Modelling issues on the railway resource management process using multi-agent system

Many infrastructure and necessity systems such as electricity and telecommunication in Europe and the Northern America were used to be operated as monopolies, if not state-owned. However, they have now been disintegrated into a group of smaller companies managed by different stakeholders. Railways are no exceptions. Since the early 1980s, there have been reforms in the shape of restructuring of the national railways in different parts of the world. Continuous refinements are still conducted to allow better utilisation of railway resources and quality of service. There has been a growing interest for the industry to understand the impacts of these reforms on the operation efficiency and constraints. A number of post-evaluations have been conducted by analysing the performance of the stakeholders on their profits (Crompton and Jupe 2003), quality of train service (Shaw 2001) and engineering operations (Watson 2001). Results from these studies are valuable for future improvement in the system, followed by a new cycle of post-evaluations. However, direct implementation of these changes is often costly and the consequences take a long period of time (e.g. years) to surface. With the advance of fast computing technologies, computer simulation is a cost-effective means to evaluate a hypothetical change in a system prior to actual implementation. For example, simulation suites have been developed to study a variety of traffic control strategies according to sophisticated models of train dynamics, traction and power systems (Goodman, Siu and Ho 1998, Ho and Yeung 2001). Unfortunately, under the restructured railway environment, it is by no means easy to model the complex behaviour of the stakeholders and the interactions between them. Multi-agent system (MAS) is a recently developed modelling technique which may be useful in assisting the railway industry to conduct simulations on the restructured railway system. In MAS, a real-world entity is modelled as a software agent that is autonomous, reactive to changes, able to initiate proactive actions and social communicative acts. It has been applied in the areas of supply-chain management processes (García-Flores, Wang and Goltz 2000, Jennings et al. 2000a, b) and e-commerce activities (Au, Ngai and Parameswaran 2003, Liu and You 2003), in which the objectives and behaviour of the buyers and sellers are captured by software agents. It is therefore beneficial to investigate the suitability or feasibility of applying agent modelling in railways and the extent to which it might help in developing better resource management strategies. This paper sets out to examine the benefits of using MAS to model the resource management process in railways. Section 2 first describes the business environment after the railway 2 Modelling issues on the railway resource management process using MAS reforms. Then the problems emerge from the restructuring process are identified in section 3. Section 4 describes the realisation of a MAS for railway resource management under the restructured scheme and the feasible studies expected from the model.

Rates of radiologically confirmed pneumonia as defined by the World Health Organization in Northern Territory Indigenous children

Objective To determine the burden of hospitalised, radiologically confirmed pneumonia (World Health Organization protocol) in Northern Territory Indigenous children. Design, setting and participants Historical, observational study of all hospital admissions for any diagnosis of NT resident Indigenous children, aged between >= 29 days and < 5 years, 1 April 1997 to 31 March 2005. Intervention All chest radiographs taken during these admissions, regardless of diagnosis, were assessed for pneumonia in accordance with the WHO protocol. Main outcome measure The primary outcome was endpoint consolidation (dense fluffy consolidation [alveolar infiltrate] of a portion of a lobe or the entire lung) present on a chest radiograph within 3 days of hospitalisation. Results We analysed data on 24 115 hospitalised episodes of care for 9492 children and 13 683 chest radiographs. The average annual cumulative incidence of endpoint consolidation was 26.6 per 1000 population per year (95% Cl, 25.3-27.9); 57.5 per 1000 per year in infants aged 1-11 months, 38.3 per 1000 per year in those aged 12-23 months, and 13.3 per 1000 per year in those aged 24-59 months. In all age groups, rates of endpoint consolidation in children in the arid southern region of NT were about twice that of children in the tropical northern region. Conclusion The rates of severe pneumonia in hospitalised NT Indigenous children are among the highest reported in the world. Reducing this unacceptable burden of disease should be a national health priority.

Hospitalisation of Indigenous children in the Northern Territory for lower respiratory illness in the first year of life

Objective To describe the epidemiology of acute lower respiratory infection (ALRI) and bronchiectasis in Northern Territory Indigenous infants hospitalised in the first year of life. Design A historical cohort study constructed from the NT Hospital Discharge Dataset and the NT Imm(u)nisation Register. Participants and setting All NT resident Indigenous infants, born 1 January 1999 to 31 December 2004, admitted to NT public hospitals and followed up to 12 months of age. Main outcome measures Incidence of ALRI and bronchiectasis (ICD-10-AM codes) and radiologically confirmed pneumonia (World Health Organization protocol). Results Data on 9295 infants, 8498 child-years of observation and 15 948 hospitalised episodes of care were analysed. ALRI incidence was 426.7 episodes per 1000 child-years (95% Cl, 416.2-437.2). Incidence rates were two times higher (relative risk, 2.12; 95% Cl, 1.98-2.27) for infants in Central Australia compared with those in the Top End. The median age at first admission for an ALRI was 4.6 months (interquartile range, 2.6-7.3). Bronchiolitis accounted for most of the disease burden, with a rate of 227 per 1000 child-years. The incidence of first diagnosis of bronchiectasis was 1.18 per 1000 child-years (95% Cl, 0.60-2.16). One or more key comorbidities were present in 1445 of the 3227 (44.8%) episodes of care for ALRI. Conclusions Rates of ALRI and bronchiectasis in NT Indigenous infants are excessive, with early onset, frequent repeat episodes, and a high prevalence of comorbidities. These high rates of disease demand urgent attention.

Impacts of vessel capacity reduction programmes on efficiency in fisheries : the case of Australia’s multispecies northern prawn fishery

Capacity reduction programmes, in the form of buybacks or decommissioning, have had relatively widespread application in fisheries in the US, Europe and Australia. A common criticism of such programmes is that they remove the least efficient vessels first, resulting in an increase in average efficiency of the remaining fleet, which tends to increase the effective fishing power of the remaining fleet. In this paper, the effects of a buyback programme on average technical efficiency in Australia’s Northern Prawn Fishery are examined using a multi-output production function approach with an explicit inefficiency model. As expected, the results indicate that average efficiency of the remaining vessels was generally greater than that of the removed vessels. Further, there was some evidence of an increase in average scale efficiency in the fleet as the remaining vessels were closer, on average, to the optimal scale. Key factors affecting technical efficiency included company structure and the number of vessels fishing. In regard to fleet size, our model suggests positive externalities associated with more boats fishing at any point in time (due to information sharing and reduced search costs), but also negative externalities due to crowding, with the latter effect dominating the former. Hence, the buyback resulted in a net increase in the individual efficiency of the remaining vessels due to reduced crowding, as well as raising average efficiency through removal of less efficient vessels.

Modal parameters identification of heavy-haul railway RC bridges: Experience acquired

Traditionally, it is not easy to carry out tests to identify modal parameters from existing railway bridges because of the testing conditions and complicated nature of civil structures. A six year (2007-2012) research program was conducted to monitor a group of 25 railway bridges. One of the tasks was to devise guidelines for identifying their modal parameters. This paper presents the experience acquired from such identification. The modal analysis of four representative bridges of this group is reported, which include B5, B15, B20 and B58A, crossing the Carajás railway in northern Brazil using three different excitations sources: drop weight, free vibration after train passage, and ambient conditions. To extract the dynamic parameters from the recorded data, Stochastic Subspace Identification and Frequency Domain Decomposition methods were used. Finite-element models were constructed to facilitate the dynamic measurements. The results show good agreement between the measured and computed natural frequencies and mode shapes. The findings provide some guidelines on methods of excitation, record length of time, methods of modal analysis including the use of projected channel and harmonic detection, helping researchers and maintenance teams obtain good dynamic characteristics from measurement data.

Patterned fen formation and development from the Great Sandy Region, south-east Queensland, Australia

The Great Sandy Region (incorporating Fraser Island and the Cooloola sand-mass), south-east Queensland, contains a significant area of Ramsar-listed coastal wetlands, including the globally important patterned fen complexes. These mires form an elaborate network of pools surrounded by vegetated peat ridges and are the only known subtropical, Southern Hemisphere examples, with wetlands of this type typically located in high northern latitudes. Sedimentological, palynological and charcoal analysis from the Wathumba and Moon Point complexes on Fraser Island indicate two periods of swamp formation (that may contain patterned fens), one commencing at 12 000 years ago (Moon Point) and the other ~4300 years ago (Wathumba). Wetland formation and development is thought to be related to a combination of biological and hydrological processes with the dominant peat-forming rush, Empodisma minus, being an important component of both patterned and non-patterned mires within the region. In contrast to Northern Hemisphere paludifying systems, the patterning appears to initiate at the start of wetland development or as part of an infilling process. The wetlands dominated by E. minus are highly resilient to disturbance, particularly burning and sea level alterations, and appear to form important refuge areas for amphibians, fish and birds (both non-migratory and migratory) over thousands of years.

Albert Namatjira: copyright estates and traditional knowledge

Albert Namatjira was Australia's first Indigenous professional artist. He adapted Western-style painting to express his cultural knowledge of the Arrernte country, for which he was a traditional custodian. In his lifetime, Albert Namatjira achieved great acclaim for his exceptional ability as an artist. However, after his untimely death, he was ignored by the mainstream Australian art world, because of the aesthetic prejudices and social policies of the time. A recent exhibition entitled Seeing the Centre: The art of Albert Namatjira (1902-1959) curated by Alison French has sought to redress this neglect, and provide a retrospective of his work. The exhibition has brought to light that the copyright in the artistic works of Albert Namatjira has not been passed onto his family descendants. In June 1957, Namatjira entered into a copyright agreement with John Brackenreg, the owner of a publishing company by the name of Legend Press, and the associated Artarmon Galleries in Sydney. It was agreed that Legend Press would pay royalties to Namatjira for the sole right to reproduce all of his paintings. Following Namatjira's death in 1959, the administration of his estate passed to the Public Trustee for the Northern Territory Government. The Public Trustee of the Northern Territory Government authorised the sale of Namatjira's copyright to Legend Press in 1983, thereby ending the ability of the descendents of Namatjira to benefit from on-going income from the reproduction of his works. Senator Aden Ridgeway of the Democrats has called on the Federal Government to enter into discussions with the Northern Territory Government to buy back the copyright in Albert Namatjira's works. He argued that exclusive control of the use and reproduction of his works should be restored to his descendants, as well as the receipt of all financial benefits that result from the use and reproduction of his works under copyright protection. The Senator said: 'By doing this, we will all be rewarded, because finally, belatedly, we will be showing Albert Namatjira the reverence that he has always deserved. We will be protecting his legacy for future generations'.

A retrospective evaluation of sustainable yields for Australia's Northern Prawn Fishery

The fundamental aim in fisheries management is to determine an optimal fishing effort for sustainably harvesting from a replenishable resource. The current management objective of Australia's Northern Prawn Fishery is to maximize the long-term net economic return following Australian government policy, resulting in an average recent catch of tiger prawn species of about 1,250 tons only. However, the maximum sustainable catch stated from different studies is around 3,000-4,700 tons. We also evaluated the net profit assuming that there was no buyback scheme in 2005 and the fishing fleet was kept at 89 vessels since 2005 and concluded that 40% more catch on average (2006-2009) and an additional total profit of A$ 17 million ( excluding crew cost) could have been gained in addition to the many millions of dollars of savings in the buyback scheme. These findings have great implications for future management in Australia and elsewhere because there is a grave concern of overfishing worldwide.

Mining in Northern British Columbia

The history of the settlement of the province is tied to patterns of exploration and min development. In Northern British Columbia the Cariboo goldfields provided the impetus for settlement of the region and the beginning for mining to extend into the watern and northern regions in a series of minor gold rushes. The northern half of the province has a geological diverse mineral base that supports a wide variety of mining, and a gradual improvement of exploration and mining methods due to scientific knowledge and technology provided opportunities for lode gold and base metal mines to be developed. The success of mining is based on world ore prices and competitive markets that impact the economic viability of developing a mine. Mining faces increasing pressures in the northern half of the province due to other resource values, such as tourism or protected areas, that claim and compete for a similar land base.