bluuebunny/crossref_metadata_2025_split huggingface dataset:
Collision-Avoidance Reliability Analysis of Autonomous Vehicle Based on Adaptive Kriging Surrogate Modeling
Authors: Liu Yixuan , Zhao Ying , Hu Zhen , Mourelatos Zissimos P. , Papadimitriou Dimitrios 
Published: November 2019

Abstract
This paper presents a reliability analysis method for automated vehicles equipped with adaptive cruise control (ACC) and autonomous emergency braking (AEB) systems to avoid collision with an obstacle in front of the vehicle. The proposed approach consists of two main elements, namely uncertainty modeling of traffic conditions and model-based reliability analysis. In the uncertainty modeling step, a recently developed Gaussian mixture copula method is employed to accurately represent the uncertainty in the road traffic conditions using the real-world data, and to capture the complicated correlations between different variables. Based on the uncertainty modeling of traffic conditions, an adaptive Kriging surrogate modeling method with an active learning function is then used to efficiently and accurately evaluate the collision-avoidance reliability of an automated vehicle. The application of the proposed method to the Department of Transportation Safety Pilot Model Deployment database and an in-house built Advanced Driver Assist Systems with ACC and AEB controllers demonstrate the effectiveness of the proposed method in evaluating the collision-avoidance reliability.
Probabilistic Modeling of Driver Behaviors at Urban Crossroads
Authors: Liu Yuan-Cheng , Chan Kuei-Yuan 
Published: November 2019

Abstract
Interactions with human drivers is one of the major challenges for autonomous vehicles. In this work we consider urban crossroads without signals where driver interactions have to happen. Crossroad parameters are defined and how drivers passing the crossroad while maintaining a desired speed without collision is studied. A point of action is defined for incoming vehicles from different directions and a probability of stopping for each car is proposed as a function of vehicle speed and the distance-to-action for both vehicles. Driver behaviors with these probability models are also proposed. The method is then analyzed and validated by data collected from human drivers. The result shows a similar maneuver as human drivers while more aspects of evaluation is needed in the future work.
Assessment of Joint Parameters in a Kinect Sensor Based Rehabilitation Game
Authors: Manna Soumya K. , Dubey Venketesh N. 
Published: November 2019

Abstract
A Kinect sensor based basketball game is developed for delivering post-stroke exercises in association with a newly developed elbow exoskeleton. Few interesting features such as audio-visual feedback and scoring have been added to the game platform to enhance patient’s engagement during exercises. After playing the game, the performance score has been calculated based on their reachable points and reaching time to measure their current health conditions. During exercises, joint parameters are measured using the motion capture technique of Kinect sensor. The measurement accuracy of Kinect sensor is validated by two comparative studies where two healthy subjects were asked to move elbow joint in front of Kinect sensor wearing the developed elbow exoskeleton. In the first study, the joint information collected from Kinect sensor was compared with the exoskeleton based sensor. In the next study, the length of upperarm and forearm measured by Kinect were compared with the standard anthropometric data. The measurement errors between Kinect and exoskeleton are turned out to be in the acceptable range; 1% for subject 1 and 0.44% for subject 2 in case of joint angle; 5.55% and 3.58% for subject 1 and subject 2 respectively in case of joint torque. The average errors of Kinect measurement as compared to the anthropometric data of the two subjects are 16.52% for upperarm length and 9.87% for forearm length. It shows that Kinect sensor can measure the activity of joint movement with a minimum margin of error.
Critical Thinking in the Design Classroom: An Analysis of Student Design Reflections
Authors: Evans Emmeline , Menold Jessica , McComb Christopher 
Published: November 2019

Abstract
Within the domain of education, the term “critical thinking” is widely understood to mean the various skills that comprise an individual’s logical and reasoning abilities. It is critical that designers possess these abilities so that they can solve the complex problems of an increasingly interconnected world. In order to better understand patterns in engineering students’ critical thinking, this research applies the classifications of the 2001 revision of Bloom’s Taxonomy to 49 reflections written by first-year engineering students on a two-hour design practicum. Reflections were thematically coded to identify when students operated in different levels of the cognitive process and knowledge dimensions. Using k-means clustering analysis, genres of reflection were then determined. Four unique clusters of responses were identified. Notable trends in clusters included application and evaluation of procedural knowledge. Additionally, a difference was observed between the two largest clusters regarding deviance from the design process. While one cluster of responses generally minimized discussion of deviance, the second largest cluster emphasized this deviance, highlighting it as an opportunity for future growth. This work provides insight into how students learn design and how they communicate their learning, providing insight for instructors hoping to encourage deeper critical thinking in design courses.
Modeling and Stability of Milling Processes With Active Damping
Authors: Lehotzky David , Dombovari Zoltan 
Published: November 2019

Abstract
In the recent decade, active dampers have been introduced to machining for the avoidance of machine tool chatter in milling processes. The tuning strategy for most of these devices is based on models which do not account for the dynamics of control loop within the active dampers, hence neglect the dynamics of actuator and measuring device, and do not consider filtering. However, these simplified models might lead to inaccurate stability predictions which can deteriorate the performance of active dampers. In order to better approximate the real behavior of milling processes controlled by active dampers, this paper develops a new mathematical model which incorporates the dynamics of control loop within these devices. In particular, the inertial actuator is modeled as an electromagnetic proof-mass transducer, while the dynamics of piezoelectric accelerometer and finite-impulse-response filtering are also taken into account. By the computation of stability lobe diagrams, it is shown that, at low-frequency actuation and at high-speed milling, the consideration of control loop dynamics in active dampers can be essential.
System Reliability Analysis With Second Order Saddlepoint Approximation
Authors: Wu Hao , Du Xiaoping 
Published: November 2019

Abstract
The second order saddlepoint approximation (SPA) has been used for component reliability analysis for higher accuracy than the traditional second order reliability method. This work extends the second order SPA to system reliability analysis. The joint distribution of all the component responses is approximated by a multivariate normal distribution. To maintain high accuracy of the approximation, the proposed method employs the second order SPA to accurately generate the marginal distributions of component responses; to simplify computations and achieve high efficiency, the proposed method estimates the covariance matrix of the multivariate normal distribution with the first order approximation to component responses. Examples demonstrate the high effectiveness of the second order SPA method for system reliability analysis.
An Underwater Magnetically Coupled Bistable Vibration Energy Harvester Using Wings
Authors: Zou Hong-Xiang , Wei Ke-Xiang , Zhao Lin-Chuan , Zhang Wen-Ming , Zuo Lei , Qian Feng 
Published: November 2019

Abstract
Piezoelectric flow energy harvesting can be a potential way to yield endless electrical energy for small mechanical systems and wireless sensors. We propose a novel magnetically coupled bistable vibration energy harvester using wings for the applications in the water environment. The water flow energy can be harvested through the induced vibration of wings. The flextensional transducer can be packaged conveniently by using non-contact magnetic coupling mechanism. The magnetic force is amplified by the flextensional structure and transferred to the piezoelectric layer, thereby achieving higher power density and better reliability. A prototype was fabricated and tested in a water flume, which attended a maximum power of about 400 μW and the average power of 55 μW at the water flow velocity of 4 m/s. No significant variation occurred to the performance of the harvester after five days of continuous operation in the water, which indicates that the magnetically coupled vibration energy harvesting method has high reliability in the underwater environment.
Chattering-Free Finite-Time Stability of a Class of Fractional-Order Nonlinear Systems
Authors: Wang Bin , Chen Yangquan , Yang Ying 
Published: November 2019

Abstract
This paper studies the chattering-free finite-time control for a class of fractional-order nonlinear systems. First, a class of fractional-order nonlinear systems with external disturbances is presented. Second, a new finite-time terminal sliding mode control method is proposed for the stability control of a class of fractional-order nonlinear systems by combining the finite-time stability theory and sliding mode control scheme. Third, by designing a controller with a differential form and introducing the arc tangent function, the chattering phenomenon is well suppressed. Additionally, a controller is developed to resist external disturbances. Finally, numerical simulations are implemented to demonstrate the feasibility and validity of the proposed method.
Testing Design Optimization for Uncertainty Reduction in Generating Off-Road Mobility Map
Authors: Hu Zhen , Mourelatos Zissimos P. , Gorsich David , Jayakumar Paramsothy , Majcher Monica 
Published: November 2019

Abstract
The Next Generation NATO Reference Mobility Model (NG-NRMM) plays a vital role in vehicle mobility prediction and mission planning. The complicated vehicle-terrain interactions and the presence of heterogeneous uncertainty sources in the modeling and simulation (M&S) result in epistemic uncertainty/errors in the vehicle mobility prediction for given terrain and soil conditions. In this paper, the uncertainty sources that cause the uncertainty in mobility prediction are first partitioned into two levels, namely uncertainty in the M&S and uncertainty in terrain and soil maps. With a focus on the epistemic uncertainty in the M&S, this paper presents a testing design optimization framework to effectively reduce the uncertainty in the M&S and thus increase the confidence in generating off-road mobility maps. A Bayesian updating approach is developed to reduce the epistemic uncertainty/errors in the M&S using mobility testing data collected under controllable terrain and soil conditions. The updated models are then employed to generate off-road mobility maps for any given terrain and soil maps. Two types of design strategies, namely testing design for model selection and testing design for uncertainty reduction, are investigated in the testing design framework to maximize the information gain subject to limited resources. Results of a numerical example demonstrate the effectiveness of the proposed mobility testing design optimization framework.
Bi-Material Re-Entrant Triangle Structures Incorporating Tailorable Thermal Expansion and Tunable Poisson’s Ratio
Authors: Xiaobing He , Yan Xie , Jingjun Yu 
Published: November 2019

Abstract
Based on the bi-material triangle lattice material, a new cellular structure: bi-material re-entrant triangle (BRT) is devised to incorporate tailorable coefficient of thermal expansion (CTE) and tunable Poisson’s ratio (PR) properties by replacing the straight base of a triangle with two hypotenuse members. An equation to systematically build the relationship among the external force, the temperature increment and the deformation for the planar lattice material with bounded joints is derived and then embedded into a theoretical model for devised BRT structure. Using master stiffness equation, effective PR, effective Young’s modulus as well as effective CTE are computed. In order to guide designers to construct an initial concept quickly, the design domain for coupling negative CTE and negative PR properties is proposed. Nine available paired characteristics for coupling effect are extracted and demonstrated with ABAQUS simulation.
It Rings a Bell! Memory’s Impact on Information Utilization by Novice Designers in the Early Design Process
Authors: Mertens Attakias T. , Toh Christine A. 
Published: November 2019

Abstract
Research in new product design still lacks an understanding of how the types of information used by designers can lead to more successful designs and what cognitive components are involved in the process of generating new ideas. Some theories have arisen that focus on memory usage that could have an impact in idea generation early on in the design process. As a first step to address this gap, an Information Archetypes Framework was developed in previous work to outline the different dimensions and levels of information commonly used by designers. This framework forms the basis of the current study, focused on identifying the underlying cognitive processes that are active during the design process. To accomplish this, undergraduate students were recruited from the University of Nebraska-Omaha. During the study, participants were presented a design problem, given information pieces that corresponded to the Information Archetypes Framework, and asked to generate ideas for a solution. Students were then asked to recall the information pieces from memory. Participants’ data were analyzed using Linguistic Inquiry Word Count (LIWC) for relevant cognitive mechanisms. Scores from LIWC captured the linguistic properties of information pieces and generated ideas, and this study was able to demonstrate that memory usage has both semantic and linguistic components that emerge during the conceptual design process.
Design of a Totally Robotic Solution for Sampling in Pharmaceutical Industry
Authors: D’Imperio Mariapaola , Cannella Ferdinando 
Published: November 2019

Abstract
Quality control in the pharmaceutical industries is a critical issue. It consists of a sampling phase and an analysis phase. There are different ways of taking a sample to be submitted for a quality control: from static to dynamic methods, from simple to more complex solutions. All these traditional procedures and their results are strictly dependent on the operator, due to the fact that this type of environment is unstructured and not very often robotised. For this reason, the aim of the paper is to push forward the state of art in the sampling methods for quality controls, by presenting a totally robotic solution in the framework of dust samples collection from closed containers.
Study on the Dynamic Response of an Unbalanced Rotor System Supported by Ball Bearings
Authors: Fang Bin , Zhang Jinhua , Yan Ke , Hong Jun 
Published: November 2019

Abstract
This paper proposed a new four-degree-of-freedom dynamic model of the bearing-rotor system based on ball bearing without Raceway Control Hypothesis, and both the inertia forces of balls and the tilting motions of rotor are fully considering in the calculation of restoring forces and moments of ball bearings. Then the dynamic model are solved by the fourth-step Runge-Kutta method, and the dynamic responses of rotor system including the displacement, velocity and center orbits are obtained, and the influences of rotating speeds, eccentricity and symmetry of rotor are studied and analyzed. The results show that both the varying compliance of ball bearing and rotor eccentric force have a great influence on the dynamic responses and motion patterns of bearing-rotor system, and the titling motion of bearing-rotor should be considered in the analysis of asymmetric rotor or the symmetric rotor under some specific conditions.
Phase-Locking and Chaotic Phenomena of Circular Mesh Antenna With 1:3 Internal Resonance
Authors: Liu Tao , Zhang Wei , Zheng Yan , Guo Xiangying 
Published: November 2019

Abstract
We study chaotic dynamics and the phase-locking phenomenon of the circular mesh antenna with 1:3 internal resonance subjected to the temperature excitation in this paper. Firstly, the frequencies and modes of the circular mesh antenna are analyzed by the finite element method, it is found that there is an approximate threefold relationship between the first-order and the fourth-order vibrations of the circular mesh antenna. Considering a composite laminated circular cylindrical shell clamped along a generatrix and with the radial pre-stretched membranes at both ends subjected to the temperature excitation, we study the nonlinear dynamic behaviors of the equivalent circular mesh antenna model based on the fourth-order Runge-Kutta algorithm, which are described by the bifurcation diagrams, waveforms, phase plots and Poincaré maps in the state-parameter space. It is found that there appear the Pomeau-Manneville type intermittent chaos. According to the topology evolution of phase trajectories, the phase-locking phenomena are found.
An Automatic Transformation Method for the Walking Assistive Device to Walk Between Flat Ground and Stairs Safely
Authors: Yang Bo-Rong , Zhang Yu-Cheng , Lee Hee-Hyol , Tanaka Eiichiro 
Published: November 2019

Abstract
The main target of this research is to assist the elderly people to walk on different road conditions independently. A method that can transform the walking motion of a walking assistive device between level walking and stair climbing automatically was proposed. To teach the target user how to walk correctly, we defined a trajectory that belongs to healthy people to help the user exercise. Stairs are common in various indoor situations and become a huge challenge for people with gait disorders. To extend the range of physical activity, walking trajectories in different surroundings were imported on the assistive device. Ultrasonic sensors were utilized to detect the distance between stairs and the swing foot. Based on the measured distance, the gait was modified according to a predefined safety distance that was determined experimentally. We also designed trajectory combination methods for changing the device motion patterns between ascending and descending stairs as the walking conditions change. The effectiveness of the system was tested through simulation. The results showed that the device smoothly shifted gait with the proposed methods in this paper. This method has the potential to solve the adaptability of various walking devices to different surroundings.
Investigation of the Effect of Long-Term Contact on Adhesion Force in Polycrystalline MEMS Devices
Authors: Othayq Mazen M. , Giganti Nino , Shavezipur Mohammad 
Published: November 2019

Abstract
The effect of long-term contact on adhesion force between MEMS silicon surfaces is investigated. A test structure is developed that can initiate the contact between the two surfaces without actuation. Therefore, the surfaces may remain in contact for a long period of time. The contacting surfaces are separated using a thermal actuator and the adhesion force is determined utilizing FEM simulations. Freshly released and long-time stored devices were tested, and their adhesion force is determined. The test results show that the adhesion force for devices in contact for a long time is drastically larger than those with short-term contact. Adhesion force values as large as 2.9 μN for long-term contact and as small as 0.4 μN for fresh contact were measured. The large adhesion force associated with long-term contact is believed to be attributed to the formation of native oxide at contacting nano-asperities and formation of covalent bonds between the surfaces, requiring larger force to break the bonds.
Hybrid Fabrication of a Soft Bending Actuator With Casting and Additive Manufacturing
Authors: Oliveira Marcos B. , Lurie Alexander , Ewen David , Long Philip , Padir Taskin , Felton Samuel M. 
Published: November 2019

Abstract
In this paper, we present the design, modeling and, fabrication of a soft bending actuator that combines casting techniques and additive manufacturing. We performed tests to evaluate the bending actuator’s angular deflection and tip force. We demonstrated flexibility in the process by varying the bladder material. We also showed the actuator’s resilience to damage by cutting and puncturing the exoskeleton prior to operation. Finally, we integrated the bending actuator into a three-finger gripper configuration and performed a gripping test for four different objects with various weights and shapes. Results show that the curvature and force obtained in these actuators are comparable to other proposed bending actuators with a faster and more adaptable fabrication process. With these results we demonstrate that fast, effective, and versatile fabrication of soft robotic components can be attained by combining casting and additive manufacturing techniques.
Lattice Structure Design for Additive Manufacturing: Unit Cell Topology Optimization
Authors: Hanks Bradley , Frecker Mary 
Published: November 2019

Abstract
Additive manufacturing is a developing technology that enhances design freedom at multiple length scales, from the macroscale, or bulk geometry, to the mesoscale, such as lattice structures, and even down to tailored microstructure. At the mesoscale, lattice structures are often used to replace solid sections of material and are typically patterned after generic topologies. The mechanical properties and performance of generic unit cell topologies are being explored by many researchers but there is a lack of development of custom lattice structures, optimized for their application, with considerations for design for additive manufacturing. This work proposes a ground structure topology optimization method for systematic unit cell optimization. Two case studies are presented to demonstrate the approach. Case Study 1 results in a range of unit cell designs that transition from maximum thermal conductivity to minimization of compliance. Case Study 2 shows the opportunity for constitutive matching of the bulk lattice properties to a target constitutive matrix. Future work will include validation of unit cell modeling, testing of optimized solutions, and further development of the approach through expansion to 3D and refinement of objective, penalty, and constraint functions.
Autonomous Vehicle Driving via Deep Deterministic Policy Gradient
Authors: Huang Wenhui , Braghin Francesco , Arrigoni Stefano 
Published: November 2019

Abstract
Autonomous driving has became one of the most hot trends in artificial intelligence area in recent years thanks to the machine learning algorithms. However, most of the autonomous driving studies are still limited to discrete action space. In this study, we propose to implement Deep Deterministic Policy Gradient algorithm for learning driving behavior over the continuous actions. For this purpose, a driving simulator is employed which interfaces with IPG CarMker software where the virtual environment and dynamical vehicle model can be built. “Human-in-the-loop” is performed in order to gather the data and a neural network which is implemented in Behavior Layer is trained to recognize two different scenarios-forward driving and stop. Based on the scenario the agent is dealing with, the actions are learnt and suggested from the DDPG algorithm. The experimental results show that DDPG algorithm is able to learn the optimal policy with continuous actions reliably for both scenarios.