bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Investigation of Oxygen Permeation Through a Ba0.5Sr0.5Co0.8Fe0.2O3−δ Ion Transport Membrane With Impingement Flow
Authors: Ben-Mansour R. , Hamdy Mohamed , Sanusi Y. , Araoye A. , Habib M. A. , Mokheimer Esmail M. A.
Published: November 2019

Ion transport membrane (ITM) is considered to be one of the promising techniques for the separation of oxygen from the air for clean energy applications. Studying flow configurations of gases around Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) membrane is presented and discussed in this paper. The effects of the sweep mass flow rate and impingement configurations for the gases flow in the feed and permeation sides have been investigated. In this regard, flow with single or double impingement and impingement with different angles have been simulated and analyzed in order to identify the configurations that would provide the maximum permeation flux. Results show that increasing the sweep flow rate, directly, increases the oxygen permeation flux. It is also found that, in case of single impingement, decreasing the distance between the nozzle and the membrane (H), directly, increases the oxygen permeation flux for constant sweep side nozzle (slot) width (D). The permeation flux increases from around 2.9–3.66 µmole/cm2 s for the ratio H:D from1:1 to 1:4 (i.e., decreasing H to one-fourth of its value). Results show that the double impingement flow gives lower results than the single impingements by about 35.7%. The results also revealed that the optimum configuration is the parallel flow with vacuum in the sweeping side, which gives the highest permeation flux with an increase of more than 41% from that of the parallel configuration with a sweeping gas. Using carbon dioxide as a sweeping gas is better than helium.
Adaptive Dynamics Learning for Small Fault Detection of Discrete-Time Nonlinear Uncertain Systems
Authors: Zhang Jingting , Yuan Chengzhi , Stegagno Paolo
Published: November 2019

This paper addresses the problem of small fault detection for discrete-time nonlinear uncertain systems. The problem is challenging due to (i) the considered system is subject to unstructured nonlinear uncertain dynamics; and (ii) the faults are considered to be “small” in the sense that system states and control inputs in faulty mode remain close to those in normal mode. To overcome these challenges, a novel adaptive dynamics learning based fault detection scheme is proposed. Specifically, an adaptive dynamics learning approach is first proposed to achieve the locally-accurate approximation of the system uncertain dynamics. Then, based on the learned knowledge, a novel residual system is designed by using the absolute measures of the change of the system dynamics resulting from the fault effect. An adaptive threshold is developed based on the residual system for real-time decision making, i.e., the fault is claimed to be detected when the associated residual signal becomes larger than the adaptive threshold. Rigorous analysis is performed to deduce the small fault detectability condition, which is shown to be significantly relaxed compared to those of existing fault detection methods. Extensive simulations have also been conducted to demonstrate the effectiveness and advantages of the proposed approach.
Hierarchical Estimator of Dual Clutch Torques for a Power-Split Hybrid Electric Vehicle
Authors: Zhang Jianwu , Xu Defeng
Published: November 2019

For fast drive mode transitions by shifting clutches equipped in the dedicated compound power-split hybrid transmission, correct estimations of pressure and torque of the clutches are crucial for control strategies. A hierarchical estimator is proposed herein for individual estimation of the clutch torques, consisting of not only the reference layer containing the unknown input observer of vehicle resistance and the reduced-order observer of drive shaft torque, but also the estimation layer combining the unknown input observer with the reduced-order observer. The estimator is implemented to strike a balance between estimation accuracy in the steady state and real time response in the transient state. For validation of the estimator, simulations and real car tests are carried out in specific drive conditions. By numerical results, it’s demonstrated that excellent predictive abilities are found including reasonably small estimation error and adaptive capability and, as a result, shift to shift induced driveline oscillations and vehicle jerks are reduced significantly.
Periodic Tracking Control Using Gain-Scheduled Fourier Series-Based Internal Models
Authors: Caverly Dylan , Caverly Ryan James , Forbes James Richard
Published: November 2019

This paper presents a gain-scheduled controller composed of a number of positive real controllers that contain internal models of reference command signals. Using the internal model principle as inspiration, and the Passivity Theorem to assure input-output closed-loop stability, the proposed controller is designed to realize tracking while maintaining input-output stability of the closed-loop system. The gain-scheduled nature of the internal models allows for a number of internal models to be simultaneously implemented. In particular, by expressing a periodic reference command as a Fourier series, the first few Fourier modes can be included as internal models in the controllers to be gain-scheduled, which reduces steady-state tracking error. An example involving tracking the outlet temperature of a heat exchanger is presented, where the first nine Fourier modes of the reference signal are used as internal models to reduce tracking error.
Experimental Autonomous Deep Learning-Based 3D Path Planning for a 7-DOF Robot Manipulator
Authors: Bertino Alex , Bagheri Mostafa , Krstić Miroslav , Naseradinmousavi Peiman
Published: November 2019

In this paper, we examine the autonomous operation of a high-DOF robot manipulator. We investigate a pick-and-place task where the position and orientation of an object, an obstacle, and a target pad are initially unknown and need to be autonomously determined. In order to complete this task, we employ a combination of computer vision, deep learning, and control techniques. First, we locate the center of each item in two captured images utilizing HSV-based scanning. Second, we utilize stereo vision techniques to determine the 3D position of each item. Third, we implement a Convolutional Neural Network in order to determine the orientation of the object. Finally, we use the calculated 3D positions of each item to establish an obstacle avoidance trajectory lifting the object over the obstacle and onto the target pad. Through the results of our research, we demonstrate that our combination of techniques has minimal error, is capable of running in real-time, and is able to reliably perform the task. Thus, we demonstrate that through the combination of specialized autonomous techniques, generalization to a complex autonomous task is possible.
A Strictly Defined Orthogonal Global Task Coordinate Frame and its Contouring Control Application on Biaxial Systems
Authors: Yang Can , Chen Zheng , Yao Bin , Helian Bobo
Published: November 2019

In this paper, a strictly defined new orthogonal global task coordinate frame (NGTCF) based on the false position method is proposed for precision contouring control of biaxial systems. In contrast to the existed global task coordinate frame (GTCF), the value of the normal coordinate in NGTCF directly represents the contour error, rather than the first-order approximation. Moreover, different from the conventional GTCF just suitable for contours with explicit shape functions, the proposed NGTCF can be utilized in various complex contours. The false position method is adopted to calculate the curve coordinates of actual points in NGTCF. Then an adaptive robust controller (ARC) is designed to deal with the effects of strong coupling of the system dynamics in the task space and modeling uncertainties. The proposed NGTCF-based ARC contouring control strategy is tested on a linear motor driven biaxial industrial gantry. Experiments under different contouring tasks with high-speed and large-curvature are conducted to verify the effectiveness of the proposed method, and the experimental results confirm that the excellent contouring performance of the proposed approach can be achieved.
Agricultural Field Coverage Using Cooperating Unmanned Ground Vehicles
Authors: Faryadi Saba , Davoodi Mohammadreza , Mohammadpour Velni Javad
Published: November 2019

In this paper, a distributed algorithm with obstacle avoidance capability is presented to deploy a group of ground robots for field-based agriculture applications. To this end, the field (consisting of many plots) is first modeled as a directed graph, and the robots are deployed to collect data from some important areas of the field (e.g., areas with high water stress or biotic stress). The key idea is to formulate the underlying problem as a locational optimization problem and then find the optimal solution based on the Voronoi partitioning of the associated graph. The proposed partitioning method is validated through simulation studies, as well as experiments using a group of mobile robots.
Enhanced Tire Blowout Modeling Using Vertical Load Redistribution and Self-Alignment Torque
Authors: Li Ao , Chen Yan , Du Xinyu , Lin Wen-Chiao
Published: November 2019

Publisher’s Note:

This paper was selected for publication in ASME Letters in Dynamic Systems and Control.

https://www.asmedigitalcollection.asme.org/lettersdynsys/article/doi/10.1115/1.4046314/1074439/Enhanced-Tire-Blowout-Modeling-Using-Vertical-Load
A Numerical Study of an Electrically Assisted Boosting System for Turbocharged Diesel Engines
Authors: Men Yifan , Martz Jason B. , Curtis Eric , Zhu Guoming G.
Published: November 2019

Modern diesel engines are normally turbocharged in order to achieve desired fuel economy and meet emission requirements. The well-known “turbo-lag”, delayed engine torque response to driver’s demand, is the main disadvantage for turbocharged engines operated under transient conditions. In addition, at low engine speed, the peak engine output torque is heavily limited by the available turbine energy. As a result, turbocharged engines have degraded peak torque at low speed and slow transient responses in general. Various technologies (variable geometry turbine, electrically assisted turbocharger, hydraulically assisted turbocharger, etc.) have been developed to improve transient response and low-speed torque performance. This paper presents a numerical study of an electrically assisted boosting (eBoost) system for a turbocharged diesel engine through 1-D simulations. This study focuses on two main areas: the electrical compensation at steady-state and turbo-lag reduction under transient operation. It is shown that the eBoost system is capable of increasing engine fuel economy at mid-speed and greatly improving low-speed peak torque. In addition, the eBoost system improves engine transient performance by reducing response time up to 60%.
Influence of Speed Forecasting on the Performance of Ecological Adaptive Cruise Control
Authors: Hyeon Eunjeong , Kim Youngki , Prakash Niket , Stefanopoulou Anna G.
Published: November 2019

In congested urban conditions, the fuel economy of a vehicle can be highly affected by traffic flow and particularly, the immediately preceding (lead) vehicle. Thus, estimating the future trajectories of the lead vehicle is essential to optimize the following vehicle’s maneuvers for its fuel economy. This paper investigates the influence of speed forecasting on the performance of an ecological adaptive cruise control (eco-ACC) strategy for connected autonomous vehicles. The real-time speed predictor proposed in [1] is applied to forecast the future speed profiles of the lead vehicle over a short prediction horizon. Under the assumption that vehicle-to-vehicle (V2V) communications are available, V2V information from multiple lead vehicles is utilized in the prediction process. Eco-ACC is formulated in a model predictive control (MPC) framework to control the connected autonomous vehicle. The influence of the state prediction to the performance of eco-ACC in terms of fuel economy and acceleration is evaluated with different number of connected vehicles.
Shared Control Between Human Driver and Automation in Cooperative Driving Based on Game Theoretic Model Predictive Control
Authors: Ko Sangjin , Langari Reza
Published: November 2019

Shared control is a control framework in which control action is shared between a human driver and an automation. In this work, the shared control is studied based on game theoretical approach of distributed model predictive control (DMPC). The solution of cooperative game is derived under DMPC framework, and then realistic driving situation is studied in cooperative game framework. Shared control strategy for fully mixed driving authority is proposed considering collision probability based on TTC (time to collision) and tracking error. Simulations were conducted using Matlab/Simulik in cooperative driving. The simulation scenarios consist of safety critical situation and non-safety critical situation. In safety critical situation, an automation takes more control authority to avoid a collision, and in non-safety critical situation a human driver takes more control authority. The simulation results show that the control authority is shared continuously by the proposed shared control strategy.
Influence of Tire Inflation Pressure on Vehicle Dynamics and Handling Performance
Authors: Wu Jianyang , Wang Zhenpo , Wang Junmin
Published: November 2019

Tire inflation pressure affects both tire longitudinal and lateral stiffness and thus may impose a considerable influence on vehicle dynamics and handling performance. This paper presents a comprehensive study revealing the effects of tire pressure variations and their distribution among four tires on vehicle dynamics and handling performance. An extended Magic Formula tire model and a modified UniTire model involving tire inflation pressure are employed to describe the tire longitudinal and lateral forces, respectively. Two groups of vehicle maneuvers are simulated in CarSim: a single lane change maneuver with braking and a double lane change maneuver, to exhibit the effects of tire inflation pressure. Various tire pressure variations including all four tires at same and different pressures are examined. A vehicle dynamics, lateral motion stability index, and driver steering workload are utilized to quantify the influence of tire pressure variations and distributions. Analyses on the simulation results indicate that: 1) a front tire pressure reduction induces vehicle understeering tendency and a larger steering angle; 2) a rear tire pressure reduction causes oversteering characteristics and a sacrifice on vehicle stability with a larger vehicle sideslip angle; 3) all-tire inflation pressure decrease will increase driver’s steering workload; and 4) lower rear-tire inflation pressure can promote the combined performance of vehicle path-tracking and driver’s steering workload.
Modeling Actuation of Ionomer Cilia in Salt Solution Under an External Electric Field
Authors: Boldini Alain , Rosen Maxwell , Cha Youngsu , Porfiri Maurizio
Published: November 2019

Publisher’s Note:

This paper was selected for publication in ASME Letters in Dynamic Systems and Control.

https://www.asmedigitalcollection.asme.org/lettersdynsys/article/doi/10.1115/1.4046366/1074565/Modeling-Actuation-of-Ionomer-Cilia-in-Salt
Geometric Trajectory Planning for Robot Motion Over a 3D Surface
Authors: Hosseini Jafari Bashir , Walker Nolan , Smaldone Ronald , Gans Nicholas
Published: November 2019

Mapping a desired 2D pattern onto a curved surface has many applications. This includes motion planning for mobile robots to perform coverage path planing, robot end effector trajectory design for tasks such as printing, depositing, wielding on a 3D surface. This problem becomes more difficult if we want the mapped pattern to keep the properties of the original pattern (i.e, least possible mapping distortion), and pass over some desired points and/or remain bounded in a specific region on the surface. In this paper, we apply surface parameterization and mapping distortion analysis, which is rarely used in robot motion planning works, to map a pattern onto 3D surface. To meet additional goals such as passing over certain points, a planar mapping determined by constrained optimization is employed on the original pattern. Our focus is on printing/depositing materials on curved surfaces, and simulations and experiments are provided to confirm the performance of the approach.
A Hybrid Electro-Thermal Energy Storage System for High Ramp Rate Power Applications
Authors: Laird Cary E. , Alleyne Andrew G.
Published: November 2019

The practice of hybridizing energy storage systems is vital to high ramp rate power applications, in which energy storage systems are constrained by strict power and energy requirements. Hybrid energy storage is typically studied in the electrical and thermal domains separately, but due to the inherent link between electrical and thermal energy domains, it is necessary to examine hybrid energy storage in both domains simultaneously. In this paper, a combined electro-thermal energy storage system is modeled and simulated. Equivalent circuit and lumped-parameter models are used to facilitate control design. PI controllers are designed for both the electrical and thermal domains to demonstrate the ability to perform multi-domain energy management.
Multiple-Scale Analysis of a Novel Piezoelectric Energy Harvester With a Tunable Potential Function
Authors: Qian Feng , Abaid Nicole , Zuo Lei
Published: November 2019

Publisher’s Note:

This paper was selected for publication in ASME Letters in Dynamic Systems and Control.

https://www.asmedigitalcollection.asme.org/lettersdynsys/article/doi/10.1115/1.4046961/1082714/Multiple-Scale-Analysis-of-a-Tunable-Bi-Stable
Behavior Identification and Prediction for a Probabilistic Risk Framework
Authors: Gill Jasprit S. , Pisu Pierluigi , Krovi Venkat N. , Schmid Matthias J.
Published: November 2019

Operation in a real world traffic requires the ability to plan motion in complex environments (multiple moving participants) from autonomous vehicles. Navigation through such environments necessitates the provision of the right search space for the trajectory or maneuver planners so that the safest motion for the ego vehicle can be identified. Analyzing risks based on the predicted trajectories of all traffic participants (given the current state of the environment and its participants) aids in the proper formulation of this search space. This study introduces a fresh taxonomy of safety and risk that an autonomous vehicle should be capable of handling. It formulates a reference system architecture for implementation as well as describes a novel way of identifying and predicting the behaviors of other traffic participants utilizing classic Multi Model Adaptive Estimation (MMAE). Detailed simulation results and a discussion about the associated tuning of the implemented model conclude this work.
Chemical-Source Localization Using a Swarm of Decentralized Unmanned Aerial Vehicles for Urban/Suburban Environments
Authors: Steiner Jake A. , Bourne Joseph R. , He Xiang , Cropek Donald M. , Leang Kam K.
Published: November 2019

In this paper, a decentralized chemical-source localization method is presented. In a real-world scenario, many challenges arise, including sporadic chemical measurements due to the complex interactions between the unmanned aerial vehicles (UAVs), the ambient air, and obstacles. The localization method is split into two phases: a search phase, where the agents cover the area and look for an initial chemical reading; followed by a convergence phase, where UAV agents utilize a particle swarm optimization (PSO) algorithm to locate the source of the chemical leak. The decentralized source-localization method enables a swarm of UAVs to safely travel in a complex environment and avoid obstacles and other agents while searching for the leaking source. The method is validated in simulation using realistic dynamic chemical plumes and through outdoor flight tests using a swarm of UAVs. The results demonstrate the feasibility of the approach.
Design and Verification of a Small-Scale District Heating Network Experiment
Authors: Krieger Melissa , Stecklair Dylan , Peluso Stephen , Stockar Stephanie
Published: November 2019

The ability to combine energy sources with intermittent performance with more consistent form of power is crucial for increasing the penetration of renewable energy sources in the electricity and heat generation sector. In this scenario, district heating networks are a promising solution but, to benefit the most from this technology, control tools must be developed with the objective of optimizing the heating load to each of the buildings in the network, while rejecting external disturbances. One of the main challenges for control design and verification is the limited access to data and experimental platforms. In addition, real systems are subjected to a large number of exogenous inputs and tests repeatability for benchmarking is a challenge. To overcome this limitation, a scaled experimental set up has been developed. This paper discusses the design of the experimental setup of a simple heat distribution network as well as the derivation, calibration and validation of a simulation model. Simulation results show that the model error in predicting temperature is always below 1 %.
Distributionally Robust Stochastic Model Predictive Control for Collision Avoidance
Authors: HomChaudhuri Baisravan
Published: November 2019

This paper focuses on distributionally robust controller design for avoiding dynamic and stochastic obstacles whose exact probability distribution is unknown. The true probability distribution of the disturbance associated with an obstacle, although unknown, is considered to belong to an ambiguity set that includes all the probability distributions that share the same first two moment. The controller thus focuses on ensuring the satisfaction of the probabilistic collision avoidance constraints for all probability distributions in the ambiguity set, hence making the solution robust to the true probability distribution of the stochastic obstacles. Techniques from robust optimization methods are used to model the distributionally robust probabilistic or chance constraints as a semi-definite programming (SDP) problem with linear matrix inequality (LMI) constraints that can be solved in a computationally tractable fashion. Simulation results for a robot obstacle avoidance problem shows the efficacy of our method.
Human Driver Modeling Based on Analytical Optimal Solutions: Stopping Behaviors at the Intersections
Authors: Han Jihun , Karbowski Dominik , Kim Namdoo , Rousseau Aymeric
Published: November 2019

Publisher’s Note:

This paper was selected for publication in ASME Letters in Dynamic Systems and Control.

https://www.asmedigitalcollection.asme.org/lettersdynsys/article/doi/10.1115/1.4046575/1075675/Human-Driver-Modeling-Based-on-Analytical-Optimal
Compressive Sensing-Based Reconstruction of Lissajous-Like Nodding Lidar Data
Authors: Benson Michael T. , Sathishchandra Harish , Clayton Garrett M. , Andersson Sean B.
Published: November 2019

Publisher’s Note:

This paper was selected for publication in ASME Letters in Dynamic Systems and Control.

https://www.asmedigitalcollection.asme.org/lettersdynsys/article/doi/10.1115/1.4046574/1075674/Compressive-Sensing-Based-Reconstruction-of
Motion Planning for Industrial Mobile Robots With Closed-Loop Stability Enhanced Prediction
Authors: Leu Jessica , Tomizuka Masayoshi
Published: November 2019

Real-time, safe, and stable motion planning in co-robot systems involving dynamic human robot interaction (HRI) remains challenging due to the time varying nature of the problem. One of the biggest challenges is to guarantee closed-loop stability of the planning algorithm in dynamic environments. Typically, this can be addressed if there exists a perfect predictor that precisely predicts the future motions of the obstacles. Unfortunately, a perfect predictor is not possible to achieve. In HRI environments in this paper, human workers and other robots are the obstacles to the ego robot. We discuss necessary conditions for the closed-loop stability of a planning problem using the framework of model predictive control (MPC). It is concluded that the predictor needs to be able to detect the obstacles’ movement mode change within a time delay allowance and the MPC needs to have a sufficient prediction horizon and a proper cost function. These allow MPC to have an uncertainty tolerance for closed-loop stability, and still avoid collision when the obstacles’ movement is not within the tolerance. Also, the closed-loop performance is investigated using a notion of M-convergence, which guarantees finite local convergence (at least M steps ahead) of the open-loop trajectories toward the closed-loop trajectory. With this notion, we verify the performance of the proposed MPC with stability enhanced prediction through simulations and experiments. With the proposed method, the robot can better deal with dynamic environments and the closed-loop cost is reduced.
An Agent-Based Model of Lost Person Dynamics for Enabling Wilderness Search and Rescue
Authors: Hashimoto Amanda , Abaid Nicole
Published: November 2019

In this paper, we introduce an agent-based model of lost person behavior that may be used to improve current methods for wilderness search and rescue (SAR). The model defines agents moving on a landscape with behavior considered as a random variable. The behavior uses a distribution of four known lost person behavior strategies in order to simulate possible trajectories for the agent. We simulate all possible distributions of behaviors in the model and compute distributions of horizontal distances traveled in a fixed time. By comparing these results to analogous data from a database of lost person cases, we explore the model’s validity with respect to real-world data.
Modeling the Gas Exchange Processes of a Modern Diesel Engine With an Integrated Physics-Based and Data-Driven Approach
Authors: Pulpeiro Gonzalez Jorge , Ankobea-Ansah King , Escuder Milian Elena , Hall Carrie M.
Published: November 2019

The gas exchange processes of engines are becoming increasingly complex since modern engines leverage technologies including variable valve actuation, turbochargers, and exhaust gas recirculation. Control of these many devices and the underlying gas flows is essential for high efficiency engine concepts. If these processes are to be controlled and estimated using model-based techniques, accurate models are required. This work explores a model framework that leverages a data-driven model of the turbocharger along with submodels of the intercooler, intake and exhaust manifolds and engine processes to provide cylinder-specific predictions of the pressure and temperatures of the gases across the system. This model is developed and validated using data from a 2.0 liter VW turbocharged, direct-injection diesel engine and shown to provide accurate prediction of critical gas properties.
Modeling and Control of Wheel Motor Based Articulated Vehicle System
Authors: Kim Heeseong , Shim Taehyun , Sung Byungjun
Published: November 2019

This paper investigates an effectiveness of vehicle dynamic control (VDC) system based on torque vectoring technique using in-wheel-motors to improve the performance of articulated vehicle systems. A 10 degree-of-freedom (DOF) articulated vehicle model including a tractor and a single axle trailer has been developed and its responses are validated with commercial vehicle software of Trucksim. This model includes a nonlinear tire model (MF tire), a hydraulic damping at the hitch, and a traction system using in-wheel-motors at the trailer axle. In this paper, a yaw control system is developed to track the reference yaw rate with application of yaw moment at the trailer axle using torque distribution of in-wheel-motors. The effectiveness of the proposed control system is validated through simulation of sinusoidal steering maneuver on high mu and slippery road conditions. The simulation results show that in-wheel-motors can improve safety and performance of articulate vehicle systems.
Educational Force Control Using a Modular 2-DOF Serial Robot Manipulator and Low-Cost 2-DOF Force Sensor
Authors: Mascaro Stephen
Published: November 2019

This paper describes a modular 2-DOF serial robotic system and accompanying experiments that have been developed to instruct robotics students in the fundamentals of dynamic force control.

In prior work, we used this same robot to showcase and compare the performance of a variety of textbook techniques for dynamic motion control (i.e. fast/accurate trajectory tracking using dynamic model-based and robust control techniques).

In this paper we now add a low-cost 3D-printed 2-DOF force sensor to this modular robot and demonstrate a variety of force control techniques for use when the robot is in physical contact with the environment. These include stiffness control, impedance control, admittance control, and hybrid position/force control. Each of these various force control schemes can be first simulated and then experimentally implemented using a MATLAB/Simulink real-time interface. The two-degrees of freedom are just enough to demonstrate how the manipulator Jacobian can be used to implement directional impedances in operational space, and to demonstrate how hybrid control can implement position and force control in different axes.

This paper will describe the 2-DOF robot system including the custom force sensor, illustrate the various force control methods that can be implemented, and demonstrate sample results from these experiments.
Electric Circuits as Seen by Thermal Imaging Cameras
Authors: Kácovský Petr
Published: November 2019

Providing instant visual feedback, thermal imaging cameras are becoming more and more popular tools not only in industrial applications, but also in physics education. Continuously decreasing prices, modules compatible with smart portable devices, and intuitive operation make thermal measurements available for schools and attractive for students. This paper deals with predominantly qualitative IR experiments designed for high school or even university students. All the experiments visualize thermal processes related to the flow of current through electric circuits and are repeatedly used with high school students. The suggested experiments could be incorporated in physics lessons separately or as a complete teaching sequence summarizing the knowledge concerning Ohm’s law, Kirchhoff’s circuit laws, and Joule heating.
Video Game Vignettes and More in the Classroom
Authors: Rosengrant David , Money Philip , Beyer Tracey , Alexander Berkil
Published: November 2019

Some educators use what we call a “hook” as a key element in their lessons. We use “hooks” to get our students interested in what it is we are teaching. Many teachers have adopted the Next Generation Science Standards and establish the phenomena as the engine that drives scientific investigation and learning in the classroom. We use phenomena to illustrate the melding of real-world scientific investigation, research, and practices with science teaching found in middle and high school settings. Interested students are more motivated, curious, and attentive. This increases the likelihood that they will not only learn the material to a greater degree, but also retain the information longer. A wider variety and volume of phenomena provides more hooks, which in turn increases the instructor’s ability to deliver an engaging lesson that immerses students in the core ideas of the scientific process.
Studying Avogadro’s Law with Arduino
Authors: Moya Antonio A.
Published: November 2019

Asensor of the type BMP180, together with Arduino, is used to easily measure at­mospheric pressure and temperature at schools. The open source Arduino microcontroller board presents countless teaching applications in science and engineering projects. It allows students to implant their creativity into a friendly environment and take ownership of their scientific explorations. Schools take advantage by incorporating Arduino into the learning and teaching process because of the inexpensive cost of the experiments and the educational experiences being provided to students. The potential of the Arduino platform in physics education is well known, and most students are usually excited by physics labs based on it.
Frequency and Pitch
Authors: Suits B. H.
Published: November 2019

Adiscussion of audio tones in the physics classroom will include mention of their frequency. The frequency of a periodic signal is a well-defined quantity that can readily be measured. A concept related to frequency is that of pitch. Pitch is a perceived quantity that cannot be measured directly and is most important when listeners characterize periodic acoustic signals. The distinction between frequency and pitch is often simplified or even overlooked entirely. Several examples are presented here that clearly illustrate that pitch and frequency are not always simply related.
Experiential learning model in two-dimensional kinematics
Authors: Daniel Ann
Published: November 2019

Researchers have shown students develop misconceptions in projectile motion for various reasons. A common misunderstanding among first-year high school physics students is the notion that the horizontal and vertical components are interchangeable in projectile motion. The students’ incorrect reasoning is connected to their personal experiences when they claim a heavier object will reach the ground before a lighter object when dropped from the same vertical height. When the students are asked about two objects projected horizontally with different speeds from the same height, they will quickly assume that the faster horizontal moving object will hit the ground first, reasoning that the horizontal speed directly affects the vertical speed. The students fail to notice that the initial vertical velocity equals zero.
Converging super-elliptic torsional shear waves in a bounded transverse isotropic viscoelastic material with nonhomogeneous outer boundary
Authors: Guidetti Martina , Caratelli Diego , Royston Thomas J.
Published: November 2019

A theoretical approach was recently introduced [Guidetti and Royston, J. Acoust. Soc. Am. 144, 2312–2323 (2018)] for the radially converging slow shear wave pattern in transverse isotropic materials subjected to axisymmetric excitation normal to the axis of isotropy at the outer boundary of the material. This approach is enabled via transformation to an elliptic coordinate system with isotropic properties. The approach is extended to converging fast shear waves driven by axisymmetric torsional motion polarized in a plane containing the axis of isotropy. The approach involves transformation to a super-elliptic shape with isotropic properties and use of a numerically efficient boundary value approximation.
The importance of underwater sounds to gadoid fishes
Authors: Hawkins Anthony D. , Picciulin Marta
Published: November 2019

The codfish family includes more than 500 species that vary greatly in their abundance in areas like the North Sea and are widely fished. Gadoids (codfish) gather at particular locations to spawn, where they exhibit complex reproductive behavior with visual and acoustic displays. Calls have been described from seven species, including the Atlantic cod and haddock. They vocalize by means of a specialized apparatus, consisting of rapidly contracting striated muscles (the drumming muscles) attached to the gas-filled swim bladder. Several gadoids, such as the ling and the Greenland cod, possess drumming muscles and are likely to make sounds. Non-vocal gadoids, such as the poor cod, lack these muscles. It is suggested that the sonic apparatus was present in the early species of the gadoids, with some species having lost their sonic ability. Interestingly, silent gadoids are mainly small schooling fishes. Gadoid species are most sensitive to sounds from 30 to 500 Hz. Gadoid hearing can be masked by ambient sound but also by anthropogenic sounds, which may therefore adversely affect their reproduction, with potential effects upon discrete local stocks. Listening for gadoid sounds provides a reliable, non-invasive way of locating spawning sites, which can enhance the protection of reproducing fish from human impacts.
The Status of Physical Education Within a Nationally Recognized School Health and Wellness Program
Authors: McLoughlin Gabriella M. , Graber Kim C. , Woods Amelia M. , Templin Tom , Metzler Mike , Khan Naiman A.
Published: November 2019

Purpose: To address the obesity epidemic and promote children’s health; several health organizations recommend that schools develop comprehensive programs designed to promote physical activity and health behavior. Given a lack of empirical investigation, the authors sought to understand how physical education programs are perceived within such initiatives. Methods: A case study was conducted to acquire insights of key stakeholders (N = 67) in a school nationally recognized for promoting physical activity and health. Data were collected using formal interviews, informal interviews, observations, and document analysis. Data were analyzed utilizing grounded theory and constant comparison. Results: Physical education was viewed positively by stakeholders; however, physical educators felt marginalized within the school infrastructure. Systemic barriers to program quality included lack of leadership, feelings of marginalization, and insufficient funding and collaboration. Discussion: Findings raise concerns about the difficulty of sustaining a high-quality physical education program even in a school recognized for significant support of physical activity.
Salivary and Serum Concentrations of Cortisol and Testosterone at Rest and in Response to Intense Exercise in Boys Versus Men
Authors: Adebero Tony , McKinlay Brandon John , Theocharidis Alexandros , Root Zach , Josse Andrea R. , Klentrou Panagiota , Falk Bareket
Published: November 2019

This study compared salivary and serum concentrations of testosterone and cortisol at rest and in response to intense multitask exercise in boys and men. Early morning saliva and venous blood samples were obtained before and 15 minutes after exercise from 30 competitive swimmers (15 boys, age 14.3 [1.9] y; 15 men, age 21.7 [3.1] y). Exercise included a swim-bench maximal strength task and an all-out 200-m swim, followed by a high-intensity interval swimming protocol (5 × 100 m, 5 × 50 m, and 5 × 25 m). At baseline, fasting testosterone (but not cortisol) concentration was higher in men than boys in serum and saliva (P < .05). Salivary and serum cortisol increased postexercise, with a greater increase in men compared with boys (men: 226% and 242%; boys: 78% and 64%, respectively; group by time interaction, P < .05). Testosterone was reduced postexercise in serum but not in saliva (men: −14.7% and 0.1%; boys: −33.9% and −4.5%, respectively, fluid by time interaction, P < .01). Serum and salivary cortisol (but not testosterone), preexercise and postexercise values were strongly correlated in both men and boys (r = .79 and .82, respectively; P < .01). In summary, early morning high-intensity exercise results in a decrease in testosterone in serum, but not saliva, and an increase in cortisol irrespective of the fluid used, in both boys and men. When examining immediate postexercise changes, the lack of correlation in testosterone between saliva and serum suggests that saliva may not be an appropriate fluid to examine changes in testosterone. The high correlation observed between serum and saliva for cortisol indicates that, in both boys and men, saliva may be used to monitor the immediate cortisol response to exercise.
Hong Kong protests hit universities
Authors: Normile Dennis
Published: November 2019

Clashes have had little impact on research, but long-term effects on schools are unclear.
Preventing undesirable behavior of intelligent machines
Authors: Thomas Philip S. , Castro da Silva Bruno , Barto Andrew G. , Giguere Stephen , Brun Yuriy , Brunskill Emma
Published: November 2019

Making well-behaved algorithms

Machine learning algorithms are being used in an ever-increasing number of applications, and many of these applications affect quality of life. Yet such algorithms often exhibit undesirable behavior, from various types of bias to causing financial loss or delaying medical diagnoses. In standard machine learning approaches, the burden of avoiding this harmful behavior is placed on the user of the algorithm, who most often is not a computer scientist. Thomas
et al.
introduce a general framework for algorithm design in which this burden is shifted from the user to the designer of the algorithm. The researchers illustrate the benefits of their approach using examples in gender fairness and diabetes management.

Science
, this issue p.
999
Beetle horns evolved from wing serial homologs
Authors: Hu Yonggang , Linz David M. , Moczek Armin P.
Published: November 2019

Where do horns come from?

One of the most pronounced examples of a sexually selected trait is the prothoracic horns of scarab beetles, which, in the most extreme cases, can be nearly half as long as the length of the beetle. It is fairly easy to understand how selection might have shaped these horns, but understanding how development shaped them from a hornless ancestor is a much more complex proposition. Hu
et al.
show that these horns are generated from wing homologs and argue that many other insect traits may have followed similar transcriptional paths (see the Perspective by Nijhout).

Science
, this issue p.
1004
; see also p.
946
Peritumoral activation of the Hippo pathway effectors YAP and TAZ suppresses liver cancer in mice
Authors: Moya Iván M. , Castaldo Stéphanie A. , Van den Mooter Laura , Soheily Soheil , Sansores-Garcia Leticia , Jacobs Jelle , Mannaerts Inge , Xie Jun , Verboven Elisabeth , Hillen Hanne , Algueró-Nadal Ana , Karaman Ruchan , Van Haele Matthias , Kowalczyk Weronika , De Waegeneer Maxime , Verhulst Stefaan , Karras Panagiotis , van Huffel Leen , Zender Lars , Marine Jean-Christophe , Roskams Tania , Johnson Randy , Aerts Stein , van Grunsven Leo A. , Halder Georg
Published: November 2019

Mixed signals at tumor margins

The Hippo signaling pathway has been implicated in tumor growth, sparking interest in the pathway as a potential therapeutic target. In a study of liver cancer in genetically manipulated mice, Moya
et al.
discovered that the role of this pathway in tumorigenesis is more complex than previously appreciated. They confirmed that activation of the Hippo pathway within tumor cells drives tumor growth; however, they also found that activation of the pathway in adjacent healthy cells has the opposite effect, suppressing tumor growth. Whether tumor cells survive or are eliminated thus appears to depend on competing signals produced by the tumor and surrounding tissue.

Science
, this issue p.
1029
A shared gene drives lateral root development and root nodule symbiosis pathways in
Lotus
Authors: Soyano Takashi , Shimoda Yoshikazu , Kawaguchi Masayoshi , Hayashi Makoto
Published: November 2019

Common gene yields different structures

Nodules form on legume roots to house symbiotic, nitrogen-fixing bacteria. Lateral roots, characteristic of a much broader range of plants, extend to take up nutrients and water from the soil. Soyano
et al.
found common ground in the developmental pathways that build nodules and lateral roots (see the Perspective by Bishopp and Bennett). Evidence from
Lotus japonicus
, a legume that can fix atmospheric nitrogen, shows that the nodule-forming pathway shares components with the lateral root pathway.

Science
, this issue p.
1021
; see also p.
953
Host resistance factor SLC11A1 restricts
Salmonella
growth through magnesium deprivation
Authors: Cunrath Olivier , Bumann Dirk
Published: November 2019

Magnesium for
Salmonella
growth

In mammals, macrophages are a first line of defense against pathogenic bacteria like
Salmonella.
These immune cells possess a metal-ion transporter called SLC11A1 or NRAMP1, which is known to be involved in infection resistance. Cunrath and Bumann studied mice that only differ in one allele of the
SLC11A1
gene, which leaves mice either susceptible or resistant to infection. Proteomic analyses showed that bacteria isolated from mice with functional
SLC11A1
alleles experienced metal starvation, particularly of magnesium. The resulting impairment of bacterial growth seems to be the primary mode of action of SLC11A1 against invading pathogens.

Science
, this issue p.
995
A cortical-brainstem circuit predicts and governs compulsive alcohol drinking
Authors: Siciliano Cody A. , Noamany Habiba , Chang Chia-Jung , Brown Alex R. , Chen Xinhong , Leible Daniel , Lee Jennifer J. , Wang Joyce , Vernon Amanda N. , Vander Weele Caitlin M. , Kimchi Eyal Y. , Heiman Myriam , Tye Kay M.
Published: November 2019

A brain circuit to control alcohol intake

Most people are exposed to alcohol at some point in their lives, but only a small fraction will develop a compulsive drinking disorder. Siciliano
et al.
first established a behavioral measure to assess how predisposition interacts with experience to produce compulsive drinking in a subset of mice (see the Perspective by Nixon and Mangieri). In search of the underlying neurobiological mechanism, they discovered that a discrete circuit between the medial prefrontal cortex and brainstem is central for the development of compulsive drinking. This circuit serves as both a biomarker for the development of compulsive drinking and a driver of its expression. It can bidirectionally control compulsive behavior by mitigating or mimicking punishment signals.

Science
, this issue p.
1008
; see also p.
947
Three-dimensional genome structure of a single cell
Authors: Tan Longzhi
Published: November 2019

Chromosome organization in diploid cells reveals a structural basis for smell
The neural regulation of cancer
Authors: Venkatesh Humsa S.
Published: November 2019

Cancers hijack mechanisms of neural plasticity to promote malignant disease progression
Complete Genome Characterization of a Novel Infectious Bursal Disease Virus Strain Isolated from a Chicken Farm in China
Authors: Xu Guanlong , Li Jie , Shen Qingchun , Hou Lidan , Xia Yingju , Li Qiuchen , Xie Shijie , Sun Shijing , Ding Jiabo , Mao Yaqing , Qin Yuming
Published: November 2019

Infectious bursal disease (IBD) is a highly infectious disease in chicken, and vaccination is the best way to prevent outbreak of infectious bursal disease virus (IBDV). In this study, we isolated a variant IBDV strain from a chicken farm with vaccinated chickens. The full genome of this IBDV strain was determined and analyzed.
Complete Genome Sequence of a Putative Densovirus Infecting the Carrot Psyllid
Bactericera trigonica
Authors: Ghosh Saptarshi , Sela Noa , Ghanim Murad
Published: November 2019

Here, we report the genome of a putative densovirus infecting the carrot psyllid
Bactericera trigonica
, obtained by inverse PCR and named
Bactericera trigonica
densovirus (BtDNV). The ambisense genome of BtDNV is identical in structure to those of the ambidensoviruses, and its encoded proteins share the highest sequence identity with the Asian citrus psyllid
Diaphorina citri
densovirus.
Complete Genome Sequences of Endophytic Bacilli Isolated from Grapevine Plants
Authors: Mardanov Andrey V. , Chizhevskaya Elena P. , Lazarev Alexander M. , Rakitin Andrey L. , Beletsky Alexey V. , Chebotar Vladimir K. , Ravin Nikolai V.
Published: November 2019

The endophytic strains
Bacillus amyloliquefaciens
V417 and V167 were isolated from cultured grape plants. We sequenced the complete genomes of these strains to reveal their potential beneficial properties for plant growth promotion and control of fungal pathogens. Genes responsible for the synthesis of antimicrobial compounds and siderophores were identified.