bluuebunny/crossref_metadata_2025 huggingface dataset:
Selection Into Mental Health Court
Authors: Luskin Mary Lee , Ray Bradley
Published: August 2015

How defendants are selected into mental health courts (MHC) is central to issues of fairness, efficacy, and successful program replication. Only recently has empirical research started to examine MHC selection, revealing a multi-stage process with multiple decision makers and multiple variables. In this study, we use classification and regression tree analysis (CART) to examine the variables suggested in recent research to predict selection into MHC. The analysis includes legal and diagnostic variables, treatment history, measures of treatability, motivation to change, violence risk, and symptom severity. We find that the MHC is more likely to accept defendants who did not have warrants issued for their arrest, who had diagnoses other than depression, and who did not report using illegal drugs around the time of their admission. Symptom severity and motivation to treatment also predict MHC admission, with their effects contingent on defendants’ statuses on other variables.
Evidence-Based Diabetes Prevention and Control Programs and Policies in Local Health Departments
Authors: Zwald Marissa , Elliott Lindsay , Brownson Ross C. , Skala Mahree
Published: August 2015

Purpose

The purpose of this study is to: (1) assess implementation of evidence-based programs and policies (EBPPs) related to diabetes prevention and control in local health departments, (2) assess feasibility of non-implemented diabetes prevention and control EBPPs, and (3) examine individual- and organizational-level factors associated with implementation of diabetes prevention and control EBPPs.

Methods

An online survey was administered in January 2015 to key representatives of all local health departments in Missouri. Descriptive statistics were used to describe implementation and perceived feasibility of 20 diabetes prevention and control EBPPs. Logistic regression was used to examine the association between individual and organizational factors and diabetes prevention and control EBPP implementation.

Results

One hundred local health departments participated (89% response rate) in the online survey. Most frequently implemented diabetes-related EBPPs in local health departments included: nutrition education for agency or community members, increased fruit and vegetable access in community settings, and community-wide campaigns to promote physical activity. Increased encouragement to others in the department to use evidence-based decision making and agency incentives to help employees use evidence-based decision making were positively associated with implementation of diabetes prevention and control EBPPs.

Conclusions

Local health departments are on the “front line” of public health, and this study demonstrates the important role these organizations play in implementing diabetes prevention and control EBPPs. Potential leverage points for more widespread adoption of diabetes-related EBPPs in local health departments include education about and encouragement of evidence-based decision making and organizational incentives for employees to integrate evidence-based decision making into their diabetes prevention and control activities.
Management of Recurrent Catheter‐Related Bloodstream Infections in an Adult Patient Receiving Home Parenteral Nutrition: Dramatic Effect of Ethanol Lock Therapy
Authors: Colvine Jennifer , Thomson Patti , Duerksen Donald R.
Published: August 2015

We report the use of ethanol lock therapy to dramatically reduce the incidence of catheter‐related bloodstream infections (CRBSIs) in a long‐term adult home parenteral nutrition (HPN) patient. This case study demonstrates the efficacy of ethanol lock therapy in eliminating CRBSIs when other treatments have been unsuccessful. We suggest that ethanol lock therapy has an important role in decreasing CRBSI in HPN patients with recurrent CRBSIs.
Constant connection as the media condition of love: where bonds become bondage
Authors: Su Hua
Published: August 2015

Lovers’ capacity to connect with each other over distance has increased drastically with the proliferation of digital media. This augmented capacity to build connection with a distant other has become an important condition of romantic relationship in our time. This article explores the implication of constant connection as a media affordance for romantic relationship by examining media use among young Chinese lovers. Based on in-depth interviews with young Chinese lovers, it argues that constant connection contributes to a continual sense of togetherness between romantic couples as they continually engage in phatic communication, but that it intensifies lovers’ negotiation of intimacy and individuality by pushing their personal boundaries on one hand and cultivating an intolerance of separation on the other. Overall, this article contributes to the scholarly conversation about media technology and human intimacy by offering a critique of social media based on the inner dynamics of romantic relationship.
Recommended Methods for Brain Processing and Quantitative Analysis in Rodent Developmental Neurotoxicity Studies
Authors: Garman Robert H. , Li Abby A. , Kaufmann Wolfgang , Auer Roland N. , Bolon Brad
Published: August 2015

Neuropathology methods in rodent developmental neurotoxicity (DNT) studies have evolved with experience and changing regulatory guidance. This article emphasizes principles and methods to promote more standardized DNT neuropathology evaluation, particularly procurement of highly homologous brain sections and collection of the most reproducible morphometric measurements. To minimize bias, brains from all animals at all dose levels should be processed from brain weighing through paraffin embedding at one time using a counterbalanced design. Morphometric measurements should be anchored by distinct neuroanatomic landmarks that can be identified reliably on the faced block or in unstained sections and which address the region-specific circuitry of the measured area. Common test article–related qualitative changes in the developing brain include abnormal cell numbers (yielding altered regional size), displaced cells (ectopia and heterotopia), and/or aberrant differentiation (indicated by defective myelination or synaptogenesis), but rarely glial or inflammatory reactions. Inclusion of digital images in the DNT pathology raw data provides confidence that the quantitative analysis was done on anatomically matched (i.e., highly homologous) sections. Interpreting DNT neuropathology data and their presumptive correlation with neurobehavioral data requires an integrative weight-of-evidence approach including consideration of maternal toxicity, body weight, brain weight, and the pattern of findings across brain regions, doses, sexes, and ages.
Mouse Models of Acute Respiratory Distress Syndrome
Authors: Aeffner Famke , Bolon Brad , Davis Ian C.
Published: August 2015

Acute respiratory distress syndrome (ARDS) is a severe pulmonary reaction requiring hospitalization, which is incited by many causes, including bacterial and viral pneumonia as well as near drowning, aspiration of gastric contents, pancreatitis, intravenous drug use, and abdominal trauma. In humans, ARDS is very well defined by a list of clinical parameters. However, until recently no consensus was available regarding the criteria of ARDS that should be evident in an experimental animal model. This lack was rectified by a 2011 workshop report by the American Thoracic Society, which defined the main features proposed to delineate the presence of ARDS in laboratory animals. These should include histological changes in parenchymal tissue, altered integrity of the alveolar capillary barrier, inflammation, and abnormal pulmonary function. Murine ARDS models typically are defined by such features as pulmonary edema and leukocyte infiltration in cytological preparations of bronchoalveolar lavage fluid and/or lung sections. Common pathophysiological indicators of ARDS in mice include impaired pulmonary gas exchange and histological evidence of inflammatory infiltrates into the lung. Thus, morphological endpoints remain a vital component of data sets assembled from animal ARDS models.
Regulatory Forum Opinion Piece: Carcinogen Risk Assessment
Authors: Downes Noel , Foster John
Published: August 2015

Throughout the last 50 years, the paradigm for carcinogenicity assessment has depended on lifetime bioassays in rodents. Since 1997, the International Conference on Harmonisation (ICH) S1B has permitted the use of a 2-year rodent bioassay (usually in the rat) and an alternative, genetically modified mouse model to support cancer risk assessment of pharmaceuticals. Since its introduction, it has become apparent that many of the stated advantages of the 6-month Tg mouse bioassay have, in actual fact, not been realized, and the concern exists that an albeit imperfect, 2-year mouse bioassay has been replaced by a similarly imperfect 6-month equivalent. This essay argues strongly that model systems, using cancer as the end point, should be discontinued, and that the recent initiatives, from the Organization for Economic Cooperation and Development and Institute of Peace and Conflict Studies, on “mode of action,” “adverse outcome pathways,” and “human relevance framework” should be embraced as being risk assessments based upon the available science. The recent suggested revisions to the ICH S1 guidelines, utilizing carcinogenicity assessment documents, go some way to developing a science-based risk assessment that does not depend almost entirely on a single, imperfect, cancer-based end point in nonrelevant animal species.
Long-term Local and Systemic Safety of Poly(l-lactide-co-epsilon-caprolactone) after Subcutaneous and Intra-articular Implantation in Rats
Authors: Ramot Yuval , Nyska Abraham , Markovitz Elana , Dekel Assaf , Klaiman Guy , Zada Moran Haim , Domb Abraham J. , Maronpot Robert R.
Published: August 2015

The use of biodegradable materials is gaining popularity in medicine, especially in orthopedic applications. However, preclinical evaluation of biodegradable materials can be challenging, since they are located in close contact with host tissues and might be implanted for a long period of time. Evaluation of these compounds requires biodegradability and biocompatibility studies and meticulous pathology examination. We describe 2 preclinical studies performed on Sprague-Dawley rats for 52 weeks, to evaluate clinical pathology, biocompatibility, biodegradability, and systemic toxicity after implantation of 2-layered films or saline-inflated balloon-shaped implants of downsized InSpace™ devices (termed “test device”). The test devices are made from a copolymer of poly-l-lactide-co-∊-caprolactone in a 70:30 ratio, identical to the device used in humans, intended for the treatment of rotator cuff tears. Intra-articular film implantation and subcutaneous implantation of the downsized device showed favorable local and systemic tolerability. Although the implanted materials have no inherent toxic or tumorigenic properties, one animal developed a fibrosarcoma at the implantation site, an event that is associated with a rodent-predilection response where solid materials cause mesenchymal neoplasms. This effect is discussed in the context of biodegradable materials along with a detailed description of expected pathology for biodegradable materials in long-term rodent studies.
Validity of the Parenting Stress Index Short Form in a Sample of At-Risk Mothers
Authors: Pérez-Padilla Javier , Menéndez Susana , Lozano Oscar
Published: August 2015

Background:

The Parenting Stress Index Short Form (PSI-SF) is a widely used instrument in scientific literature to evaluate the levels of stress a parent feels when facing parenting-related tasks. Despite the potential usefulness of the PSI-SF with at-risk families, no validation studies have been carried out on this population in Spain.

Objectives:

The main objective of this study is to report evidences of the reliability and validity of PSI-SF with a sample of at-risk mothers. Specifically, (1) to examine the discriminative capacity of PSI-SF to differentiate between a community sample and another sample composed of families with various levels of risk and (2) to analyze the relationships with general health indicators and parental sense of competence.

Results:

Analyses reported in this article show satisfactory results regarding appropriate internal consistency coefficients for the scale. With respect to the evidences of validity, results reported here suggest that the total PSI-SF score, but not the two subscales, could be useful to differentiate between different groups of mothers with different levels of risk. The Childrearing stress subscale was associated with a poorer perception as a mother as well as with an external locus of control, and the Personal distress subscale was related to all the general health indicators, explaining a high percentage of variance.

Conclusion:

The results reported show that the total score or the subscales should be used in a differentiated way according to the professional’s objectives. Hence, PSI-SF may be a useful instrument for researchers and practitioners who work with at-risk families.
The Conversational Chameleon
Authors: Kulesza Wojciech , Dolinski Dariusz , Wicher Paula , Huisman Avia
Published: August 2015

Verbal mimicry research claims that repeating words spoken by another makes people more eager to comply with requests made by the mimicker (e.g., fulfilling a request to donate to charity). Instead, another mechanism might explain these results. Recent studies found that when a request was preceded by engaging a participant in dialogue (defined as a short conversation), the participant was more willing to fulfill the request. Thus, verbal mimicry might be perceived in the same way as dialogue. If this is the case, a theoretical confound would be revealed. To test whether the mechanisms are different of the same, two field studies were conducted using a 2 (dialogue: yes/no) × 2 (mimicry: yes/no) design. The study results revealed two main effects and no interaction effects, which means that verbal mimicry and dialogue are two distinct mechanisms. Interestingly, additive effects for these mechanisms were found.
Accumulation by dispossession and the informal economy – Struggles over knowledge, being and waste at a Soweto garbage dump
Authors: Samson Melanie
Published: August 2015

Recent scholarship highlights that accumulation by dispossession creates surplus populations who must sustain themselves outside wage labor, often through informal work. This article theorizes a different aspect of the relationship between the informal economy and accumulation by dispossession by analyzing how the state and capital seek to capture new spheres of accumulation created by informal workers. Drawing on Searle's theorization of social ontology it explores how reclaimers at a Soweto garbage dump reconceptualized trash as holding potential value and transformed the landfill from a commodity cemetery into a resource mine. The attempt to enclose the landfill therefore required appropriating not only the materials at the dump but the very framing of these materials as valuable. Reclaimers' grievance over this “epistemic injustice” fueled their successful opposition to the enclosure, demonstrating the centrality of “epistemic dispossession” to accumulation by dispossession. Highlighting the epistemic and social agency of informal workers considered the epitome of “human waste” establishes the need to recognize all informal workers as producers of knowledge and social reality and facilitates more nuanced understandings of accumulation by dispossession, how and why it is contested, and how alternatives can be forged.
Markets, bodies, and rhythms: A rhythmanalysis of financial markets from open-outcry trading to high-frequency trading
Authors: Borch Christian , Hansen Kristian Bondo , Lange Ann-Christina
Published: August 2015

This article explores the relationship between bodily rhythms and market rhythms in two distinctly different financial market configurations, namely the open-outcry pit (prevalent especially in the early 20th century) and present-day high-frequency trading. Drawing on Henri Lefebvre's rhythmanalysis, we show how traders seek to calibrate their bodily rhythms to those of the market. We argue that, in the case of early-20th-century open-outcry trading pits, traders tried to enact a total merger of bodily and market rhythms. We also demonstrate how, in the 1920s and '30s, market observers began to respond to a widely perceived problem, namely that market rhythms might be contagious and that some form of separation of bodily and market rhythms might therefore be needed. Finally, we show how current high-frequency trading, despite being purely algorithmic, does not render the traders' bodies irrelevant. Yet high-frequency trading does change the role of the body rather than seeking to attune their bodies to the markets, high-frequency traders seek to calibrate their bodies to their algorithms. While the article demonstrates the usefulness of deploying Lefebvre's rhythmanalysis in analyses of financial markets, it also suggests that high-frequency trading in particular might produce new types of market rhythms that, contra Lefebvre, do not revolve around traders' bodies.
From paths to blocks: New measures for street patterns
Authors: Barthelemy Marc
Published: August 2015

The street network is an important aspect of cities and contains crucial information about their organization and evolution. Characterizing and comparing various street networks could then be helpful for a better understanding of the mechanisms governing the formation and evolution of these systems. Their characterization is however not easy: there are no simple tools to classify planar networks and most of the measures developed for complex networks are not useful when space is relevant. Here, we describe recent efforts in this direction and new methods adapted to spatial networks. We will first discuss measures based on the structure of shortest paths, among which the betweenness centrality. In particular for time-evolving road networks, we will show that the spatial distribution of the betweenness centrality is able to reveal the impact of important structural transformations. Shortest paths are however not the only relevant ones. In particular, they can be very different from those with the smallest number of turns—the simplest paths. The statistical comparison of the lengths of the shortest and simplest paths provides a nontrivial and nonlocal information about the spatial organization of planar graphs. We define the simplicity index as the average ratio of these lengths and the simplicity profile characterizes the simplicity at different scales. Measuring these quantities on artificial (roads, highways, railways) and natural networks (leaves, insect wings) show that there are fundamental differences—probably related to their different function—in the organization of urban and biological systems: there is a clear hierarchy of the lengths of straight lines in biological cases, but they are randomly distributed in urban systems. The paths are however not enough to fully characterize the spatial pattern of planar networks such as streets and roads. Another promising direction is to analyze the statistics of blocks of the planar network. More precisely, we can use the conditional probability distribution of the shape factor of blocks with a given area, and define what could constitute the fingerprint of a city. These fingerprints can then serve as a basis for a classification of cities based on their street patterns. This method applied on more than 130 cities in the world leads to four broad families of cities characterized by different abundances of blocks of a certain area and shape. This classification will be helpful for identifying dominant mechanisms governing the formation and evolution of street patterns.
Urban configuration, accessibility, and property prices: a case study of Cardiff, Wales
Authors: Xiao Yang , Orford Scott , Webster Chris J
Published: August 2015

The specification of locational attributes in hedonic houseprice models has traditionally been problematic. Whilst many studies use similar sets of structural attributes the range of locational attributes can be diverse and inconsistent both in their identification and in their measurement. To address this problem, researchers have adopted concepts related to urban configuration such as the monocentric city and the access – space trade-off model, and later multicentric and multiple accessibility models, to structure their enquiry. This has led to issues related to a priori variable specification using geometrically defined accessibility measures that can also lead to problems such as spatial autocorrelation. In this research, we investigate the use of network accessibility metrics in hedonic house price research using Cardiff, Wales as a case study. We hypothesize that a network-modelling approach to measuring accessibility will improve performance compared with conventional planar geometry specifications. We find that estimating centrality variables across a variety of spatial scales allows the impact on property prices of urban configurations to be modelled more accurately. The research shows that not all dimensions of accessibility can be adequately captured by network measures and that conventional planar geometry measures of accessibility can add additional explanatory power in certain circumstances.
Improving Medical Decision Making and Health Promotion through Culture-Sensitive Health Communication
Authors: Betsch Cornelia , Böhm Robert , Airhihenbuwa Collins O. , Butler Robb , Chapman Gretchen B. , Haase Niels , Herrmann Benedikt , Igarashi Tasuku , Kitayama Shinobu , Korn Lars , Nurm Ülla-Karin , Rohrmann Bernd , Rothman Alexander J. , Shavitt Sharon , Updegraff John A. , Uskul Ayse K.
Published: August 2015

This review introduces the concept of culture-sensitive health communication. The basic premise is that congruency between the recipient’s cultural characteristics and the respective message will increase the communication’s effectiveness. Culture-sensitive health communication is therefore defined as the deliberate and evidence-informed adaptation of health communication to the recipients’ cultural background in order to increase knowledge and improve preparation for medical decision making and to enhance the persuasiveness of messages in health promotion. To achieve effective health communication in varying cultural contexts, an empirically and theoretically based understanding of culture will be indispensable. We therefore define culture, discuss which evolutionary and structural factors contribute to the development of cultural diversity, and examine how differences are conceptualized as scientific constructs in current models of cultural differences. In addition, we will explicate the implications of cultural differences for psychological theorizing, because common constructs of health behavior theories and decision making, such as attitudes or risk perception, are subject to cultural variation. In terms of communication, we will review both communication strategies and channels that are used to disseminate health messages, and we will discuss the implications of cultural differences for their effectiveness. Finally, we propose an agenda both for science and for practice to advance and apply the evidence base for culture-sensitive health communication. This calls for more interdisciplinary research between science and practice but also between scientific disciplines and between basic and applied research.
Can I Count on Getting Better? Association between Math Anxiety and Poorer Understanding of Medical Risk Reductions
Authors: Rolison Jonathan J. , Morsanyi Kinga , O’Connor Patrick A.
Published: August 2015

Background. Lower numerical ability is associated with poorer understanding of health statistics, such as risk reductions of medical treatment. For many people, despite good numeracy skills, math provokes anxiety that impedes an ability to evaluate numerical information. Math-anxious individuals also report less confidence in their ability to perform math tasks. We hypothesized that, independent of objective numeracy, math anxiety would be associated with poorer responding and lower confidence when calculating risk reductions of medical treatments. Methods. Objective numeracy was assessed using an 11-item objective numeracy scale. A 13-item self-report scale was used to assess math anxiety. In experiment 1, participants were asked to interpret the baseline risk of disease and risk reductions associated with treatment options. Participants in experiment 2 were additionally provided a graphical display designed to facilitate the processing of math information and alleviate effects of math anxiety. Confidence ratings were provided on a 7-point scale. Results. Individuals of higher objective numeracy were more likely to respond correctly to baseline risks and risk reductions associated with treatment options and were more confident in their interpretations. Individuals who scored high in math anxiety were instead less likely to correctly interpret the baseline risks and risk reductions and were less confident in their risk calculations as well as in their assessments of the effectiveness of treatment options. Math anxiety predicted confidence levels but not correct responding when controlling for objective numeracy. The graphical display was most effective in increasing confidence among math-anxious individuals. Conclusions. The findings suggest that math anxiety is associated with poorer medical risk interpretation but is more strongly related to confidence in interpretations.
Tractable locomotion planning for RoboSimian
Authors: Satzinger Brian W. , Lau Chelsea , Byl Marten , Byl Katie
Published: August 2015

This paper investigates practical solutions for low-bandwidth, teleoperated mobility for RoboSimian in complex environments. Locomotion planning for this robot is challenging due to kinematic redundancy. We present an end-to-end planning method that exploits a reduced-dimension rapidly-exploring random tree search, constraining a subset of limbs to an inverse kinematics table. Then, we evaluate the performance of this approach through simulations in randomized environments and in the style of the Defense Advanced Research Projects Agency Robotics Challenges terrain both in simulation and with hardware.

We also illustrate the importance of allowing for significant body motion during swing leg motions on extreme terrain and quantify the trade-offs between computation time and execution time, subject to velocity and acceleration limits of the joints. These results lead us to hypothesize that appropriate statistical “investment” of parallel computing resources between competing formulations or flavors of random planning algorithms can improve motion planning performance significantly. Motivated by the need to improve the speed of limbed mobility for the Defense Advanced Research Projects Agency Robotics Challenge, we introduce one formulation of this resource allocation problem as a toy example and discuss advantages and implications of such trajectory planning for tractable locomotion on complex terrain.
Topological trajectory classification with filtrations of simplicial complexes and persistent homology
Authors: Pokorny Florian T. , Hawasly Majd , Ramamoorthy Subramanian
Published: August 2015

In this work, we present a sampling-based approach to trajectory classification which enables automated high-level reasoning about topological classes of trajectories. Our approach is applicable to general configuration spaces and relies only on the availability of collision free samples. Unlike previous sampling-based approaches in robotics which use graphs to capture information about the path-connectedness of a configuration space, we construct a multiscale approximation of neighborhoods of the collision free configurations based on filtrations of simplicial complexes. Our approach thereby extracts additional homological information which is essential for a topological trajectory classification. We propose a multiscale classification algorithm for trajectories in configuration spaces of arbitrary dimension and for sets of trajectories starting and ending in two fixed points. Using a cone construction, we then generalize this approach to classify sets of trajectories even when trajectory start and end points are allowed to vary in path-connected subsets. We furthermore show how an augmented filtration of simplicial complexes based on an arbitrary function on the configuration space, such as a costmap, can be defined to incorporate additional constraints. We present an evaluation of our approach in 2-, 3-, 4- and 6-dimensional configuration spaces in simulation and in real-world experiments using a Baxter robot and motion capture data.
Dynamics and trajectory optimization for a soft spatial fluidic elastomer manipulator
Authors: Marchese Andrew D. , Tedrake Russ , Rus Daniela
Published: August 2015

The goal of this work is to develop a soft-robotic manipulation system that is capable of autonomous, dynamic, and safe interactions with humans and its environment. First, we develop a dynamic model for a multi-body fluidic elastomer manipulator that is composed entirely from soft rubber and subject to the self-loading effects of gravity. Then, we present a strategy for independently identifying all of the unknown components of the system; these are the soft manipulator, its distributed fluidic elastomer actuators, as well as the drive cylinders that supply fluid energy. Next, using this model and trajectory-optimization techniques we find locally-optimal open-loop policies that allow the system to perform dynamic maneuvers we call grabs. In 37 experimental trials with a physical prototype, we successfully perform a grab 92% of the time. Last, we introduce the idea of static bracing for a soft elastomer arm and discuss how forming environmental braces might be an effective manipulation strategy for this class of robots. By studying such an extreme example of a soft robot, we can begin to solve hard problems inhibiting the mainstream use of soft machines.
Relative continuous-time SLAM
Authors: Anderson Sean , MacTavish Kirk , Barfoot Timothy D.
Published: August 2015

Appearance-based techniques for simultaneous localization and mapping (SLAM) have been highly successful in assisting robot-motion estimation; however, these vision-based technologies have long assumed the use of imaging sensors with a global shutter, which are well suited to the traditional, discrete-time formulation of visual problems. In order to adapt these technologies to use scanning sensors, we propose novel methods for both outlier rejection and batch nonlinear estimation. Traditionally, the SLAM problem has been formulated in a single-privileged coordinate frame, which can become computationally expensive over long distances, particularly when a loop closure requires the adjustment of many pose variables. Recent discrete-time estimators have shown that a completely relative coordinate framework can be used to incrementally find a close approximation of the full maximum-likelihood solution in constant time. In order to use scanning sensors, we propose moving the relative coordinate formulation of SLAM into continuous time by estimating the velocity profile of the robot. We derive the relative formulation of the continuous-time robot trajectory and formulate an estimator using temporal basis functions. A motion-compensated outlier rejection scheme is proposed by using a constant-velocity model for the random sample consensus algorithm. Our experimental results use intensity imagery from a two-axis scanning lidar; due to the sensors’ scanning nature, it behaves similarly to a slow rolling-shutter camera. Both algorithms are validated using a sequence of 6880 lidar frames acquired over a 1.1 km traversal.
A novel type of compliant and underactuated robotic hand for dexterous grasping
Authors: Deimel Raphael , Brock Oliver
Published: August 2015

The usefulness and versatility of a robotic end-effector depends on the diversity of grasps it can accomplish and also on the complexity of the control methods required to achieve them. We believe that soft hands are able to provide diverse and robust grasping with low control complexity. They possess many mechanical degrees of freedom and are able to implement complex deformations. At the same time, due to the inherent compliance of soft materials, only very few of these mechanical degrees have to be controlled explicitly. Soft hands therefore may combine the best of both worlds. In this paper, we present RBO Hand 2, a highly compliant, underactuated, robust, and dexterous anthropomorphic hand. The hand is inexpensive to manufacture and the morphology can easily be adapted to specific applications. To enable efficient hand design, we derive and evaluate computational models for the mechanical properties of the hand’s basic building blocks, called PneuFlex actuators. The versatility of RBO Hand 2 is evaluated by implementing the comprehensive Feix taxonomy of human grasps. The manipulator’s capabilities and limits are demonstrated using the Kapandji test and grasping experiments with a variety of objects of varying weight. Furthermore, we demonstrate that the effective dimensionality of grasp postures exceeds the dimensionality of the actuation signals, illustrating that complex grasping behavior can be achieved with relatively simple control.
Exponentially stabilizing continuous-time controllers for periodic orbits of hybrid systems: Application to bipedal locomotion with ground height variations
Authors: Hamed Kaveh Akbari , Buss Brian G. , Grizzle Jessy W.
Published: August 2015

This paper presents a systematic approach for the design of continuous-time controllers to robustly and exponentially stabilize periodic orbits of hybrid dynamical systems arising from bipedal walking. A parameterized family of continuous-time controllers is assumed so that (1) a periodic orbit is induced for the hybrid system, and (2) the orbit is invariant under the choice of controller parameters. Properties of the Poincaré map and its first- and second-order derivatives are used to translate the problem of exponential stabilization of the periodic orbit into a set of bilinear matrix inequalities (BMIs). A BMI optimization problem is then set up to tune the parameters of the continuous-time controller so that the Jacobian of the Poincaré map has its eigenvalues in the unit circle. It is also shown how robustness against uncertainty in the switching condition of the hybrid system can be incorporated into the design problem. The power of this approach is illustrated by finding robust and stabilizing continuous-time feedback laws for walking gaits of two underactuated 3D bipedal robots.
Multi-Heuristic A*
Authors: Aine Sandip , Swaminathan Siddharth , Narayanan Venkatraman , Hwang Victor , Likhachev Maxim
Published: August 2015

The performance of heuristic search-based planners depends heavily on the quality of the heuristic function used to focus the search. These algorithms work fast and generate high-quality solutions, even for high-dimensional problems, as long as they are given a well-designed heuristic function. On the other hand, their performance can degrade considerably if there are large heuristic depression regions, i.e. regions in the search space where heuristic values do not correlate well with the actual cost-to-goal values. Consequently, the research in developing an efficient planner for a specific domain becomes the design of a good heuristic function. However, for many domains, it is hard to design a single heuristic function that captures all of the complexities of the problem. Furthermore, it is hard to ensure that heuristics are admissible (provide lower bounds on the cost-to-goal) and consistent, which is necessary for A* like searches to provide guarantees on completeness and bounds on sub-optimality. In this paper, we develop a novel heuristic search, called Multi-Heuristic A* (MHA*), that takes in multiple, arbitrarily inadmissible heuristic functions in addition to a single consistent heuristic, and uses all of them simultaneously to search in a way that preserves guarantees on completeness and bounds on sub-optimality. This enables the search to combine very effectively the guiding powers of different heuristic functions and simplifies dramatically the process of designing heuristic functions by a user because these functions no longer need to be admissible or consistent. We support these claims with experimental analysis on several domains ranging from inherently continuous domains such as full-body manipulation and navigation to inherently discrete domains such as the sliding tile puzzle.
Optimal trajectories for kinematic planar rigid bodies with switching costs
Authors: Lyu Yu-Han , Balkcom Devin
Published: August 2015

The optimal trajectory with respect to some metric for a system with a discrete set of controls may require very many switches between controls, or even infinitely many, a phenomenon called chattering; this can be problematic for existing motion planning algorithms that plan using a finite set of motion primitives. One remedy is to add some penalty for switching between controls. This paper explores the implications of this switching cost for optimal trajectories, using kinematic rigid bodies in the plane (which have been studied extensively in the cost-free-switch model) as an example system. Blatt’s Indifference Principle is used to derive necessary conditions on optimal trajectories; Lipschitzian optimization techniques together with an A* search yield an algorithm for finding trajectories that can arbitrarily approximate the optimal trajectories.
Pre- and post-contact policy decomposition for planar contact manipulation under uncertainty
Authors: Koval Michael C. , Pollard Nancy S. , Srinivasa Siddhartha S.
Published: August 2015

We consider the problem of using real-time feedback from contact sensors to create closed-loop pushing actions. To do so, we formulate the problem as a partially observable Markov decision process (POMDP) with a transition model based on a physics simulator and a reward function that drives the robot towards a successful grasp. We demonstrate that it is intractable to solve the full POMDP with traditional techniques and introduce a novel decomposition of the policy into pre- and post-contact stages to reduce the computational complexity.

Our method uses an offline point-based solver on a variable-resolution discretization of the state space to solve for a post-contact policy as a pre-computation step. Then, at runtime, we use an A* search to compute a pre-contact trajectory. We prove that the value of the resulting policy is within a bound of the value of the optimal policy and give intuition about when it performs well. Additionally, we show the policy produced by our algorithm achieves a successful grasp more quickly and with higher probability than a baseline QMDP policy on two different objects in simulation. Finally, we validate our simulation results on a real robot using commercially available tactile sensors.
Massively parallel motion planning algorithms under uncertainty using POMDP
Authors: Lee Taekhee , Kim Young J.
Published: August 2015

We present new parallel algorithms that solve continuous-state partially observable Markov decision process (POMDP) problems using the GPU (gPOMDP) and a hybrid of the GPU and CPU (hPOMDP). We choose the Monte Carlo value iteration (MCVI) method as our base algorithm and parallelize this algorithm using the multi-level parallel formulation of MCVI. For each parallel level, we propose efficient algorithms to utilize the massive data parallelism available on modern GPUs. Our GPU-based method uses the two workload distribution techniques, compute/data interleaving and workload balancing, in order to obtain the maximum parallel performance at the highest level. Here we also present a CPU–GPU hybrid method that takes advantage of both CPU and GPU parallelism in order to solve highly complex POMDP planning problems. The CPU is responsible for data preparation, while the GPU performs Monte Cacrlo simulations; these operations are performed concurrently using the compute/data overlap technique between the CPU and GPU. To the best of the authors’ knowledge, our algorithms are the first parallel algorithms that efficiently execute POMDP in a massively parallel fashion utilizing the GPU or a hybrid of the GPU and CPU. Our algorithms outperform the existing CPU-based algorithm by a factor of 75–99 based on the chosen benchmark.
Chromatic Dimensions Earthy, Watery, Airy, and Fiery
Authors: Albertazzi Liliana , Koenderink Jan J. , van Doorn Andrea
Published: August 2015

In our study, for a small number of antonyms, we investigate whether they are cross-modally or ideaesthetically related to the space of colors. We analyze the affinities of seven antonyms ( cold–hot, dull–radiant, dead–vivid, soft–hard, transparent–chalky, dry–wet, and acid–treacly) and their intermediate connotations ( cool–warm, matt–shiny, numb–lively, mellow–firm, semi-transparent–opaque, semi-dry–moist, and sour–sweet) as a function of color. We find that some antonyms relate to chromatic dimensions, others to achromatic ones. The cold–hot antonym proves to be the most salient dimension. The dry–wet dimension coincides with the cold–hot dimension, with dry corresponding to hot and wet to cold. The acid–treacly dimension proves to be transversal to the cold–hot dimension; hence, the pairs mutually span the chromatic domain. The cold–hot and acid–treacly antonyms perhaps recall Hering’s opponent color system. The dull–radiant, transparent–chalky, and dead–vivid pairs depend little upon chromaticity. Of all seven antonyms, only the soft–hard one turns out to be independent of the chromatic structure.
Common Priority Map for Selection History, Reward and Emotion in the Oculomotor System
Authors: Belopolsky Artem V.
Published: August 2015

In natural scenes, many objects compete for visual selection. However, it is not always clear why certain objects win this competition. I will demonstrate that the eye movement system lives in a constant state of competition among different oculomotor programs. This competition is not limited to the competition between the current goals of the observer and salient objects in the environment but incorporates independent influences from memory, reward, and emotional systems. These involuntary and automatic biases often overcome the goal-directed selection and expose severe limits in goal-driven control. There is also a striking similarity in the way that these very different sources of bias activate the oculomotor system and compete for representation. The inputs from various information sources are integrated in the common map in the oculomotor system for the sole purpose of improving the efficiency of oculomotor selection.
Numerical Priming Between Touch and Vision Depends on Tactile Discrimination
Authors: Faivre Nathan , Salomon Roy , Vuillaume Laurène , Blanke Olaf
Published: August 2015

Although the interaction between vision and touch is of crucial importance for perceptual and bodily self-consciousness, only little is known regarding the link between conscious access and tactile processing. Here, we tested whether the numerical encoding of tactile stimuli depends on conscious discrimination. On each trial, participants received between zero and three taps at low, medium, or high intensity and had to enumerate the number of visual items subsequently presented as a visual target. We measured tactovisual numerical priming, that is, the modulation of reaction times according to the numerical distance between the visual target and tactile prime values. While numerical priming and repetition priming were respectively elicited by high and medium intensity stimuli, no effect was found for low intensity stimuli that were not discriminable. This suggests that numerical priming between touch and vision depends on tactile discrimination. We discuss our results considering recent advances in unconscious visual numerical priming.
Thinking cities through elsewhere
Authors: Robinson Jennifer
Published: August 2015

Inspired by postcolonial critiques, urban studies today is characterized by conceptual and methodological experimentation in pursuit of a more global approach to understanding cities. The challenge is to develop methods and theoretical practices which allow conceptual innovation to emerge from any urban situation or urbanization process, sustaining wider conversations while insisting that concepts are open to revision. This maps well on to the core methodological problematic of comparison. Mindful of the strong limits to comparison presented by conventional quasi-scientific methods, this paper sets out the basis for a reformatted comparative method. A new grounding for comparison is proposed, specific to the field of the urban, and a new typology of tactics for undertaking urban comparative research is suggested. The paper weaves together classic approaches and more recent innovations in comparison from within urban studies with a wider philosophical analysis of the issues at stake in reframing the architecture of comparison. The paper stands as an invitation to practise global urban studies differently – comparatively – but also to practise comparison differently, in a way that opens urban studies to a more global repertoire of potential insights. The paper develops this invitation and methodological quest through Marxist political-economy; through actually-existing vernacular comparative practices of urban studies; and through insights gleaned from Gilles Deleuze’s philosophical project. The last section of the paper explains how this new vocabulary of comparative method can be put to work through a review of some recent experiments in the field of global urban studies.