Engineering Commons^™

Modeling And Validation Of A Fault Mitigation Method In Induction Motor-Drive Systems Using Magnetic Equivalent Circuits, Shaohua Suo

Master's Theses (2009 -)

In this thesis, a fault mitigation method for delta-connected induction motor-drive systems under a two-phase open-delta faulty operating condition is analyzed and verified. More specifically, this fault mitigation technique can provide a set of almost balanced motor line currents, and significantly reduce torque ripples, even when the machine runs under the aforementioned two-phase open-delta faulty operating condition. This condition is analyzed using a Magnetic Equivalent Circuit (MEC) model. This model is developed for a delta-connected induction motor which is coupled to its drive system, including the fault mitigation controller. That is, the MEC model is linked to its associated PWM …

One-Dimensional Strain Initiated By Rapid Compaction Of A Heterogenous Granular Mixture Consisting Of Cu, Fe, Sio2, C, Mos2, And Sn, Cullen Braun

Master's Theses (2009 -)

The dynamic compaction of metal powders is of great interest to the metallurgical and military communities. The compaction of a heterogeneous granular mixture consisting of copper, iron, silica, graphite, molybdenum-disulde, and tin predominately used in aviation break-pad creation is presented. The initial density of the material was on average 2.756 g/cm3 . The research also required developing a working projectile velocity measurement system and a proper target assembly for pressure measurements. Manganin gages were used to record the shock wave transit time and the pressure of the transmitted waveform into the powder mixture. An impedance matching technique was utilized to …

Unstructured Grid Technologies For Hydrodynamic Applications With Bodies In Relative Motion And Mesh Deformation, Lei Ji

Masters Theses and Doctoral Dissertations

Unstructured grid technologies for hydrodynamic applications with bodies in relative motion and mesh deformation are presented. A parallel universal mesh deformation scheme is developed to manage deforming surface and volume grids for both aerodynamic and hydrodynamic applications. The approach is universal and independent of grid type. Also, it requires minimal inter-processor communication and is thus perfectly suitable to a parallel platform. The original scheme of Allen (2006) has difficulty deforming volume grids in regions near concave geometry features and for abrupt grid resolution changes. Several modifications are proposed to overcome these problems. Grid quality can be improved significantly by adding …

Worse-Than-Rayleigh Fading: Experimental Results And Theoretical Models, David W. Matolak, Jeff Frolik

Faculty Publications

This article is motivated by the recent recognition that channel fading for new wireless applications is not always well described by traditional models used for mobile communication systems. In particular, fading data collected for vehicleto- vehicle and wireless sensor network applications has motivated new models for conditions in which channel fading statistics can be worse than Rayleigh. We review the use of statistical channel models, describe our example applications, and provide both measured and modeling results for these severe fading conditions.

Comparison Of Aquifer Sustainability Under Groundwater Administrations In Oklahoma And Texas, Aaron R. Mittelstet, Michael D. Smolen, Garey A. Fox, Damian C. Adams

Department of Agricultural and Biological Systems Engineering: Faculty Publications

We compared two approaches to administration of groundwater law on a hydrologic model of the North Canadian River, an alluvial aquifer in northwestern Oklahoma. Oklahoma limits pumping rates to retain 50% aquifer saturated thickness after 20 years of groundwater use. The Texas Panhandle Groundwater Conservation District’s (GCD) rules limit pumping to a rate that consumes no more than 50% of saturated thickness in 50 years, with reevaluation and readjustment of permits every 5 years. Using a hydrologic model (MODFLOW), we simulated river-groundwater interaction and aquifer dynamics under increasing levels of ‘‘development’’ (i.e., increasing groundwater withdrawals). Oklahoma’s approach initially would limit …

Fusing Heterogeneous Modalities For Video And Image Re-Ranking, Hung-Khoon Tan, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Multimedia documents in popular image and video sharing websites such as Flickr and Youtube are heterogeneous documents with diverse ways of representations and rich user-supplied information. In this paper, we investigate how the agreement among heterogeneous modalities can be exploited to guide data fusion. The problem of fusion is cast as the simultaneous mining of agreement from different modalities and adaptation of fusion weights to construct a fused graph from these modalities. An iterative framework based on agreement-fusion optimization is thus proposed. We plug in two well-known algorithms: random walk and semi-supervised learning to this framework to illustrate the idea …

Learning Feature Dependencies For Noise Correction In Biomedical Prediction, Ghim-Eng Yap, Ah-Hwee Tan, Hwee Hwa Pang

Research Collection School Of Computing and Information Systems

The presence of noise or errors in the stated feature values of biomedical data can lead to incorrect prediction. We introduce a Bayesian Network-based Noise Correction framework named BN-NC. After data preprocessing, a Bayesian Network (BN) is learned to capture the feature dependencies. Using the BN to predict each feature in turn, BN-NC estimates a feature's error rate as the deviation between its predicted and stated values in the training data, and allocates the appropriate uncertainty to its subsequent findings during prediction. BN-NC automatically generates a probabilistic rule to explain BN prediction on the class variable using the feature values …

A High-Throughput Routing Metric For Reliable Multicast In Multi-Rate Wireless Mesh Networks, Xin Zhao, Jun Guo, Chun Tung Chou, Archan Misra, Sanjay Jha

Research Collection School Of Computing and Information Systems

We propose a routing metric for enabling highthroughput reliable multicast in multi-rate wireless mesh networks. This new multicast routing metric, called expected multicast transmission time (EMTT), captures the combined effects of 1) MAC-layer retransmission-based reliability, 2) transmission rate diversity, 3) wireless broadcast advantage, and 4) link quality awareness. The EMTT of one-hop transmission of a multicast packet minimizes the amount of expected transmission time (including that required for retransmissions). This is achieved by allowing the sender to adapt its bit-rate for each ongoing transmission/retransmission, optimized exclusively for its nexthop receivers that have not yet received the multicast packet. We model …

Natural Gas As Petroleum Fuel Substitution: Analysis Of Supply-Demand Projections, Infrastructures, Investments And End-User Prices, Abdul Qoyum Tjandranegara, Arsegianto Arsegianto, Widodo Wahyu Purwanto

Makara Journal of Technology

The petroleum fuels (PF) subsidy has long burdens the government spending, and discourages less expensive energy usage such as natural gas (NG). Exporting NG and importing the more expensive PF products cause financial losses to Indonesia. The lack of NG infrastructure is the main hurdle in maximizing domestic NG usage and so does the perception of its high investment costs burdening government spending and pushing the NG transportation cost up. This study calculates the required NG infrastructure and its investments for several levels of PF substitutions up to 2030. To balance the NG demands, the supply from each field and …

The Synergy Of Recombinant Xylanolytic Enzyme On Xylan Hydrolysis, One Asmarani, Bambang Prajogo Eko Wardojo, Ni Nyoman Tri Puspaningsih

Makara Journal of Technology

Microbial xylanases or xylanolytic enzyme have received considerable attention over the last years owing to a multitude of possible applications. These enzymes have potential in the biodegradation of lignocellulosic biomass to fuels, chemicals, fruit juice, animal feed and in improving rumen digestion. More recently, the use of xylanases as bleaching agent in the pulp and paper industry has been suggested to replace of some of the chemicals presently used for this purpose. Such applications could have an important positive impact on the environment. The purpose of this research was determining the synergy of 3 recombinant xylanolytic enzymes (β-xylosidase, exo-xylanase and …

The Dominant Role Of The Hip In Multijoint Reflex Responses In Human Spinal Cord Injury, Tanya Onushko

Dissertations (1934 -)

Following a spinal cord injury (SCI), people often experience exaggerated reflexes, such that mild provocations can cause prolonged and uncontrolled muscle activity throughout the entire leg. These reflexes can be problematic and are known to interfere with functional tasks, such as transferring to and from a wheelchair, and they may interfere with locomotor function by prolonging muscle activity and/or inappropriately activating muscles during attempts to walk. While these multijoint reflexes have been shown to originate from several afferent cues, hip afferent input is a particularly potent sensory signal that readily triggers multijoint reflexes. The overall objective of this dissertation was …

Cradle To Gate Simple Life Cycle Assessment Of Biodiesel Production In Indonesi, Akhmad Hidayatno, Teuku Yuri M. Zagloel, Widodo Wahyu Purwanto, Carissa Carissa, Lindi Anggraini

Makara Journal of Technology

The focus of this research is to analyze potential environmental impact in the supply chain of palm oil biodiesel industries. Simple Life Cycle Assessment (LCA) is applied to analyze impacts, produced by the three main units in the supply chain of Palm-Oil-based Biodiesel, which are Palm Plantation, CPO mill, and Biodiesel Plant. We developed LCA calculation model using spreadsheet software, used to assess a number of input scenarios to evaluate the best scenario, in variation of: land quality, land area and the rate of clearing, land clearing technique and type of the original land. The biggest potential environmental impact is …

Characterization Of Surface Active Shell Charcoal Nyamplung Seeds (Calophyllum Inophyllum Linn), Santiyo Wibowo, Wasrin Syafi, Gustan Pari

Makara Journal of Technology

Characterization of Surface Active Shell Charcoal Nyamplung Seeds (Calophyllum inophyllum Linn). Chemical and physical activation of nyamplung shell with 0%, 5%, and 10% H3PO4 for 60 and 120 minutes has been carried out to prepare activated charcoal. The purpose of this experiment was to look into the characteristic of nyamplung shell activated charcoal surface. Nyamplung shell was carbonized into charcoal, then activated by immersion in H3PO4 solution using 0%, 5% and 10%, for 24 hours, and heated in retort at two temperatures (700 and 800 oC) and two duration (60 and 120 minutes). The material were characterized by fourier transform …

An Investigation Into The Resistance/Powering And Seakeeping Characteristics Of River Catamaran And Trimarana, Murdijanto Murdijanto, I Ketut Aria Pria Utama, Andi Jamaluddin

Makara Journal of Technology

The increase of fuel price has caused fleet operational and shipping business to be in danger situation. The fuel consumption of a ship is influenced by ship volume or wetted area which contributes directly to the increase of ship resistance and the size of main engine. In order to find out the appropriate answers, a series of investigation into river transportation using monohull, catamaran and trimaran types of vessel was carried out. The work focused on the estimation of total resistance and powering as well as seakeeping characteristics and carried out experimentally using tank test and numerically using a ship …

Determining The Standard Value Of The Oily Distortion Of Acquisition The Fingerprint Images, Rahmat Syam, Mochamad Hariadi, Mauridhi Hery Purnomo

Makara Journal of Technology

Determining the Standard Value of the Oily Distortion of Acquisition the Fingerprint Images. This research describes a novel procedure for determining the standard value of the oily distortion of acquisition the fingerprint images based on the score of clarity and ridge-valley thickness ratio. The fingerprint image is quantized into blocks size 32 x 32 pixels. Inside each block, an orientation line, which perpendicular to the ridge direction, is computed. The center of the block along the ridge direction, a two-dimension (2-D) vector V1 (slanted square) with the pixel size 32 x 13 pixels can be extracted and transformed to a …

Are Ieee 754 32-Bit And 64-Bit Binary Floating-Point Accurate Enough?, Bernaridho Hutabarat, I Ketut Eddy Purnama, Mochamad Hariadi, Mauridhi Hery Purnomo

Makara Journal of Technology

This paper describes a research toward the accuracy of floating-point values, and effort to reveal the real accuracy. The methods used in this research paper are assignment of values, assignment of value of arithmetic expressions, and output the values using floating-point value format that helps reveal the accuracy. The programming-tool used are Visual C# 9, Visual C++ 9, Java 5, and Visual BASIC 9. These tools run on top of Intel 80 x 86 hardware. The results show that 1*10-x cannot be accurately represented, and the approximate accuracy ranges only from 7 to 16 decimal digits.

Ergonomic Analysis Of Garment Industry Using Posture Evaluation Index (Pei) In Virtual Environment, Erlinda Muslim, Boy Nurtjahyo, Romadhani Ardi

Makara Journal of Technology

Ergonomic Analysis of Garment Industry using Posture Evaluation Index (PEI) in Virtual Environment. This research tried to study, in a virtual environment, the ergonomics of four divisions in garment industry: cutting division, sewing division, button division, and finishing division. Variables that influence the working conditions in each division are different; depend on the real situations that happened. The purpose is to assess the real working conditions based on ergonomics study using Posture Evaluation Index (PEI). PEI integrates the scores of low back analysis (LBA), ovako working posture (OWAS), and rapid upper limb assessment (RULA). Analysis phase was done using digital …

Formation Of Caco3 Particle And Conductivity Of Na2co3 And Cacl2 Solution Under Magnetic Field On Dynamic Fluid System, Nelson Saksono, Setijo Bismo, Roekmijati Widaningroem, Azwar Manaf

Makara Journal of Technology

Hard water causes the CaCO3 scale formation on the pipe walls and heat exchanger equipments in industrial or domestic water processes. A great number of experimental researches on the prevention of the CaCO3 precipitation process by magnetic field have been carried out. In this research, Na2CO3 and CaCl2 solutions was magnetized in the circulated flow condition (dynamic fluid system). The velocity of fluid and the circulation time was modified to examine its influences to the magnetization process. CaCO3 content was measured by titration method of EDTA complexometry. Conductivity test was conducted to find out hydrate ion bonding. The results showed …

Two-Class Classification With Various Characteristics Based On Kernel Principal Component Analysis And Support Vector Machines, Ivanna Kristianti Timotius, Iwan Setyawan, Andreas Ardian Febrianto

Makara Journal of Technology

Two class pattern classification problems appeared in many applications. In some applications, the characteristic of the members in a class is dissimilar. This paper proposed a classification system for this problem. The proposed system was developed based on the combination of kernel principal component analysis (KPCA) and support vector machines (SVMs). This system has been implemented in a two class face recognition problem. The average of the classification rate in this face image classification is 82.5%.

Evaluation Of An Innovative System For Improving Readability Of Passive Uhf Rfid Tags Attached To Reusable Plastic Containers, Jay A. Singh, S. Roy, B. Roesner

Industrial Technology and Packaging

Radio frequency identification (RFID) is a contactless identification technology that has proven to work well in conjunction with reusable plastic containers (RPCs). The impact of this technology on returnable containers has been explored by several past studies. This study evaluates an innovative system for improving readability of passive UHF RFID tags in conjunction with RPCs. The system involves an energy transfer device (ETD), which when attached to the RPCs, passively transfers radio frequency signals to interior regions of a unitized load thereby improving the readability of all RFID tags attached to the RPCs. This study included an evaluation of the …

Analytical And Numerical Comparisons Of Biogeography-Based Optimization And Genetic Algorithms., Daniel J. Simon, Rick Rarick, Mehmet Ergezer, Dawei Du

Electrical and Computer Engineering Faculty Publications

We show that biogeography-based optimization (BBO) is a generalization of a genetic algorithm with global uniform recombination (GA/GUR). Based on the common features of BBO and GA/GUR, we use a previously-derived BBO Markov model to obtain a GA/GUR Markov model. One BBO characteristic which makes it distinctive from GA/GUR is its migration mechanism, which affects selection pressure (i.e., the probability of retaining certain features in the population from one generation to the next). We compare the BBO and GA/GUR algorithms using results from analytical Markov models and continuous optimization benchmark problems. We show that the unique selection pressure provided by …

Blended Biogeography-Based Optimization For Constrained Optimization, Haiping Ma, Daniel J. Simon

Electrical and Computer Engineering Faculty Publications

Biogeography-based optimization (BBO) is a new evolutionary optimization method that is based on the science of biogeography. We propose two extensions to BBO. First, we propose a blended migration operator. Benchmark results show that blended BBO outperforms standard BBO. Second, we employ blended BBO to solve constrained optimization problems. Constraints are handled by modifying the BBO immigration and emigration procedures. The approach that we use does not require any additional tuning parameters beyond those that are required for unconstrained problems. The constrained blended BBO algorithm is compared with solutions based on a stud genetic algorithm (SGA) and standard particle swarm …

Behavior-Based Mobility Prediction For Seamless Handoffs In Mobile Wireless Networks, Weetit Wanalertlak, Ben Lee, Chansu Yu, Myungchul Kim, Seung-Min Park, Won-Tae Kim

Electrical and Computer Engineering Faculty Publications

The field of wireless networking has received unprecedented attention from the research community during the last decade due to its great potential to create new horizons for communicating beyond the Internet. Wireless LANs (WLANs) based on the IEEE 802.11 standard have become prevalent in public as well as residential areas, and their importance as an enabling technology will continue to grow for future pervasive computing applications. However, as their scale and complexity continue to grow, reducing handoff latency is particularly important. This paper presents the Behavior-based Mobility Prediction scheme to eliminate the scanning overhead incurred in IEEE 802.11 networks. This …

Light Sensor Platform Based On The Integration Of Bacteriorhodopsin With A Single Electron Transistor, Karl A. Walczak, Paul L. Bergstrom, Craig Richard Freidrich

Department of Electrical and Computer Engineering Publications

This paper reports on the integration of an optical protein with single electron transistors to form a nano-bio-hybrid device for sensing. Bacteriorhodopsin (bR) is an optoelectric protein that translocates a proton across a distance of several nanometers in response to an absorbed photon of incident light. This charge gradient results in a measurable voltage in the dried state. Single electron transistors (SETs) have active regions consisting of one or more quantum islands with a size typically 10 nanometers or less. Integrating bacteriorhodopsin with the gate of a SET provides a device capable of a modulated electrical output in response to …

An Atomistic Study Of Thermal Conductance Across A Metal-Graphene Nanoribbon Interface, Zhen Huang, Timothy S. Fisher, Jayathi Y. Murthy

Birck and NCN Publications

This paper presents an atomistic Green's function study of phonon transport through a heterogeneous interface between bulk TiC substrates and graphene nanoribbons (GNRs). The force constants that govern the lattice dynamical equations are obtained from first-principles density functional theory (DFT) calculations and then optimized for the Green's function formulation. Phonon vibrational properties of TiC and GNRs are investigated by lattice dynamics calculations with optimized force constants that correlate well to direct DFT results. Thermal conductances of TiC-GNR-TiC systems are studied together with TiC-GNR structures. The conductances of TiC-GNR interfaces are normalized by ribbon width and are found to converge. The …

Calculation Of Single Chain Cellulose Elasticity Using Fully Atomistic Modeling, Xiawa Wu, Robert Moon, Ashlie Martini

Birck and NCN Publications

Cellulose nanocrystals, a potential base material for green nanocomposites, are ordered bundles of cellulose chains. The properties of these chains have been studied for many years using atomic-scale modeling. However, model predictions are difficult to interpret because of the significant dependence of predicted properties on model details. The goal of this study is to begin to understand these dependencies. We focus on the investigation on model cellulose chains with different lengths and having both periodic and nonperiodic boundary conditions, and predict elasticity in the axial (chain) direction with three commonly used calculation methods. We find that chain length, boundary conditions, …

Analysis Of Airport Security Screening Checkpoints Using Queuing Networks And Discrete Event Simulation: A Theoretical And Empirical Approach, Stephen Louis Dorton

Doctoral Dissertations and Master's Theses

This study utilized discrete event simulation (DES) and queuing networks to investigate the effects of baggage volume and alarm rate at the Security Screening Checkpoint (SSCP) of a small origin and destination airport. A Jackson queuing network was considered for a theoretical assessment to SSCP performance. A DES model using Arena version 12 was utilized for an empirical approach. Data was collected from both literature and by manual collection methods. Manual data was collected during the peak operating time of 6am-7am local time at the airport being modeled. The simulation model was verified and validated qualitatively and quantitatively by statistical …

Ultimate Compression After Impact Load Prediction In Graphite/Epoxy Coupons Using Neural Network And Multivariate Statistical Analyses, Alexandre David Grégoire

Doctoral Dissertations and Master's Theses

The goal of this research was to accurately predict the ultimate compressive load of impact damaged graphite/epoxy coupons using a Kohonen self-organizing map (SOM) neural network and multivariate statistical regression analysis (MSRA). An optimized use of these data treatment tools allowed the generation of a simple, physically understandable equation that predicts the ultimate failure load of an impacted damaged coupon based uniquely on the acoustic emissions it emits at low proof loads. Acoustic emission (AE) data were collected using two 150 kHz resonant transducers which detected and recorded the AE activity given off during compression to failure of thirty-four impacted …

Effects Of Online Training On Aircrew Monitoring Behaviors: A Field Study, Brian A. Potter

Doctoral Dissertations and Master's Theses

Data from aircraft accidents and line observation studies indicate that inadequate pilot monitoring is a growing safety concern. In the cockpit environment, pilots who fail to properly manage their workload commit more monitoring errors. Given the lack of training and educational programs available to pilots which emphasize improving their monitoring skills, more research is needed to assess the usefulness of types of training that can be used to improve pilots' monitoring. This research project sets out to determine if the potential exists to enhance pilots' monitoring skills through online training. For this study, 40 military helicopter pilots (participants) were divided …

Preliminary Design Of An Asteroid Hopping Mission, Michael D. Scheppa

Doctoral Dissertations and Master's Theses

In 2010, NASA announced that its new vision is to support private space launch operations. It is anticipated that this new direction will create the need for new and innovative ideas that push the current boundaries of space exploration and contain the promise of substantial gain, both in research and capital.

The purpose of the study is to plan and estimate the feasibility of a mission to visit a number of near Earth asteroids (NEAs). The mission would take place before the end of the 21st century, and would only use commercially available technology. Throughout the mission design process, while …