Towards more train paths through early passenger intention inference

© 2015 ATRF, Commonwealth of Australia. All rights reserved. In public train stations, the designed way finding tends to induce individuals to conform to specific egress patterns. Whilst this is desirable for a number of reasons, it can cumulate into congestion at specific points in the station. Which, in turn, can increase dwell time; for example, loading and unloading time increases with concentrations of people trying to load/unload onto the same carriage. Clearly, an influencing strategy that is more responsive to the current station situation could have advantages. Our prior research studies in Perth Station demonstrated the feasibility of reliably and predictably influencing passengers egress patterns in real time during operations. This capability suggests the possibility of active counterbalancing of the egress-alternatives while maintaining way finding. However, the prerequisite for such capability is the availability of knowledge of passenger's intention at a point in their journey where viable egress-alternatives to their destination exist. This work details an approach towards an early (in the passenger journey) passenger intention inference system necessary to enable active egress-alternative influencing. Our contextually grounded approach infers intention through reasoning upon observed system and passenger cues in conjunction with a-priori knowledge of how train stations are used. The empirical validation of our intention inference system, which was conducted with data acquired during operations on a platform in Brisbane’s Central train station in Queensland, is presented and discussed. The findings are then employed to argue the feasibility of an influencing system to reduce passenger congestion and the potential service impacts

Statistics of first-passage times in disordered systems using backward master equations and their exact renormalization rules

We consider the non-equilibrium dynamics of disordered systems as defined by a master equation involving transition rates between configurations (detailed balance is not assumed). To compute the important dynamical time scales in finite-size systems without simulating the actual time evolution which can be extremely slow, we propose to focus on first-passage times that satisfy 'backward master equations'. Upon the iterative elimination of configurations, we obtain the exact renormalization rules that can be followed numerically. To test this approach, we study the statistics of some first-passage times for two disordered models : (i) for the random walk in a two-dimensional self-affine random potential of Hurst exponent $H$, we focus on the first exit time from a square of size $L \times L$ if one starts at the square center. (ii) for the dynamics of the ferromagnetic Sherrington-Kirkpatrick model of $N$ spins, we consider the first passage time $t_f$ to zero-magnetization when starting from a fully magnetized configuration. Besides the expected linear growth of the averaged barrier $\bar{\ln t_{f}} \sim N$, we find that the rescaled distribution of the barrier $(\ln t_{f})$ decays as $e^{- u^{\eta}}$ for large $u$ with a tail exponent of order $\eta \simeq 1.72$. This value can be simply interpreted in terms of rare events if the sample-to-sample fluctuation exponent for the barrier is $\psi_{width}=1/3$.Comment: 8 pages, 4 figure

Rare region effects at classical, quantum, and non-equilibrium phase transitions

Rare regions, i.e., rare large spatial disorder fluctuations, can dramatically change the properties of a phase transition in a quenched disordered system. In generic classical equilibrium systems, they lead to an essential singularity, the so-called Griffiths singularity, of the free energy in the vicinity of the phase transition. Stronger effects can be observed at zero-temperature quantum phase transitions, at nonequilibrium phase transitions, and in systems with correlated disorder. In some cases, rare regions can actually completely destroy the sharp phase transition by smearing. This topical review presents a unifying framework for rare region effects at weakly disordered classical, quantum, and nonequilibrium phase transitions based on the effective dimensionality of the rare regions. Explicit examples include disordered classical Ising and Heisenberg models, insulating and metallic random quantum magnets, and the disordered contact process.Comment: Topical review, 68 pages, 14 figures, final version as publishe

Towards more train paths through early passenger intention inference

© 2015 ATRF, Commonwealth of Australia. All rights reserved. In public train stations, the designed way finding tends to induce individuals to conform to specific egress patterns. Whilst this is desirable for a number of reasons, it can cumulate into congestion at specific points in the station. Which, in turn, can increase dwell time; for example, loading and unloading time increases with concentrations of people trying to load/unload onto the same carriage. Clearly, an influencing strategy that is more responsive to the current station situation could have advantages. Our prior research studies in Perth Station demonstrated the feasibility of reliably and predictably influencing passengers egress patterns in real time during operations. This capability suggests the possibility of active counterbalancing of the egress-alternatives while maintaining way finding. However, the prerequisite for such capability is the availability of knowledge of passenger's intention at a point in their journey where viable egress-alternatives to their destination exist. This work details an approach towards an early (in the passenger journey) passenger intention inference system necessary to enable active egress-alternative influencing. Our contextually grounded approach infers intention through reasoning upon observed system and passenger cues in conjunction with a-priori knowledge of how train stations are used. The empirical validation of our intention inference system, which was conducted with data acquired during operations on a platform in Brisbane’s Central train station in Queensland, is presented and discussed. The findings are then employed to argue the feasibility of an influencing system to reduce passenger congestion and the potential service impacts

Identification of predation events in wild fish using novel acoustic transmitters

Background: Acoustic telemetry is a commonly used tool to gain knowledge about aquatic animal ecology through the study of their movements. In telemetry studies researchers must make inferences regarding the movements and the fates of tagged animals. Until recently, predation has been inferred in telemetry data using a variety of methods including abrupt changes in movement patterns or habitat use. An acoustic telemetry transmitter has been developed to detect predation events of tagged animals, and while they have performed well in controlled laboratory trials, literature regarding the application of these novel transmitters in field settings is limited. The objective of this research was to describe the detection data obtained from field studies using predation tags and propose methods to incorporate this information in decision-making about the fate of tagged animals. We implanted 60 yellow perch (Perca flavescens) with predation transmitters and evaluated their spatial use in a receiver array (34 ha) using a combination of centres of activity, roaming indices, and step length measures to examine detection data. Results: Over 5 months, 19 apparent predation events were identified by the transmitters. Roaming indices and centres of activity revealed a variety of detection patterns, including instances of altered behaviour before and after predation that matched tag-indentified predation events, dropped tags post-predation, and detections that ceased post-predation indicating the predator might have left the array. Based on the observed patterns, probable predation was inferred for 15 of 19 triggered tags, with unclear fates for four fish. Conclusions: Our study provided a framework to assess the fate of animals tagged with predation transmitters and demonstrate how these tags can contribute to telemetry studies. We showed how detections can be categorized using tag status to compare movement metrics among individuals, provided tools to explore space use surrounding predation events, and synthesized this information to inform uncertainty surrounding tag-identified predation events. Predation tags do not remove all uncertainty about the fate of tagged individuals, but combined with other metrics they increase the likelihood of identifying abnormal movements that could otherwise introduce biased detection histories into studies of small-sized fishes

Inclusion for STEM, the institution, or minoritized youth? Exploring how educators navigate the discourses that shape social justice in informal science learning practices

Understanding equitable practice is crucial for science education since science, technology, engineering, and mathematics (STEM) fields and STEM learning practices remain significantly marked by structural inequalities. In this paper, building on theories of discourse and situated meaning developed by Foucault, Gee, and Sedgewick, we explore how educators navigated discourses about social justice in informal science learning (ISL) across four UK sites. We draw on qualitative, multimodal data across 5 years of a research–practice partnership between a university, a zoo, a social enterprise working to support girls and nonbinary youth in STEM, a community digital arts center, and a science center. We identify three key discourses that shaped social justice practices across all four practice–partner sites: (1) “inclusion” for STEM, (2) “inclusion” for the institution, and (3) “inclusion” for minoritized youth. We discuss how educators (n = 17) enacted, negotiated, resisted, and reworked these discourses to create equitable practice. We argue that while the three key discourses shaped the possible meanings and practices of equitable ISL in different ways, educators used their agency and creativity to develop more expansive visions of social justice. We discuss how the affordances, pitfalls, and contradictions that emerged within and between the three discourses were strategically navigated and disrupted by educators to support the minoritized youth they worked with, as well as to protect and promote equity in ISL. This paper contributes to research on social justice in ISL by grounding sometimes abstract questions about power and discourse in ISL educators' everyday work

Re-expression of SMARCA4/BRG1 in Small Cell Carcinoma of Ovary, Hypercalcemic Type (SCCOHT) promotes an epithelial-like gene signature through an AP-1-dependent mechanism

Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT) is a rare and aggressive form of ovarian cancer. SCCOHT tumors have inactivating mutations in SMARCA4 (BRG1), one of the two mutually exclusive ATPases of the SWI/SNF chromatin remodeling complex. To address the role that BRG1 loss plays in SCCOHT tumorigenesis, we performed integrative multi-omic analyses in SCCOHT cell lines +/- BRG1 reexpression. BRG1 reexpression induced a gene and protein signature similar to an epithelial cell and gained chromatin accessibility sites correlated with other epithelial originating TCGA tumors. Gained chromatin accessibility and BRG1 recruited sites were strongly enriched for transcription-factor-binding motifs of AP-1 family members. Furthermore, AP-1 motifs were enriched at the promoters of highly upregulated epithelial genes. Using a dominant-negative AP-1 cell line, we found that both AP-1 DNA-binding activity and BRG1 reexpression are necessary for the gene and protein expression of epithelial genes. Our study demonstrates that BRG1 reexpression drives an epithelial-like gene and protein signature in SCCOHT cells that depends upon by AP-1 activity