Similitude: Interfacing a Traffic Simulator and Network Simulator with Emulated Android Clients

Mobile phone apps are increasingly part and parcel of today's intelligent transportation systems (ITS). Evaluating these apps at scale requires modeling of phones and networks, along with vehicles, people and roads. In this paper, we present Similitude, a system comprising a traffic simulator, network simulator, and cluster of Android emulators that has applications in mobile app development as well as modern transport simulation. Apps with their wireless network stack are run on an Android emulator, with network packet delivery modeled in detail via a network simulator. Each phone's location and human interaction elements are obtained through interfacing with a microscopic traffic simulator running driver and pedestrian behavioral models. A prototype of the system is shown to scale well up to 300 simultaneous connected Android emulators, with individual system components scaling upwards of thousands of agents. An ITS app that does road space rationing is used as the case study demonstrating a potential use case of Similitude

Modeling reaction time within a traffic simulation model

Human reaction time has a substantial effect on modeling of human behavior at a microscopic level. Drivers and pedestrian do not react to an event instantaneously; rather, they take time to perceive the event, process the information, decide on a response and finally enact their decision. All these processes introduce delay. As human movement is simulated at increasingly fine-grained resolutions, it becomes critical to consider the delay due to reaction time if one is to achieve accurate results. Most existing simulators over-simplify the reaction time implementation to reduce computational overhead and memory requirements. In this paper, we detail the framework which we are developing within the SimMobility Short Term Simulator (a microscopic traffic simulator), which is capable of explicitly modeling reaction time for each person in a detailed, flexible manner. This framework will enable modelers to set realistic reaction time values, relying on the simulator to handle implementation and optimization considerations. Following this, we report our findings demonstrating the impact of reaction time on traffic dynamics within several simulation scenarios. The findings indicate that in the incorporation of reaction time within microscopic simulations improves the traffic dynamics that produces more realistic traffic condition.Singapore-MIT Alliance for Research and Technolog

Dreaming of Colonialism: Imagining “Place” in Richard Brome’s The Antipodes

This article explores the colonial mindset behind the depiction of space and travel in Richard Brome’s The Antipodes. Using Benedict Anderson’s Imagined Communities and Robert T. Tally Jr.’s “On Literary Cartography: Narrative as a Spatially Symbolic Act” as frames for reading travel and travel literature in the text offers new insight into reading Antipodes’ underlying colonial mindset that is intertwined with the complex metatheatrical elements of the play. I read Peregrine as a British explorer going into the exotic to reform and impose his own ways of knowing on the people of the Antipodes. However, the complex metatheatrical elements further complicate this colonial reading of the text. The text uses metatheatrical elements that ultimately makes the audience aware of their own role in the space of the play—invoking a sense of self reflection. By focusing on the ways in which the exotic world is constructed and imagined, the nation as a performance, and the colonial discourse and power dynamics underlying the text I argue that The Antipodes can be read through modern literary theory to better understand and display the emerging difficulties and problems that accompany the developing sense of English nationalism and proto-colonialism. In doing so, the text displays the inherent colonial structures that inform and limit the role of both travel literature and the romance genre in “imaging” nations—something that is pivotal to both questioning and understanding the role of the nation in an increasingly global context

A response to Dolliver's "Evaluating drug trafficking on the Tor Network: Silk Road 2, the sequel"

The leading aim of Dolliver's (2015) paper “Evaluating drug trafficking on the Tor Network: Silk Road 2, the sequel” is to document changes in the size and structure of cryptomarkets following the demise of SILK ROAD 1 (SR1) using data she collected from SILK ROAD 2 (SR2), which she casts as successor to its namesake

Task-dependent activation of distinct fast and slow(er) motor pathways during motor imagery

Background: Motor imagery and actual movements share overlapping activation of brain areas but little is known about task-specific activation of distinct motor pathways during mental simulation of movements. For real contractions, it was demonstrated that the slow(er) motor pathways are activated differently in ballistic compared to tonic contractions but it is unknown if this also holds true for imagined contractions.Objective: The aim of the present study was to assess the activity of fast and slow(er) motor pathways during mentally simulated movements of ballistic and tonic contractions.Methods: H-reflexes were conditioned with transcranial magnetic stimulation at different interstimulus intervals to assess the excitability of fast and slow(er) motor pathways during a) the execution of tonic and ballistic contractions, b) motor imagery of these contraction types, and c) at rest.Results: In contrast to the fast motor pathways, the slow(er) pathways displayed a task-specific activation: for imagined ballistic as well as real ballistic contractions, the activation was reduced compared to rest whereas enhanced activation was found for imagined tonic and real tonic contractions.Conclusions: This study provides evidence that the excitability of fast and slow(er) motor pathways during motor imagery resembles the activation pattern observed during real contractions. The findings indicate that motor imagery results in task- and pathway-specific subliminal activation of distinct subsets of neurons in the primary motor cortex

Beyond the Surface: The essential role of university staff in transformational reconciliation policy in higher education

The work of the Truth and Reconciliation Commission (TRC) pushed Canada into an era of ‘reconciliation’ and higher education institutions have indicated their desire to respond towards the elusive goal of reconciliation. The TRC report elicited a change to the narrative being used in higher education, shifting the policy focus from one solely based on inclusion, to the consideration of a more transformational goal of reconciliation. The shift spurred an expanded policy audience with reconciliation requiring equal participation from non-Indigenous people. Staff from all corners of campus have found themselves interacting with reconciliation policy. Despite these developments, conceptualization of reconciliation has remained elusive and progress is likely to remain limited given the unshakable foundation of colonialism in the higher education sector. With no concrete answers of how university staff can work in contribution to reconciliation, this paper culminates with an exploration of questions and tensions. The case study of alumni relations is used to provide a more specific and thorough examination; however, the process is intended to be applicable to other areas within the university

Short-term mindfulness practice attenuates reward prediction errors signals in the brain

Activity changes in dopaminergic neurons encode the ongoing discrepancy between expected and actual value of a stimulus, providing a teaching signal for a reward prediction process. Previous work comparing a cohort of long-term Zen meditators to controls demonstrated an attenuation of reward prediction signals to appetitive reward in the striatum. Using a cross-commodity design encompassing primary- and secondary-reward conditioning experiments, the present study asks the question of whether reward prediction signals are causally altered by mindfulness training in naive subjects. Volunteers were randomly assigned to 8 weeks of mindfulness training (MT), active control training (CT), or a one-time mindfulness induction group (MI). We observed a decreased response to positive prediction errors in the putamen in the MT group compared to CT using both a primary and a secondary-reward experiment. Furthermore, the posterior insula showed greater activation to primary rewards, independently of their predictability, in the MT group, relative to CT and MI group. These results support the notion that increased attention to the present moment and its interoceptive features - a core component of mindfulness practice - may reduce predictability effects in reward processing, without dampening (in fact, enhancing) the response to the actual delivery of the stimulus

Sensitive Nonlinear Laser-Based Spectroscopic Studies of Chemical and Biological Agents for Biomedical and Security Applications

Nonlinear laser wave-mixing spectroscopy is presented as an ultrasensitive detection method for chemical and biological agents in thin-film and liquid-phase samples. Wave mixing is an unusually sensitive absorption-based detection method that offers inherent advantages including excellent sensitivity, small sample requirements, short optical path length, high spatial resolution and excellent standoff detection capability. Wave mixing offers excellent optical absorption detection sensitivity even when using thin samples (<0.1 mm), and hence, it is inherently suitable for interfacing to microarrays, microfluidics, and capillary electrophoresis. Laser excitation wavelengths can be tuned to detect multiple chem/bio agents in their native form. Since the wave-mixing signal is a coherent laser-like beam with its own propagation direction, it offers excellent S/N and allows remote standoff detection capability. Laser wave mixing is presented as a way to natively detect small biomolecules and nitroaromatic explosives at zeptomole mass detection limits. The absorbance of select neurotransmitters and nitroaromatic explosives at ultraviolet wavelengths make their detection possible using a compact pulsed UV-laser. The detection of these analytes is successfully accomplished both on UV-transparent surfaces and by using capillary electrophoresis separation. Wave mixing is used for the ultrasensitive detection of cellular proteins and antibodies using fluorescent and non-fluorescent labels. Using sodium dodecyl sulfate capillary gel electrophoresis, proteins can be separated by their size using an appropriate sieving matrix. Newly developed methods employ wave-mixing and capillary electrophoresis for the zeptomole mass detection of cellular proteins and antibodies without the need for time consuming capillary preparation steps. The HIV-1 p24 capsid protein has been detected using laser wave-mixing spectroscopy and capillary electrophoresis using chromophore and fluorophore labels. Size-based capillary electrophoresis separation has also been used to analyze the products of a p24 antibody-antigen reaction. These studies show the potential of wave mixing to be used to create field-deployable and relatively inexpensive HIV viral load screens in resource-limited settings