Defining reference service life : an open innovation approach

The endeavour to obtain estimates of durability of components for use in lifecycle assessment or costing and infrastructure and maintenance planning systems is large. The factor method and the reference service life concept provide a very valuable structure, but do not resolve the central dilemma of the need to derive an extensive database of service life. Traditional methods of estimating service life, such as dose functions or degradation models, can play a role in developing this database, however the scale of the problem clearly indicates that individual dose functions cannot be derived for each component in each different local and geographic setting. Thus, a wider range of techniques is required in order to devise reference service life. This paper outlines the approaches being taken in the Cooperative Research Centre for Construction Innovation project to predict reference service life. Approaches include the development of fundamental degradation and microclimate models, the development of a situation-based reasoning ‘engine’ to vary the ‘estimator’ of service life, and the development of a database on expert performance (Delphi study). These methods should be viewed as complementary rather than as discrete alternatives. As discussed in the paper, the situation-based reasoning approach in fact has the possibility of encompassing all other methods.

‘We don’t leave our identities at the city limits’ : Aboriginal and Torres Strait Islander people living in urban localities

Aboriginal and Torres Strait Islander people who live in cities and towns are often thought of as ‘less Indigenous’ than those who live ‘in the bush’, as though they were ‘fake’ Aboriginal people — while ‘real’ Aboriginal people live ‘on communities’ and ‘real’ Torres Strait Islander people live ‘on islands’. Yet more than 70 percent of Australia’s Indigenous peoples live in urban locations (ABS 2007), and urban living is just as much part of a reality for Aboriginal and Torres Strait Islander people as living in remote discrete communities. This paper examines the contradictions and struggles that Aboriginal and Torres Strait Islander people experience when living in urban environments. It looks at the symbols of place and space on display in the Australian cities of Melbourne and Brisbane to demonstrate how prevailing social, political and economic values are displayed. Symbols of place and space are never neutral, and this paper argues that they can either marginalise and oppress urban Aboriginal and Torres Strait Islander people, or demonstrate that they are included and engaged.

Measurement, modelling and capacity analysis for novel, fixed multi-user single-antenna MIMO-OFDM system, in rural environments

High-speed broadband internet access is widely recognised as a catalyst to social and economic development. However, the provision of broadband Internet services with the existing solutions to rural population, scattered over an extensive geographical area, remains both an economic and technical challenge. As a feasible solution, the Commonwealth Scientific and Industrial Research Organization (CSIRO) proposed a highly spectrally efficient, innovative and cost-effective fixed wireless broadband access technology, which uses analogue TV frequency spectrum and Multi-User MIMO (MUMIMO) technology with Orthogonal-Frequency-Division-Multiplexing (OFDM). MIMO systems have emerged as a promising solution for the increasing demand of higher data rates, better quality of service, and higher network capacity. However, the performance of MIMO systems can be significantly affected by different types of propagation environments e.g., indoor, outdoor urban, or outdoor rural and operating frequencies. For instance, large spectral efficiencies associated with MIMO systems, which assume a rich scattering environment in urban environments, may not be valid for all propagation environments, such as outdoor rural environments, due to the presence of less scatterer densities. Since this is the first time a MU-MIMO-OFDM fixed broadband wireless access solution is deployed in a rural environment, questions from both theoretical and practical standpoints arise; For example, what capacity gains are available for the proposed solution under realistic rural propagation conditions?. Currently, no comprehensive channel measurement and capacity analysis results are available for MU-MIMO-OFDM fixed broadband wireless access systems which employ large scale multiple antennas at the Access Point (AP) and analogue TV frequency spectrum in rural environments. Moreover, according to the literature, no deterministic MU-MIMO channel models exist that define rural wireless channels by accounting for terrain effects. This thesis fills the aforementioned knowledge gaps with channel measurements, channel modeling and comprehensive capacity analysis for MU-MIMO-OFDM fixed wireless broadband access systems in rural environments. For the first time, channel measurements were conducted in a rural farmland near Smithton, Tasmania using CSIRO's broadband wireless access solution. A novel deterministic MU-MIMO-OFDM channel model, which can be used for accurate performance prediction of rural MUMIMO channels with dominant Line-of-Sight (LoS) paths, was developed under this research. Results show that the proposed solution can achieve 43.7 bits/s/Hz at a Signal-to- Noise Ratio (SNR) of 20 dB in rural environments. Based on channel measurement results, this thesis verifies that the deterministic channel model accurately predicts channel capacity in rural environments with a Root Mean Square (RMS) error of 0.18 bits/s/Hz. Moreover, this study presents a comprehensive capacity analysis of rural MU-MIMOOFDM channels using experimental, simulated and theoretical models. Based on the validated deterministic model, further investigations on channel capacity and the eects of capacity variation, with different user distribution angles (θ) around the AP, were analysed. For instance, when SNR = 20dB, the capacity increases from 15.5 bits/s/Hz to 43.7 bits/s/Hz as θ increases from 10° to 360°. Strategies to mitigate these capacity degradation effects are also presented by employing a suitable user grouping method. Outcomes of this thesis have already been used by CSIRO scientists to determine optimum user distribution angles around the AP, and are of great significance for researchers and MU-MUMO-OFDM system developers to understand the advantages and potential capacity gains of MU-MIMO systems in rural environments. Also, results of this study are useful to further improve the performance of MU-MIMO-OFDM systems in rural environments. Ultimately, this knowledge contribution will be useful in delivering efficient, cost-effective high-speed wireless broadband systems that are tailor-made for rural environments, thus, improving the quality of life and economic prosperity of rural populations.

Designing mobile systems for social navigation in urban public places

This thesis presents social requirements and design considerations from a study evaluating interactive approaches to social navigation and user-generated information sharing in urban environments using mobile devices. It investigates innovative ways to leverage mobile information and communication technology in order to provide a social navigation platform for residents and visitors in and for public urban places. Through a design case study this work presents CityFlocks, a mobile information system that offers an easy way for information-seeking new residents or visitors to access tacit knowledge from local people about their new community. It is intended to enable visitors and new residents in a city to tap into the knowledge and experiences of local residents in order to gather information about their new environment. Its design specifically aims to lower existing barriers of access and facilitate social navigation in urban places. In various user tests it evaluates two general user interaction alternatives – direct and indirect social navigation – and analyses which interaction method works better for people using a mobile device to socially navigate urban environments. The outcomes are relevant for the user interaction design of future mobile information systems that leverage the social navigation approach.

Nano and ultrafine particle number concentrations in different environments : application towards air quality regulations

Particle number concentrations vary significantly with environment and, in this study, we attempt to assess the significance of these differences. Towards this aim, we reviewed 85 papers that have reported particle number concentrations levels at 126 sites covering different environments. We grouped the results into eight categories according to measurement location including: road tunnel, on-road, road-side, street canyon, urban, urban background, rural, and clean background. From these reports, the overall median number concentration for each of the eight site categories was calculated. The eight location categories may be classified into four distinct groups. The mean median particle number locations for these four types were found to be statistically different from each other. Rural and clean background sites had the lowest concentrations of about 3x103 cm-3. Urban and urban background sites showed concentrations that were three times higher (9x103 cm-3). The mean concentration for the street canyon, roadside and on-road measurement sites was 4.6x104 cm-3, while the highest concentrations were observed in the road tunnels (8.6x104 cm-3). This variation is important when assessing human exposure-response for which there is very little data available, making it difficult to develop health guidelines, a basis for national regulations. Our analyses shows that the current levels in environments affected by vehicle emissions are 3 to 28 times higher than in the natural environments. At present, there is no threshold level in response to exposure to ultrafine particles. Therefore, future control and management strategies should target a decrease of these particles in urban environments by more than one order of magnitude to bring them down to the natural background. At present there is a long way to go to achieve this.

Bats (Mammalia: Chiroptera) in urban fragments of Maringá, Paraná, Brazil

Bat assemblages in two urban fragments of Maringá city, north of the state of Paraná, southern Brazil, were inventoried. These fragments, Parque do Ingá (48 ha) and Parque Florestal dos Pioneiros (59 ha), are located in a subtropical region covered by semideciduous Atlantic forest. Bats were sampled with mist-nets from August 2006 to July 2007, over 24 nights (12 hours a night), adding up to a total of 30,240 h.m2 of net effort. A total of 839 individuals were captured belonging to 10 species and four families. Artibeus lituratus was the most abundant species (66% of the sample). The observed richness represents 22% of the bat species recorded for the state, 24% of the bat species occurring in the seasonal semideciduous forest of Paraná, 26% of the species previously recorded in urban environments in Brazil, and 83.4% of the estimated richness by Jackknife 1 (n= 12 species). Studies that provide data on richness and abundance of bat species in urban fragments are becoming increasingly important, but are still poorly available in Brazil. This habitat is especially interesting because anthropogenic pressure can be harmful to bat assemblages, reducing their diversity. © 2013 Check List and Authors.

Exploring Urban Environments Using Virtual and Augmented Reality

In this paper, we propose the use of specific system architecture, based on mobile device, for navigation in urban environments. The aim of this work is to assess how virtual and augmented reality interface paradigms can provide enhanced location based services using real-time techniques in the context of these two different technologies. The virtual reality interface is based on faithful graphical representation of the localities of interest, coupled with sensory information on the location and orientation of the user, while the augmented reality interface uses computer vision techniques to capture patterns from the real environment and overlay additional way-finding information, aligned with real imagery, in real-time. The knowledge obtained from the evaluation of the virtual reality navigational experience has been used to inform the design of the augmented reality interface. Initial results of the user testing of the experimental augmented reality system for navigation are presented.

Ultrasonic sensors in urban traffic driving-aid systems

Currently, vehicles are often equipped with active safety systems to reduce the risk of accidents, most of which occur in urban environments. The most prominent include Antilock Braking Systems (ABS), Traction Control and Stability Control. All these systems use different kinds of sensors to constantly monitor the conditions of the vehicle, and act in an emergency. In this paper the use of ultrasonic sensors in active safety systems for urban traffic is proposed, and the advantages and disadvantages when compared to other sensors are discussed. Adaptive Cruise Control (ACC) for urban traffic based on ultrasounds is presented as an application example. The proposed system has been implemented in a fully-automated prototype vehicle and has been tested under real traffic conditions. The results confirm the good performance of ultrasonic sensors in these systems. ©2011 by the authors.

Semi-parametric geolocation estimation in NLOS environments

The position of a stationary target can be determined using triangulation in combination with time of arrival measurements at several sensors. In urban environments, none-line-of-sight (NLOS) propagation leads to biased time estimation and thus to inaccurate position estimates. Here, a semi-parametric approach is proposed to mitigate the effects of NLOS propagation. The degree of contamination by NLOS components in the observations, which result in asymmetric noise statistics, is determined and incorporated into the estimator. The proposed method is adequate for environments where the NLOS error plays a dominant role and outperforms previous approaches that assume a symmetric noise statistic.

Recomposing the City: New Directions in Urban Sound Art

This special edition, which we were invited by the journal editors to edit, highlights the proceedings of our International Symposium on sound art and urban architecture. We selected these and other authors from multiple disciplines and practices, including sound art, planning, architecture, and anthropology to analyze how sound might be better understood in urban environments.

Hybrid place : blurring the edge between the digital and physical layers of urban environments

The purpose of this paper is to investigate the edge condition between the digital layers and the physical layers of the city and how tangible expressions of the interrelationships between them to create and define new experiences of place, creating hybrid place. To date there has been discussion and investigation into understanding the importance of place, similarly into defining hybrid space. This paper explores principles of place and space to question how they can be applied into defining and proposing the notion of hybrid place in urban environments. The integration of media spaces into architecture provide infrastructure for the development of hybrid place. The physical boundaries of urban spaces become blurred through the integration of media such as computer technologies connecting the physical environment with the digital. Literature and case studies that reflect the current trends of use of technology by people in space and place within urban environments are examined.

Barriers to Subcontracted Labor Productivity in Urban Development Projects: An On-site Project Management Perspective

Considering the confined and complex nature of urban construction projects, labor productivity is one of the key factors attributing to project success. With the proliferation of sub-contracted labor, there is a necessity to consider the ramifications of this practice to the sector. This research aims to outline how project managers can optimise productivity levels of sub-contracted labor in urban construction projects, by addressing the barriers that most restrict these efficiency levels. A qualitative research approach is employed, incorporating semi-structured interviews based on three case studies from an urban context. The results are scrutinised using mind mapping software and accompanying analytical techniques. The findings from this research indicate that the effective on-site management of sub-contracted labor has a significant impact on the degree of success of an urban development project. The two core barriers to sub-contracted labor productivity are; 1) ineffective supervision of sub-contracted labor, and 2) lack of skilled sub-contracted labor. The implication of this research is that on-site project management play an integral role in the level of productivity achieved by sub-contracted labor in urban development projects. Therefore, on-site management situated in urban, confined construction sites, are encouraged to take heed of the findings herein and address the barriers documented. The value of this research is obtained through consideration of the critical factors; construction management professionals can mitigate such barriers, in order to optimise subcontracted labor productivity on-site.

A soft approach to solving hard problems in construction project management

Construction projects are faced with a challenge that must not be underestimated. These projects are increasingly becoming highly competitive, more complex, and difficult to manage. They become ‘wicked problems’, which are difficult to solve using traditional approaches. Soft Systems Methodology (SSM) is a systems approach that is used for analysis and problem solving in such complex and messy situations. SSM uses “systems thinking” in a cycle of action research, learning and reflection to help understand the various perceptions that exist in the minds of the different people involved in the situation. This paper examines the benefits of applying SSM to wicked problems in construction project management, especially those situations that are challenging to understand and difficult to act upon. It includes relevant examples of its use in dealing with the confusing situations that incorporate human, organizational and technical aspects.