Computer-Aided Engineering and Design Commons^™

Influence Of Motion Artifacts On Instantaneous Frequency Based Heart Rate Variability Of Arterial Pulse Signals Measured By A Tactile Sensor: An Analytical Study, Mamun Hasan, Zhili Hao

Mechanical & Aerospace Engineering Faculty Publications

Objective: Heart rate variability (HRV), quantified via the instantaneous frequency (IF) of arterial pulse signals, is a key indicator of cardiovascular (CV) regulation. This study presents a theoretical and experimental investigation of how motion artifacts (MA) influence IF-and thus HRVmeasured with a tactile sensor, emphasizing underlying mechanisms rather than population-level validation. Approach: Building on a previously developed single-degree-of-freedom (SDOF) model of the tissue-contact-sensor (TCS) stack between the sensor and the artery, MA is represented as low-frequency baseline drift and time-varying system parameters (TVSP) of the TCS stack. Analytical expressions quantify the effect of MA on the IF of each harmonic …

40 - Design, Fabrication, And Installation Of Morphing Control Surfaces For Small-Scale Uas, Kyle Purser

Undergraduate Research Symposium

Morphing control surface technology, inspired by organic structures and compliant mechanisms, offers significant potential for enhancing the aerodynamic efficiency and performance of unmanned aerial systems (UAS). Despite these benefits, its adoption has been hindered by complexities in design, manufacturing, and installation, particularly when compared to traditional flap systems. This research explores the design, fabrication, and integration of morphing control surfaces for small-scale UAS using additive manufacturing techniques. To reduce costs and streamline the design process, fused deposition modeling (FDM) additive manufacturing was employed for component fabrication. An off-the-shelf Horizon Sport Cub S2 served as the testing platform, modified with a …

Effect Of Post-Cured Through Thickness Reinforcement On Disbonding Behavior In Skin-Stringer Configuration, Jimesh D. Bhagatji, Christopher Morris, Yogaraja Sridhar, Bodhisatwa Bhattacharjee, Krishnanand N. Kaipa, Oleksandr G. Kravchenko

Mechanical & Aerospace Engineering Faculty Publications

An experimental investigation of interlaminar toughness for post-cured through-thickness reinforcement (PTTR) skin-stringer sub-element is presented. The improvement in the crack resistance capability of skin-stringer samples was shown through experimental testing and finite element analysis (FEA) modeling. The performance of PTTR was evaluated on a pristine and initial-disbond of the skin-stringer specimen. A macro-scale pin-spring modeling approach was employed in FEA using a non-linear spring to capture the pin failure under the mixed-mode load. The experimental results showed a 15.5% and 20.9% increase in strength for the pristine-PTTR and initial-disbond PTTR specimens, respectively. The modeling approach accurately represents the overall structural …

Gradient-Based Trade-Off Design For Engineering Applications, Lena A. Royster, Gene Hou

Mechanical & Aerospace Engineering Faculty Publications

The goal of the trade-off design method presented in this study is to achieve newly targeted performance requirements by modifying the current values of the design variables. The trade-off design problem is formulated in the framework of Sequential Quadratic Programming. The method is computationally efficient as it is gradient-based, which, however, requires the performance functions to be differentiable. A new equation to calculate the scale factor to control the size of the design variables is introduced in this study, which can ensure the new design achieves the targeted performance objective. Three formal approaches are developed in this study for trade-off …

Optimal Domain-Partitioning Algorithm For Real-Life Transportation Networks And Finite Element Meshes, Jimesh Bhagatji, Sharanabasaweshwara Asundi, Eric Thompson, Duc T. Nguyen

Civil & Environmental Engineering Faculty Publications

For large-scale engineering problems, it has been generally accepted that domain-partitioning algorithms are highly desirable for general-purpose finite element analysis (FEA). This paper presents a heuristic numerical algorithm that can efficiently partition any transportation network (or any finite element mesh) into a specified number of subdomains (usually depending on the number of parallel processors available on a computer), which will result in “minimising the total number of system BOUNDARY nodes” (as a primary criterion) and achieve “balancing work loads” amongst the subdomains (as a secondary criterion). The proposed seven-step heuristic algorithm (with enhancement features) is based on engineering common sense …

Using Strategic Options Development And Analysis (Soda) To Understand The Simulation Accessibility Problem, Andrew J. Collins, Ying Thaviphoke, Antuela A. Tako

Engineering Management & Systems Engineering Faculty Publications

Simulation modelling is applied to a wide range of problems, including defense and healthcare. However, there is a concern within the simulation community that there is a limited use and implementation of simulation studies in practice. This suggests that despite its benefits, simulation may not be reaching its potential in making a real-world impact. The main reason for this could be that simulation tools are not widely accessible in industry. In this paper, we investigate the issues that affect simulation modelling accessibility through a workshop with simulation practitioners. We use Strategic Options Development and Analysis (SODA), a problem-structuring approach that …

Human Ergonomic Simulation To Support The Design Of An Exoskeleton For Lashing/De-Lashing Operations Of Containers Cargo, Francesco Longo, Antonio Padovano, Vittorio Solina, Virginia D' Augusta, Stefan Venzl, Roberto Calbi, Michele Bartuni, Ornella Anastasi, Rafael Diaz

VMASC Publications

Lashing and de-lashing operations of containers cargo on board containerships are considered as quite strenuous activities in which operators are required to work continuously over a 6 or 8 hours shift with very limited break. This is mostly because containerships need to leave the port as soon as possible and containers loading and unloading operations must be executed with very high productivity (stay moored in a port is a totally unproductive time for a ship and a loss-making business for a shipping company). Operators performing lashing and de-lashing operations are subjected to intense ergonomic stress and uncomfortable working postures. To …

Agent-Based Modelling Of Values: The Case Of Value Sensitive Design For Refugee Logistics, Christine Boshuijzen-Van Burken, Ross J. Gore, Frank Dignum, Lamber Royakkers, Phillip Wozny, F. Leron Shults

VMASC Publications

We have used value sensitive design as a method to develop an agent-based model of values in humanitarian logistics for refugees. Schwartz’s theory of universal values is implemented in the model in such a way that agents can make value trade-offs, which are operationalized into a measure of refugee wellbeing and a measure of public opinion about how the refugee logistics is being handled. By trying out different ‘value scenarios’, stakeholders who are responsible for, or involved in refugee logistics can have insights into the effects of various value choices. The model is visualized and made usable as a platform …

Interface Model Of Pem Fuel Cell Membrane Steady-Dtate Behavior, Russell L. Edwards, Ayodeji Demuren

Mechanical & Aerospace Engineering Faculty Publications

Modeling works which simulate the proton-exchange membrane fuel cell with the computational fluid dynamics approach involve the simultaneous solution of multiple, interconnected physics equations for fluid flows, heat transport, electrochemical reactions, and both protonic and electronic conduction. Modeling efforts vary by how they treat the physics within and adjacent to the membrane-electrode assembly (MEA). Certain approaches treat the MEA not as part of the computational domain, but rather an interface connecting the anode and cathode computational domains. These approaches may lack the ability to consistently model catalyst layer losses and MEA ohmic resistance. This work presents an upgraded interface formulation …

Creating The Fleet Maker - Lessons Learned From The First Series Of Workshops On Maker Concepts For Active Duty Personnel, Karina Arcaute, Michel Albert Audette, Vukica Jovanovic, Anthony Dean, Dipankar Ghosh

STEMPS Faculty Publications

The US Navy has supported research related to the 3D printing or Additive Manufacturing area for more than 20 years. More recently, efforts like the Print the Fleet initiative and Marine Makers are exploring ways to design and create solutions to future problems with the possibility of reducing maintenance costs, increasing equipment readiness, and improving combat effectiveness. The Creating the Fleet Maker project is an effort supported by the Navy and Marine Corps Science, Technology, Engineering and Mathematics Education, Outreach and Workforce Program of the Office of Naval Research. It examines the concept of making in order to develop skills …

Tuskegee University Amateur Radio Station- Vhf/Uhf Digital Communication With Legacy Systems, Sharanabasaweshwara A. Asundi, Sharath S. Byakod

Mechanical & Aerospace Engineering Faculty Publications

No abstract provided.

A Comparative Analysis Of Spatial Visualization Ability And Drafting Models For Industrial And Technology Education Students, Petros Katsioloudis, Vukica Jovanović, Mildred Jones

Engineering Technology Faculty Publications

The article presents the comparative study on the drafting models and spatial visualization ability of industrial and technology education students in the U.S. It discusses how the study was conducted which examined the issue based on technical drawings and with regards to the impacts of model types. The results reportedly revealed three-dimensional models are effective for promoting learning, however more studies have to be conducted.

Review Of Development Stages In The Conceptual Design Of An Electro Hydrostatic Actuator For Robotics, Velibor Karanović, Mitar Jocanović, Vukica Jovanović

Engineering Technology Faculty Publications

The design of modern robotic devices faces numerous requirements and limitations which are related to optimization and robustness. Consequently, these stringent requirements have caused improvements in many engineering areas and lead to development of new optimization methods which better handle new complex products designed for application in industrial robots. One of the newly developed methods used in industrial robotics is the concept of a self-contained power device, an Electro-Hydrostatic Actuator (EHA). EHA devices were designed with a central idea, to avoid the possible drawbacks which were present in other types of actuators that are currently used in robotic systems. This …

Implementation And Assessment Of A Virtual Reality Experiment In The Undergraduate Themo-Fluids Laboratory, Sushil Chaturvedi, Jaewan Yoon, Rick Mckenzie, Petros J. Katsioloudis, Hector M. Garcia, Shuo Ren

Mechanical & Aerospace Engineering Faculty Publications

Results are presented from an NSF supported project that is geared towards advancing the development and use of virtual reality (VR) laboratories, designed to emulate the learning environment of physical laboratories. As part of this project, an experiment in the undergraduate thermo-fluids laboratory course titled "Jet Impact Force" was transformed into a 3-D virtual reality experiment using the widely used MAYA R and VIRTOOLS R software. In order to facilitate students' interactions with the newly created 3-D interactive, immersive and stereoscopic virtual laboratory environment, the human computer interfaces (HCI) were programmed and incorporated in the simulation software. Two immersion levels …

Multidisciplinary Design Optimization Of Transonic Airfoil Sections Using Multiobjective Optimization And Computational Intelligence Tools, Amit A. Kulkarni

Mechanical & Aerospace Engineering Theses & Dissertations

The design of transonic airfoils for civil aviation applications has been a major engineering challenge in the last fifty years. This design problem arises due to the need to limit shock wave drag at a given transonic speed. In recent years, the requirement to reduce the levels of aircraft noise has started to affect the airfoil design process. The multidisciplinary aerodynamic shape optimization problem is treated in this thesis using a multi-objective approach. The objectives correspond to the design of transonic airfoil sections with low drag during cruise and low trailing edge noise levels during the approach condition. The optimization …

Uncertainty Analysis And Instrument Selection Using A Web-Based Virtual Experiment, Praveen Malali, Pooja Bais, Robert Choate, Sushil Chaturvedi

Mechanical & Aerospace Engineering Faculty Publications

A methodology has been developed and successfully implemented for transforming physical experiments in an undergraduate thermo-fluids laboratory at Old Dominion University (ODU), a doctoral university, into web-based virtual experiments while the Mechanical Engineering (ME) faculty at Western Kentucky University (WKU), an undergraduate university, have developed and implemented a Design of Experiments (DOE) Plan to assure that graduates of their program have acquired the skills necessary to design and conduct experiments and analyze experimental results. This paper presents details about a web-based virtual experiment designed to teach students about selection of instruments based on the uncertainty estimated from the virtual experiment. …

An Integrated Simulation Design With Three-Dimensional Motions And A Hydraulic Stewart Simulator, Cheng Lin, Gene Hou, Yuzhong Shen, Hector Garcia

Engineering Technology Faculty Publications

This paper presents an integrated design process and tests of a Stewart simulator with a virtual visualization tool, which uses Virtools to create and generate three-dimensional motions. An inverse kinematic algorithm is written to convert each visualized motion to the displacements of six cylinders in a Stewart motion simulator. Information of the displacements is then transferred through the User Datagram Protocol (UDP) to a personal computer which has the LabVIEW software. An NI USB-6251 data acquisition device is applied to interact with the LabVIEW program and the Stewart hydraulic simulator. The approach presented in this paper to function an old …

Using Basic Computer Aided Drafting And Design Courses At The Freshman Level To Improve Technology Students Competitiveness In Obtaining Early Academic Career Internships, Anthony Dean, Mustafa Moustafa, Julie Moustafa

Engineering Technology Faculty Publications

Many students have the desire to have internships and part-time employment during their academic careers. Often students in their freshman and sophomore years in four year engineering and technology programs find it difficult to be competitive against more senior students for these positions. This paper discusses how students, in the Mechanical Engineering Technology (MET) program at ________________University, through taking CAD and Solid Modeling courses early in their academic careers are well suited to be competitive in obtaining internships and part time employment. This paper discusses the MET programs first two years’ curriculum and how it prepares the students to enter …

Support For A Delivery Train Based Material Handling Mechanism, Sai P. Boyedapu

Electrical & Computer Engineering Theses & Dissertations

Modeling a delivery train system is more challenging than traditional forklift systems as the delivery train model consists of a tugger, cart and a controller that combine to deliver materials within a manufacturing plant. Also, the decision logic for selection of carts and tuggers, joining of loads to particular delivery trains is more complicated than forklift systems. Simulation software such as Arena, Automod and Flexsim do not provide direct support for modeling delivery train systems.

In this thesis, an object-oriented, platform and language independent model of a delivery train was designed. The model was then implemented as an extension to …

Rapid Prototyping For The Design Of Virtual Worlds, Prabhu V. Krishnan

Electrical & Computer Engineering Theses & Dissertations

Development of Virtual Reality (VR) applications is challenging where application developers are required to have expertise in the target VR technologies along with the problem domain expertise. New VR technologies impose a significant learning curve to even the most experienced VR developer. The proposed solution relies on synthesis to automate the migration of a VR application to a new unfamiliar VR platform/technology. To solve the problem, the Common Scene Definition Framework (CSDF) was developed, that serves as a superset/model representation of the target virtual world. Input modules were developed to populate the framework with the capabilities of the virtual world …

Mapping Of Thermo-Fluids Laboratory Experiments Into Web-Based Experiments, Sushil Chaturvedi, Rick Mckenzie, O. A. Akan, A. Priyadershini

Mechanical & Aerospace Engineering Faculty Publications

A methodology is being developed for transforming physical experiments from the undergraduate thermo-fluids laboratory into a web-based virtual experiments. Important characteristics of physical experiments are identified in order to preserve them in physical to virtual domain mapping. Several commercially available software are employed to incorporate in the web-based experiments characteristics such as recreation of physical phenomenon in the virtual domain, measurement of physical quantities on a computer screen, assembly of virtual probes and coupling of the virtual experiment with a data acquisition software. A virtual reality software has been incorporated to enable web-based students to navigate through the virtual laboratory, …

Design Optimization Module For Hierarchical Research And Learning Environment, Oktay Baysal, Mehti Koklu, Ahmed K. Noor

Mechanical & Aerospace Engineering Faculty Publications

The present paper describes a learning module on design optimization courses within a hierarchical research and learning network (HRLN). In this environment a knowledge organization can be created as a hierarchical learning network to link diverse inter- and trans- disciplinary teams from a consortium of universities, industry, government agencies and the providers of learning technologies. It is an approach that builds on computer-based training, intelligent tutoring systems, interactive learning, collaborative-distributed learning, and learning networks. The present design optimization module has been developed and described herein, as a demonstrator of a learning module in this environment. This module allows for the …

Evaluation Of Distributed Effects In Field Effect Transistors For High Frequency Applications, Srinivas Rowjee Cuddapah

Electrical & Computer Engineering Theses & Dissertations

Metal Semiconductor Field Effect Transistors are at the heart of currently used microwave and millimeter-wave devices. CAD (Computer Aided Design) models for MESFET are used in the development and optimization of high-speed microwave devices. The increase in the chip density demands more accurate models. A distributed small signal model was developed for a GaAs MESFET account of the high frequency effects.

The lumped model of the MESFET is inadequate at frequencies where the wavelength of operation approaches device dimensions. This is because different regions in the device can experience different amplitudes and phases of the biasing signal. In this thesis, …

Building Lms Adaptive Filters With Register-Based Fpgas, Li Ding

Electrical & Computer Engineering Theses & Dissertations

In this thesis, an 8-bit least mean squares (LMS) adaptive digital filter with 16 coefficients is implemented on a single FPGA, using the MaxPlus+2 design environment. The system is constructed as a hierarchical structure, using four different levels of design hierarchy. Subdesigns at each level of the hierarchy project are complied, fitted and simulated to test and verify their functional correctness. The complete system is tested and verified by checking the MaxPlus+2 simulator results against fixed-point integer arithmetic simulations written in Matlab. The resulting adaptive filter is subsequently mapped to the Alters FLEX I OK20TC144-3 device, resulting in a 14,500 …

An Approach For Multidisciplinary Design Optimization, Robert V. Krueger

Mechanical & Aerospace Engineering Theses & Dissertations

Multidisciplinary Design Optimization (MDO) is an optimization technique that allows complex designs to be improved by managing conflicting goals in such a fashion so as to improve the overall design. This thesis presents a nonhierarchic MDO formulation and gives a general explanation of how it is to be applied to various appropriate problems. In addition, this thesis evaluates the viability of this MDO technique by applying it to two distinct, multidisciplinary problems that have been used as examples in other literature. The first example problem is a combined aerodynamic/structural problem and the second example is an alkylation process problem. First, …

Neural Network Based Vowel Articulation Training Aid For The Deaf, Andrew E. Beck

Electrical & Computer Engineering Theses & Dissertations

Teaching the hearing-impaired to speak is both a challenging and rewarding task. Computer-based training aids are valuable teaching tools and complement the speech therapist in the speech training process. We have developed a computer based vowel articulation training aid designed to provide visual feedback for vowel production to the hearing-impaired user. This system transforms speech spectra from a multi-dimensional acoustic space to a two-dimensional phonetic space which is displayed on a computer monitor. The system signal processing includes feature extraction designed to mimic the properties of the human ear, and a transformation to a two-dimensional display space. The dimensionality transformation …

Computer-Aided Analysis And Design Of Rectangular Buried Tank Walls And Its Safety Factor Evaluation Based On Yield Line Analysis, Rakiya J. Fatoohi

Civil & Environmental Engineering Theses & Dissertations

This thesis presents the results of a study that determines the true safety factor of underground square reinforced concrete tank walls.

The walls are analyzed and designed by elastic method. The amount and distribution of the reinforcement was determined by use of the alternate design method (working stress) in compliance with all ACI code requirements. The wall's ultimate moment was computed by use of yield line theory assuming non-isotropic reinforcement. The ultimate value of the earth pressure was computed and compared with the elastic analysis and design values to give the true safety factor.

The results of this study indicate …

Structural Sensitivity Analysis On A Parallel Computer, Niu Kian Teck

Civil & Environmental Engineering Theses & Dissertations

Substructuring formulation using adjoint variable approach has been developed for design sensitivity analysis and optimization of large scale structures. In this study, the procedure for statics and sensitivity analysis are re-examined to propose a programming scheme which can be implemented either in a sequential or parallel environment. The computational times of the substructuring formulation using a single processor versus multi-processors are compared to see the effectiveness of the formulation in the concurrent computing environment.

Design Of Multivariable Feedback Control Systems Via Spectral Assignment, Mohsen Marefat

Electrical & Computer Engineering Theses & Dissertations

During the past 15 year s significant advances have been made towards developing viable synthesis- techniques for multivariable feedback control systems. The entire aggregate of this theoretical work has been reviewed and consolidated. Diverse notations have been standardized into a single system. A two-step design philosophy for spectral assignment has been developed which first meets stability and time response requirements by assigning eigenvalues and eigenvector s and then provides for attainment of secondary objectives without significant deviation from the initial assignment. Finally, a computer-aided design package has been created to streamline the process of mathematical calculation and to allow users …

Analog Computer Simulation With Automatic Scaling By Digital Computer, Mark Anthony Motter

Electrical & Computer Engineering Theses & Dissertations

A computer-aided design approach for the simplification of analog computer simulation is presented. The simulation configuration consists of an EAI 2000 analog computer with serial communications link to a PDP — 11/24 digital computer. Under control of the PDP-11, the analog simulations are realized with appropriate time and magnitude scaling which adjusts the range of the simulation coefficients and prevents overloads of the analog components. The analog computer hardware configuration accommodates both stable plants up to eighth order and closed-loop systems up to tenth order. Cascade compensation is provided for the closed-loop systems.

The plant may be described by either …