bluuebunny/crossref_metadata_2025 huggingface dataset:
Online Powermanagement With Embedded Optimization for a Multi-Source Hybrid With Dynamic Power Sharing Between Components
Authors: Moulik Bedatri , Söffker Dirk
Published: January 2016

The need for the development of online powermanagement strategies applicable to real-time hybrid powertrain systems is an important issue in the transportation sector. A powermanagement strategy alone does not necessarily ensure optimal power distribution amongst the drive train components. Thus optimization of powemanagement is another task which needs to be considered in terms of multiple objectives. Apart from online applicability of powermanagement optimization, a consideration of useful combinations of drivetrain components such as two storage elements together with a primary source may also be useful. In this contribution, an online powermanagement strategy is applied to a three-source hybrid electric powertrain. An optimization of controller parameters with embedded-online optimization is proposed.
Li-O Battery Aging Process: A Comprehensive Review With Respect to the Integration of Aging Into System’s Powermanagement
Authors: Beganovic Nejra , Moulik Bedatri , Söffker Dirk
Published: January 2016

Intensive development of hybrid electric vehicles in recent years is conditioned by ecological requirements reflecting in the reduction of greenhouse gas emission and by the limitation of the use of fossil fuel. Lithium-Ion Batteries (LIBs) become unavoidable component serving as an energy storage element in transportation industry as well as in solar and wind energy systems. The problems related to battery state monitoring in hybrid electric vehicles refer to the estimation of immeasurable degradation parameters. Concerning existing literature, the measurements indirectly correlated to the deterioration process are used for the calculation of degradation parameters. Special attention is given to LIB parameters related to battery aging such as capacity fade and internal resistance increase. Existing approaches to these parameters estimation/calculation concern no direct measurement of degradation parameters. Indirect relations can be established assuming suitable assumptions. The contribution addresses the main issues related to LIB parameters monitoring as well as to the adopted control strategy providing high energy efficiency while maintaining as less as possible rate of component degradation.
Casimir and Van der Waals Effects on Voltage Response of Electrostatically Actuated MEMS/NEMS Plates
Authors: Caruntu Dumitru I. , Oyervides Reynaldo , Garcia Valeria
Published: January 2016

This paper deals with electrostatically actuated MEMS plates. The model consists of a flexible MEMS plate above a parallel ground plate. An AC voltage of frequency near natural frequency of the plate provides the electrostatic force that actuates the flexible MEMS plate. This leads to parametric resonance. The effect of Casimir and/or van der Waals forces on the voltage-amplitude response of the plate is investigated.
Active Wide-Band Vibration Rejection for Semiconductor Manufacturing Robots
Authors: Wang Zining , Wang Cong , Tomizuka Masayoshi
Published: January 2016

Currently, the semiconductor manufacturing industries over the world are upgrading from processing 300mm wafers to processing 450mm wafers. In order to satisfy the requirements of producing and processing 450mm wafers, vibration control of wafer handling tools has to make new breakthroughs. This paper introduces an active wide-band vibration rejection method with a vibrotactile actuator and applies it to a wafer transfer robot. Compared to conventional methods based on motor control of the robot, active vibration cancellation with a separate actuator does not risk compromising the tracking accuracy of wafer transfer motions. A three-step controller synthesis scheme is developed by analyzing and combining the strengths of several control strategies. Experimental validation shows a vibration reduction of more than 40% in energy and 30% in amplitude.
Velocity Control of a Cylindrical Rolling Robot by Surface-Morphing
Authors: Puopolo Michael , Jacob J. D.
Published: January 2016

A mathematical model is developed for a rolling robot with a cylindrically-shaped, elliptical outer surface that has the ability to alter its shape as it rolls, resulting in a torque imbalance that accelerates or decelerates the robot. A control scheme is implemented, whereby angular position and angular velocity are used as feedback to trigger and define morphing actuation. The goal of the control is to direct the robot to follow a given angular velocity profile. Equations of motion for the rolling robot are formulated and solved numerically. Results show that by automatically morphing its shape in a periodic fashion, the rolling robot is able to start from rest, achieve constant average velocity and slow itself in order to follow a desired velocity profile with significant accuracy.
Model Order Reduction of Electrochemical Batteries Using Galerkin Method
Authors: Fan Guodong , Canova Marcello
Published: January 2016

This paper presents a model order reduction (MOR) method for modeling and estimation of a first-principles electrochemical Lithium-ion battery. The MOR approach combines the Galerkin method with coordinate transformation and is applied to solve the spherical diffusion problem with non-zero flux boundary conditions. The order of the reduced-order model (ROM) is carefully selected based on analysis in the frequency domain. With the reduced-order diffusion model, an enhanced single particle model which incorporates the electrolyte dynamics is developed and validated against the experimental data.
Application of Integrated Control Structure Design Using BMI Theory and Robust Feedback Linearization to Excavator Bucket Level Control
Authors: Kassen Daniel M. , Zhou Hui , Tulpule Punit J. , Kelkar Atul G.
Published: January 2016

Integrated design of controlled mechanical systems — wherein structure and controls are designed concurrently as opposed to sequentially — has proven to yield a better optimal design. Early work in this area from the co-authors has led to the development of a novel design tool: Integrated Robust Optimal Design (IROD). IROD offers an integrated design framework that can be applied to a variety of robust optimal design problems. This paper presents the addition of feedback linearization control strategy to the robust design framework and demonstrates its application to an excavator bucket leveling control system design problem. The excavator dynamic model is highly nonlinear and it includes both the multibody linkage dynamics and the hydraulic actuator dynamics. The hydraulic system consists of a pump, four way spool valve, and pistons. The performance, robustness, and required control energy of the IROD design are compared with traditional sequential design using a full SimScape model. The results clearly demonstrate the effectiveness of IROD over traditional design methodologies.
Speed Control of an Inertia Load Connected to a Motor Through a Compliant Mechanical Transmission System
Authors: Raul Pramod R. , Dwivedula Ramamurthy V. , Pagilla Prabhakar R.
Published: January 2016

In this paper, we focus on the problem of controlling the load speed of a mechanical transmission system consisting of a belt-pulley and a gear-pair. We consider two inertias (motor and load) system connected by a compliant transmission. Because of the transmission dynamics, regulation of motor shaft speed may not translate to regulation of load speed. Further, determination of whether to use of motor speed or load speed feedback or a combination of both that would facilitate control of load speed is of importance. In this paper we investigate both the motor and load speed feedback options by considering transmission compliance and utilizing the singular perturbation method. We propose a two degree of freedom control system that utilizes both motor and load speed feedback and an adaptive feedforward scheme to reject torque disturbances on the load. Experiments conducted on a typical industrial transmission system that is commonly employed in roll-to-roll manufacturing are discussed,. A representation sample of the experimental results are presented and discussed.
Multi-Objective Optimization to Minimize Battery Degradation and Electricity Cost for Demand Response in Datacenters
Authors: Mamun Abdullah-Al , Narayanan Iyswarya , Wang Di , Sivasubramaniam Anand , Fathy Hosam K.
Published: January 2016

This paper presents a Lithium-ion battery control framework to achieve minimum health degradation and electricity cost when batteries are used for datacenter demand response (DR). Demand response in datacenters refers to the adjustment of demand for grid electricity to minimize electricity cost. Utilizing batteries for demand response will reduce the electricity cost but might accelerate health degradation. This tradeoff makes battery control for demand response a multi-objective optimization problem. Current research focuses only on minimizing the cost of demand response and does not capture battery transient and degradation dynamics. We address this multi-objective optimization problem using a second-order equivalent circuit model and an empirical capacity fade model of Lithium-ion batteries. To the best of our knowledge, this is the first study to use a nonlinear Lithium-ion battery and health degradation model for health-aware optimal control in the context of datacenters. The optimization problem is solved using a differential evolution (DE) algorithm and repeated for different battery pack sizes. Simulation results furnish a Pareto front that makes it possible to examine tradeoffs between the two optimization objectives and size the battery pack accordingly.
Mode Controllability and Disturbance Rejection in Consensus Networks
Authors: Abohtyra Rammah M.
Published: January 2016

This paper considers a new notion of mode controllability for interconnected systems. A new method based on canceling natural system modes that arise from non-zero initial conditions is proposed. A system of first-order linear differential equations is used to represent an interconnected system where the links are static gains. The paper focuses on the initial conditions of the nodes. The system is said to be mode controllable if every initial condition mode can be canceled, while the system is not mode controllable if there exists at least one initial condition mode that cannot be cancelled. A test of model controllability is developed, which is equivalent to the standard controllability. We test this method by rejecting all natural system modes using the minimum input control. Finally, the paper concludes an illustrative example with simulation results and future work.
The Stick-Slip Motion of a Chaplygin Sleigh With a Piecewise Smooth Nonholonomic Constraint
Authors: Fedonyuk Vitaliy , Tallapragada Phanindra
Published: January 2016

The Chaplygin sleigh is a canonical problem of mechanical systems with nonholonomic constraints, which arises due to the role of friction. The motion of the cart has often been studied under the assumption that the magnitude of friction is as high as necessary to prevent slipping. We relax this assumption by setting a maximum finite value to the friction. The Chaplygin sleigh is then under a piecewise smooth nonholonomic constraint and transitions between ‘slip’ and ‘stick’ modes. We investigate these transitions and the resulting non smooth dynamics of the system. Further more the piecewise smooth constraint offers the possibility of controlling the speed of the sleigh and we investigate this with numerical simulations.
Crane Workspace Mapping Using QR Codes
Authors: Rahman M. Sazzad , Vaughan Joshua
Published: January 2016

This paper presents a novel approach of mapping a crane workspace using a combination of QR code-based and image-segmentation-based mapping algorithms. Known objects in the workspace are labeled with a QR code, and a database contains the information of the objects. A camera mounted on the crane trolley takes pictures as the crane moves through the workspace. The images are then used to produce an image-segmentation-based map of the workspace. To produce the QR code-based map, the QR codes in the images taken with the camera are decoded, and the information of the corresponding objects are read from the database file. The object position and orientation are calculated from the position and orientation of the QR codes, and the map is drawn. Results showed that the mapping algorithms are more reliable together than they are individually.
Cross Coupling in Parallel Kinematic MEMS Nanopositioners
Authors: Maroufi Mohammad , Moheimani S. O. Reza
Published: January 2016

In this paper we study the origins of the cross coupling phenomenon in MEMS nanopositioners with a parallel kinematic mechanism. An analytical model is provided for a generic 2-DOF MEMS nanopositioner. The model accounts for the potential mechanical asymmetries present in the device due to micro-fabrication imperfections. Simulations are performed based on the obtained model and compared with experimental data from a previously reported MEMS nanopositioner. A close agreement is observed between the analytical and experimental results, leading to a better understanding of the phenomenon.
Continuous Structures With Viscoelastic Supports: Tuning of Material Parameters and Support Location
Authors: Singh Kumar Vikram , Oliver Danielle , Ling Xiaoxuan
Published: January 2016

Polymeric smart materials exhibit viscoelastic behavior and their dynamic characteristics are dependent on both frequency and temperature. This allows the tuning of material properties (stiffness and loss factor) to manipulate the vibration behavior for a wide range of engineering applications. In this research, the effects of viscoelastic supports on the vibration of continuous structures such as axially vibrating rods and transversely vibrating beams are investigated. The governing equations of motion for harmonically excited rods with end supports, and the free vibration of beams with intermediate viscoelastic support are developed. The analytical response equation for a harmonically excited rod with viscoelastic ends is obtained. The resulting frequency response equations are then used to design the modification of the stiffness and loss factor of the viscoelastic materials in order to achieve the desired vibration response of the rod. By solving the resulting transcendental eigenvalue problems, the natural frequencies and damping ratios as a function of viscoelastic support parameters are computed for beams. The performance of structures with viscoelastic support is demonstrated with various numerical examples. The formulation and results can be utilized for estimating the optimal material tuning parameters as well as support locations for controlling and manipulating the vibration response of the structures.
Multi-Objective Optimization of Impedance Parameters in a Prosthesis Test Robot
Authors: Khalaf Poya , Richter Hanz , van den Bogert Antonie J. , Simon Dan
Published: January 2016

We design a control system for a prosthesis test robot that was previously developed for transfemoral prosthesis design and test. The robot’s control system aims to mimic human walking in the sagittal plane. It has been seen in previous work that trajectory control alone fails to produce human-like forces. Therefore, we utilize an impedance controller to achieve reasonable tracking of motion and force simultaneously. However, these objectives conflict. Impedance control design can therefore be viewed as a multi-objective optimization problem. We use an evolutionary multi-objective strategy called Multi-Objective Invasive Weed Optimization (MOIWO) to design the impedance controller. The multi-objective optimization problem admits a set of equally valid alternative solutions known as the Pareto optimal set. We use a pseudo weight vector approach to select a single solution from the Pareto optimal set. Simulation results show that a solution that is selected for pure motion tracking performs very accurate motion tracking (RMS error of 0.06 cm) but fails to produce the desired forces (RMS error of 70% peak load). On the other hand, a solution that is selected for pure force tracking successfully tracks the desired force (RMS error of 12.7% peak load) at the expense of motion trajectory errors (RMS error of 4.5 cm).
Modeling and Simulation of Residential Power Demand Including Transportation
Authors: Maiorino Mario , Stockar Stephanie , Sorrentino Marco , Rizzoni Giorgio
Published: January 2016

Personal transportation has a significant impact on the residential electric energy usage due to the interaction of alternative fueled vehicles with the electric grid. This phenomenon is projected to grow significantly, as several studies confirm that the market penetration of alternative fueled vehicles will steadily increase in the future.

This paper presents a control-oriented model that predicts the daily residential power demand considering multiple energy carriers and different types of alternative fueled vehicles for personal transportation. The model has been used to perform an energy analysis on a large sample of homes with the objective of evaluating the impact of personal transportation on the residential electric power demand. Two penetration levels are considered in the study and the results are evaluated based on several metrics.
Tracking Control of Non-Minimum Phase Systems Using Filtered Basis Functions: A NURBS-Based Approach
Authors: Duan Molong , Ramani Keval S. , Okwudire Chinedum E.
Published: January 2016

This paper proposes an approach for minimizing tracking errors in systems with non-minimum phase (NMP) zeros by using filtered basis functions. The output of the tracking controller is represented as a linear combination of basis functions having unknown coefficients. The basis functions are forward filtered using the dynamics of the NMP system and their coefficients selected to minimize the errors in tracking a given trajectory. The control designer is free to choose any suitable set of basis functions but, in this paper, a set of basis functions derived from the widely-used non uniform rational B-spline (NURBS) curve is employed. Analyses and illustrative examples are presented to demonstrate the effectiveness of the proposed approach in comparison to popular approximate model inversion methods like zero phase error tracking control.
Active Control of MR Wearable Robotic Orthosis for Pathological Tremor Suppression
Authors: Case David , Taheri Behzad , Richer Edmond
Published: January 2016

Given the side effects and possible complications of current clinical treatments for severe pathological tremor, many researchers pursue the less invasive alternative of suppression at the musculo-skeletal level. In wearable robotics applications, the high strength-to-weight ratio, the low power consumption, and their adaptability allow magnetorheological (MR) fluid dampers and actuators to be personalized to the individual needs of a patient. Moreover, their rapid dynamic response makes them suitable for use in real time active devices. This paper presents the theoretical development and experimental validation of a tremor suppression control algorithm based on a dynamic lump parameter model of the MR damper and a real time adaptive tremor frequency estimator. The control strategy was experimentally evaluated using a one-DOF joint simulator. Experiments with ten datasets from patients with severe Parkinsonian and Essential Tremor show suppressions for the first and second harmonics of 28.7±2.2 dB and 11.8±4.8 dB, respectively. These results compare favorably with the suppression levels obtained by other researchers using constant current approach. In addition, the resistance that the orthotic device imposes to the voluntary motion was reduced by 33% under the active control strategy, while the power usage was dramatically reduced by nearly an order of magnitude.
Operator Testing on Dual-Hoist Cranes Moving Triangular Payloads
Authors: Rhee Caroline , Miller Alexander S. , Singhose William
Published: January 2016

Certain heavy-lifting applications require the coordinated movement of multiple cranes. Such tasks dramatically increase the complexity of crane operation, especially when the payload has a non-uniform shape. Therefore, controlling such a complex dynamic system requires skilled operators. However, even with extensive operator training, manipulating a crane with a large payload is difficult and presents serious safety hazards. This paper studies the dynamic behavior of a dual-hoist bridge crane moving triangular payloads. Test subjects used a wireless controller to move a dual-hoist crane with a triangular payload. They drove the payload through an obstacle course under various operating conditions. The time required to complete the course and the operator effort were recorded. Test runs were completed with and without input-shaping oscillation control. The result shows that using input-shaping oscillation control significantly reduces not only the task completion time but also the number of button pushes.
Reconstruction of Nonlinear Characteristics by Means of Advanced Observer Design Approaches
Authors: Bakhshande Fateme , Söffker Dirk
Published: January 2016

The paper introduces into the concept of model-based force estimation of flexible structures with impacts. The advantage of using extended PI-Observer (MAPIO) in comparison with the well-known PI-Observer is investigated with respect to the reconstruction of a complex nonlinear unknown input. Therefore a clamped beam example is considered. The task of the observer scheme is to estimate the tip position and the effecting input as unknown input. This task is also realized in the presence of measurement noise. The reconstruction of complex nonlinear spring behavior is performed to prove the performance of MAPI-Observer in comparison to PI-Observer.
Spring-Mass Walking With ATRIAS in 3D: Robust Gait Control Spanning Zero to 4.3 KPH on a Heavily Underactuated Bipedal Robot
Authors: Rezazadeh Siavash , Hubicki Christian , Jones Mikhail , Peekema Andrew , Van Why Johnathan , Abate Andy , Hurst Jonathan
Published: January 2016

We present a reduced-order approach for dynamic and efficient bipedal control, culminating in 3D balancing and walking with ATRIAS, a heavily underactuated bipedal robot. These results are a development toward solving a number of enduring challenges in bipedal locomotion: achieving robust 3D gaits at various speeds and transitioning between them, all while minimally draining on-board energy supplies. Our reduced-order control methodology works by extracting and exploiting general dynamical behaviors from the spring-mass model of bipedal walking. When implemented on a robot with spring-mass passive dynamics, e.g. ATRIAS, this controller is sufficiently robust to balance while subjected to pushes, kicks, and successive dodge-ball strikes. The controller further allowed smooth transitions between stepping in place and walking at a variety of speeds (up to 1.2 m/s). The resulting gait dynamics also match qualitatively to the reduced-order model, and additionally, measurements of human walking. We argue that the presented locomotion performance is compelling evidence of the effectiveness of the presented approach; both the control concepts and the practice of building robots with passive dynamics to accommodate them.
Shared Fuzzy Control of Multiple Quadrotor UAVs With Time-Dependent Delay and Bounded Control-Input Constraint
Authors: Johnson Mark D. , Ayoubi Mohammad A.
Published: January 2016

We propose a shared fuzzy controller for position and attitude control of multiple quadrotor unmanned aerial vehicles (UAVs). Using the nonlinear governing equations of motion and kinematics of a quadrotor, we develop a Takagi-Sugeno (T-S) fuzzy model for a quadrotor. Then, we consider time-varying delays due to wireless connectioninto the T-S fuzzy model. We use the sufficient stability condition based on the Lyapunov-Krasovskii stability theorem and the parallel distributed compensation (PDC) technique to determine the fuzzy control law. For practical purposes, we include actuator amplitude constraint into the design process. The problem of designing a shared fuzzy controller is cast in the form of linear matrix inequalities (LMIs). A feasible solution region is found in terms of maximum magnitude and rate of time-varying delay. In the end, the stability, performance, and robustness of the proposed shared fuzzy controller are examined via numerical simulation.
Electrochemical Model-Based Adaptive Estimation of Li-Ion Battery State of Charge
Authors: Lotfi N. , Landers R. G. , Li J. , Park J.
Published: January 2016

Electrochemical model-based estimation techniques have attracted increasing attention in the past decade due to their inherent insight about the internal battery operating conditions and limits while being able to monitor important li-ion battery states. The applicability of these methods is, however, limited due to the implementation complexity of their underlying models. In order to facilitate online implementation while maintaining the physical insight, a reduced-order electrochemical model is used in this work. This model, which is based on the commonly-used single particle model, is further improved by incorporating the electrolyte-phase potential. Furthermore, an output-injection observer, suitable for online implementation, is proposed to estimate SOC. The observer convergence is proved analytically using Lyapunov theory. Although the proposed observer shows great performance at low C rates, its accuracy deteriorates at high C-rates. To overcome this issue and achieve accurate SOC estimates for such charge/discharge rates, an adaptation algorithm is augmented to the observer. The adaptation algorithm, which can be implemented online, is used to compensate for model uncertainties, especially at higher C rates. Finally, simulation results based on a full-order electrochemical model are used to validate the observer performance and effectiveness.
Automated Multi-Zone Linear Parametric Black Box Modeling Approach for Building HVAC Systems
Authors: Chintala Rohit H. , Rasmussen Bryan P.
Published: January 2016

Optimal control algorithms such as distributed model predictive control (DMPC) offer tremendous potential in reducing energy consumption of building operations. Heating, ventilation and air-conditioning (HVAC) systems which form a major part of the building operations contain a large number of interconnected subsystems. One of the challenges associated with implementing DMPC is the development of reliable models of individual subsystems for prediction, especially for large scale systems. In this paper an automated method is proposed to develop linear parametric black box models for individual building HVAC subsystems. The modeling method proposed identifies the significant inputs, and the upstream and downstream neighbors of each subsystem before performing regression analysis to determine the model parameters. Automation of the model development makes the implementation of the model-based control algorithms much more feasible. The modeling method is then verified through an EnergyPLus model, and using data of a real office building.
Supernumerary Robotic Fingers as a Therapeutic Device for Hemiparetic Patients
Authors: Ort Teddy , Wu Faye , Hensel Nicholas C. , Asada H. Harry
Published: January 2016

Patients with hemiparesis often have limited functionality in the left or right hand. The standard therapeutic approach requires the patient to attempt to make use of the weak hand even though it is not functionally capable, which can result in feelings of frustration. Furthermore, hemiparetic patients also face challenges in completing many bimanual tasks, for example walker manipulation, that are critical to patients’ independence and quality of life. A prototype therapeutic device with two supernumerary robotic fingers was used to determine if robotic fingers could functionally assist a human in the performance of bimanual tasks by observing the pose of the healthy hand. Specific focus was placed on the identification of a straightforward control routine which would allow a patient to carry out simple manipulation tasks with some intermittent input from a therapist. Part of this routine involved allowing a patient to switch between active and inactive monitoring of hand position, resulting in additional manipulation capabilities. The prototype successfully enabled a test subject to complete various bimanual tasks using the robotic fingers in place of normal hand motions. From these results, it is clear that the device could allow a hemiparetic patient to complete tasks which would previously have been impossible to perform.
Output Feedback Control Design for Quadrotors in the Presence of Uncertainties
Authors: Lee Joonho , Choi Jongeun
Published: January 2016

This paper proposes an output feedback control design for quadrotor Unmanned Aerial Vehicles (UAVs) to deal with unmeasured system states, system uncertainties, and external disturbances. Extended High-Gain Observers (EHGOs) are used to estimate the uncertainties and unmeasured system states. Dynamic inversion utilizes the estimates from EHGOs in the second and third fastest time scales in order to deal with input uncertainties and a form of non-affine control inputs. In plant dynamics, rotational dynamics in the fourth fastest time scale, is forced to be faster than translational dynamics in the slowest time scale to overcome the lack of the number of control inputs in this underactuated mechanical system. Using the singular perturbation method, stability of the closed-loop system is conducted. Throughout numerical simulations, the proposed control algorithm is verified.
Control of the Intake Air Dynamics on a Single-Cylinder Engine, to Replicate Multi-Cylinder Engine Dynamics
Authors: Moskwa John J. , Murphy Mark B.
Published: January 2016

Single-cylinder test engines are used extensively in engine research, and sparingly in engine development, as an inexpensive way to test or evaluate new concepts or to understand in-cylinder motion or combustion. They also allow good access to the cylinder for instrumentation, however, these single-cylinder engines differ significantly in rotational dynamics, gas intake dynamics, heat transfer dynamics, dynamic coupling between cylinders, and in other areas. Charge motion within the cylinder, even during the closed period differs from the multi-cylinder engine because of the differences in both instantaneous flow and momentum.

Researchers in the Powertrain Control Research Laboratory (PCRL) at the University of Wisconsin-Madison have developed single-cylinder engine transient test systems that control the instantaneous dynamic cylinder boundary conditions to replicate those in the target multi-cylinder engine. The overall goal is to exploit the benefits of the single-cylinder engine, while eliminating the negative aspects of this device, and to have the single-cylinder “think” it is dynamically operating within a multi-cylinder engine.

This paper describes the latest developments in controlling the intake gas dynamics of the single-cylinder engine to meet these goals. A combination of both rotary and proportional valves are used to accurately replicate the instantaneous intake airflow that exists in the multi-cylinder engine, including during transients. A Fourier-based approach instead of the previous time-based trajectory control is used to accomplish these goals. This is a third generation of intake air simulator (IAS3) that is a significant step forward in both simplifying the system, and in significantly expanding the operating envelop of the engine to include the full engine operating range of the multi-cylinder engine. A brief introduction of the entire transient test system will show the reader how rotational, heat transfer, and gas dynamics are controlled, and how the IAS3 fits into this overall system.
Control Design for a Hand Tremor Suppression Pen
Authors: Ou Che , Gouldstone Andrew , Jaeger Beverly Kris , Sipahi Rifat
Published: January 2016

Active feedback control is utilized in this study in order to regulate pen-tip deviations in a novel pen design with the aim to minimize the effects of hand tremors on handwriting. The pen comprises a pendulum-like pen-rod that swings inside a tubular shaped pen casing, and between the pen and the casing, certain compliance and active actuation is considered. Since by the nature of the system dynamics, arbitrary pole placement is not possible in the design of the controller, a nonlinear optimization scheme is constructed to design the controller gains. With these gains, pen-tip deviations are minimized (≈ −47 dB) when the pen casing is subjected tremor-induced cyclic disturbances, and pen-tip response against impulsive perturbations is satisfactorily improved (settling time ≈ 1 sec) while keeping the controller effort around 2 N. Simulation studies are presented comparing the efficacy of the proposed controller with respect to a passively controlled pen, along with trade-offs within the design parameter space.
Nonlinear Model Predictive Controller for an Unmanned Ground Vehicle on Variable Terrain
Authors: Eick Andrew , Bevly David
Published: January 2016

Rough, off-road terrain contains multiple hazards for an unmanned ground vehicle (UGV). In this paper, hazards are classified into three groups: obstacles, rough traversable terrain, and rough untraversable terrain. These three types of hazards create a rollover risk for a UGV. A nonlinear model predictive controller (NMPC) that is capable of navigating a UGV through these hazards is presented. The control algorithm features a nonlinear tire model which more accurately captures the dynamics of the UGV when compared to a linearized tire model, and has a fast enough run time for real time implementation. On an actual vehicle, the UGV is assumed to be equipped with a perception based sensor, such as a Light Detection And Ranging (LiDAR) unit, to provide information of the terrain roughness, grade, and elevation. This information is used by the NMPC to safely control the vehicle to a target location. However, for the purposes of this paper, control inputs and terrain are simulated in Car-Sim [1], and the feasibility of real time implementation is investigated.
In situ synthesis of metallic nanowire arrays for ionization gauge electron sources
Authors: Roustaie Farough , Quednau Sebastian , Dassinger Florian , Schlaak Helmut F. , Lotz Marcel , Wilfert Stefan
Published: January 2016

An in situ synthesis process for nanowire arrays was used to fabricate a customized field emitter array for use as a nonthermal electron source in an ionization gauge. The wire arrays fabricated with this process had a density of 1.6 × 106 cm−2 using optimized deposition of the wires in template foils on predefined electrodes. The diameter of the wires varied from 100 to 400 nm and their length ranged from 8 to 100 μm. This method can enclose with nanowires a wide area of predefined electrodes, and is possible for areas larger than 3 cm2. Further, the cylindrical shape of the nanowires was modified into a conical geometry to achieve improved thermomechanical stability.
Trap studies in silicon nanowire junctionless transistors using low-frequency noise
Authors: Opondo Noah , Ramadurgam Sarath , Yang Chen , Mohammadi Saeed
Published: January 2016

A method to envisage trap density in the semiconductor bandgap near the semiconductor/oxide interface of nanoscale silicon junctionless transistors (JLTs) is presented. JLTs are fabricated in a bottom-up fabrication technique using in situ highly doped nanowires grown by low pressure chemical vapor deposition. Low-frequency noise characterization of JLTs biased in saturation is conducted at different gate biases. The noise spectrum indicates either a Lorentzian or 1/f noise depending on the gate bias. Analysis of the results indicates very low trap densities in the order of 1016 cm−3eV−1. Low trap densities in these devices are associated with their simple fabrication technique, in situ oxide formation, and the absence of semiconductor junction and the ion implantation step in the process. A simple analysis of the low-frequency noise data leads to the density of the traps and their energy within the semiconductor bandgap and their location from the Si/SiO2 interface.
Multiwalled carbon nanotube field emitter as an electron source for a microcolumn
Authors: Kanth Sanjeev Kumar , Sharma Anjli , Park Byong Chon , Kim Ho Seob
Published: January 2016

A multiwalled carbon nanotube (MWCNT) field emitter is developed as the electron source for a microcolumn-based field-emission scanning electron microscope (SEM). A MWCNT is first attached onto a tungsten (W) support tip using the nanomanipulator in the SEM. Then, an electrical bias is applied between the MWCNT field emitter and W tip to improve the contact between them, which lowers the threshold voltage for field emission. An emission current stability test showed that the emission current is stable. The fabricated MWCNT emitter exhibits a high emission current of 12 μA and sample current of around 2 nA, even at a low tip bias of 350 V in the microcolumn. The tip bias is much lower, and the sample current is higher than the equivalent values reported for W tips. The authors acquired images of a 1000-mesh copper grid using the microcolumn-based SEM with a MWCNT field emitter as the source. Our results suggest that MWCNTs should be considered a promising candidate as an electron source for microcolumns.
Postprimary Tuberculosis and Macrophage Necrosis: Is There a Big ConNECtion?
Authors: Wong Ka-Wing , Jacobs William R.
Published: January 2016

Adult or postprimary tuberculosis (TB) accounts for most TB cases. Its hallmark is pulmonary cavitation, which occurs as a result of necrosis in the lung in individuals with tuberculous pneumonia. Postprimary TB has previously been known to be associated with vascular thrombosis and delayed-type hypersensitivity, but their roles in pulmonary cavitation are unclear. A necrosis-associated extracellular cluster (NEC) refers to a cluster of drug-tolerantMycobacterium tuberculosisattached to lysed host materials and is proposed to contribute to granulomatous TB. Here we suggest that NECs, perhaps due to big size, produce a distinct host response leading to postprimary TB. We propose that vascular thrombosis and pneumonia arise from NEC and that these processes are promoted by inflammatory cytokines produced from cell-mediated delayed-type hypersensitivity, such as interleukin-17 and gamma interferon, eventually triggering necrosis in the lung and causing cavitation. According to this view, targeting NEC represents a necessary strategy to control adult TB.
Molecular and Structural Analysis of the Helicobacter pylori
cag
Type IV Secretion System Core Complex
Authors: Frick-Cheng Arwen E. , Pyburn Tasia M. , Voss Bradley J. , McDonald W. Hayes , Ohi Melanie D. , Cover Timothy L.
Published: January 2016

Bacterial type IV secretion systems (T4SSs) can function to export or import DNA, and can deliver effector proteins into a wide range of target cells. Relatively little is known about the structural organization of T4SSs that secrete effector proteins. In this report, we describe the isolation and analysis of a membrane-spanning core complex from the
Helicobacter pylori
cag
T4SS, which has an important role in the pathogenesis of gastric cancer. We show that this complex contains five
H. pylori
proteins, CagM, CagT, Cag3, CagX, and CagY, each of which is required for
cag
T4SS activity. CagX and CagY are orthologous to the VirB9 and VirB10 components of T4SSs in other bacterial species, and the other three Cag proteins are unique to
H. pylori
. Negative stain single-particle electron microscopy revealed complexes 41 nm in diameter, characterized by a 19-nm-diameter central ring linked to an outer ring by spoke-like linkers. Incomplete complexes formed by Δ
cag3
or Δ
cagT
mutants retain the 19-nm-diameter ring but lack an organized outer ring. Immunogold labeling studies confirm that Cag3 is a peripheral component of the complex. The
cag
T4SS core complex has an overall diameter and structural organization that differ considerably from the corresponding features of conjugative T4SSs. These results highlight specialized features of the
H. pylori cag
T4SS that are optimized for function in the human gastric mucosal environment.

IMPORTANCE
Type IV secretion systems (T4SSs) are versatile macromolecular machines that are present in many bacterial species. In this study, we investigated a T4SS found in the bacterium
Helicobacter pylori
.
H. pylori
is an important cause of stomach cancer, and the
H. pylori
T4SS contributes to cancer pathogenesis by mediating entry of CagA (an effector protein regarded as a “bacterial oncoprotein”) into gastric epithelial cells. We isolated and analyzed the membrane-spanning core complex of the
H. pylori
T4SS and showed that it contains unique proteins unrelated to components of T4SSs in other bacterial species. These results constitute the first structural analysis of the core complex from this important secretion system.
Metabolic Model-Based Integration of Microbiome Taxonomic and Metabolomic Profiles Elucidates Mechanistic Links between Ecological and Metabolic Variation
Authors: Noecker Cecilia , Eng Alexander , Srinivasan Sujatha , Theriot Casey M. , Young Vincent B. , Jansson Janet K. , Fredricks David N. , Borenstein Elhanan
Published: January 2016

Studies characterizing both the taxonomic composition and metabolic profile of various microbial communities are becoming increasingly common, yet new computational methods are needed to integrate and interpret these data in terms of known biological mechanisms. Here, we introduce an analytical framework to link species composition and metabolite measurements, using a simple model to predict the effects of community ecology on metabolite concentrations and evaluating whether these predictions agree with measured metabolomic profiles. We find that a surprisingly large proportion of metabolite variation in the vaginal microbiome can be predicted based on species composition (including dramatic shifts associated with disease), identify putative mechanisms underlying these predictions, and evaluate the roles of individual bacterial species and genes. Analysis of gut microbiome data using this framework recovers similar community metabolic trends. This framework lays the foundation for model-based multi-omic integrative studies, ultimately improving our understanding of microbial community metabolism.
ADAGE-Based Integration of Publicly Available Pseudomonas aeruginosa Gene Expression Data with Denoising Autoencoders Illuminates Microbe-Host Interactions
Authors: Tan Jie , Hammond John H. , Hogan Deborah A. , Greene Casey S.
Published: January 2016

The quantity and breadth of genome-scale data sets that examine RNA expression in diverse bacterial and eukaryotic species are increasing more rapidly than for curated knowledge. Our ADAGE method integrates such data without requiring gene function, gene pathway, or experiment labeling, making practical its application to any large gene expression compendium. We built a
Pseudomonas aeruginosa
ADAGE model from a diverse set of publicly available experiments without any prespecified biological knowledge, and this model was accurate and predictive. We provide ADAGE results for the complete
P. aeruginosa
GeneChip compendium for use by researchers studying
P. aeruginosa
and source code that facilitates ADAGE’s application to other species and data types.
C-reactive protein point-of-care testing in acutely ill children: a mixed methods study in primary care
Authors: Van den Bruel Ann , Jones Caroline , Thompson Matthew , Mant David
Published: January 2016

Background

Point-of-care C-reactive protein (CRP) testing of adults with acute respiratory infection in primary care reduces antibiotic prescribing by 22%. The acceptability and impact of CRP testing in children is unknown

Objective

To determine the acceptability and impact of CRP testing in acutely ill children.

Design

Mixed methods study comprising an observational cohort with a nested randomised controlled trial and embedded qualitative study.

Subjects and setting

Children presenting with an acute illness to general practice out-of-hours services; children with a temperature ≥38°C were randomised in the nested trial; parents and clinical staff were invited to the qualitative study.

Main outcomes

Informed consent rates; parental and staff views on testing.

Results

Consent to involvement in the study was obtained for 200/297 children (67.3%, 95% CI 61.7% to 72.6%); the finger-prick test might have been a contributory factor for 63 of the 97 children declining participation but it was cited as a definite factor in only 10 cases. None of the parents or staff raised concerns about the acceptability of testing, describing the pain caused as minor and transient. General practitioner views on the utility of the CRP test were inconsistent.

Conclusions

CRP point-of-care testing in children is feasible in primary care and is likely to be acceptable. However, it will not reduce antibiotic prescribing and hospital referrals until general practitioners accept its diagnostic value in children.

Trial registration number

ISRCTN 69736109.
Determinants of never having tested for HIV among MSM in the Netherlands
Authors: den Daas Chantal , Doppen Martine , Schmidt Axel J , Op de Coul Eline
Published: January 2016

Objectives

Men who have sex with men (MSM) who are unaware of their HIV infection are more likely to infect others, and unable to receive treatment. Therefore, we aimed to identify the proportion and characteristics of Dutch MSM who never tested for HIV.

Methods

In 2010, the European MSM Internet Survey (EMIS) recruited 174 209 men from 38 countries through an anonymous online questionnaire in 25 languages. We analysed data from participants living in the Netherlands (N=3787). The outcome we investigated was having never (lifetime) been tested for HIV.

Results

A total of 770 MSM (20.4%) had never been tested for HIV. In multivariate regression analyses, not being from Amsterdam (adjusted OR, aOR 1.54, CI 1.17 to 2.03), with low education (aOR 1.28, CI 1.04 to 1.57) and low knowledge on HIV-testing (aOR 2.23, CI 1.37 to 3.64) were significantly associated with never having tested. Lower sexual risk (including having fewer sexual partners (aOR 2.19, CI 1.57 to 3.04) and no anal intercourse (aOR 5.99, CI 3.04 to 11.77)), and less social engagement (including being less out (aOR 1.93, CI 1.55 to 2.40)) were also associated with having never been tested. Additionally, 36.1% of MSM who never tested for HIV reported high-risk sexual behaviour that may have put them at HIV risk.

Conclusions

MSM make their own risk assessments that inform their choices about HIV-testing. Nevertheless, MSM who were never tested may have been at risk for HIV, and remain important to target for HIV interventions.
Does the use of IV tPA in the current era of rapid and predictable recanalization by mechanical embolectomy represent good value?
Authors: Chandra Ronil V , Leslie-Mazwi Thabele M , Mehta Brijesh P , Derdeyn Colin P , Demchuk Andrew M , Menon Bijoy K , Goyal Mayank , González R Gilberto , Hirsch Joshua A
Published: January 2016

As healthcare delivery in the USA transforms into a model that at its core requires value-based considerations, ischemic stroke is confronted by intersecting forces. Modern techniques allow rapid revascularization in the majority of patients with large vessel occlusions. Dramatic advances in the evidentiary basis for mechanical embolectomy are increasing the number of patients treated with this therapy. A key part of the therapeutic arsenal in many patients treated with interventional techniques has been concurrent intravenous thrombolysis. We consider whether this paradigm warrants change.