bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Model and Vibrational Analysis of a Dolphin’s Acoustic System
Authors: Dryden Alec , Huhmann Brianna , Martin-Garcia Oscar , Duan Shawn 
Published: January 2020

Abstract
In this paper, a vibrational model of a dolphin’s acoustic system is presented. The working mechanism encompasses the dolphin’s lungs and nasal passage which hosts air pockets, the phonic lips, anterior and posterior bursae, the melon, lower jaw, and the brain. However, this study’s components of interest were the phonic lips, anterior bursa, and the surrounding muscle tissues. The phonic lips were modeled as rigid plates, surrounding muscles were modeled as springs, and the bursa was modeled as a damper. The chosen mechanical elements produced an underdamped system.
There were two cases considered: a system in which the dolphin produces one click and a system in which the dolphin produces a series of clicks, called a click train. The former case is produced when the posterior phonic lip quickly and suddenly impacts the anterior phonic lip. Therefore, this was modeled as an impulse input. The latter case is produced when the posterior and anterior lip periodically engage one another. This was modeled as a sawtooth input. Using commercial computer software, a total of four different scenarios were considered, a healthy dolphin scenario and sick dolphin scenario for each input type.
A Preliminary Study of the Effects of Micro-Encapsulated Phase Change Materials Intermixed With Grout in Vertical Borehole Heat Exchangers
Authors: Aljabr Ahmad , Chiasson Andrew , Selvacanabady Abinesh , Alsagri Ali Sulaiman 
Published: January 2020

Abstract
A thermal analysis of a GCHP system is performed to investigate the effect of adding micro-encapsulated PCM into the borehole grout to improve the thermal performance of GCHP systems. The apparent heat capacity method is used in the numerical model, simulated in COMSOL. The PCM’s thermal properties were varied to study the effect of each property, such as PCM melting temperature, transition temperature range, PCM thermal conductivity, and the amount of PCM within the grout.
Even though the low thermal conductivity of PCM compared to ordinary grout adversely affects the GCHP system performance, a potential reduction (∼2%) in borehole length is achieved. The best melting temperature is that which results in a complete melting of PCM around the peak load, instead of around the average load. The melting temperature must be chosen properly for each GCHP scenario, otherwise the benefit from using PCM may not be achieved. There is an insignificant change in the heat pump consumption because EFT is more favorable in PCM cases around the melting temperature, but less favorable after melting completely.
Rapid Qualification of Additive Manufactured Parts Using OpenMETA
Authors: Myers Michael R. 
Published: January 2020

Abstract
This paper focuses on a method to integrate additive manufacturing (AM) structure, processing, and property-geometry modeling methods to facilitate the qualification and certification of AM-fabricated metal parts and enable their rapid deployment. The conventional approach to qualifying AM parts is to destructively evaluate a significant number of parts, measure the properties of interest, and look for anomalies in each part. This approach also requires statistical sampling of parts for destructive testing to verify the process is still operating correctly over time. This is costly, time consuming, and negates much of the benefits offered by AM. The approach outlined in this paper leverages OpenMETA, a suite of tools that provide a unified design space, a unified system representation across engineering specialties, and multidisciplinary workflow for optimization, design-of-experiments, and trade-off studies. OpenMETA provides the ability to conduct high-fidelity, low-fidelity, and hybrid analyses within one framework. Test benches are built within OpenMETA that capture the requirements for the component in an executable manner to support automated analysis such as thermal analysis, finite element analysis, and high-fidelity physics-based (HFPB) analysis. Test benches also describe the intended environment in which the component will be used after manufacture. This description of the environment might include details of the surrounding components, the interfaces to those components, and corrosive agents. Test bench results are used to estimate and assess component performance related to requirements. This paper focuses on one technology for manufacturing the parts, a wire-fed, robotic, pulsed-arc AM process, although the OpenMETA platform can be applied to other AM technologies.
Control Design of a Mobile Robot in the Environment of Obstacles Based on a Rounded V-Shape Lyapunov Function
Authors: Lee Ho-Hoon 
Published: January 2020

Abstract
This paper proposes a V-shape Lyapunov function method with application to the design of a control scheme for a mobile robot navigating through multiple obstacles. The proposed design method solves the serious problem of input saturation due to big position errors in the beginning of the control associated with the conventional parabolic Lyapunov function method. The resulting control consists of a trajectory generation scheme and a motion control scheme. The trajectory generation scheme computes the translational and rotational reference velocities in real time that drive the robot to a given goal position while avoiding multiple obstacles. The motion control scheme computes the driving force and rotational torque to track the reference velocities. The nonholonomic constraints of the mobile robot are used in the design of the kinematic trajectory generation scheme, where a repulsive potential function is used for obstacle avoidance. The dynamic model of the robot is used in the design of the motion control scheme. Under certain conditions, the proposed control guarantees asymptotic stability while keeping all internal signals bounded. The effectiveness of the proposed control method has been shown with realistic computer simulations.
Vibration Correction With Kalman Filtering Based Data Fusion for Absolute Gravimeters
Authors: Wen Yi , Wu Kang , Li Zhenxing , Yao Jiamin , Guo Meiying , Wang Lijun 
Published: January 2020

Abstract
Free-fall absolute gravimeters are important classical high precision absolute gravimeters in many branches of scientific research. But its performance is always troubled by the ground vibration. Vibration correction method is used to correct the result by detecting the ground vibration with sensors. A Kalman filter based fusion method is proposed to obtain more accurate ground vibration signal by fusing the outputs of the seismometer and the accelerometer. Experiment is conducted with the homemade T-1 absolute gravimeter, the standard deviation of the corrected results using seismometer data and fused data are 586.32 μGal (1 μGal = 10−8 m/s2) and 508.59 μGal respectively, much better than the uncorrected result’s 6548.96 μGal. The results prove the superiority of fused data over data measured from single sensor. It is believed that the application scene of the vibration correction will be broadened and the performance of the vibration correction will also be improved by using the proposed fusion method in the future.
Optimal Design for Deployable Structures Using Origami Tessellations
Authors: Cardona Carolina , Tovar Andres , Anwar Sohel 
Published: January 2020

Abstract
This work presents innovative origami optimization methods for the design of unit cells for complex origami tessellations that can be utilized for the design of deployable structures. The design method used to create origami tiles utilizes the principles of discrete topology optimization for ground structures applied to origami crease patterns. The initial design space shows all possible creases and is given the desired input and output forces. Taking into account foldability constraints derived from Maekawa’s and Kawasaki’s theorems, the algorithm designates creases as active or passive. Geometric constraints are defined from the target 3D object. The periodic reproduction of this unit cell allows us to create tessellations that are used in the creation of deployable shelters. Design requirements for structurally sound tessellations are discussed and used to evaluate the effectiveness of our results. Future work includes the applications of unit cells and tessellation design for origami inspired mechanisms. Special focus will be given to self-deployable structures, including shelters for natural disasters.
A Case Study of the Unsteady Response of a Hingeless Helicopter Rotor Blade
Authors: Sarker Pratik , Chakravarty Uttam K. 
Published: January 2020

Abstract
The helicopter is an essential means of transport for numerous tasks including carrying passengers and equipment, providing air medical services, firefighting, and other military and civil tasks. While in operation, the nature of the unsteady aerodynamic environment surrounding the rotor blades gives rise to a significant amount of vibration to the helicopter. In this study, the unsteady forced response of the Bo 105 hingeless helicopter rotor blade is investigated at the forward flight in terms of the coupled flapping, lead-lag, and torsional deformations. The mathematical model for the steady-state response of the rotor blade is modified to include the unsteady airfoil behavior by using the Theodorsen’s lift deficiency function for three degrees of freedom of motion. The nonlinear mathematical model is solved by the generalized method of lines in terms of the time-varying deflections of the rotor blade. The unsteady airloads are found to create larger deformations compared to that of the steady-state condition for a given advance ratio. The azimuth locations of the peak loadings also vary with different degrees of freedom. The first three natural frequencies and mode shapes of the rotor blade are presented. The model for the forced response analysis is validated by finite element results.
A Fast Estimation Model for Angular Spectrum Based Focused Ultrasound Wave Simulation in Layered Tissue Media
Authors: Arif Tariq M. , Ji Zhiming 
Published: January 2020

Abstract
High-Intensity Focused Ultrasound (HIFU) is a popular non-invasive therapeutic tool and widely used in many clinical settings. The simulation models used for HIFU responses are computationally expensive and time-consuming. Among many numerical HIFU simulation methods, the Rayleigh-Sommerfeld approach is considered to be a reliable one. However, Rayleigh-Sommerfeld is suitable for homogeneous medium, and for a heterogeneous media, many approximations should be made in order to reduce the calculation time. In this study, we propose a fast methodology for estimating focused ultrasound pressure-temperature field responses through layered tissue media. A computationally efficient nonlinear angular spectrum-based method that can address the effects of varying attenuations, reflections and refractions from tissue layers is implemented to calculate reference datasets. From the simulation datasets, a profile function coupled with a GUI code is constructed for estimating the pressure-temperature response by using a Gaussian function and a Genetic Algorithm. The HIFU response model illustrated in this study can be advantageous and time-effective when multiple simulations are required on a similar complex patient model, and it can be used to guide and reduce the sets of simulations required for planning HIFU treatment.
Characteristics Study of Mild-Detonating Fuse and Flexible Linear Shaped Charge for Metal Plate Cutting
Authors: Lee Juho , Lee Joosik , Lee Heon Joo , Kang YounKil 
Published: January 2020

Abstract
In many types of spacecraft and missile systems, the vehicle’s skin cutting are carried out by using the mild-detonating fuse (MDF) or the flexible linear shaped charge (FLSC). MDF is a very thin metal tube that filled with explosive charges and has an axisymmetric shape. FLSC is an inverted chevron-shaped flexible tube that generates hypervelocity jet to penetrate or cut thick metal structures. In this study, the characteristics of MDF and FLSC for metal plate cutting are identified. First, the fracture mechanisms due to MDF and FLSC are numerically analyzed in 2-D plane strain using ANSYS AUTODYN, one of commercial hydrocodes. By using proposed numerical scheme, the effects of the cutting methods and the design parameters on cutting performance, fragmentation and backward shock waves are studied; the pros and cons of MDF and FLSC for metal plate cutting are clarified. The numerical method and the results of this study provide the guidelines to select metal plate cutting method and help to establish the design method for optimal metal plate cutting; the number of the expensive explosive experiments can be reduced.
Development of Small-Sized Motor-Driven Gyroscopic Power Generator Works Under Low-Frequency Vibration
Authors: Toyoshima Akio , Hosaka Hiroshi , Yamashita Akira 
Published: January 2020

Abstract
In order to realize a small-sized energy harvester with high output, this study prototypes a small motor-driven gyroscopic power generator. Supplying energy to sensors and devices is the biggest problem for Internet of Things (IoT) systems. One solution is gyroscopic power generators, which are a type of vibrational generator that amplify the inertia force of weights by rotating them at high speed, and in doing so can obtain greater output than conventional generators that use simple vibration for the same mass weight. This paper reports on a motor-driven type gyroscopic generator in which the flywheel is spun with an embedded motor, and which is superior in applicability to random vibration generators. The generators of this type that have been studied thus far are very large and have been primarily used for wave power generation in the ocean. However, when the shape of this gyroscopic power generator type is miniaturized proportionally, the output per volume decreases in proportion to the fifth power of the dimension. This makes it difficult to maintain the power output while miniaturizing the generator size. In this research, the structure of the gyroscopic power generator is thoroughly refined and miniaturization is realized by making full use of the available space. By using a motor with high design freedom, the spindle motor and flywheel are unified. From this accomplishment, not only is the required space reduced, the number of mechanical parts and the friction loss are decreased as well. The prototype generator has a size of about 150 mm on its long side. When a swinging vibration of 50 degrees in amplitude and 2 Hz in frequency is applied, a net output of 0.104 W is obtained. This output power is sufficient to drive sensors and low power wide area (LPWA) radio circuits.
Precise Control of Precursor Sticking Coefficient on Substrates With Large Aspect Ratios in ALD
Authors: Kunene T. J. , Tartibu L. , Jen T. C. 
Published: January 2020

Abstract
In this paper, the Atomic Layer Deposition (ALD) process in the reactor scale was simulated using ANSYS® Fluent® 19.1 and ChemKin-PRO commercial packages in order to solve transport and chemistry equations. Trenched substrates with large aspect ratios (AR) of 33 ≤ AR ≤ 300, at a reactor scale of an ALD process, were considered a temperature of 473K and 573K. Trimethlyaluminum (TMA) and Ozone reactants were used to formulate a precise Sticking Coefficients (SC) for a satisfactory dose (precursor exposure level) in order to deposit conforming Al2O3 films. The estimated error in the empirical correlation of SCs was determined and compared to published experimental data. An empirical correlation based on simulated models was derived. This correlation can be exploited to determine precise precursor exposure levels for an ALD process irrespective of the type of reactor used.
Packaging Challenges of Thin High Bandwidth POP
Authors: Tung Fletcher (Cheng-Piao) , Tsai Jensen (Ying-Chou) , Wang Yu-Po , Lin Joe (Chih-Nan) , Fan Gary (Yue-Long) 
Published: January 2020

Abstract
Components for Smartphone has been the biggest driving force of IC industry for years, and one of the most important IC is application processor (AP). AP needs to work with low power double data rate (LPDDR), the mobile DRAM together for the primary processing of cellular phone and other smart functions. At the beginning, they were packaged separately and then mounted onto printed circuit board (PCB) very close to each other. Nowadays, AP for flagship Smartphone is packaged with a variety of PoP (package on package) structures to shorten the communication distance between AP and LPDDR as well as to save more rooms for battery. High bandwidth package on package (HBW-POP) is the most popular structure among them. As compared to other substrate based PoP, HBW-POP provides the most top side pin count while keeps larger ball pitch for system assembly house to mount LPDDR packaged by fine-pitch ball grid array (FBGA) on top of it. And compared to novel Fan-Out based PoP, HBW-POP has lower cost for AP packaging.
In addition, maximum package height of HBW-POP has been shrinking. It is because when LPDDR is mounted onto HBW-POP, the combination is always the tallest chips on the PCB, which determines how slim specific Smartphone can be. HBW-POP consists of 3 parts to encapsulate AP die, and they are top 2-layer substrate, middle molding and bottom 3-layer substrate. Each part has its own coefficient of thermal expansion (CTE) and rigidity, and the warpage performance of HBW-POP is important to align the warpage behavior of LPDDR.
The warpage of HBW-POP needs to align with FBGA properly during reflow for good joint, but when HBW-POP becomes thinner, the rigidity of its different parts is changed, which result in different warpage behavior during the reflow.
In this paper, we will review the challenges of thin HBW-POP packaging, meanwhile we will explore possible solutions to address each challenge. The study includes the screening of different thickness combination of the 3 parts of HBW-POP, and the optimization of the rigidity and CTE of them. Design of Experiments (DOE) are conducted to find solutions which can meet warpage target, and finally, we present more different tests to prove the reliability of our results.
Investigation of Conduit Flow Past Corrugated Structures Using Large Eddy Simulations
Authors: Kumar Sushrut , Suri Ujjwal , Sachdeva Paras , Singh Raj Kumar 
Published: January 2020

Abstract
The present paper studies the characteristics of a fully turbulent flow of water through a conduit by use of corrugated structures. Methodologies including rough-ribbed walls and particle injection have been utilized for turbulence attenuation in the past. Screens and corrugations are yet another effective tools for reducing turbulence. The proposed investigation focuses on the application of square and hexagonal cross-sectional corrugations which are introduced in the flow for turbulence attenuation inside rectangular conduits. Large Eddy Simulations in three dimensions were performed with OpenFOAM using a pressure-implicit solver and the standard Smagorinsky subgrid-scale model. Dampening of the spanwise velocity component and a relative increase in streamwise velocity component downstream of the corrugation was observed. The power spectral densities (PSD) of the flow upstream and downstream of the corrugation were examined and compared. A significant decrease in turbulent flow power density was observed. Furthermore, characteristics including turbulence intensity contours and isosurfaces of the Q-criterion were visualized. The results conclusively indicate a subsequent decrease in the turbulent nature of flow past corrugated structures.
Prediction of Oscillatory Heat Transfer Coefficient in Heat Exchangers of Thermo-Acoustic Systems
Authors: Machesa M. G. K. , Tartibu L. K. , Tekweme F. K. , Okwu M. O. 
Published: January 2020

Abstract
The characterisation of heat transfer in oscillatory flow of thermo-acoustic based heat exchangers is a cumbersome issue. This is due to the nature of the heat transfer between the gas particles moving along the device at high amplitude and the solid surface of the heat exchangers. In addition, the change in velocity, pressure and temperature induces nonlinear effect. As a result, the performance of heat exchangers negatively affects the efficiency of thermo-acoustic systems. Hence, it is necessary to determine to oscillatory heat transfer coefficient in order to measure the performance of heat exchangers in thermo-acoustic systems. Although it is possible to conduct experimental investigation or perform numerical analysis in order to determine oscillatory heat transfer coefficient, the former requires costly time consuming experiment while the latter involves the resolution of complex mathematical models. In this paper, an improved adaptive neurofuzzy inference system and artificial neural network trained by particle swarm optimization are proposed to predict oscillatory heat transfer coefficient. This paper is intending to provide clarity on the benefits of these new approaches on the computation of geometrical configuration and the working parameters of heat exchangers in thermo-acoustic systems.
Technical Issues Associated With Arterial Pulse Signal Measurements Using a Microfluidic-Based Tactile Sensor
Authors: Wang Dan , Reynolds Leryn , Alberts Thomas , Vahala Linda , Hao Zhili 
Published: January 2020

Abstract
This paper presents three technical issues associated with arterial pulse signal measurements using a microfluidic-based tactile sensor: motion artifact, overlying tissue at an artery and inter-subject variation. Arising from the sensor-artery interaction upon hold-down pressure on the sensor, a measured pulse signal is a combination of the sensor design, hold-down pressure, overlying tissue at an artery, the arterial wall and the true pulse signal in the artery. Meanwhile, motion artifact causes change in the sensor-artery interaction and also plays a non-negligible role in a measured pulse signal. The influence of motion artifact on a measured pulse signal can be reduced by a sensor with high stiffness. To obtain a pulse signal at near-zero transmural pressure with reasonable accuracy, matching the sensor design with the overlying tissue at an artery is critical for achieving good conformity of the sensor to the artery (for signal transmission) with minimal distortion of the true one in the artery. For simplicity, a uniform layer is utilized to adjust the sensor design. While a uniform layer added to a sensor improves its conformity with the radial artery (RA) embedded deep under the skin, a uniform layer is also needed as a cushion to reduce suppression of the true pulse signal at the superficial temporal artery (STA) near the skin. Due to inter-subject variation (i.e, overlying tissue and artery size), the absolute values of arterial indices derived from a measured pulse signal at the same artery are not comparable between subjects. Post-exercise recovery of arterial indices derived from measured pulse signals is suggested to serve as a better assessment of the cardiovascular (CV) system.
Different Methods of Programming for Mechanical Engineering Students: A Case Study
Authors: Han Mingli , Duan Chang 
Published: January 2020

Abstract
The paper is to present a case study where different methods of programming are utilized by Mechanical Engineering Students to design a device. The objective is to provoke discussion and explore best practices on teaching Mechanical Engineering students the programming aspects. The task is to design a low-cost device that can accurately measure the period of a simple pendulum. Same raw materials, infrared break beam sensor and Arduino microcontroller, are given. But different programming approaches can be undertaken. Option 1 is to use C language and Arduino’s free Integrated Development Environment. Option 2 is to use Simulink with Arduino Support. Student survey is designed based on whether it is intuitive, whether it is easier to debug, etc. Further studies can be conducted to understand the effectiveness of a mixture of these different methods and sequence of exposure to these different methods.