided full details of the shear buckling and strength characteristics of LSBs, and showed the presence of considerable improvements to web shear buckling in LSBs and associated post-buckling strength. This paper presents the details of the finite element models of LSBs and the results. Both finite element analysis and experimental results showed that the current design rules in cold-formed steel codes are very conservative for the shear design of LSBs. The ultimate shear capacities from finite element analyses confirmed the accuracy of proposed shear strength equations for LSBs based on the North American specification and DSM design equations. Developed finite element models were used to investigate the reduction to shear capacity of LSBs when full height web side plates were not used or when only one web side plate was used, and these results are also presented in this paper.

New design rules for the shear strength of LiteSteel Beams with web openings

Abstract: LiteSteel beam (LSB) is a new cold-formed steel hollow flange channel section produced using a patented manufacturing process involving simultaneous cold-forming and dual electric resistance welding. The LSBs are commonly used as floor joists and bearers with web openings in residential, industrial and commercial buildings. Their shear strengths are considerably reduced when web openings are included for the purpose of locating building services. However, no research has been undertaken on the shear behaviour and strength of LSBs with web openings. Therefore experimental and numerical studies were undertaken to investigate the shear behaviour and strength of LSBs with web openings. In this research, finite element models of LSBs with web openings in shear were developed to simulate the shear behaviour and strength of LSBs including their buckling characteristics. They were then validated by comparing their results with available experimental test results and used in a detailed parametric study. The results showed that the current design rules in cold-formed steel structures design codes are very conservative for the shear design of LSBs with web openings. Improved design equations have been proposed for the shear capacity of LSBs with web openings based on both experimental and parametric study results. An alternative shear design method based on an equivalent reduced web thickness was also proposed. It was found that the same shear strength design rules developed for LSBs without web openings can be used for LSBs with web openings provided the equivalent reduced web thickness equation developed in this paper is used. This is a significant advancement as it simplifies the shear design methods of LSBs with web openings considerably.

Philanthropic capacity to support Indigenous causes : the journey to improvement

The role of philanthropy in addressing Indigenous causes is still conceptually emerging in Australia despite many years of practice. This paper reports on a qualitative study with grantmakers and grantseekers to better understand the issues affecting the philanthropic grantmaking system for Indigenous causes in Australia. An attitudinal emphasis on human rights for politically, economically and socially disadvantaged groups and an impetus for structural change emerged that has yet to deliver real funding equity. The way forward is still largely focussed on ‘improving’ Indigenous community capacity in organisational governance systems. In contrast, this study points to strategic leverage points within philanthropic organisations which could be used to first assess and then develop policies, processes and their underlying attitudes which impact on cross-cultural work i.e. the ‘cultural competence ’ of philanthropic organisations. It is argued such an approach would support improved social justice practice in the sector and subsequently Indigenous outcomes.

Numerical modelling and design of LiteSteel Beams subject to lateral buckling

The LiteSteel Beam (LSB) is a new hollow flange channel section developed using a patented dual electric resistance welding and cold-forming process. It has a unique geometry consisting of torsionally rigid rectangular hollow flanges and a slender web, and is commonly used as flexural members. However, the LSB flexural members are subjected to a relatively new lateral distortional buckling mode, which reduces their moment capacities. Unlike lateral torsional buckling, the lateral distortional buckling of LSBs is characterised by simultaneous lateral deflection, twist and cross sectional change due to web distortion. Therefore a detailed investigation into the lateral buckling behaviour of LSB flexural members was undertaken using experiments and finite element analyses. This paper presents the details of suitable finite element models developed to simulate the behaviour and capacity of LSB flexural members subject to lateral buckling. The models included all significant effects that influence the ultimate moment capacities of such members, including material inelasticity, lateral distortional buckling deformations, web distortion, residual stresses, and geometric imperfections. Comparison of elastic buckling and ultimate moment capacity results with predictions from other numerical analyses and available buckling moment equations, and experimental results showed that the developed finite element models accurately predict the behaviour and moment capacities of LSBs. The validated model was then used in a detailed parametric study that produced accurate moment capacity data for all the LSB sections and improved design rules for LSB flexural members subject to lateral distortional buckling.

Behaviour and design of cold-formed steel beams subject to lateral-torsional buckling

Cold-formed steel beams are increasingly used as floor joists and bearers in buildings. Their behaviour and moment capacities are influenced by lateral-torsional buckling when they are not laterally restrained adequately. Past research on lateral-torsional buckling has concentrated on hot-rolled steel beams. Hence a numerical study was undertaken to investigate the lateral-torsional buckling behaviour of simply supported cold-formed steel lipped channel beams subjected to uniform bending. For this purpose a finite element model was developed using ABAQUS and its accuracy was verified using available numerical and experimental results. It was then used in a detailed parametric study to simulate the lateral-torsional buckling behaviour and capacity of cold-formed steel beams under varying conditions. The moment capacity results were compared with the predictions from the current design rules in many cold-formed steel codes and suitable recommendations were made. European design rules were found to be conservative while Australian/New Zealand and North American design rules were unconservative. Hence the moment capacity design equations in these codes were modified in this paper based on the available finite element analysis results. This paper presents the details of the parametric study, recommendations to current design rules and the new design rules proposed in this research for lateral-torsional buckling of cold-formed steel lipped channel beams.

Numerical study of cold-formed steel beam subject to lateral-torsional buckling

The use of cold-formed steel members as structural columns and beams in residential, industrial and commercial buildings has increased significantly in recent times. This study is focused on the use of cold-formed steel sections as flexural members subject to lateral-torsional buckling. For this purpose a finite element model of a simply supported lipped channel beam under uniform bending was developed, validated using available numerical and experimental results, and used in a detailed parametric study. The moment capacity results were then compared with the predictions from the current ambient temperature design rules in the cold-formed steel structures codes of Australia, New Zealand, North America and Europe. European design rules were found to be conservative while Australian and American design rules were unsafe. This paper presents the results of the numerical study, the comparison with the current design rules and the new proposed design rules.

Lateral torsional buckling behaviour of cold-formed steel beams at elevated temperatures

Abstract: This paper presents the details of a study into the behaviour and moment capacities of cold-formed steel lipped channel beams (LCB) subject to lateral-torsional buckling at elevated temperatures. It was based on a validated numerical model of a simply supported and laterally unrestrained LCB subjected to a uniform moment. The ultimate moment capacities from this study were compared with the predicted values using ambient and fire design methods. This study showed that the lateral torsional buckling capacity is strongly influenced by the level of non-linearity in the stress-strain curves of steel at elevated temperatures. Hence most of the current design methods based on a single buckling curve were not adequate to determine the moment capacities. This paper proposes a new design method for the cold-formed steel LCBs subject lateral-torsional buckling at elevated temperatures.

Time-varying bispectral analysis of auditory evoked multi-channel scalp EEG

Time-varying bispectra, computed using a classical sliding window short-time Fourier approach, are analyzed for scalp EEG potentials evoked by an auditory stimulus and new observations are presented. A single, short duration tone is presented from the left or the right, direction unknown to the test subject. The subject responds by moving the eyes to the direction of the sound. EEG epochs sampled at 200 Hz for repeated trials are processed between -70 ms and +1200 ms with reference to the stimulus. It is observed that for an ensemble of correctly recognized cases, the best matching timevarying bispectra at (8 Hz, 8Hz) are for PZ-FZ channels and this is also largely the case for grand averages but not for power spectra at 8 Hz. Out of 11 subjects, the only exception for time-varying bispectral match was a subject with family history of Alzheimer’s disease and the difference was in bicoherence, not biphase.

Modeling ion channel dynamics through reflected stochastic differential equations

Ion channels are membrane proteins that open and close at random and play a vital role in the electrical dynamics of excitable cells. The stochastic nature of the conformational changes these proteins undergo can be significant, however current stochastic modeling methodologies limit the ability to study such systems. Discrete-state Markov chain models are seen as the "gold standard," but are computationally intensive, restricting investigation of stochastic effects to the single-cell level. Continuous stochastic methods that use stochastic differential equations (SDEs) to model the system are more efficient but can lead to simulations that have no biological meaning. In this paper we show that modeling the behavior of ion channel dynamics by a reflected SDE ensures biologically realistic simulations, and we argue that this model follows from the continuous approximation of the discrete-state Markov chain model. Open channel and action potential statistics from simulations of ion channel dynamics using the reflected SDE are compared with those of a discrete-state Markov chain method. Results show that the reflected SDE simulations are in good agreement with the discrete-state approach. The reflected SDE model therefore provides a computationally efficient method to simulate ion channel dynamics while preserving the distributional properties of the discrete-state Markov chain model and also ensuring biologically realistic solutions. This framework could easily be extended to other biochemical reaction networks. © 2012 American Physical Society.

Managing open incremental process innovation : absorptive capacity and distributed learning

In this conceptual article, we extend earlier work on Open Innovation and Absorptive Capacity. We suggest that the literature on Absorptive Capacity does not place sufficient emphasis on distributed knowledge and learning or on the application of innovative knowledge. To accomplish physical transformations, organisations need specific Innovative Capacities that extend beyond knowledge management. Accessive Capacity is the ability to collect, sort and analyse knowledge from both internal and external sources. Adaptive Capacity is needed to ensure that new pieces of equipment are suitable for the organisation's own purposes even though they may have been originally developed for other uses. Integrative Capacity makes it possible for a new or modified piece of equipment to be fitted into an existing production process with a minimum of inessential and expensive adjustment elsewhere in the process. These Innovative Capacities are controlled and coordinated by Innovative Management Capacity, a higher-order dynamic capability.