Report : stochastic analysis of road asset data for maintenance cost prediction

Reliable budget/cost estimates for road maintenance and rehabilitation are subjected to uncertainties and variability in road asset condition and characteristics of road users. The CRC CI research project 2003-029-C ‘Maintenance Cost Prediction for Road’ developed a method for assessing variation and reliability in budget/cost estimates for road maintenance and rehabilitation. The method is based on probability-based reliable theory and statistical method. The next stage of the current project is to apply the developed method to predict maintenance/rehabilitation budgets/costs of large networks for strategic investment. The first task is to assess the variability of road data. This report presents initial results of the analysis in assessing the variability of road data. A case study of the analysis for dry non reactive soil is presented to demonstrate the concept in analysing the variability of road data for large road networks. In assessing the variability of road data, large road networks were categorised into categories with common characteristics according to soil and climatic conditions, pavement conditions, pavement types, surface types and annual average daily traffic. The probability distributions, statistical means, and standard deviation values of asset conditions and annual average daily traffic for each type were quantified. The probability distributions and the statistical information obtained in this analysis will be used to asset the variation and reliability in budget/cost estimates in later stage. Generally, we usually used mean values of asset data of each category as input values for investment analysis. The variability of asset data in each category is not taken into account. This analysis method demonstrated that it can be used for practical application taking into account the variability of road data in analysing large road networks for maintenance/rehabilitation investment analysis.

Strategies for minimising the whole of life cycle cost of reinforced concrete bridge exposed to aggressive environments

n design of bridge structures, it is common to adopt a 100 year design life. However, analysis of a number of case study bridges in Australia has indicated that the actual design life can be significantly reduced due to premature deterioration resulting from exposure to aggressive environments. A closer analysis of the cost of rehabilitation of these structures has raised some interesting questions. What would be the real service life of a bridge exposed to certain aggressive environments? What is the strategy of conducting bridge rehabilitation? And what are the life cycle costs associated with rehabilitation? A research project funded by the CRC for Construction Innovation in Australia is aimed at addressing these issues. This paper presents a concept map for assisting decision makers to appropriately choose the best treatment for bridge rehabilitation affected by premature deterioration through exposure to aggressive environments in Australia. The decision analysis is referred to a whole of life cycle cost analysis by considering appropriate elements of bridge rehabilitation costs. In addition, the results of bridges inspections in Queensland are presented

Identification of critical input variables for risk-based cost estimates for road maintenance and rehabilitation

An estimation of costs for maintenance and rehabilitation is subject to variation due to the uncertainties of input parameters. This paper presents the results of an analysis to identify input parameters that affect the prediction of variation in road deterioration. Road data obtained from 1688 km of a national highway located in the tropical northeast of Queensland in Australia were used in the analysis. Data were analysed using a probability-based method, the Monte Carlo simulation technique and HDM-4’s roughness prediction model. The results of the analysis indicated that among the input parameters the variability of pavement strength, rut depth, annual equivalent axle load and initial roughness affected the variability of the predicted roughness. The second part of the paper presents an analysis to assess the variation in cost estimates due to the variability of the overall identified critical input parameters.

HVAC system size – getting it right

There is evidence that many heating, ventilating & air conditioning (HVAC) systems, installed in larger buildings, have more capacity than is ever required to keep the occupants comfortable. This paper explores the reasons why this can occur, by examining a typical brief/design/documentation process. Over-sized HVAC systems cost more to install and operate and may not be able to control thermal comfort as well as a “right-sized” system. These impacts are evaluated, where data exists. Finally, some suggestions are developed to minimise both the extent of, and the negative impacts of, HVAC system over-sizing, for example: • Challenge “rules of thumb” and/or brief requirements which may be out of date. • Conduct an accurate load estimate, using AIRAH design data, specific to project location, and then resist the temptation to apply “safety factors • Use a load estimation program that accounts for thermal storage and diversification of peak loads for each zone and air handling system. • Select chiller sizes and staged or variable speed pumps and fans to ensure good part load performance. • Allow for unknown future tenancies by designing flexibility into the system, not by over-sizing. For example, generous sizing of distribution pipework and ductwork will allow available capacity to be redistributed. • Provide an auxiliary tenant condenser water loop to handle high load areas. • Consider using an Integrated Design Process, build an integrated load and energy use simulation model and test different operational scenarios • Use comprehensive Life Cycle Cost analysis for selection of the most optimal design solutions. This paper is an interim report on the findings of CRC-CI project 2002-051-B, Right-Sizing HVAC Systems, which is due for completion in January 2006.

The cost-effectiveness of routine follow-up after primary total hip arthroplasty

Routine postsurgery assessment of primary total hip arthroplasty (THA) is recommended in many countries. Whether the benefits of this activity are justified by the costs is not known. We used a decision-analytic Markov model to compare the costs and health outcomes of 3 different follow-up strategies after primary THA. If there is no routine follow-up of patients for 7 years after primary THA, there would be cost savings between AU$6.5 and $11.9 million and gains of between 1.8 and 8.8 quality-adjusted life years. Policy makers should investigate less resource-intensive alternatives to common routine postsurgical assessment.

Reading Squadron: Crossing borders in literacy experiences for preservice teachers.

Teaching literacy requires accurate and current knowledge in the field (Commonwealth of Australia, 2005). There have been persistent inquiries into what constitutes specialist knowledge and skills for teaching students to be literate. Preservice teacher education is fundamental to literacy development, which includes the approaches universities employ to prepare graduates for teaching literacy. Indeed, preservice teacher programs and literacy education also elicit insatiable media coverage. There is a continued push to improve literacy outcomes for school students across the nation and prepare the literacy knowledge and skills of Australian teachers. This study mainly focuses on 10 final-year preservice teachers attending a regional university campus who volunteered for further experiences to teach students to read traditional texts. These preservice teachers completed three university literacy units before commencing with practical applications. A literacy program, titled Reading Squadron, was developed in partnership between a local primary school and the university. Primary students were identified by the school as requiring literacy support. Preservice teachers attended a whole day training session run by school staff at the university and then visited the school for two one-hour sessions each week over a six-week period. Each preservice teacher was assigned two students and worked with each student for half an hour twice a week. The aim of this small-scale qualitative study was to investigate the perceptions of the preservice teachers and school staff as a result of their involvement in the Reading Squadron program. The preservice teachers completed a questionnaire to determine their views of the program and ascertain how it assisted their development. Further data were gathered from the preservice teachers through individual face-to-face interviews. Three school staff involved in the program also completed a questionnaire to determine the value of the program. Results indicated that the preservice teachers made links between theory and practice, and felt they gained knowledge about teaching reading. Three preservice teachers noted it was difficult to work around timetable commitments but gained from the experience and suggested embedding such experiences into university literacy units. Data gathered from school staff indicated that six-weeks was not sufficient time to measure improvements in the school students, however, they were supportive of such a program, particularly for its continuation. Collaborations between schools and universities can provide opportunities for preservice teachers to use theoretical knowledge gained from core university subjects with application to assist primary students’ literacy development in schools. Teachers in this study were supportive of the Reading Squadron program, however, more data needed to be collected to understand the literacy improvement of students. Longitudinal studies are required to ascertain specific knowledge and skills gained by preservice teachers to teach reading and how these programs enhance students’ literacy levels.

Twisted Edwards curves revisited

This paper introduces fast algorithms for performing group operations on twisted Edwards curves, pushing the recent speed limits of Elliptic Curve Cryptography (ECC) forward in a wide range of applications. Notably, the new addition algorithm uses for suitably selected curve constants. In comparison, the fastest point addition algorithms for (twisted) Edwards curves stated in the literature use . It is also shown that the new addition algorithm can be implemented with four processors dropping the effective cost to . This implies an effective speed increase by the full factor of 4 over the sequential case. Our results allow faster implementation of elliptic curve scalar multiplication. In addition, the new point addition algorithm can be used to provide a natural protection from side channel attacks based on simple power analysis (SPA).

Power over, with and through : another look at micropolitics

Understanding micropolitics has become an important part of understanding leadership and power relations within schools. In this paper we review some of the pertinent literature and writing in the field, particularly as it relates to school leadership. Drawing on a couple of existing models, we present a new model that highlights three central power-based leadership approaches—‘power with’, ‘power through’ and ‘power over’. We put forward two contrasting vignettes that reveal a variety of micropolitical strategies used by school principals in the governance of their schools. These strategies range from favouritism and control at one end to empowerment and collaboration at the other. The vignettes are analysed in the light of the model and micropolitical literature presented in this article.

Hybrid system simulation of computer control applications over communication networks

Discrete event-driven simulations of digital communication networks have been used widely. However, it is difficult to use a network simulator to simulate a hybrid system in which some objects are not discrete event-driven but are continuous time-driven. A networked control system (NCS) is such an application, in which physical process dynamics are continuous by nature. We have designed and implemented a hybrid simulation environment which effectively integrates models of continuous-time plant processes and discrete-event communication networks by extending the open source network simulator NS-2. To do this a synchronisation mechanism was developed to connect a continuous plant simulation with a discrete network simulation. Furthermore, for evaluating co-design approaches in an NCS environment, a piggybacking method was adopted to allow the control period to be adjusted during simulations. The effectiveness of the technique is demonstrated through case studies which simulate a networked control scenario in which the communication and control system properties are defined explicitly.

Prediction of highway truck conveyance configuration under over-limit prohibition and conveyance equilibrium

Aiming at the shortage of prevailing prediction methods about highway truck conveyance configuration in over-limit freight research that transferring the goods attributed to over-limit portion to another fully loaded truck of the same configuration and developing the truck traffic volume synchronously, a new way to get accumulated probability function of truck power tonnage in basal year by highway truck classified by wheel and axle type load mass spectrum investigation was presented. Logit models were used to forecast overall highway freight diversion and single cargo tonnage diversion when the weight rules and strict of enforcement intensity of overload were changed in scheme year. Assumption that the probability distribution of single truck loadage should be consistent with the probability distribution of single goods freighted, the model describes the truck conveyance configuration in the future under strict over-limit prohibition. The model was used and tested in Highway Over-limit Research Project in Anhui by World Bank.

"Over The Hill" is not so far away : crossing teaching contexts to create benefits for all through rural teaching experiences.

Attracting and retaining quality teachers to rural and remote areas has been a challenge over the last decade. Many preservice teachers are reluctant to experience a rural and remote practicum and may not consider applying to teach in such areas when they graduate. Education departments and universities need to explore innovative ways that will encourage graduates to consider undertaking a teaching position in the bush. As a way forward, preservice teachers from a regional campus of a Queensland University were invited to participate in a six-day rural experience entitled ‘Over the Hill’ that included being billeted with local families, participating in community activities and observing and teaching in classrooms. Fifteen preservice teachers were accompanied by two university academics who returned to work in a classroom as teacher for their own rural and remote professional experience. The aim of this qualitative study was to explore and describe the perceptions of a rural and remote teaching experience from the perspectives of the preservice teachers, the accompanying academics and the school staff hosting the program. Data were collected from the preservice teachers and accompanying academics in the form of written reflections while fourteen school staff completed a related questionnaire. The results indicated that a six-day rural and remote teaching program can provide professional benefits for all involved, preservice teachers, accompanying academics and the school staff hosting the program. Indeed, this study indicates that short experiences such as “Over the Hill” not only assist preservice teachers to make informed decisions about teaching in rural and remote areas but can provide professional benefits for accompanying academics and the schools.

Building for competitive advantage in early stage start-ups : the role of entrepreneurial capabilities

Recent theoretical work has suggested “entrepreneurial capabilities” themselves may provide the resource foundations to deliver competitive advantage for entrepreneurial firms. This paper empirically examines how start-ups use such entrepreneurial capabilities to build competitive advantage. We investigate the effects of technological and marketing expertise, knowledge of market trends, flexibility and networking on the ability to obtain a cost leadership or differentiation advantage. Using a large dataset of 1,108 start-ups obtained after random sampling of over 30,193 households, we find that differentiation strategies benefit from most resource advantages. Cost leadership strategies, however, seem only to benefit from technological expertise and flexibility and not related to market-based advantages. By doing so, this study contributes to both entrepreneurship and RBV-theories by showing how entrepreneurial capabilities lead to competitive advantages in nascent and early-stage start-ups.

Prags Boulevard in Copenhagen : from run-down strip to boulevard

Prags Boulevard will form a 2km long pedestrian spine running east-west between the historic cities of Copenhagen and Amager. It is located on a some-what run down site, which accommodated illicit functions such as casual drug use and drinking, as well as sheds for squatters. The renovation of this site by the city of Copenhagen forms part of the Holmbladsgade renovation project, and a two-phase competition was held in 2001 to develop a green area and meeting place, transforming it into a place that residents would want to visit rather than avoid. The designer, local landscape architect Kristine Jensens recognises that though the site is linear it ‘has no traffic importance’, though as she notes ‘we like the project because it runs straight east west from the city pulse to the water of Oresund’. In developing the project, she has attempted to allow it to ‘run parallel’ to its existing illicit uses, using a ‘light touch’ of insertions. While it would be hard to describe the project as truly light in its touch (graphically, it is a very bold scheme), there is no doubt that it is parallel: in terms of use it runs alongside rather than against existing uses; in terms of its type it’s all about length, like a boulevard, although it clearly differs from a boulevard in other respects.