Traffic control enforcement : the problems and dilemma in maintaining post-disaster road infrastructure assets : a case study from Aceh, Indonesia

In 2004, Aceh province was devastated by the earthquake and tsunami. Within the four-year reconstruction period between 2005 and 2009, more than 3600 km of roads were rehabilitated and reconstructed. The ownerships of the reconstructed road assets were transferred back to the Local Governments for the operational and maintenance needs. Hence, the responsibility to maintain most of the road sections are now held by the Local Governments. This paper highlights the problems and dilemmas identified in enforcing the traffic loading control as part of the road maintenance efforts. The data was collected from the literature, documents and through semi-structured interviews conducted with 28 respondents from the case study districts in Aceh province. The finding suggest that conflicting institutional arrangement and policies, socioeconomic consideration and corruption have been the major constraints to effective traffic control enforcement efforts

MSF-Model: Modeling Metastable Failures in Replicated Storage Systems

Metastable failure is a recent abstraction of a pattern of failures that occurs frequently in real-world distributed storage systems. In this paper, we propose a formal analysis and modeling of metastable failures in replicated storage systems. We focus on a foundational problem in distributed systems -- the problem of consensus -- to have an impact on a large class of systems. Our main contribution is the development of a queuing-based analytical model, MSF-Model, that can be used to characterize and predict metastable failures. MSF-Model integrates novel modeling concepts that allow modeling metastable failures which was interactable to model prior to our work. We also perform real experiments to reproduce and validate our model. Our real experiments show that MSF-Model predicts metastable failures with high accuracy by comparing the real experiment with the predictions from the queuing-based model

Performance measures of net-enabled hypercompetitive industries: the case of tourism

This paper investigates the theory and practise of e-metrics. It examines the tourism sector as one of the most successful sectors on-line and identifies best practice in the industry. Qualitative research with top e-Marketing executives demonstrates the usage and satisfaction levels from current e-metrics deployment, selection of e-metrics for ROI calculation as well as intention of new e-metrics implementation and future trends and developments. This paper concludes that tourism organizations gradually realise the value of e-measurement and are willing to implement e-metrics to enable them evaluate the effectiveness of their planning processes and assess their results against their short and the long term objectives

Effects of Cognitive Loading on Pilots and Air Traffic Controller Performance: Implications for Neural Dynamics and Cognitive Flow

The digitized environment in aviation operations has seen marked growth and expansion as new technologies arrive and are implemented. The flight deck and air traffic control functions are two areas where growth is particularly robust. Previous work has identified the effects of compounded cognitive loading and SHELL interfaces in these work environments, and the potential consequences when relief or collaborative resource management is not employed effectively. This paper examines the relationship of cognitive loading in the context of cognitive flow to identify potential areas where neural metrics might aid in a better understanding of the dynamics to determine thresholds of overload. Application of the Triple- Network Model of neural regulation dynamics and Polyvagal Theory are explored for potential relationships to compromised situation awareness and working memory constraints. Conclusions indicate that when cognitive flow is disrupted, cognitive processing loads on working memory expand exponentially and rapidly reach a plateau that inhibits safe performance. Implications suggest a more focused effort in systems and training to address neural metrics and cognitive processing rates

Study of space shuttle environmental control and life support problems

Four problem areas were treated: (1) cargo module environmental control and life support systems; (2) space shuttle/space station interfaces; (3) thermal control considerations for payloads; and (4) feasibility of improving system reusability

Design and Evaluation of a Session-Aware Admission Control Framework for Improving Service Providers' Profitability

International audienceService-aware network management is a key issue for the current and next generation service-oriented networks. In this work, we focus on improving the QoS user experience (QoE) of Internet subscribers connecting to heavily loaded servers. Firstly, we advocate an innovative architecture for fine-grained admission-control of Internet servers subjected to multiple flow-based sessions. The proposed architecture is based on original concepts which meet the constraints of multiple-flow based sessions by explicitly identifying the flows pertaining to a single subscriber's session. Secondly, based on an economically-justified service model, we investigate novel session-aware admission-control for improving providers' profitability. Our fundamental observation is that it is sometimes desirable to reject some customers' new sessions so that others may be completed and thereby generate some revenue for the service provider. We evaluate the performance of the advocated model by conducting advanced simulations where we consider realistic CBR voice traffic. Results demonstrate that responsive session-aware admission-control improves service provider's benefits. For a satisfactory operator's revenue, session-aware admission-control improves the success rate by more than 69 %, compared to standard request-aware admission-control