bluuebunny/crossref_metadata_2025 huggingface dataset:
Wind Turbine Power Optimization: Experimental Validation of Extremum Seeking and Perturb/Observe Strategies
Authors: Wang Fa , Wheeler Laura , Garcia-Sanz Mario
Published: February 2017

This paper presents an experimental methodology to test and validate two Maximum Power Point Tracking (MPPT) strategies on variable speed wind turbines. The first technique of this study is an Extremum Seeking (ES) control strategy which does not require any wind turbine model or wind speed measurements. The analysis shows that its convergence can be quite slow in some cases. For this reason, we improve the ES control with a specific inner-loop that speeds up the convergence of the strategy. Additionally a conventional Perturb and Observe (P&O) algorithm is also implemented for comparison purposes. The proposed ES strategy with an additional inner loop controller shows fast tracking capability and high stability under both constant and variable wind speed in simulations and experiments. Both approaches are verified in Matlab simulations and experiments with a lab-scale wind turbine and a fully instrumented wind tunnel at CWRU-CESC.
Development of a Mobile Robot Providing a Natural Way to Interact With Electronic Devices
Authors: Chen Jinfa , Kim Won-jong
Published: February 2017

This paper provides a natural, yet low-cost way for human to interact with electronic devices indoor: the development of a human-following mobile robot capable of controlling other electrical devices for the user based on the user’s gesture commands. The overall experimental setup consists of a skid-steered mobile robot, Kinect sensor, laptop, wide-angle camera and two lamps. The OpenNI middleware is used to process data from the Kinect sensor, and the OpenCV is used to process data from the wide-angle camera. A new human-following algorithm is proposed based on human motion estimation. The human-following control system consists of two feedback control loop for linear and rotational motions, respectively. A lead-lag and lead controller are developed for the linear and rotational motion control loop, respectively. Experimental results show that the tracking algorithm is robust and reduced the distance and angular error by 40% and 50%, respectively. There are small delays (0.5 s for linear motion and 1.5 s for rotational motion) and steady-state errors (0.1 m for linear motion and 1.5° for rotational motion) of the system’s response. However, the delays and errors are acceptable since they do not cause the tracking distance or angle out of the desirable range (±0.05m and ±10° of the reference input). There are four gestures designed for the user to control the robot, two switch-mode gestures, lamp-creation, lamp-selection and color change gesture. Success rates of gesture recognition are more than 90% within the detectable range of the Kinect sensor.
Deployment of an Arbitrary Distribution of a Multi-Agent System With Finite Size on a Desired Formation
Authors: Rastgoftar Hossein , Atkins Ella M.
Published: February 2017

This paper considers the problem of deploying an arbitrary multi-agent system in a desired formation over an n-dimensional motion space. Each agent is considered to be a ball and collision avoidance is addressed. System evolution in ℝn is decomposed into n one dimensional motion problems, where evolution of the agents qth (q = 1, 2, 3) components are independently guided by two q-leaders. The remaining agents are considered q-followers, updating the qth component of their positions by local interactions with two neighboring q-agents. Communications among the q-agents are weighted by values consistent with the qth position components of agents in the desired configuration. This paper shows how specifying certain constraints on q-leader motion can address the problem of inter-agent collision avoidance when followers acquire their desired positions only by local communication.
Fish Like Aquatic Robot Demonstrates Characteristics of a Linear System
Authors: Pollard Beau , Tallapragada Phanindra
Published: February 2017

In the recent past the design of many aquatic robots has been inspired by the motion of fish. In some recent work the authors described an underactuated planar swimming robot, that is propelled via the motion of an internal rotor. This robot is inspired by a simplified model of the fluid-body interaction mediated by singular distributions of vorticity. Such a model is a significant simplification of the fluid-structure interaction that can be understood using resource intensive numerical computations of the Navier Stokes equation that are unwieldy from a controls perspective. At the same time the simplified model incorporates the creation of vorticity and interaction of the body with the vorticity which many control theoretical models ignore. In this paper we show that despite the complexity of the interaction between the aquatic robot and the ambient vorticity in a fluid, the response of the robot is a nearly linear function of the control input. This surprisingly simple feature emerges in our theoretical model and is validated by our experimental data of the motion of the robot. This simplifying observation is an important step towards developing control algorithms for aquatic robots.
Dynamics of a Rotor-Pendulum With a Small, Stiff Propeller in Wind
Authors: Craig William , Yeo Derrick , Paley Derek A.
Published: February 2017

As small rotorcraft grow in capability, the possibilities for their application increase dramatically. Many of these new applications require stable outdoor flight, necessitating a closer look at the aerodynamic response of the aircraft in windy environments. This paper develops the equations of motion for a single-propeller test stand by analyzing the blade-flapping response of a small-stiff propeller in wind. The system dynamics are simulated to show behavior under various wind conditions, and stable system equilibria are identified. Experiments with a rotor-pendulum validate the simulations, including system equilibria and gust response.
Frequency Domain Uncertainty Modeling and Quantification of the Laser Metal Deposition Process
Authors: Sammons Patrick M. , Bristow Douglas A. , Landers Robert G.
Published: February 2017

Additive Manufacturing (AM) is a growing class of manufacturing processes where parts are fabricated by repeated addition of material. Many of these processes show great promise for the production of complex, functional parts for use in critical applications. One such process, Laser Metal Deposition (LMD), uses a laser and a coaxial blown metal powder source to produce functional metal parts. However, it has been demonstrated that the LMD process possesses complex two-dimensional dynamics which, when not appropriately accounted for in the modeling and control stages, can lead to build failures. Additionally, even when the two-dimensionality of the process is accounted for, modeling and process uncertainties can lead to degraded performance or instability. Here, in the context of a control oriented model of the LMD process developed previously, process and modeling uncertainties are modeled and quantified in the frequency domain.
Multi Degree-of-Freedom Hydraulic Human Power Amplifier With Rendering of Assistive Dynamics
Authors: Lee Sangyoon , Eskilsson Fredrik , Li Perry Y.
Published: February 2017

The hydraulic human power amplifier (HPA) is a tool similar to exoskeleton that uses hydraulic actuation to amplify the applied human force. The control objective is to make the system behave like a passive mechanical tool that interacts with the human and the environment passively with a specified power scaling factor. In our previous work, a virtual velocity coordination approach recasts the single degree-of-freedom human power amplifier control problem into a velocity coordination with a fictitious reference mechanical system. Force amplification becomes a natural consequence of the velocity coordination. In this paper, this control approach is extended for fully coupled multi-DoF systems. A passivity based control approach that uses the natural energy storage of the hydraulic actuator to take full account of the nonlinear pressure dynamics is used to define the flow requirement. Additional passive assistance dynamics are designed and implemented to enable the user to perform specific tasks more easily. Guidance is achieved using a passive velocity field controller (PVFC), and obstacle avoidance is achieved using a potential field. Experimental results demonstrate good performance on a 2-DoF Human Power Amplifier.
Estimation of Central Aortic Blood Pressure From Non-Invasive Cuff Pressure Oscillation Signals via System Identification
Authors: Ghasemi Zahra , Kim Chang-Sei , Ginsberg Eric , Duell John , Gupta Anuj , Hahn Jin-Oh
Published: February 2017

This paper presents a model-based system identification approach to estimation of central aortic blood pressure waveform from non-invasive cuff pressure oscillation signals. First, we developed a mathematical model that can reproduce the relationship between central aortic blood pressure waveform and non-invasive cuff pressure oscillation signals at diametric locations by combining models to represent wave propagation in the artery, arterial pressure-volume relationship, and mechanics of the occlusive cuff. Second, we formulated the problem of estimating central aortic blood pressure waveform from non-invasive cuff pressure oscillation signals into a system identification problem. Third, we showed the proof-of-concept of the approach using simulated central aortic blood pressure waveform and cuff pressure oscillation signals. Finally, we illustrated the feasibility of the approach using central aortic blood pressure waveform and cuff pressure oscillation signals collected from a human subject. We showed that the proposed approach could estimate central aortic blood pressure waveform with accuracy: the root-mean-squared error associated with the central aortic blood pressure waveform was 1.7 mmHg (amounting to 1.6 % of the underlying mean blood pressure) while the errors associated with central aortic systolic and pulse pressures were −0.4 mmHg and −1.5 mmHg (amounting to −0.3 % and −1.4 % of the underlying mean blood pressure).
An Approximation Algorithm for a Shortest Dubins Path Problem
Authors: Rathinam Sivakumar , Khargonekar Pramod
Published: February 2017

The problem of finding the shortest path for a vehicle visiting a given sequence of target points subject to the motion constraints of the vehicle is an important problem that arises in several monitoring and surveillance applications involving unmanned aerial vehicles. There is currently no algorithm that can find an optimal solution to this problem. Therefore, heuristics that can find approximate solutions with guarantees on the quality of the solutions are useful. The best approximation algorithm currently available for the case when the distance between any two adjacent target points in the sequence is at least equal to twice the minimum radius of the vehicle has a guarantee of 3.04. This article provides a new approximation algorithm which improves this guarantee to 1+π3≈2.04. The developed algorithm is also implemented for hundreds of typical instances involving at most 30 points to corroborate the performance of the proposed approach.
Nonlinear Model Predictive Control Strategies for a Parallel Evaporator Diesel Engine Waste Heat Recovery System
Authors: Yebi Adamu , Xu Bin , Liu Xiaobing , Shutty John , Anschel Paul , Onori Simona , Filipi Zoran , Hoffman Mark
Published: February 2017

This paper discusses the control challenges of a parallel evaporator organic Rankine cycle (ORC) waste heat recovery (WHR) system for a diesel engine. A nonlinear model predictive control (NMPC) is proposed to regulate the mixed working fluid outlet temperature of both evaporators, ensuring efficient and safe ORC system operation. The NMPC is designed using a reduced order control model of the moving boundary heat exchanger system. In the NMPC formulation, the temperature difference between evaporator outlets is penalized so that the mixed temperature can be controlled smoothly without exceeding maximum or minimum working fluid temperature limits in either evaporator. The NMPC performance is demonstrated in simulation over an experimentally validated, high fidelity, physics based ORC plant model. NMPC performance is further validated through comparison with a classical PID control for selected high load and low load engine operating conditions. Compared to PID control, NMPC provides significantly improved performance in terms of control response time, overshoot, and temperature regulation.
Runtime Verification of Trust-Based Symbolic Robot Motion Planning With Human-in-the-Loop
Authors: Mahani Maziar Fooladi , Wang Yue
Published: February 2017

In this paper, we address the runtime verification problem of robot motion planning with human-in-the-loop. By bringing together approaches from runtime verification, trust model, and symbolic motion planning, we developed a framework which guarantees that a robot is able to safely satisfy task specifications while improving task efficiency by switches between human supervision and autonomous motion planning. A simple robot model in a domain path planning scenario is considered and the robot is assumed to have perfect localization capabilities. The task domain is partitioned into a finite number of identical cells. A trust model based on the robot and human performance is used to provide a switching logic between different modes. Model checking techniques are utilized to generate plans in autonomous motion planning and for this purpose, Linear Temporal Logic (LTL) as a task specification language is employed to formally express specifications in model checking. The whole system is implemented in a runtime verification framework to monitor and verifies the system execution at runtime using ROSRV. Finally, we illustrated the effectiveness of this framework as well as its feasibility through a simulated case study.
Enhancing Haptic Effects Displayed via Neuromuscular Electrical Stimulation
Authors: Harris Maxwell , McCarty Mitchell , Montes Andre , Celik Ozkan
Published: February 2017

This paper presents an experimental setup and results on enhancing sensations of a common haptic effect -a virtual wall-induced via neuromuscular electrical stimulation (NMES). A single degree of freedom (DOF) elbow platform with position sensing was constructed. This platform supports the arm in the horizontal plane while elbow flexion and extension torques are generated by stimulation of triceps brachii or the biceps brachii muscles. The response of the system was experimentally characterized by determining the latency, and the relationship between stimulation pulse width, stimulation current, joint position and generated output torques. After system characterization, stimulation control methods to enhance haptic sensations were designed, implemented and pilot tested under a variety of virtual wall hit scenarios. Our results indicate that the wall hit trajectories and interaction were improved by control laws that initiated low intensity stimulation prior to the wall hit and utilized co-contraction for damping. The “priming” of the muscle with low intensity stimulation prior to the main stimulation improved the responsiveness of muscle contractions.
Air Compression Performance Improvement via Trajectory Optimization: Experimental Validation
Authors: Saadat Mohsen , Srivatsa Anirudh , Li Perry Y. , Simon Terrence
Published: February 2017

In an isothermal compressed air energy storage (CAES) system, it is critical that the high pressure air compressor/expander is both efficient and power dense. The fundamental trade-off between efficiency and power density is due to limitation in heat transfer capacity during the compression/expansion process. In our previous works, optimization of the compression/expansion trajectory has been proposed as a means to mitigate this trade-off. Analysis and simulations have shown that the use of optimized trajectory can increase power density significantly (2–3 fold) over ad-hoc linear or sinusoidal trajectories without sacrificing efficiency especially for high pressure ratios. This paper presents the first experimental validation of this approach in high pressure (7bar to 200bar) compression. Experiments are performed on an instrumented liquid piston compressor. Correlations for the heat transfer coefficient were obtained empirically from a set of CFD simulations under different conditions. Dynamic programming approach is used to calculate the optimal compression trajectories by minimizing the compression time for a range of desired compression efficiencies. These compression profiles (as function of compression time) are then tracked in a liquid piston air compressor testbed using a combination of feed-forward and feedback control strategy. Compared to ad-hoc constant flow rate trajectories, the optimal trajectories double the power density at 80% efficiency or improve the thermal efficiency by 5% over a range of power densities.
Disturbance Observer Based Control Design for Wind Turbine Speed Regulation
Authors: Yuan Yuan , Chen Xu , Tang Jiong
Published: February 2017

Disturbance observer based (DOB) control has been implemented in motion control to reject unknown or time-varying disturbances. In this research, an internal model-based disturbance observer (DOB) design combined with a PID type feedback controller is formulated for wind turbine speed and power regulation. The DOB controller facilitates model-based estimation and cancellation of disturbance using an inner feedback control loop. The disturbance observer combined with a compensator is further designed to deal with the model mismatch. The proposed method is applied to National Renewable Energy laboratory (NREL) offshore 5-MW wind turbine. Our case studies show that the DOB controller can achieve improved speed and power regulation compared to the baseline PID controller, and exhibit excellent robustness under different turbulent wind fields.
Vibration-Based Structural Damage Identification Under Interval Uncertainty
Authors: Yoo David , Tang Jiong
Published: February 2017

Identifying damages in mechanical structures in advance is essential part of preventing catastrophic losses. Among several non-destructive methods, the vibration-based method, which utilizes global characteristics of the structures, has several advantages such as not requiring prior information on possible damage location and physical access to it. In the meantime, the mechanical structures are inevitably subject to uncertainties, whose distribution is often unknown in practical situations due to such as limited amount of available data. Uncertainties are treated as interval uncertainty in such cases. In this regard, this study presents vibration-based damage identification under interval uncertainty. To obtain reliable result, this research does not assume any random distribution, e.g., uniform distribution, inside interval. Since detected damage is not assumed to be monotonic function with respect to interval uncertainty either, traditional fuzzy interval arithmetic is not applicable. Instead, we first carry out exhaustive search to see the effect of the interval uncertainty on the identified damage; i.e., discretizing interval uncertainty into sub-intervals and executing damage identification under all possible combinations to see the effect of the interval uncertainty on the identified damage. We then develop the unique algorithm based on M-H algorithm to facility computational efficiency.
A Modular 2-DOF Serial Robot Manipulator for Education in Robot Control
Authors: Mascaro Stephen
Published: February 2017

This paper describes a modular 2-DOF serial robot manipulator and accompanying experiments that have been developed to introduce students to the fundamentals of robot control. The robot is designed to be safe and simple to use, and to have just enough complexity (in terms of nonlinear dynamics) that it can be used to showcase and compare the performance of a variety of textbook robot control techniques including computed torque feedforward control, inverse dynamics control, robust sliding-mode control, and adaptive control. These various motion control schemes can be easily implemented in joint space or operational space using a MATLAB/Simulink real-time interface.

By adding a simple 2-DOF force sensor to the end-effector, the robot can also be used to showcase a variety of force control techniques including impedance control, admittance control, and hybrid force/position control. The 2-DOF robots can also be used in pairs to demonstrate control architectures for multi-arm coordination and master/slave teleoperation.

This paper will describe the 2-DOF robot and control hardware/software, illustrate the spectrum of robot control methods that can be implemented, and show sample results from these experiments.
Regularized Filtered Basis Functions Approach for Accurate Tracking of Discrete-Time Linear Time Invariant Systems With Bounded Random Uncertainties
Authors: Ramani Keval S. , Okwudire Chinedum E.
Published: February 2017

This paper proposes a regularized filtered basis functions (RFBF) approach for robust tracking of discrete-time linear time invariant systems with bounded random (unstructured) uncertainties. Identical to the filtered basis functions (FBF) approach, studied in prior work by the authors, the RFBF approach expresses the control trajectory as a linear combination of user-defined basis functions with unknown coefficients. The basis functions are forward filtered using a model of the system and their coefficients are selected to fulfill the tracking control objective. The two approaches differ in the coefficient selection process. The FBF approach selects the coefficients such that the tracking error is minimized in the absence of uncertainties, whereas, the proposed RFBF approach formulates the coefficient selection problem as a constrained game-type problem where the coefficients are selected to minimize the worst case tracking error in the presence of model uncertainty. Illustrative examples are used to demonstrate significantly more accurate tracking of uncertain systems using RFBF compared with FBF.
Tracking of a Target Payload via a Combination of Input Shaping, Zero Phase Error Tracking Control, and Fuzzy Logic
Authors: Schmidt Robert , Begneaud Matthew , Vaughan Joshua
Published: February 2017

During crane operation, the task of retrieval and deployment of payloads can be partitioned into two components: the initial move towards the target or deployment location and the retrieval or deployment of the payload. If the payload is not stationary, as is the case in the retrieval of a sea-going vessel, a third component, tracking, must be included. The target payload in this research is an Autonomous Surface Vehicle (ASV) primarily used for surveying. This paper studies the transition between the initial move towards the payload and the initialization of tracking. Input Shaping is used to limit residual vibration caused by the initial move to the ASV. A set of Fuzzy Logic membership functions are then used to transition from the initial move to the tracking portion of the retrieval process. These membership functions map position and velocity error to a gain that is applied to the tracking controller. As the gain increases, the contribution of the tracking controller input is increased. Zero Phase Error Tracking Control is utilized for accurate tracking of the target payload. Through a combination of these control methods, the tracking accuracy is improved.
Development of a Novel Shoulder Exoskeleton Using Parallel Actuation and Slip
Authors: Hunt Justin , Artemiadis Panagiotis , Lee Hyunglae
Published: February 2017

This paper presents a 5 degree-of-freedom (DoF) low inertia shoulder exoskeleton that was developed using two novel technologies with a broad range of application. The first novelty is a 3-DoF spherical parallel manipulator (SPM) that uses three linear actuators. Each actuator is designed using a method of motion coupling such that the pitch and linear stroke DoF are dependent. By using an SPM, this shoulder exoskeleton takes advantage of the inherent low effective inertia property of parallel architecture. The second novelty is a 2-DoF passive slip mechanism that couples the user’s upper arm to the SPM. This slip mechanism increases system mobility and prevents joint misalignment caused by the translational motion of the user’s glenohumeral joint from introducing mechanical interference that could affect the device’s kinematic solution or harm the user. An experiment to validate the kinematics of the SPM was performed using motion capture. A computational slip model was created to quantify the slip mechanism’s response for different conditions of joint misalignment. In addition to offering a low inertia solution for the rehabilitation or augmentation of the human shoulder, the presented device demonstrates the technologies of actuator motion coupling and passive slip for use in exoskeletal systems. The use of motion coupling could be applied to other types of parallel actuated architectures in order to constrain the kinematics or improve stiffness characteristics. Passive slip mechanisms could have application in either serial or parallel actuated systems as a means of negating the adverse effects of joint misalignment.
Walking-Stair Climbing Control for Powered Knee Prostheses
Authors: Wu Molei , Shen Xiangrong
Published: February 2017

Recent progresses in powered lower-limb prostheses have the potential of enabling amputee users to conduct energetically demanding locomotive tasks, which are usually beyond the capability of traditional unpowered prostheses. Realizing such potential, however, requires responsive and reliable control of the power provided by prosthetic joints. In this paper, an integrated walking-stair climbing control approach is presented for transfemoral prostheses with powered knee joints. Leveraging the similarities between walking and stair climbing, this new approach adopts the general finite-state impedance control framework. Furthermore, important modifications are introduced to model the biomechanical characteristics that are beyond the capability of standard impedance control. The transition between the walking and stair-climbing modes is triggered through the real-time measurement of the spatial orientation of the user’s thigh, which provides a reliable indicator of the user’s intention of making such transition. This new control approach has been implemented on a powered knee prosthesis, and its effectiveness was demonstrated in human subject testing.
Stabilizing and Control of Tilting-Rotor Quadcopter in Case of a Propeller Failure
Authors: Nemati Alireza , Kumar Rumit , Kumar Manish
Published: February 2017

In this paper, stability and control of tilting-rotor quadcopters is presented upon failure of one propeller during flight. A tilting rotor quadcopter provides advantage in terms of additional stable configurations and maneuverability. Upon failure of one propeller, a traditional quadcopter has a tendency of spinning about the primary axis fixed to the vehicle as an outcome of the asymmetry about the yaw axis. This forces the quadcopter to land abandoning its mission. The tilting-rotor configuration is an over-actuated form of a traditional quadcopter and it is capable of handling a propeller failure, thus making it a fault tolerant system. In this paper, a dynamic model of tilting-rotor quadcopter with one propeller failure is derived and a controller is designed to achieve hovering and navigation capability. The simulation results showing the effectiveness of the proposed controller is presented using the translational and hovering motion.
Automatic Glass Pick and Place by Industrial Robot
Authors: Yu Xiaowen , Zhao Yu , Tomizuka Masayoshi
Published: February 2017

In glass manufacturing industry, glass grinding process has significant involvement of human workers. Human workers need to load and unload glass pieces to/from the grinder. A 6 DOF industrial robot could be used to automate the process by the “pick and place” task. In this paper, a vision system is implemented to robustly detect glass piece location and the placing destination. Two distinct detection methods are used for different glass settings. A “pick and place” trajectory is automatically generated based on the detected locations. A simulation is first performed to visualize robot motion before operating on the robot.
Kinematics and Statics for Soft Continuum Manipulators With Heterogeneous Soft Materials
Authors: Jiang Fei , Zhang Haijie , Zhao Jianguo
Published: February 2017

Continuum manipulators are continuously bending robots with unlimited number of kinematic degrees of freedom. Most existing continuum manipulators have a central strut made of a single elastic material, and multiple cables placed around the strut are employed to actuate the manipulator. The kinematics for such robots has been extensively studied by assuming the manipulator has a circular shape. In this paper, we aim to investigate the kinematic and static modeling for novel soft continuum manipulators fabricated by multi-material 3D printing with heterogeneous soft materials. We model cylindrical shape manipulators consisting of three sections with three different materials, and they are actuated by three independent cables placed symmetrically. By pulling the cables with different displacements, the manipulators can be bent in three-dimensional space. As our initial study, we employ a single cable for all prototypes. Experimental results are compared with the simulation results to validate the proposed modeling method.
Force Analysis and Modelling of Soft Actuators for Catheter Robots
Authors: Gilbertson Mark , Beekman Darrin , Mohanty Biswaranjan , Hashemi Saeed , Lee Sangyoon , Van de Ven James D. , Kowalewski Timothy M.
Published: February 2017

Soft robotic actuators may provide the means to develop a soft robotic catheter, enabling safer and more effective transcatheter procedures. In many clinical applications, device contact force affects the quality of diagnostic or the degree of therapy delivered. Therefore precise end effector force control will be a requirement for the soft robotic catheter. In this study a bending soft actuator system was fabricated, and the relationship between volume input and end effector contact force is examined. Static and dynamic system identification were conducted under two different loading conditions loosely related to actuation in a blood vessel. The experimental data from these tests led to the creation of a non-linear system model. A reduced term model was developed using a Root Mean Square Error (RMSE) method in order to observe the importance of system dynamics and nonlinearities. A different system model was designed for each loading condition. These two reduced models matched with experimental result, but differed in model terms and parameters, suggesting that either loading condition identification or end effector closed-loop sensing will be needed for accurate contact force control of a soft robotic actuator in an intravascular environment.
A Low-Cost Soft Coiled Sensor for Soft Robots
Authors: Zhao Jianguo , Abbas Ali
Published: February 2017

Soft robots made from soft materials can closely emulate biological system using simple soft mechanical structures. Compared with traditional rigid-link robots, they are safe to work with humans and can adapt to confined environments. As a result, they are widely used for various robotic locomotions and manipulations. Nevertheless, for soft robots, being able to sense its state to enable closed-loop control using soft sensors remains a challenge. Existing sensors include external sensors such as camera systems, electromagnetic tracking systems, and internal sensors such as optical fibers, conductive liquid, and carbon black filled strips.

In this paper, we investigate a new soft sensor made from low-cost conductive nylon sewing threads. By continuously inserting twists into a thread under some weight, coils can be formed to enable a coiled soft sensor. The resistance of the sensor varies with the change of length. The fabrication and experiments for this new coiled sensor is described in this paper. Embedding this sensor to a 3D printed soft manipulator demonstrates the sensing capability. Compared to existing soft sensors, the coiled sensor is low-cost, easy to fabricate, and can also be used as an actuator. It can be embedded to any soft robot to measure the deformation for closed-loop feedback control.
Efficient Optical Localization for Mobile Robots via Kalman Filtering-Based Location Prediction
Authors: Greenberg Jason N. , Tan Xiaobo
Published: February 2017

Localization and communication are both essential functionalities of any practical mobile sensor network. Achieving both capabilities through a single Simultaneous Localization And Communication (SLAC) would greatly reduce the complexity of system implementation. In this paper a technique for localizing a mobile agent using the line of sight (LOS) detection of an LED-based optical communication system is proposed. Specifically, in a two-dimensional (2D) setting, the lines of sight between a mobile robot and two base nodes enable the latter to acquire bearing information of the robot and compute its location. However, due to the mobile nature of the robot, establishing its LOS with the base nodes would require extensive scan for all parties, severely limiting the temporal resolution and spatial precision of the localization. We propose the use of a Kalman filter to predict the position of the robot based on past localization results, which allows the nodes to significantly reduce the search range in establishing LOS. Simulation results and preliminary experimental results are presented to illustrate and support the proposed approach.
The Influence of the Romantic Genius in Early Christian Studies
Authors: Walsh Robyn Faith
Published: February 2017

This article proposes that critical scholarship of the New Testament has inherited from German Romantic and Idealistic thought a number of presumptions about the role of the author that have contributed to idiosyncratic approaches to these texts when compared with allied studies of ancient literature. Namely, ``critical'' scholarship has continued to impose anachronistic, Romantic ideas of an implicit Volk (people, nation) or inspirational Geist (spirit) onto early literature about Jesus. I offer an alternative reading of the authorship of the gospels that reads them like other ancient literature, centered on concrete evidence for ancient literary practices.
The Blackwell Companion to the Study of Religion
Authors: Segal Robert A.
Published: February 2017

This article presents the approach to religion taken by the Blackwell Companion to the Study of Religion, edited by Robert Segal. The approach taken is largely, though not wholly, that of the social sciences: anthropology, economics, psychology, and sociology. The social scientific approach to religion is pitted against the approach taken by the field of religious studies itself—an approach called “religionist.” The claims by the religionist approach against the social sciences are identified and refuted.
III-V semiconductor extended short-wave infrared detectors
Authors: Savich Gregory R. , Sidor Daniel E. , Du Xiaoyu , Wicks Gary W. , Debnath Mukul C. , Mishima Tetsuya D. , Santos Michael B. , Golding Terry D. , Jain Manish , Craig Adam P. , Marshall Andrew R. J.
Published: February 2017

The extended-shortwave infrared wavelength range, encompassing wavelengths from 2.2 to 3 μm, is significantly underdeveloped when compared to the shortwave and midwave infrared bands. Achieving high performance detectors in the extended-shortwave range is desirable; however, it is unclear whether to approach the wavelength range via the detector structures and materials common to the shortwave regime or those common to the midwave regime. Both approaches are studied here. Electrical and optical characteristics of conventional photodiodes and nBn architecture detectors with 2.8 μm cutoff wavelengths are analyzed for detectors with both lattice-mismatched InGaAs and lattice-matched InGaAsSb absorbing regions. Regardless of the absorber material, the nBn detectors show nearly 3 orders of magnitude improvements in performance over the conventional photodiode architecture, and the lattice-matched InGaAsSb nBn exhibits a further reduction in the dark current by more than an order of magnitude when compared to the lattice-mismatched InGaAs nBn. The InGaAsSb nBn exhibits high quality optical detection resulting in a high performance detector in the extended-shortwave infrared band.
Membrane acoustic metamaterial absorbers with magnetic negative stiffness
Authors: Zhao Junjuan , Li Xianhui , Wang Yueyue , Wang Wenjiang , Zhang Bin , Gai Xiaoling
Published: February 2017

A membrane absorber usually requires a large back cavity to achieve low-frequency sound absorption. This paper describes the design of a membrane acoustic metamaterial absorber in which magnetic negative stiffness is employed to reduce the size of the back cavity. As a baseline for the present research, analysis of a typical membrane sound absorber based on an equivalent circuit model is presented first. Then, a theoretical model is established by introducing negative stiffness into a standard absorber. It is demonstrated that a small cavity with negative stiffness can achieve the acoustic impedance of a large cavity and that the absorption peak is shifted to lower frequencies. Experimental results from an impedance tube test are also presented to validate this idea and show that negative stiffness can be employed to design compact low-frequency membrane absorbers.
Delayed differentiation of potent effector CD8
+
T cells reducing viremia and reservoir seeding in acute HIV infection
Authors: Takata Hiroshi , Buranapraditkun Supranee , Kessing Cari , Fletcher James L. K. , Muir Roshell , Tardif Virginie , Cartwright Pearline , Vandergeeten Claire , Bakeman Wendy , Nichols Carmen N. , Pinyakorn Suteeraporn , Hansasuta Pokrath , Kroon Eugene , Chalermchai Thep , O’Connell Robert , Kim Jerome , Phanuphak Nittaya , Robb Merlin L. , Michael Nelson L. , Chomont Nicolas , Haddad Elias K. , Ananworanich Jintanat , Trautmann Lydie ,   on behalf of the RV254/SEARCH010 and the RV304/SEARCH013 Study Groups
Published: February 2017

Potent CD8
+
T cells endowed with effector functions able to kill HIV-producing cells and reduce the seeding of the HIV reservoir are only detected at peak viremia in acute HIV infection.
Switching tracks in fear memories
Authors: Etkin Amit
Published: February 2017

The brain circuits underlying fear memories can be reorganized by updating old memories with new information.
Winter is coming: Tumor cells go into hibernation
Authors: Lund Amanda W.
Published: February 2017

In response to hypoxia in the primary tumor microenvironment, tumor cells induce a state of dormancy enabling their persistence at metastatic sites and resistance to therapy.
Identification of Human Junctional Adhesion Molecule 1 as a Functional Receptor for the Hom-1 Calicivirus on Human Cells
Authors: Sosnovtsev Stanislav V. , Sandoval-Jaime Carlos , Parra Gabriel I. , Tin Christine M. , Jones Ronald W. , Soden Jo , Barnes Donna , Freeth Jim , Smith Alvin W. , Green Kim Y.
Published: February 2017

The Hom-1 vesivirus was reported in 1998 following the inadvertent transmission of the animal calicivirus San Miguel sea lion virus to a human host in a laboratory. We characterized the Hom-1 strain and investigated the mechanism by which human cells could be infected. An expression library of 3,559 human plasma membrane proteins was screened for reactivity with Hom-1 virus-like particles, and a single interacting protein, human junctional adhesion molecule 1 (hJAM1), was identified. Transient expression of hJAM1 conferred susceptibility to Hom-1 infection on nonpermissive Chinese hamster ovary (CHO) cells. Virus infection was markedly inhibited when CHO cells stably expressing hJAM were pretreated with anti-hJAM1 monoclonal antibodies. Cell lines of human origin were tested for growth of Hom-1, and efficient replication was observed in HepG2, HuH7, and SK-CO15 cells. The three cell lines (of hepatic or intestinal origin) were confirmed to express hJAM1 on their surface, and clustered regularly interspaced short palindromic repeats/Cas9-mediated knockout of the hJAM1 gene in each line abolished Hom-1 propagation. Taken together, our data indicate that entry of the Hom-1 vesivirus into these permissive human cell lines is mediated by the plasma membrane protein hJAM1 as a functional receptor.

IMPORTANCE
Vesiviruses, such as San Miguel sea lion virus and feline calicivirus, are typically associated with infection in animal hosts. Following the accidental infection of a laboratory worker with San Miguel sea lion virus, a related virus was isolated in cell culture and named Hom-1. In this study, we found that Hom-1 could be propagated in a number of human cell lines, making it the first calicivirus to replicate efficiently in cultured human cells. Screening of a library of human cell surface membrane proteins showed that the virus could utilize human junctional adhesion molecule 1 as a receptor to enter cells and initiate replication. The Hom-1 virus presents a new system for the study of calicivirus biology and species specificity.
FANCD2 Binds Human Papillomavirus Genomes and Associates with a Distinct Set of DNA Repair Proteins to Regulate Viral Replication
Authors: Spriggs Chelsey C. , Laimins Laimonis A.
Published: February 2017

The life cycle of human papillomavirus (HPV) is dependent on the differentiation state of its host cell. HPV genomes are maintained as low-copy episomes in basal epithelial cells and amplified to thousands of copies per cell in differentiated layers. Replication of high-risk HPVs requires the activation of the ataxia telangiectasia-mutated (ATM) and ATM and Rad3-related (ATR) DNA repair pathways. The Fanconi anemia (FA) pathway is a part of the DNA damage response and mediates cross talk between the ATM and ATR pathways. Our studies show that HPV activates the FA pathway, leading to the accumulation of a key regulatory protein, FANCD2, in large nuclear foci. These HPV-dependent foci colocalize with a distinct population of DNA repair proteins, including ATM components γH2AX and BRCA1, but infrequently with p-SMC1, which is required for viral genome amplification in differentiated cells. Furthermore, FANCD2 is found at viral replication foci, where it is preferentially recruited to viral genomes compared to cellular chromosomes and is required for maintenance of HPV episomes in undifferentiated cells. These findings identify FANCD2 as an important regulator of HPV replication and provide insight into the role of the DNA damage response in the differentiation-dependent life cycle of HPV.

IMPORTANCE
High-risk human papillomaviruses (HPVs) are the etiological agents of cervical cancer and are linked to the development of many other anogenital and oropharyngeal cancers. Identification of host cellular pathways involved in regulating the viral life cycle may be helpful in identifying treatments for HPV lesions. Mutations in genes of the Fanconi anemia (FA) DNA repair pathway lead to genomic instability in patients and a predisposition to HPV-associated malignancies. Our studies demonstrate that FA pathway component FANCD2 is recruited to HPV DNA, associates with members of the ATM DNA repair pathway, and is essential for the maintenance of viral episomes in basal epithelial cells. Disruption of the FA pathway may result in increased integration events and a higher incidence of HPV-related cancer. Our study identifies new links between HPV and the FA pathway that may help to identify new therapeutic targets for the treatment of existing HPV infections and cancers.
Genomic Microdiversity ofBifidobacterium pseudocatenulatumUnderlying Differential Strain-Level Responses to Dietary Carbohydrate Intervention
Authors: Wu Guojun , Zhang Chenhong , Wu Huan , Wang Ruirui , Shen Jian , Wang Linghua , Zhao Yufeng , Pang Xiaoyan , Zhang Xiaojun , Zhao Liping , Zhang Menghui
Published: February 2017

The genomic basis of the response to dietary intervention of human gut beneficial bacteria remains elusive, which hinders precise manipulation of the microbiota for human health. After receiving a dietary intervention enriched with nondigestible carbohydrates for 105 days, a genetically obese child with Prader-Willi syndrome lost 18.4% of his body weight and showed significant improvement in his bioclinical parameters. We obtained five isolates (C1, C15, C55, C62, and C95) of one of the most abundantly promoted beneficial species,Bifidobacterium pseudocatenulatum, from a postintervention fecal sample. Intriguingly, these fiveB. pseudocatenulatumstrains showed differential responses during the dietary intervention. Two strains were largely unaffected, while the other three were promoted to different extents by the changes in dietary carbohydrate resources. The differential responses of these strains were consistent with their functional clustering based on the COGs (Clusters of Orthologous Groups), including those involved with the ABC-type sugar transport systems, suggesting that the strain-specific genomic variations may have contributed to the niche adaption. Particularly,B. pseudocatenulatumC15, which had the most diverse types and highest gene copy numbers of carbohydrate-active enzymes targeting plant polysaccharides, had the highest abundance after the dietary intervention. These studies show the importance of understanding genomic diversity of specific members of the gut microbiota if precise nutrition approaches are to be realized.

IMPORTANCEThe manipulation of the gut microbiota via dietary approaches is a promising option for improving human health. Our findings showed differential responses of multipleB. pseudocatenulatumstrains isolated from the same habitat to the dietary intervention, as well as strain-specific correlations with bioclinical parameters of the host. The comparative genomics revealed a genome-level microdiversity of related functional genes, which may have contributed to these differences. These results highlight the necessity of understanding strain-level differences if precise manipulation of gut microbiota through dietary approaches is to be realized.
The Baltic Sea Virome: Diversity and Transcriptional Activity of DNA and RNA Viruses
Authors: Zeigler Allen Lisa , McCrow John P. , Ininbergs Karolina , Dupont Christopher L. , Badger Jonathan H. , Hoffman Jeffery M. , Ekman Martin , Allen Andrew E. , Bergman Birgitta , Venter J. Craig
Published: February 2017

Inferred virus-host relationships, community structures of ubiquitous ecologically relevant groups, and identification of transcriptionally active populations have been achieved with our Baltic Sea study. Further, these data, highlighting the transcriptional activity of viruses, represent one of the more powerful uses of omics concerning ecosystem health. The use of omics-related data to assess ecosystem health holds great promise for rapid and relatively inexpensive determination of perturbations and risk, explicitly with regard to viral assemblages, as no single marker gene is suitable for widespread taxonomic coverage.
Glioblastoma with primitive neuronal pattern in a girl aged 3 months: a rare diagnosis at an unusual age
Authors: Tan Chi Hau , Phung Teik Beng , Xenos Chris
Published: February 2017

A girl aged 3 months presented with multiple seizures within 12 hours and was noted to have a palpable swelling over the right temporal region. MRI of the brain revealed a large right frontotemporal tumour, suggestive of supratentorial primitive neuroectodermal tumour. She underwent a stealth-guided craniotomy and debulking of the tumour. Histopathology and immunochemistry of the specimen, however, indicated a high-grade tumour with glioblastoma and neuroblastic components. She underwent adjuvant chemotherapy following the surgery and is well at 7-month follow-up. This case underscores the importance of considering the rare entity of glioblastoma with primitive neuronal pattern as a differential diagnosis in a young child.