Engineering Commons^™

Contour Data Acquisition System For Electric Vehicle Distance Estimation System, Kuew Wai Chew, Chee Ken Leong

Journal of Marine Science and Technology–Taiwan

The conventional distance estimation system only uses a constant speed and a constant level of road elevation to estimate the driving range of a vehicle. This technique leads to low prediction accuracy. In this project, a new estimation technique namely the Contour Positioning System (CPS) for an electric vehicle is proposed. The CPS provides a more reliable estimation of the electric vehicle battery energy usage by taking into consideration additional factors such as road elevation and regenerative braking energy. In order to perform the CPS calculation, first and foremost, the elevation profile of the selected destination must be determined. In …

Periodic Damage Evaluation Of Aging Offshore Jackets Based On Continuous Dynamic Tests, Fu-Shun Liu, Hong-Chao Lu, Wei-Ying Wang, Dong-Ping Yang

Journal of Marine Science and Technology–Taiwan

This study proposes a new method for evaluating the damage of aging offshore platforms, based on dynamic tests. The proposed method involves a new damage indicator for reducing the effects of occurred damages accumulated before the first measurement. One theoretical improvement is that the requirement of using the stiffness matrix of the finite element model to replace that of the measured model can be ignored in calculating the modal strain energy of the measured model. The other development is that the proposed approach can be used for providing reasonable evaluations of damages that occurred between two adjacent dynamic tests. This …

Development Of An Intelligent Energy Saving Heat Pump For Water Heater With Fuzzy Logic Controller, Cong-Hui Huang

Journal of Marine Science and Technology–Taiwan

There is a growing awareness of the importance of using clean and environmentally friendly sources of energy. This paper presents the development of an intelligent energy saving heat pump for a water heater with a fuzzy logic controller that analyzes the heating efficiency of the heat pump heater. The fuzzy logic controller is employed for developing a heating algorithm to raise the efficiency of the heat pump heater and suppress unnecessary heating at high temperatures. Experimental results show that our heat pump heater produces an energy saving of 60% of total energy input, compared to the 23% for a gas …

A Study On Optimization Of Ship Hull Form Based On Neuro-Response Surface Method (Nrsm), Soon-Sub Lee, Jae-Chul Lee, Sung-Chul Shin, Soo-Young Kim, Hyun-Sik Yoon

Journal of Marine Science and Technology–Taiwan

Building large and eco-friendly ships has become a clear trend in the ship building industry. Research to minimize ship resistance has actively been investigated for energy savings and environmental protection. However, optimization of the full geometry, while taking into account the hydrodynamic performance is difficult because extensive time is needed to calculate the performance factors, such as the resistance and propulsion. Hence we suggest an optimal design framework based on the neuro-response surface method (NRSM) for optimal shape design in consideration of hydrodynamic performance. The optimization algorithm of the constructed framework consists of the back-propagation neural network (BPN) and the …

Automated Scratchpad Mapping And Allocation For Embedded Processors, Yang Gao

Theses and Dissertations

Embedded system-on-chip processors such as the Texas Instruments C66 DSP and the IBM Cell provide the programmer with a software controlled on-chip memory to supplement a traditional but simple two-level cache. By decomposing data sets and their corresponding workload into small subsets that fit within this on-chip memory, the processor can potentially achieve equivalent or better performance, power efficiency, and area efficiency than with its sophisticated cache. However, program controlled on chip memory requires a shift in the responsibility for management and allocation from the hardware to the programmer. Specifically, this requires the explicit mapping of program arrays to specific …

Slow Wave Structures Integrated With Ferro-Magnetic And Ferro-Electric Thin Films For Smart Rf Applications, B M Farid Rahman

Theses and Dissertations

Modern communications systems are following a common trend to increase the operational frequency, level of integration and number of frequency bands. Although 90-95% components in a cell phone are passives which take 80% of the total board area. High performance RF passive components play limited role and are desired towards this technological advancement. Slow wave structure is one of the most promising candidates to design compact RF and mm-Wave passive components. Slow wave structures are the specially designed transmission line realized by placing the alternate narrow and wide signal conductors in order to reduce the physical size of the components. …

Finite Element Analysis Simulations Of Micro And Nano-Electromechanical Sensors For Design Optimization, Nicholas Frank Deroller

Theses and Dissertations

Micro and Nano-electromechanical sensors (MEMS and NEMS) provide a means of actively sensing minute changes in the surrounding environment. Small changes in temperature, momentum, and strain may be sensed in passive modes while greater sensing possibilities exist in active modes. Theoretical femto-gram resolution mass detection and heated element sensing methods may be used while volatile organic compound (VOC) sensing may be achieved when combined with a functionalization layer or device heating. These devices offer a great reduction in cost and offer increased mobility by allowing a "lab-on-chip" solution for the prospective user while also greatly reducing the amount of energy …

Research On Sealing Performance Of Hydrostatic Pressure Mechanical Seal, Wei-Bing Zhu, He-Shun Wang, Sheng-Ren Zhou

Journal of Marine Science and Technology–Taiwan

The hydrostatic pressure mechanical seal has many advantages, and it can be used in rotating machines with lower speed. Based on the externally pressurized stable gas lubrication theory, the control equation of end face flow field for hydrostatic pressure mechanical seal with orifice compensation was established. The functional extremum algorithm and the finite element method were used to solve this equation. The effects of gas film thickness, air supply pressure, throttle orifice number and diameter, on face opening force and gas film stiffness were discussed in detail. The results show that the opening force decreases with the widening of face …

Performance Evaluation Of Three Types Of Passive Micromixer With Convergent-Divergent Sinusoidal Walls, Arshad Afzal, Kwang-Yong Kim

Journal of Marine Science and Technology–Taiwan

A passive split-and-recombination micromixer with convergent-divergent channel walls of sinusoidal variation has been investigated using numerical simulations. With water and ethanol as working fluids, the analysis was performed using Navier-Stokes equations with convection-diffusion model in a Reynolds number range, 10  Re  70. Performances of three configurations with different split-and-recombination arrangements were evaluated in terms of mixing index and pressure drop. A parametric study was also conducted with two geometrical parameters, i.e., the ratios of throat-width to diameter of circular wall and diameter of circular wall to amplitude. The results showed a significant dependence of the mixing performance on …

Design Of A New Electromagnetic Valve With A Hybrid Pm/Em Actuator In Si Engines, Ly Vinh Dat, Yaojung Shiao

Journal of Marine Science and Technology–Taiwan

Numerous devices have been developed for controlling valve timings in SI engines. Among them, the electromagnetic valve train (EMV) actuator can fully control valve timings to improve fuel consumption and emission. In addition, an EMV with a permanent-magnet and electromagnetic-coil (PM/EM) hybrid actuator has several advantages of control, energy consumption, and time response compared over conventional EMVs. This paper proposes a novel EMV with a PM/EM hybrid actuator that differs considerably from existing EMVs. Finite element analysis was used for analyzing the EMV design. The optimization was based on criteria that ensured the EMV to satisfy holding forces in closed …

Effective Orifice Area Of A Newly Developed Polyurethane Aortic Valve: Manufacturing And Evaluation, Wu-Chiao Shih, Ha-Hai Vu, Cheung-Hwa Hsu, Kai-Wen Yang, Yaw-Hong Kang

Journal of Marine Science and Technology–Taiwan

An optimal design for a polyurethane (PU) aortic valve was developed in a previous study. The current study investigated an approach for manufacturing PU aortic valves, evaluating the effective orifice areas (EOAs) of the prototypes. Two manufacturing approaches, assembly and single-piece forming methods, were developed. In the assembly method, support frames and valve leaflets were manufactured separately and then glued together by using an adhesive substance. By contrast, in the single-piece forming method, two main components of the valve were fabricated simultaneously by using a molding technique. This study established an experimental loop that mimics natural circulation from the left …

Discoid And Asymmetrical Gyroless Micro-Satellite Off-Modulation Attitude Control With Kalman Filter, Ho-Nien Shou

Journal of Marine Science and Technology–Taiwan

The gyroless attitude control method and kalman algorithm procedures presented in this paper are applicable to asymmetrical microsatellites of any shape with large mass variation and without angular rate sensors. The attitude sensors include a three-axis magnetometer, a horizon sensor, and a coarse sun sensor (CSS), which together serve as an analytic platform and help in ensuring the stability of attitude controls. The attitude control problem of microsatellites has become a focal point because microsatellite fabrication processes are short, costless, and can be flexibly used for various purposes. The center of mass of the microsatellite can be offset because of …

Applying Fuzzy Logic Controller To Intelligent Solar Panel Cleaning System, Cong-Hui Huang

Journal of Marine Science and Technology–Taiwan

This paper presents an intelligent solar panel cleaning system that utilizes a fuzzy logic controller. The output voltage of the solar panel is applied to calculate whether to activate the cleaning mechanism. The direction and position of the system is set using a light sensor that is parallel to the direction of the sunlight. The data from the light sensors, combined with fuzzy logic control software developed using LabVIEW, determine the control commands (stop, forward, and reverse) for the stepper motors controlling the cleaning process. The cleaning process, which is repeated until the power output from the solar panels is …

Synthetic Physical Models For Animating Unsteady Fish Motions, Shyh-Kuang Ueng, Hong-Kai Chen

Journal of Marine Science and Technology–Taiwan

This paper presents physical models for simulating unsteady fish motions, including bursting, gliding, braking, turning, ascending and descending. A new wave model, the controllable body wave model, is developed to undulate the fish body to produce bursting and gliding motions. A key frame approach is adopted to realize braking, turning, descending and ascending. In the key frame method, individual motions are decomposed into sequences of key steps. The gestures of the fish in these key steps are recorded and regarded as key frames. In the run time, these recorded key frames are sequentially reproduced to generate swimming patterns. In addition …

Modeling And Control Of A Novel Ball Screw Mechanism, Wen-Hsiang Hsieh, Kai-Bi Chang

Journal of Marine Science and Technology–Taiwan

This study proposes a systematic approach for the design and control of a novel ball screw transmission system. We investigated the structure of the system, performed kinematic analysis, and conducted dimensional synthesis by optimization. The mathematical model of the system was determined by system identification and a refined PID controller was designed. Computer simulation was conducted to verify the feasibility of the proposed design. A prototype machine and an experimental setup were built and tested. The experimental results show that the output with the controller agrees well with the required output. Therefore, the proposed design can produce the expected output …

Fault Diagnosis And Performance Assessment For A Rotary Actuator Based On Neural Network Observer, Jian Ma, Xin Li, Chen Lu, Zi-Li Wang

Journal of Marine Science and Technology–Taiwan

Substantial damage may occur when a rotary actuator fails during operation. Therefore, effective fault diagnosis of a rotary actuator is crucial to ensuring the safety of the device. However, only a few studies on fault detection, fault isolation, and performance assessment have focused on rotary actuators. In this study, fault detection and fault isolation processes were implemented by designing two observers based on a neural network, and a method that assesses the performance of the rotary actuator is proposed. First, two observers are established according to the structure of the rotary actuator. Data in their normal state are used to …

Approximation And Relaxation Approaches For Parallel And Distributed Machine Learning, Stephen Tyree

McKelvey School of Engineering Graduate Student Theses & Dissertations

Large scale machine learning requires tradeoffs. Commonly this tradeoff has led practitioners to choose simpler, less powerful models, e.g. linear models, in order to process more training examples in a limited time. In this work, we introduce parallelism to the training of non-linear models by leveraging a different tradeoff--approximation. We demonstrate various techniques by which non-linear models can be made amenable to larger data sets and significantly more training parallelism by strategically introducing approximation in certain optimization steps.

For gradient boosted regression tree ensembles, we replace precise selection of tree splits with a coarse-grained, approximate split selection, yielding both faster …

Accelerating Heuristic Search For Ai Planning, You Xu

McKelvey School of Engineering Graduate Student Theses & Dissertations

AI Planning is an important research field. Heuristic search is the most commonly used method in solving planning problems. Despite recent advances in improving the quality of heuristics and devising better search strategies, the high computational cost of heuristic search remains a barrier that severely limits its application to real world problems. In this dissertation, we propose theories, algorithms and systems to accelerate heuristic search for AI planning.

We make four major contributions in this dissertation. First, we propose a state-space reduction method called Stratified Planning to accelerate heuristic search. Stratified Planning can be combined with any heuristic search to …

Snowboard, Ski, And Skateboard Sensor System Application, Adrien Doiron, Michael Fernandez, Victor Ojeda, Robert Ross

Mechanical Engineering Senior Theses

The goal of this project was develop a sensor for the commercial market for skiers, snowboarders, and skateboarders that can give them the data such as speed, elevation, pressure, temperature, flex, acceleration, position, and other performance data such as trick characterization. This was done by using a variety of sensors, including a GPS, flex sensors, accelerometer, and others to provide data such as speed, position, position, and temperature. The sensors were placed in an external polycarbonate casing attached to the ski or board by using an adhesive pad on the bottom of the casing. These sensors then transmit the data …

Synthesis Of Au And Ag Catalysts With Controlled Sizes Of Metal Particles, Eleni A. Kyriakidou

Theses and Dissertations

The performance of supported metal catalysts largely depends on the structure and composition of the metal particles and the nature of the support. In order to achieve better control over these parameters, synthetic route based on the use of templating agents has been proposed. Among the different templating agents, poly(amidoamine) (PAMAM) dendrimers have attracted a lot of recent attention as nanoparticle stabilizers. In this thesis, Au/G4OH nanocomposites were synthesized in aqueous solutions and used as precursors for the preparation of SiO2-supported Au nanoparticles. Elemental analysis, UV-Vis, and STEM measurements were used to estimate the extent of the Au-dendrimer interactions and …

On The Development Of High Strain Rate Experiments For The Characterization Of Engineering Materials, Silas P. Mallon

Theses and Dissertations

In order to predict the damage accumulation and failure processes associated with highly dynamic events such as blast loading, shock wave loading, and ballistic impact loading, a commensurate understanding of the fundamental constitutive and fracture behavior of materials subjected to such high rate loading conditions is necessary. In this effort, high strain rate experimental facilities consisting of a shock tube apparatus and a torsional split Hopkinson bar apparatus have been designed, constructed, and subsequently used to investigate the mechanical properties of an array of engineering materials subjected to a variety of dynamic loading conditions. Designs for the experimental equipment utilized …

Functionalized Graphitic Nanoreinforcement For Cement Composites, Nima Zohhadi

Theses and Dissertations

Physical and mechanical properties of graphitic nanomaterials, in particular multiwalled carbon nanotubes (MWCNTs) and graphene nano-platelets (GNPs) make them promising candidates for nanoreinforcement of cement composites. The two key challenges associated with the incorporation of MWCNTs and GNPs are to attain uniform dispersion and interfacial bonding within the composite matrix. The effects of three main-stream dispersion techniques (namely, ultrasonication, acid-etching, and surfactant-coating) on the mechanical properties and microstructure of MWCNT- and GNP-cement composites were experimentally studied. Compressive strength tests and different characterization techniques including dynamic light scattering, Raman spectroscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission …

Influence Of Defects In Epitaxial Graphene Towards Material Growth And Device Performances, Shamaita Shithi Shetu

Theses and Dissertations

Since its invention in 2004, Graphene, a two dimensional array of SP2 bonded carbon atoms has received significant interest by the scientific community due to its unique electrical, optical and mechanical properties. A promising route to the synthesis of large-area graphene, is epitaxial graphene formed by sublimation of silicon atoms from Silicon carbide at elevated temperatures (>1200oC). Although the electronic and mechanical properties of graphene with perfect atomic lattice are outstanding, the structural defects, which may appear during graphene growth, can influence the growth mechanism and material properties. However, deviations from perfection, i.e. introducing dopants in semiconductors often considered …

Fabrication And Characterization Of Novel Electrodes For Solid Oxide Fuel Cell For Efficient Energy Conversion, Yu Chen

Theses and Dissertations

Solid oxide fuel cells (SOFCs) have been considered as one of the most promising technologies for future energy conversion since they can in principle be operated with fuels ranging from H2 to any hydrocarbon fuel. However, the system cost and coking (when using hydrocarbon as fuel) issues for the state-of-art electrode materials/designs often limit their further application. The objective of this Ph.D dissertation is aiming at overcoming these problems and accelerating SOFC commercialization. One approach to cost reduction is lowering the SOFC operating temperature to below 800 or even 600 oC, so that inexpensive materials can be used and quick …

Characterization Of Electrodeposited Copper Foil Surface Roughness For Accurate Conductor Power Loss Modeling, Michael B. Griesi

Theses and Dissertations

As computer data rates have increased, designers observed that the standard models for estimating the impact of copper foil surface roughness on conductor loss are limited to a few GHz. The more recent snowball model (a “snowball” estimation of the Huray Model) has demonstrated improved conductor loss predictions up to 50 GHz by estimating the necessary parameters using reasonable assumptions about the geometric surface features of electrodeposited copper foil. Since then, the Huray Model has been incorporated into commercial electromagnetic field simulators. However, a standard method of characterizing the electrodeposited copper foil used in high-speed circuits to directly implement the …

Comprehensive Joint Time-Frequency Analysis Toward Condition Based Maintenance Regimes For Electrical And Mechanical Components, David Lee Coats

Theses and Dissertations

Based upon a framework of time-frequency analysis, we outline condition based maintenance (CBM), or maintenance only upon evidence of need, for both electrical and mechanical systems. We apply novel time-frequency cross-correlation metrics to helicopter drivetrain systems and electrical cables as remaining useful life assessments by non-destructive and non-invasive tests. In both cases, these metrics for health assessment provide a basis for diagnostic and prognostic analysis of underlying systems and components by performing accelerated condition tests on actual mechanical and electrical systems. We present novel time-frequency domain vibration analysis of a gearbox failure in an AH-64 Apache drivetrain testbed and quantify …

Novel Biofabrication Technologies To Recapitulate In Vivo Geometries In Collagen Hydrogels, Veronica Rodriguez-Rivera

Theses and Dissertations

Tissue engineering and regenerative medicine aims to restore form and function to tissues that have been lost or damaged due to disease, congenital defect, or trauma. Biomaterials suitable to restore these complex tissues need to provide a balance between chemical and mechanical properties, providing accurate cell-matrix interaction and induce in vivo behaviors such as proliferation, differentiation and migration. It also requires that physical and chemical cues be presented to the body in the proper temporal and spatial pattern. The extracellular matrix exerts forces that are transmitted through focal adhesion causing changes in the cell behavior. The hypothesis for this dissertation …

Practical Concurrency Support For Web Service Transactions, Emad Alsuwat

Theses and Dissertations

Traditional database concurrency control methods use locking, timestampordering, and optimistic-ordering to achieve DB consistency. However, these approaches are not suitable for long-running Web Service Compositions (WSCs) due to associated performance degradation. Our hypothesis asserts that, using transactional semantic and ordering information, the execution time of a WSC can be reduced, thus allowing the use of traditional database concurrency control methods while avoiding unacceptable performance degradation. Our solution is based on the following approaches: § We model a WSC as WS-BPEL specification, i.e., a partial order of WS transactions. § We allow some of the WS transactions in the WSC to …

Numerical Modeling Of Free Surface Flows Using Depth Averaged And 3d Models, Khaled Mamdouh Mohamed Abdo

Theses and Dissertations

The objectives of the research presented in this dissertation are to develop and apply numerical models to study free surface flows under different boundary conditions, bedform geometry and channel configuration. A 2D depth-averaged model is developed by solving the Saint Venant or the shallow water equations using a finite volume method. An existing 3D model, developed in-house, that solves the Reynoldsaveraged Navier-Stokes equations and conservation equations for suspended sediment and conservative species is adapted for free surface flows by solving the volume of fluid (VOF) equation using a compressive interface capturing scheme for arbitrary meshes, CICSAM. The depth-averaged or shallow …

Quantitative Comparison Of Time-Frequency Decomposed Gait Emg Signals, L. Patrick Mitchell

Theses and Dissertations

Falls in the senior population represent an immediate threat to both current and future generations’ quality of life. The results of falls can be disastrous, create a long road to recovery, and in many cases result in death. Hypertension represents a difficult-to-quantify condition which is known to contribute to gait and balance dysfunction. Accurate assessment of conditions such as these represents an area of primary investigative need. In order to meet this need, a new experimental setup is developed which combines time-frequency analysis with surface electromyography (sEMG) signals obtained during ambulation. 3-bit pressure data is acquired using a pressure-sensitive mat, …