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Methodologies For Automated Microassembly, Mohammad A. Mayyas Dec 2007

Methodologies For Automated Microassembly, Mohammad A. Mayyas

Mechanical and Aerospace Engineering Dissertations - Archive

The development of micromachining technologies has provided wide applications in micro sensing and actuation. However, most of the demonstrated devices are selectively constructed by fabrication processes that are limited to complexity, configuration, dimension, and material variation. The monolithic fabrication has limitations and does not allow the inclusion of multiple components of incompatible processes. Therefore, the construction of 3D microstructures by heterogeneous microassembly is an alternate manufacturing route. In deterministic, monitored or controlled microassembly there has been considerable research in developing, analyzing and applying distributed algorithms for sensor and sensorless based assembly processes. Meso-scale teleoperated work-cells supported by Nano manipulators have …


Improved Covariance Model Parameter Estimation Using Rna Thermodynamic Properties, Jennifer A. Smith, Kay C. Wiese Dec 2007

Improved Covariance Model Parameter Estimation Using Rna Thermodynamic Properties, Jennifer A. Smith, Kay C. Wiese

Electrical and Computer Engineering Faculty Publications and Presentations

Covariance models are a powerful description of non-coding RNA (ncRNA) families that can be used to search nucleotide databases for new members of these ncRNA families. Currently, estimation of the parameters of a covariance model (state transition and emission scores) is based only on the observed frequencies of mutations, insertions, and deletions in known ncRNA sequences. For families with very few known members, this can result in rather uninformative models where the consensus sequence has a good score and most deviations from consensus have a fairly uniform poor score. It is proposed here to combine the traditional observed-frequency information with …


Surface Modification Of Microfluidic Devices, P Kumlangdudsana, S T. Dubas, L Dubas Dec 2007

Surface Modification Of Microfluidic Devices, P Kumlangdudsana, S T. Dubas, L Dubas

Journal of Metals, Materials and Minerals

Microfluidic is a multidisciplinary which encompasses the fields of physics, chemistry, nanotechnology, engineering, and biotechnology. It has been developed extensively for many applications such as handling biological entities such as DNA separation, immunoassay, cell sorting, biosensors, and enzymatic assays due to the potential offered by miniaturizing, high throughput of analysis, low cost of fabrication, multiplex functionality and portability. The surface modification of microfluidic devices has also been a major focus in research to help to enhance their efficiency. There is a variety of surface modification methods and in this paper we reviews and presents an overview of the surface modification …


Creating Micro- And Nanostructures On Tubular And Spherical Surfaces, O. Lima, L. Tan, A. Goel, Lmehrdad Negahban, Z. Li Dec 2007

Creating Micro- And Nanostructures On Tubular And Spherical Surfaces, O. Lima, L. Tan, A. Goel, Lmehrdad Negahban, Z. Li

Nebraska Center for Materials and Nanoscience: Faculty Publications

The authors developed a new technique to create micro- and nanometer scale structures on curved free-standing objects by combining embossing/imprinting lithography approaches with mechanical loadings on elastic films. Embossing/imprinting generates small structures and mechanical loading determines shape or geometry of the final object. As a result, a portion of the tubes with a radius between 0.5 and 3.5 mm and a portion of the spheres with a radius between 2.4 and 7.0 mm were fabricated with grating line features (period of 700 nm) and microlens array features (lens radius of 2.5 µm) atop, respectively. It was found that both static …


A Coupled Fluid-Structure Model Of A Therapeutic Ultrasound Angioplasty Wire Waveguide, Graham Gavin, Finbar Dolan, M.S. Hashmi, Garrett Mcguinness Dec 2007

A Coupled Fluid-Structure Model Of A Therapeutic Ultrasound Angioplasty Wire Waveguide, Graham Gavin, Finbar Dolan, M.S. Hashmi, Garrett Mcguinness

Articles

Ultrasonic longitudinal displacements, delivered to the distal tips of small diameter wire waveguides, have been shown to be capable of disrupting complicated atherosclerotic plaques during vascular interventions. These ultrasonic displacements can disrupt plaques by direct contact ablation but also by pressure waves, associated cavitation and acoustic streaming developed in the surrounding blood and tissue cavities. The pressure waves developed within the arterial lumen appear to play a major role but are complex to predict as they are determined by the distal tip output of the wire waveguide (both displacement and frequency), the geometric features of the waveguide tip and the …


A Closed Form Solution For Multiple-Input Spike Based Adaptive Filters, Il Park, António R.C. Paiva, José C. Príncipe, John G. Harris Dec 2007

A Closed Form Solution For Multiple-Input Spike Based Adaptive Filters, Il Park, António R.C. Paiva, José C. Príncipe, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

Neurons are point process systems, in the sense that the inputs and output which are spike trains can be treated as point processes. System identification of a point process system has been studied mostly with single input. However, multiple input is required in many applications such as liquid state machines or neural prosthetics. We propose a simple multiple-input spike based adaptive filter which is based on an integrate-and-fire neuron model. The optimal closed solution is derived, and the performance is analyzed with respect to noise in various parameters and measurement. ©2007 IEEE.


An Estimation Of Distribution Improved Particle Swarm Optimization Algorithm, Raghavendra V. Kulkarni, Ganesh K. Venayagamoorthy Dec 2007

An Estimation Of Distribution Improved Particle Swarm Optimization Algorithm, Raghavendra V. Kulkarni, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

PSO is a powerful evolutionary algorithm used for finding global solution to a multidimensional problem. Particles in PSO tend to re-explore already visited bad solution regions of search space because they do not learn as a whole. This is avoided by restricting particles into promising regions through probabilistic modeling of the archive of best solutions. This paper presents hybrids of estimation of distribution algorithm and two PSO variants. These algorithms are tested on benchmark functions having high dimensionalities. Results indicate that the methods strengthen the global optimization abilities of PSO and therefore, serve as attractive choices to determine solutions to …


Using Science, Engineering, And Education To Address Water Supply Challenges In The Highlands Of Guatemala, Andrew Curtis Elmore, William Fahrenholtz Dec 2007

Using Science, Engineering, And Education To Address Water Supply Challenges In The Highlands Of Guatemala, Andrew Curtis Elmore, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

The Guatemalan Highlands is a Popular Destination for Non-Government Organizations Interested in Performing Relief Projects. U.S.-Based Organizations Such as Rotary International, Engineers Without Borders, and Various Religious Organizations Travel to Guatemala to Conduct Humanitarian Activities Which May Be Effective for the Short Term, But It is Not Clear that the Efforts Have a Systematic Impact. Students and Faculty at the University of Missouri-Rolla Have Systematically Studied Water Supply Issues Including Undergraduate and Graduate Research Projects and Undergraduate Engineering Courses Such as International Capstone Design. Materials Engineers Have Been Involved in the Study of Ceramic-Based Water Treatment Devices. These Microfilters Have …


Design Of An Active Orthotic Device For Joint Management., Steven Clayton Anderson Dec 2007

Design Of An Active Orthotic Device For Joint Management., Steven Clayton Anderson

Electronic Theses and Dissertations

Existing treatment programs and procedures are incapable of addressing the complications encountered with patients who experience spasticity and hypertonia related joint contractures. Current passive therapy procedures and devices are only capable of managing the extent of joint contractures on patients with chronic and acute onset severe neurological disorders. The project was conceived as a means to develop an active device that is capable of adapting to the state of the joint to mange the extent of contractures and to permit consideration for the prevalence of spastic activity episodes and hypertonia. The project focused on the design of the physical prototype …


The Tri-Frame Model, Elsje Pienaar, Hendrik J. Viljoen Dec 2007

The Tri-Frame Model, Elsje Pienaar, Hendrik J. Viljoen

Hendrik J. Viljoen Publications

The tri-frame model gives mathematical expression to the transcription and translation processes, and considers all three reading frames. RNA polymerases transcribe DNA in single nucleotide increments, but ribosomes translate mRNA in pairings of three (triplets or codons). The set of triplets in the mRNA, starting with the initiation codon (usually AUG) defines the open reading frame (ORF). Since ribosomes do not always translocate three nucleotide positions, two additional reading frames are accessible. The -1RF and the +1RF are triplet pairings of the mRNA which are accessed by shifting one nucleotide position in the 5’ and 3’ directions respectively. Transcription is …


Conversion Of Biomass Resource To Useful Forms Of Energy And Other Products, Latosha Johnson Dec 2007

Conversion Of Biomass Resource To Useful Forms Of Energy And Other Products, Latosha Johnson

Chemical Engineering Undergraduate Honors Theses

The United States is facing increasing pressure to find renewable energy sources due to rising energy costs. With world energy demand at an all time high, renewable energy has been thrust into the forefront of research as a means to mitigate this looming crisis. Throughout the United States, there is a large quantity of agricultural biomass that could be used to generate energy and lessen the dependence on diminishing resources. Specifically, animal feeding operations (AFOs) such as dairies generate large amounts of cow manure, which, when improperly handled, causes both air and water pollution. Currently, most manure is temporarily stockpiled …


Biohydrogen Production By The Hyperthermophilic Bacterium Thermotoga Neapolitana, Xiaohui Yu Dec 2007

Biohydrogen Production By The Hyperthermophilic Bacterium Thermotoga Neapolitana, Xiaohui Yu

All Dissertations

ABSTRACT Thermotoga neapolitana can use different sources of carbon and nitrogen for growth and produces biological hydrogen. Sources of carbon (glucose, sucrose, xylose, xylan, cellulose, cellobiose, starch, corn starch, beet bulp pellet, and rice flour) and nitrogen (yeast extract, fish meal, cottonseed meal, canola meal, linseed meal, and soybean meal) were compared. In the carbon studies, glucose, sucrose, rice flour, and xylan produced similar levels of hydrogen. In the nitrogen studies, Trypticase combined with alternative nitrogen sources can efficiently increases the yield of hydrogen produced by Thermotoga neapolitana. Yeast extract with trypticase as the dual nitrogen sources produced significantly increased …


Vulnerability Of Shallow Aquifers Of The Conterminous United States To Nitrate: Assessment Of Methodologies, Karthik Kumarasamy Dec 2007

Vulnerability Of Shallow Aquifers Of The Conterminous United States To Nitrate: Assessment Of Methodologies, Karthik Kumarasamy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Groundwater is an important natural resource for numerous human activities, accounting for more than 50% of the total water used in the United States. Groundwater is vulnerable to contamination by several organic and inorganic pollutants such as nitrate, heavy metals, and pesticides. Assessment of groundwater vulnerability aids in the management and protection of limited groundwater resources.

The focus of this thesis is to (1) statistically compare two groundwater vulnerability assessment models; modified DRASTIC (Acronym for Depth to water, net Recharge, Aquifer media, Soil media, Topography, Impact of vadose zone, and hydraulic Conductivity of aquifer) and ordinal logistic regression for NO …


Moment Analysis Of Near-Equilibrium Binding Interactions During Electrophoresis, Yousef Daneshbod, James D. Sterling, Ali Nadim Nov 2007

Moment Analysis Of Near-Equilibrium Binding Interactions During Electrophoresis, Yousef Daneshbod, James D. Sterling, Ali Nadim

Business and Information Technology Faculty Research & Creative Works

The electrophoretic transport of three chemically reacting species, two of which can bind reversibly to form the third, is analyzed mathematically. The species are assumed to move horizontally through a long channel with different electrophoretic mobilities and diffusion coefficients. By considering small perturbations of the system about equilibrium or when one of the two binding species is much more abundant than the other, the governing advection-reaction- diffusion equations can be linearized and studied via the method of moments. The result is a set of coupled ordinary differential equations for the moments that can be solved analytically. Analysis of the long-time …


2007 Fall Engr333/Biol354 Project Footprint Poster, 2007 Fall Engr333, 2007 Fall Biol354 Nov 2007

2007 Fall Engr333/Biol354 Project Footprint Poster, 2007 Fall Engr333, 2007 Fall Biol354

ENGR 333

The students of Calvin College’s Engineering 333 and Biology 354 classes were given the task of determining “What would it take to make Calvin College Carbon Neutral?” At first glance, it would not appear that classes on Advanced Thermal System Design and Investigations in Plant Ecology would have much in common. However, the biology and engineering students comprising these classes banded together to tackle the problem. Coming to a satisfactory conclusion would require: Creating an inventory of Green House Gas (GHG) emissions and sequestration potential Coming up with detailed solutions to achieve Carbon Neutrality Working out a practical schedule to …


Modeling Streambed Heating In Shallow Streams, Robert Leslie Annear Jr. Nov 2007

Modeling Streambed Heating In Shallow Streams, Robert Leslie Annear Jr.

Dissertations and Theses

The Oregon Department of Environmental Quality is developing Total Maximum Daily Loads to address water quality concerns and threatened and endangered species habitat requirements. Approximately 940 water body segments are listed as water quality limited for temperature in Oregon. CE-QUAL-W2 Version 3 is a two-dimensional water quality and hydrodynamic model capable of modeling rivers, reservoirs and estuaries. An important aspect of modeling stream temperature is handling the short-wave solar radiation that penetrates the water surface and impacts the streambed, which can affect water temperatures under low-flow conditions. The Bull Run River-Reservoir system is a 264 km2 watershed 42 km east …


Ion-Implanting Modification Of Layered Manganese Dioxide And Its Electrochemical Performance, He-Ning Huang, Dong-Ping Lv, Xing-Kang Huang, Qi-Wei Zhang, Yong Yang Nov 2007

Ion-Implanting Modification Of Layered Manganese Dioxide And Its Electrochemical Performance, He-Ning Huang, Dong-Ping Lv, Xing-Kang Huang, Qi-Wei Zhang, Yong Yang

Journal of Electrochemistry

Layered MnO2(δ-MnO2) was prepared by thermal decomposition of potassium permanganate.Ti was ion-implanted into such δ-MnO2 by physical techniques,forming a composite(δ-MnO2-Ti).These materials were characterized by XRD,SEM,XPS techniques and their electrochemical proprieties were investigated.The results showed that the layered structure of δ-MnO2 did not been destroyed after Ti ion implantation,and the implanted Ti element was mainly Ti4+ as indicated by XPS.Both of the first and the highest discharge specific capacities of the ion-implanted layered MnO2(δ-MnO2-Ti),compared to those of δ-MnO2,were improved significantly.


Electrochemical Behavior And Determination Of Luteolin At A Glassy Carbon Electrode, Ai-Lin Liu, Shao-Bo Zhang, Xiao-Sha Wu, Li-Ping Li, Yang-Yuan Cao, Li-Ying Huang, Xin-Hua Lin Nov 2007

Electrochemical Behavior And Determination Of Luteolin At A Glassy Carbon Electrode, Ai-Lin Liu, Shao-Bo Zhang, Xiao-Sha Wu, Li-Ping Li, Yang-Yuan Cao, Li-Ying Huang, Xin-Hua Lin

Journal of Electrochemistry

The electrochemical behavior of luteolin was studied by voltammetry at a glassy carbon electrode in phosphate buffer solution.The results exhibited that the well-defined redox peak of luteolin is observed and the electrode process is adsorption-controlled.The charge transfer coefficient(α) was calculated as 0.66 in phosphate buffer solution(pH 4.0).The relationships between oxidation peak current and the concentration of luteolin are linear in the range of 1.0×10-8 ~ 5.0×10-6 mol·L-1 by differential pulse voltammetric method.The detection limit had been estimated as 1.0×10-8 molL-1.This method can be used for the determination of luteolin with satisfactory results.


Digitally Controlled Zvs Quasi-Resonant Boost Converter With M-Type Switch, Taufik, Patrick Luther, Makbul Anwari Nov 2007

Digitally Controlled Zvs Quasi-Resonant Boost Converter With M-Type Switch, Taufik, Patrick Luther, Makbul Anwari

Electrical Engineering

This paper presents the analysis, modeling and design of zero-voltage-switching (ZVS) quasi resonant boost converter. The use of M-type switch in the topology will be described, including circuitpsilas mode of operation along with the derivations of critical voltage and current equations in each mode. Computer simulation using OrCAD Pspice and hardware development for the resonant converter with digital control will be presented. Results from both simulation and laboratory measurements to compare with theoretical analysis will be discussed.


Mechanical Behavior And Failure Analysis Of Prosthetic Retaining Screws After Long‐Term Use In Vivo. Part 1: Characterization Of Adhesive Wear And Structure Of Retaining Screws, Youssef S. Al Jabbari, Raymond Fournelle, Gerald J. Ziebert, Jeffrey M. Toth, Anthony Iacopino Nov 2007

Mechanical Behavior And Failure Analysis Of Prosthetic Retaining Screws After Long‐Term Use In Vivo. Part 1: Characterization Of Adhesive Wear And Structure Of Retaining Screws, Youssef S. Al Jabbari, Raymond Fournelle, Gerald J. Ziebert, Jeffrey M. Toth, Anthony Iacopino

Biomedical Engineering Faculty Research and Publications

Purpose: The general aim of this study and those presented in Parts 2–4 of this series was to characterize the structure, properties, wear, and fracture of prosthetic retaining screws in fixed detachable hybrid prostheses after long‐term use in vivo. This part of the overall investigation addresses whether there are differences in thread wear between the screws closest to the fulcrum and those that are farthest from the fulcrum in fixed detachable hybrid prostheses.

Materials and Methods: The total number of prosthetic retaining screws used in this study was 100 (10 new and 90 used). New screws (controls) from Nobel Biocare …


Undergraduate Research: Experiences From A Three-Year Project, Peter Schuster, Charles Birdsong Nov 2007

Undergraduate Research: Experiences From A Three-Year Project, Peter Schuster, Charles Birdsong

Mechanical Engineering

There are significant benefits of research for the involved undergraduate student. These include exposure to advanced topics, introduction to research methods, and direct interaction with faculty and other students. Faculty and institutions benefit as well by the increased interaction with students – fresh eyes in research projects, more energized research groups, and more engaged alumni. However, there are some challenges in designing a research program to work primarily with undergraduates. These include the students’ lack of exposure to advanced topics, short tenure on the project, and potentially lower commitment to the results. There are a number of ways to address …


A Nondestructive Technique For Determining Complex Permittivity And Permeability Of Magnetic Sheet Materials Using Two Flanged Rectangular Waveguides, Milo W. Hyde Iv, Michael J. Havrilla Nov 2007

A Nondestructive Technique For Determining Complex Permittivity And Permeability Of Magnetic Sheet Materials Using Two Flanged Rectangular Waveguides, Milo W. Hyde Iv, Michael J. Havrilla

Faculty Publications

In this paper, a nondestructive technique for determining the complex permittivity and permeability of magnetic sheet materials using two flanged rectangular waveguides is presented. The technique extends existing single probe methods by its ability to simultaneously measure reflection and transmission coefficients imperative for extracting both permittivity and permeability over all frequencies. Using Love’s Equivalence Principle, a system of coupled magnetic field integral equations (MFIEs) is formed. Evaluation of one of the two resulting spectral domain integrals via complex plane integration is discussed. The system, solved via the Method of Moments (MoM),yields theoretical values for the reflection and transmission coefficients. These …


Effects Of Climate Change On Aquatic Invasive Species And Implications For Management And Research (Powerpoint Presentation), Britta Bierwagen, Roxanne Thomas, Kathryn Mengerink, Austin Kane Nov 2007

Effects Of Climate Change On Aquatic Invasive Species And Implications For Management And Research (Powerpoint Presentation), Britta Bierwagen, Roxanne Thomas, Kathryn Mengerink, Austin Kane

United States Environmental Protection Agency: Publications

Contents:
Five Key Lessons from Report
Climate Change Effects on Aquatic Ecosystems
Climate Change Effects on Aquatic Invasive Species may…
Other stressors may…
Why focus on AIS?
This Report Includes
Report Process
Climate Change & Invasion Pathway
Climate Change & Interacting Stressors
AIS Management Activities
State Managers’ Reported Concerns
Capacity to Adapt to Climate Change
Accounting for Changing Conditions
Information & Research Needs
Research Recommendations
Possible Next Steps
On-going Activities


Are There Rearrangement Hotspots In The Human Genome?, Max A. Alekseyev, Pavel A. Pevzner Nov 2007

Are There Rearrangement Hotspots In The Human Genome?, Max A. Alekseyev, Pavel A. Pevzner

Faculty Publications

In a landmark paper, Nadeau and Taylor [18] formulated the random breakage model (RBM) of chromosome evolution that postulates that there are no rearrangement hotspots in the human genome. In the next two decades, numerous studies with progressively increasing levels of resolution made RBM the de facto theory of chromosome evolution. Despite the fact that RBM had prophetic prediction power, it was recently refuted by Pevzner and Tesler [4], who introduced the fragile breakage model (FBM), postulating that the human genome is a mosaic of solid regions (with low propensity for rearrangements) and fragile regions (rearrangement hotspots). However, the rebuttal …


Transfected Cell Arrays For The High-Throughput Analysis Of Transcription Factor Activity, Abigail D. Bellis, Angela K. Pannier, Lonnie D Shea Nov 2007

Transfected Cell Arrays For The High-Throughput Analysis Of Transcription Factor Activity, Abigail D. Bellis, Angela K. Pannier, Lonnie D Shea

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Transfected cell arrays offer a high-throughput method that allows for the parallel analysis of multiple pathways or genes within a physiological context. We have developed a transfected cell array that employs a dual-plasmid system that gives the ability to normalize for spot-to-spot variation in transfection efficiency. Each spot within the array contains a constitutively active normalization plasmid encoding for renilla luciferase as well as a functional plasmid that contains transcription factor specific binding elements driving the expression of firefly luciferase. Dual bioluminescent imaging provides highly sensitive analysis while limiting post-transfectional processing. Adequate transfection poses a significant challenge in extending this …


Method Of Introducing A Plurality Of Genes Into Plants, Vincent Lee C. Chiang, Laigeng Li Oct 2007

Method Of Introducing A Plurality Of Genes Into Plants, Vincent Lee C. Chiang, Laigeng Li

Michigan Tech Patents

A method of concurrently introducing multiple genes to plants and trees is provided. The method includes an Agrobacterium-mediated gene delivery system by which multiple genes together with a single selectable marker gene are simultaneously transferred and inserted into the genome of plants, including trees.


Genetic Engineering Of Syringyl-Enriched Lignin In Plants, Vincent Lee C. Chiang, Laigeng Li Oct 2007

Genetic Engineering Of Syringyl-Enriched Lignin In Plants, Vincent Lee C. Chiang, Laigeng Li

Michigan Tech Patents

The present invention relates to a novel DNA sequence, which encodes a previously unidentified lignin biosynthetic pathway enzyme, sinapyl alcohol dehydrogenase (SAD) that regulates the biosynthesis of syringyl lignin in plants. Also provided are methods for incorporating this novel SAD gene sequence or substantially similar sequences into a plant genome for genetic engineering of syringyl-enriched lignin in plants.


Use Of Ellipsometry And Surface Plasmon Resonance In Monitoring Thin Film Deposition Or Removal From A Substrate Surface, John A. Woollam, Blaine D. Johs, Thomas E. Tiwald, Martin M. Liphardt, James D. Welch Oct 2007

Use Of Ellipsometry And Surface Plasmon Resonance In Monitoring Thin Film Deposition Or Removal From A Substrate Surface, John A. Woollam, Blaine D. Johs, Thomas E. Tiwald, Martin M. Liphardt, James D. Welch

Department of Electrical and Computer Engineering: Faculty Publications

Improved methodology for monitoring deposition or removal of material to or from a process and/or Wittness substrate Which demonstrates a negative e1 at some Wave length. The method involves detection of changes in P-polarized electromagnetism ellipsometric DELTA at SPR Resonance Angle-of-lncidence (A01) to monitor deposition of and/or removal of minute amounts of materials onto, or from, said process and/or Witness substrate. The methodology can optionally monitor ellipsometric PS1, and involves simultaneously or sequentially applying non-P-polarized electromagnetism at the same angle of incidence, or electromagnetic radiation of any polarization at a different angle-of-incidence and Wavelength to the process or Witt ness …


Integrated Piezoresistive Sensing For Feedback Control Of Compliant Mems, Robert K. Messenger Oct 2007

Integrated Piezoresistive Sensing For Feedback Control Of Compliant Mems, Robert K. Messenger

Theses and Dissertations

Feedback control of MEMS devices has the potential to significantly improve device performance and reliability. One of the main obstacles to its broader use is the small number of on-chip sensing options available to MEMS designers. A method of using integrated piezoresistive sensing is proposed and demonstrated as another option. Integrated piezoresistive sensing utilizes the inherent piezoresistive property of polycrystalline silicon from which many MEMS devices are fabricated. As compliant MEMS structures flex to perform their functions, their resistance changes. That resistance change can be used to transduce the structures' deflection into an electrical signal. This dissertation addresses three topics …


Aggregation In Biological Systems: Computational Aspects, Vladik Kreinovich, Max Shpak Oct 2007

Aggregation In Biological Systems: Computational Aspects, Vladik Kreinovich, Max Shpak

Departmental Technical Reports (CS)

Many biologically relevant dynamical systems are aggregable, in the sense that one can divide their (micro) variables x1,...,xn into several (k) non-intersecting groups and find functions y1,...,yk (k < n) from these groups (macrovariables) whose dynamics only depend on the initial state of the macrovariable. For example, the state of a population genetic system can be described by listing the frequencies xi of different genotypes, so that the corresponding dynamical system describe the effects of mutation, recombination, and natural selection. The goal of aggregation approaches in population genetics is to find macrovariables y1,...,yk to which aggregated mutation, recombination, and selection functions could be applied. Population genetic models are formally equivalent to genetic algorithms, and are therefore of wide interest in the computational sciences.

Another example of a multi-variable biological system of interest arises in ecology. Ecosystems contain many interacting species, and because of the complexity of multi-variable nonlinear systems, it would be of value to derive a formal description that reduces the number of variables to some macrostates that are weighted sums of the densities of individual species.

In this chapter, we explore different computational aspects of aggregability for linear and non-linear systems. Specifically, we …