Traffic flow models with 'slow-to-start' rules

We investigate two models for traffic flow with modified acceleration ('slow-to-start') rules. Even in the simplest case $v_{max}=1$ these rules break the 'particle-hole` symmetry of the model. We determine the fundamental diagram (flow-density relationship) using the so-called car-oriented mean-field approach (COMF) which yields the exact solution of the basic model with $v_{max}=1$. Here we find that this is no longer true for the models with modified acceleration rules, but the results are still in good agreement with simulations. We also compare the effects of the two different slow-to-start rules and discuss their relevance for real traffic. In addition, in one of these models we find a new phase transition to a completely jammed state.Comment: Latex, 15 pages, 6 ps-figure

Best Practices for Research Analytics & Business Intelligence within the Research Domain

While an increased number of industries with business operations have been shaping their use of data analytics, the use of such tools and methods within the higher education research domain, specifically research administration, is still in its infancy. This mixed-methods study collected data to identify best practices in how universities and other research organizations use data analytics to drive their strategic agendas, create efficiency in operations, and promote complex research proposals throughout their institutions. Research methods included a survey to collect data on how research offices are using analytics and business intelligence tools, Rasch analysis (Rasch, 1993) to examine survey instrument quality and provide insights into the use of analytics and business intelligence tools in research offices, and interviews with research administrators and stakeholders to identify best practices in using data tools to impact their decisions, processes, and programming. Results from the Rasch analysis showed that except for two recommendations for individual scales, all survey scales exhibited satisfactory reliabilities and rating scale performance. Findings from interviews revealed best practices such as clear ownership and definitions of the data entry process, identified stewards of each of the high-level areas of data, and confirmed understanding of terms after data requests

Practical high-throughput content-based routing using unicast state and probabilistic encodings

We address the problem that existing publish/subscribe messaging systems, including such commonly used ones as Apache’s ActiveMQ and IBM’s WebSphere MQ, exhibit degraded end-to-end throughput performance in a wide-area network setting. We contend that the cause of this problem is the lack of an appropriate routing protocol. Building on the idea of a content-based network, we introduce a protocol called B-DRP that can demonstrably improve the situation. A content-based network is a content-based publish/subscribe system architected as a datagram network: a message is forwarded hop-by-hop and delivered to any and all hosts that have expressed interest in the message content. This fits well with the character of a wide-area messaging system. B-DRP is based on two main techniques: a message delivery mechanism that utilizes and exploits unicast forwarding state, which can be easily maintained using standard protocols, and a probabilistic data structure to effciently represent and evaluate receiver interests. We present the design of B-DRP and the results of an experimental evaluation that demonstrates its support for improved throughput in a wide-area setting

Categorization of indoor places using the Kinect sensor

The categorization of places in indoor environments is an important capability for service robots working and interacting with humans. In this paper we present a method to categorize different areas in indoor environments using a mobile robot equipped with a Kinect camera. Our approach transforms depth and grey scale images taken at each place into histograms of local binary patterns (LBPs) whose dimensionality is further reduced following a uniform criterion. The histograms are then combined into a single feature vector which is categorized using a supervised method. In this work we compare the performance of support vector machines and random forests as supervised classifiers. Finally, we apply our technique to distinguish five different place categories: corridors, laboratories, offices, kitchens, and study rooms. Experimental results show that we can categorize these places with high accuracy using our approach

Following the Problem Organisation: A Design Strategy for Engineering Emergence

To support the development of self-organising systems, we explain and rationalise the following architectural strategy: directly mapping the solution decomposition on the problem organisation and only relying on the problem abstractions for the design. We illustrate this with an example from swarm robotics

Energy and Economy: Recognizing High-Energy Modernity as a Historical Period

This introduction to Economic Anthropology’s special issue on “Energy and Economy” argues that we might find inspiration for a much more engaged and public anthropology in an unlikely place—19th century evolutionist thought. In addition to studying the particularities of energy transitions, which anthropology does so well, a more engaged anthropology might also broaden its temporal horizons to consider the nature of the future “stage” into which humanity is hurtling in an era of resource depletion and climate change. Net energy (EROEI), or the energy “surplus” on which we build and maintain our complex societal arrangements, is a key tool for anthropologists as we bring our trademark cross-cultural, ethnographically grounded knowledge and perspectives to bear in examining the complex interplay of material infrastructures, energy flows, social organization, and culture. We are now mindful of the always already cultural nature of such circuitry and interactions—in ways obviously unavailable to our nineteenth-century forebears. And yet even as our energy futures are neither predetermined nor inevitable, neither are they as unfettered by material constraints as many have come to think. A robust anthropology of energy informed by awareness of the energetic basis of the historically specific moment in which we find ourselves seems poised to help us get beyond the developmentalist ideas of Morgan and Tylor and to overcome a seeming inability to think comprehensively about the human predicament in simultaneously general and particular terms. We have a chance in the space now opening to get beyond the antinomies—materialist—mentalist, infrastructure—superstructure, agency—structure, objective—subjective, and so on—that dominated much of twentieth-century anthropology

Spatially resolved mid-infrared observations of the triple system T Tauri

To enhance our knowledge of the characteristics and distribution of the circumstellar dust associated with the individual components of the young hierarchical triple system T Tau, observations in the N-band with MIDI at the VLTI were performed. Our study is based on both the interferometric and the spectrophotometric measurements and is supplemented by new visual and infrared photometry. Also, the phases were investigated to determine the dominating mid-infrared source in the close southern binary. The data were fit with the help of a sophisticated physical disc model. This model utilises the radiative transfer code MC3D that is based on the Monte-Carlo method. Extended mid-infrared emission is found around all three components of the system. Simultaneous fits to the photometric and interferometric data confirm the picture of an almost face-on circumstellar disc around T Tau N. Towards this star, the silicate band is seen in emission. This emission feature is used to model the dust content of the circumstellar disc. Clear signs of dust processing are found. Towards T Tau S, the silicate band is seen in absorption. This absorption is strongly pronounced towards the infrared companion T Tau Sa as can be seen from the first individual N-band spectra for the two southern components. Our fits support the previous suggestion that an almost edge-on disc is present around T Tau Sa. This disc is thus misaligned with respect to the circumstellar disc around T Tau N. The interferometric data indicate that the disc around T Tau Sa is oriented in the north-south direction, which favours this source as launching site for the east-western jet. We further determine from the interferometric data the relative positions of the components of the southern binary.Comment: 24 pages, 19 figures, accepted for publication in A&

Discourse and emotions in international relations

The field of International Relations (IR) has recently witnessed the emergence of a wide variety of different approaches to make sense of the many ways emotions work in and through discourse. This forum takes stock of and investigates this link based on two interrelated questions: Why study emotions through discourse? How can we study emotions through discourse? Concerning the first question, we argue that textual and verbal utterances provide us with a promising way to make emotions empirically accessible for researchers. Regarding the second question, we argue that it is essential to develop specific criteria for the study of emotions via speech acts. We propose three criteria that the study of emotion discourse must answer to, which revolve around theory (what is an emotion?), expression (how are emotions communicated?), and effects (what do emotions do?). In a step toward fostering engagement and dialogue on these questions, the contributors of this forum propose a variety of approaches to study emotion discourse in world politics. The idea is to explore the ways in which discourse evokes, reveals, and engages emotions and how these effects can speak to larger questions in IR. Precisely, the goal with this forum is to go beyond the “emotions matter” approach of the first wave of emotions scholarship in IR to offer more specific ways to integrate the consideration of emotion into existing research, particularly that of a constructivist vein