Abstract
In highly populated urban zones, it is common to notice headway deviations (HD) between pairs of buses. When these events occur in a bus stop, they often cause bus bunching (BB) in the following bus stops. Several proposals have been suggested to mitigate this problem. In this paper, we propose to find BBS (Bunching Black Spots) - sequences of bus stops where systematic HD events cause the formation of BB. We run a sequence mining algorithm, named PrefixSpan, to find interesting events available in time series. We prove that we can accurately model the BB trip usual pattern like a frequent sequence mining problem. The subsequences proved to be a promising way of identify the route' schedule points to adjust in order to mitigate such events. © 2012 Springer-Verlag.

Abstract
A high sensitivity Fabry-Perot (FP) strain sensor based on hollow-core ring photonic crystal fiber was investigated. A low-finesse FP cavity was fabricated by splicing a section of hollow-core ring photonic crystal fiber between two standard single mode fibers. The geometry presents a low cross section area of silica enabling to achieve high strain sensitivity. Strain measurements were performed by considering the FP cavity length in a range of 1000 mu m. The total length of the strain gauge at which strain was applied was also studied for a range of 900 mm. The FP cavity length variation highly influenced the strain sensitivity, and for a length of 13 mu m a sensitivity of 15.4 pm/mu epsilon was attained. Relatively to the strain gauge length, its dependence to strain sensitivity is low. Finally, the FP cavity presented residual temperature sensitivity (similar to 0.81 pm/degrees C). (C) 2012 Optical Society of America

Abstract

Abstract
A systematic tool-based method is outlined that raises questions about the circumstances surrounding an incident: why it happened and what went wrong. The approach offers a practical and systematic way to apply a distributed cognition perspective to incident investigations, focusing on how available information resources (or the lack of them) may shape user action, rather than just on causal chains. This perspective supports a deeper understanding of the more systemic causes of incidents. The analysis is based on a higher order-logic model describing how information resources may have influenced the actions of those involved in the incident. The PVS theorem proving system is used to identify situations where available resources may afford unsafe user actions. The method is illustrated using a healthcare case study. © 2012 Springer-Verlag.

Abstract

Abstract
Tabled evaluation is a recognized and powerful technique that overcomes some limitations of traditional Prolog systems in dealing with recursion and redundant sub-computations. During tabled execution, several decisions have to be made. These are determined by the scheduling strategy. Whereas a strategy can achieve very good performance for certain applications, for others it might add overheads and even lead to unacceptable inefficiency. The two most successful tabling scheduling strategies are local scheduling and batched scheduling. In previous work, we have developed a framework, on top of the Yap system, that supports the combination of different linear tabling strategies for local scheduling. In this work, we propose the extension of our framework, to support batched scheduling. In particular, we are interested in the two most successful linear tabling strategies, the DRA and DRE strategies. To the best of our knowledge, no single tabling Prolog system supports both strategies simultaneously for batched scheduling.