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2014

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Articles 11431 - 11460 of 12299

Full-Text Articles in Physical Sciences and Mathematics

An Investigation Of Rock Fall And Pore Water Pressure Using Lidar In Highway 63 Rock Cuts, Norbert H. Maerz Jan 2014

An Investigation Of Rock Fall And Pore Water Pressure Using Lidar In Highway 63 Rock Cuts, Norbert H. Maerz

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

No abstract provided.

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Experimental Study And Analysis Of A Polymer Fiber Bragg Grating Embedded In A Composite Material, Ginu Rajan, Manjusha Ramakrishnan, Yuliya Semenova, Eliathamby Ambikairajah, Gerald Farrell, Gang-Ding Peng Jan 2014

Experimental Study And Analysis Of A Polymer Fiber Bragg Grating Embedded In A Composite Material, Ginu Rajan, Manjusha Ramakrishnan, Yuliya Semenova, Eliathamby Ambikairajah, Gerald Farrell, Gang-Ding Peng

Articles

The characteristics of polymer fiber Bragg gratings (FBGs) embedded in composite materials are studied in this paper and are compared with characteristics of their silica counterparts. A polymer FBG of 10 mm length which exhibits a peak reflected wavelength circa 1530 nm is fabricated and characterized for this purpose. A silica FBG with a peak reflected wavelength circa 1553 nm is also embedded in the composite material for a comparison study. The fabricated composite material sample with embedded sensors is subjected to temperature and strain changes and the corresponding effects on the embedded polymer and silica FBGs are studied. The …

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Effects Of Salinity And Temperature On Bioelectrical Impedance Analysis Of Gulf Killifish, Fundulus Grandis, Shea A. Miller Jan 2014

Effects Of Salinity And Temperature On Bioelectrical Impedance Analysis Of Gulf Killifish, Fundulus Grandis, Shea A. Miller

LSU Master's Theses

Bioelectrical impedance analysis (BIA) has been proposed as an easy and accurate technique for a non-lethal index of condition in fish; however, factors affecting its accuracy have yet to be properly identified. The technique uses the resistance (R) and reactance (Xc) of water and lipids in contiguous tissues to estimate lipid content. Studies have investigated the use of BIA on fish, but with mixed results, possibly caused by unrecognized sources of influences. Our study explored possible sources of variance for BIA measurements in gulf killifish, Fundulus grandis, through laboratory feeding and fasting experiments, and experimental exposures to acute changes in …

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Assessment Of Habitat Quality For Red Snapper, Lutjanus Campechanus, In The Northwestern Gulf Of Mexico: Natural Vs. Artificial Reefs, Brittany Dawn Schwartzkopf Jan 2014

Assessment Of Habitat Quality For Red Snapper, Lutjanus Campechanus, In The Northwestern Gulf Of Mexico: Natural Vs. Artificial Reefs, Brittany Dawn Schwartzkopf

LSU Master's Theses

Habitat quality of natural and artificial reefs for red snapper (Lutjanus campechanus) in the northwestern Gulf of Mexico (Gulf) is important as this area is home to the majority of the Gulf’s artificial reef system, in the form of oil and gas platforms, in addition to the largest extent of high vertical relief natural habitat. This study sought to assess habitat quality of natural reefs of varying habitat complexity and an artificial reef complex located on the LA continental shelf. Habitat quality was assessed by comparing red snapper diets and foraging patterns, and nutritional condition using the liver-somatic index (LSI) …

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Effect Of Hydrologic, Geomorphic, And Vegetative Conditions On Avian Communities In The Middle Rio Grande Of New Mexico, Sarah G. Hamilton Jan 2014

Effect Of Hydrologic, Geomorphic, And Vegetative Conditions On Avian Communities In The Middle Rio Grande Of New Mexico, Sarah G. Hamilton

LSU Master's Theses

Anthropogenic regulation of the Middle Rio Grande (MRG) of New Mexico has altered the hydrogeomorphology of the system and led to a rapid decline in breeding riparian-obligate birds as native riparian forests are replaced by exotic tamarisk stands. In this study, I evaluated the relationships among hydrogeomorphology, vegetation structure and composition, and avian communities of the San Acacia Reach (SAR) of the MRG. I conducted avian point count surveys and collected habitat data to determine avian community structure and abundance, geomorphic feature, surface flooding, and vegetation structure and composition along 44 transects throughout the SAR. A total of 999 point …

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Fault Kinematics Along The Coastal Plain Of South Louisiana: Implications For Tectono-Climatic-Induced Deformation Along A Passive Continental Margin, Ali A. Al Dhamen Jan 2014

Fault Kinematics Along The Coastal Plain Of South Louisiana: Implications For Tectono-Climatic-Induced Deformation Along A Passive Continental Margin, Ali A. Al Dhamen

LSU Master's Theses

Kinematic analysis of faults along the northern coastal plain of the Gulf of Mexico shows a correlation between pulses of faulting during the late Cenozoic and changes in the tectonic and climatic settings acting on the source areas which provide sediments to the Gulf. Pulses of faulting during the Oligocene-Early Miocene, Late Miocene, Pliocene, and Pleistocene correlate to major tectonic and climatic changes in the source region of sediments. Slip rates of faulting increase with younger events. The increase in slip rates is likely related to a combination of increase in sedimentation rates and pre-weakened Oligocene –Miocene rock that resulted …

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Effect Of Predicting Motion On Student Understanding Of Kinematic Graphs, Charles William Redding Jan 2014

Effect Of Predicting Motion On Student Understanding Of Kinematic Graphs, Charles William Redding

LSU Master's Theses

Different interactive engagements strategies have given students more hands-on involvement in the classroom and helped increase conceptual learning in physics. The purpose of this study was to test the effect of predicting motion graphs by utilizing motion analysis software. Two groups of high school students followed a modified version of Sokoloff and Thornton’s seven step ILD process. One group was taught by making predictions. A second group was taught by watching demonstrations. To test for differences in the two groups understanding of kinematic graphs, pre and posttest where taken using the FMCE and Tug-K. The results of both the FMCE …

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Does Reproductive Potential Of Red Snapper In The Northern Gulf Of Mexico Differ Among Natural And Artificial Habitats?, Hilary Day Glenn Jan 2014

Does Reproductive Potential Of Red Snapper In The Northern Gulf Of Mexico Differ Among Natural And Artificial Habitats?, Hilary Day Glenn

LSU Master's Theses

This study compares the reproductive potential of red snapper (Lutjanus campechanus) at artificial and natural habitats. Natural habitats are areas of vertical relief created from biogenic/geologic processes that are thought to be the historical centers of abundance for red snapper in the northern Gulf of Mexico. Red snapper were collected from 2011 to 2013 at three natural habitat sites and two artificial habitat oil and gas platform sites. The mean gonadosomatic indices (GSI), maturity at size and age, spawning indicators, batch fecundity, spawning frequency, and annual fecundity for red snapper at each habitat were analyzed to examine reproductive potential among …

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Using Topology To Explore Mathematics Education Reform, Carling Sugarman Jan 2014

Using Topology To Explore Mathematics Education Reform, Carling Sugarman

HMC Senior Theses

Mathematics education is a constant topic of conversation in the United States. Many attempts have been made historically to reform teaching methods and improve student results. Particularly, past ideas have emphasized problem-solving to make math feel more applicable and enjoyable. Many have additionally tackled the widespread problem of “math anxiety” by creating lessons that are more discussion-based than drill-based to shift focus from speed and accuracy. In my project, I explored past reform goals and some added goals concerning students' perceptions of mathematics. To do so, I created and tested a pilot workshop in topology, a creative and intuitive field, …

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A New Subgroup Chain For The Finite Affine Group, David Alan Lingenbrink Jr. Jan 2014

A New Subgroup Chain For The Finite Affine Group, David Alan Lingenbrink Jr.

HMC Senior Theses

The finite affine group is a matrix group whose entries come from a finite field. A natural subgroup consists of those matrices whose entries all come from a subfield instead. In this paper, I will introduce intermediate sub- groups with entries from both the field and a subfield. I will also examine the representations of these intermediate subgroups as well as the branch- ing diagram for the resulting subgroup chain. This will allow us to create a fast Fourier transform for the group that uses asymptotically fewer opera- tions than the brute force algorithm.

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Experimental Realization Of Slowly Rotating Modes Of Light, Fangzhao A. An Jan 2014

Experimental Realization Of Slowly Rotating Modes Of Light, Fangzhao A. An

HMC Senior Theses

Beams of light can carry spin and orbital angular momentum. Spin angular momentum describes how the direction of the electric field rotates about the propagation axis, while orbital angular momentum describes the rotation of the field amplitude pattern. These concepts are well understood for monochromatic beams, but previous theoretical studies have constructed polychromatic superpositions where the connection between angular momentum and rotation of the electric field becomes much less clear. These states are superpositions of two states of light carrying opposite signs of angular momentum and slightly detuned frequencies. They rotate at the typically small detuning frequency and thus we …

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Arithmetical Graphs, Riemann-Roch Structure For Lattices, And The Frobenius Number Problem, Jeremy Usatine Jan 2014

Arithmetical Graphs, Riemann-Roch Structure For Lattices, And The Frobenius Number Problem, Jeremy Usatine

HMC Senior Theses

If R is a list of positive integers with greatest common denominator equal to 1, calculating the Frobenius number of R is in general NP-hard. Dino Lorenzini defines the arithmetical graph, which naturally arises in arithmetic geometry, and a notion of genus, the g-number, that in specific cases coincides with the Frobenius number of R. A result of Dino Lorenzini's gives a method for quickly calculating upper bounds for the g-number of arithmetical graphs. We discuss the arithmetic geometry related to arithmetical graphs and present an example of an arithmetical graph that arises in this context. We also discuss the …

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Characterizing Forced Communication In Networks, Samuel C. Gutekunst Jan 2014

Characterizing Forced Communication In Networks, Samuel C. Gutekunst

HMC Senior Theses

This thesis studies a problem that has been proposed as a novel way to disrupt communication networks: the load maximization problem. The load on a member of a network represents the amount of communication that the member is forced to be involved in. By maximizing the load on an important member of the network, we hope to increase that member's visibility and susceptibility to capture. In this thesis we characterize load as a combinatorial property of graphs and expose possible connections between load and spectral graph theory. We specifically describe the load and how it changes in several canonical classes …

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Reed's Conjecture And Cycle-Power Graphs, Alexa Serrato Jan 2014

Reed's Conjecture And Cycle-Power Graphs, Alexa Serrato

HMC Senior Theses

Reed's conjecture is a proposed upper bound for the chromatic number of a graph. Reed's conjecture has already been proven for several families of graphs. In this paper, I show how one of those families of graphs can be extended to include additional graphs and also show that Reed's conjecture holds for a family of graphs known as cycle-power graphs, and also for their complements.

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There And Back Again: Elliptic Curves, Modular Forms, And L-Functions, Allison F. Arnold-Roksandich Jan 2014

There And Back Again: Elliptic Curves, Modular Forms, And L-Functions, Allison F. Arnold-Roksandich

HMC Senior Theses

L-functions form a connection between elliptic curves and modular forms. The goals of this thesis will be to discuss this connection, and to see similar connections for arithmetic functions.

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Infinitely Many Rotationally Symmetric Solutions To A Class Of Semilinear Laplace-Beltrami Equations On The Unit Sphere, Emily M. Fischer Jan 2014

Infinitely Many Rotationally Symmetric Solutions To A Class Of Semilinear Laplace-Beltrami Equations On The Unit Sphere, Emily M. Fischer

HMC Senior Theses

I show that a class of semilinear Laplace-Beltrami equations has infinitely many solutions on the unit sphere which are symmetric with respect to rotations around some axis. This equation corresponds to a singular ordinary differential equation, which we solve using energy analysis. We obtain a Pohozaev-type identity to prove that the energy is continuously increasing with the initial condition and then use phase plane analysis to prove the existence of infinitely many solutions.

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A Mathematical Framework For Unmanned Aerial Vehicle Obstacle Avoidance, Sorathan Chaturapruek Jan 2014

A Mathematical Framework For Unmanned Aerial Vehicle Obstacle Avoidance, Sorathan Chaturapruek

HMC Senior Theses

The obstacle avoidance navigation problem for Unmanned Aerial Vehicles (UAVs) is a very challenging problem. It lies at the intersection of many fields such as probability, differential geometry, optimal control, and robotics. We build a mathematical framework to solve this problem for quadrotors using both a theoretical approach through a Hamiltonian system and a machine learning approach that learns from human sub-experts' multiple demonstrations in obstacle avoidance. Prior research on the machine learning approach uses an algorithm that does not incorporate geometry. We have developed tools to solve and test the obstacle avoidance problem through mathematics.

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Experiments On Surfactants And Thin Fluid Films, Peter Megson Jan 2014

Experiments On Surfactants And Thin Fluid Films, Peter Megson

HMC Senior Theses

We investigate the spatiotemporal dynamics of a surfactant monolayer on a thin fluid film spreading inward into a region devoid of surfactant, a system motivated by the alveolus of the human lung. We perform experiments that simultaneously measure the fluid height profile and the fluorescence intensity due to our fluorescent surfactant, NBD-PC. We perform experiments on both a Newtonian layer of glycerol and a shear-thinning fluid layer consisting of xanthan gum mixed with glycerol. We can very successfully extract height profiles on the xanthan gum fluid, although the simultaneous measurement of fluorescent intensity profiles proved problematic, as the laser tended …

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Cycle Lengths Of Θ-Biased Random Permutations, Tongjia Shi Jan 2014

Cycle Lengths Of Θ-Biased Random Permutations, Tongjia Shi

HMC Senior Theses

Consider a probability distribution on the permutations of n elements. If the probability of each permutation is proportional to θK, where K is the number of cycles in the permutation, then we say that the distribution generates a θ-biased random permutation. A random permutation is a special θ-biased random permutation with θ = 1. The mth moment of the rth longest cycle of a random permutation is Θ(nm), regardless of r and θ. The joint moments are derived, and it is shown that the longest cycles of a permutation can either be positively or …

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Energy-Driven Pattern Formation In Planar Dipole-Dipole Systems, Jaron P. Kent-Dobias Jan 2014

Energy-Driven Pattern Formation In Planar Dipole-Dipole Systems, Jaron P. Kent-Dobias

HMC Senior Theses

A variety of two-dimensional fluid systems, known as dipole-mediated systems, exhibit a dipole-dipole interaction between their fluid constituents. The com- petition of this repulsive dipolar force with the cohesive fluid forces cause these systems to form intricate and patterned structures in their boundaries. In this thesis, we show that the microscopic details of any such system are irrelevant in the macroscopic limit and contribute only to a constant offset in the system’s energy. A numeric model is developed, and some important stable domain morphologies are characterized. Previously unresolved bifurcating branches are explored. Finally, by applying a random energy background to …

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Energy Drinks And Caffeine: The Science Behind The Billion- Dollar Industry, Eric Villarreal Jan 2014

Energy Drinks And Caffeine: The Science Behind The Billion- Dollar Industry, Eric Villarreal

Honors Theses

Ask any college student how he or she gets through long study sessions, all-nighters, and the always grueling finals week and he or she will most likely reference some caffeine-containing beverage as the antidote, with energy drinks becoming an ever increasing option. The effects, both physiological and psychological, of the ingredients in energy drinks (caffeine and, to a lesser degree, glucose) dictate their usefulness to consumers. A review of the available research literature from http://scholar.google.com using the following keywords: caffeine, energy drink, Red Bull, caffeinated beverage, caffeine drink, energy drink industry, energy drink company, and glucose yielded the references that …

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Study Of The Low Energy Solar Neutrino Spectrometer (Lens) Concept With The Ulens Prototype, Liudmyla Afanasieva Jan 2014

Study Of The Low Energy Solar Neutrino Spectrometer (Lens) Concept With The Ulens Prototype, Liudmyla Afanasieva

LSU Master's Theses

Neutrinos are a useful tool that serves as an immediate probe of the Sun’s core providing insight into the details of the Sun’s energy production, internal composition and structure. Across the globe a number of solar neutrinos experiments have helped to clarify various characteristics of the solar neutrino spectrum. However, little experimental information is known regarding low-energy solar neutrinos, which comprise about 90% of the total solar neutrino spectrum. With this in mind, we are developing the Low Energy Solar Neutrino Spectrometer (LENS), an indium-based liquid scintillator detector with the capability to precisely measure the full spectrum of solar neutrinos, …

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Sediment Patterns In Relation To Vegetative Community Shifts At Catahoula Lake, Louisiana, Karen Doerr Latuso Jan 2014

Sediment Patterns In Relation To Vegetative Community Shifts At Catahoula Lake, Louisiana, Karen Doerr Latuso

LSU Master's Theses

The processes that control species composition and structure in wetland ecosystems are complex and controlled by many factors including seasonality, depth and duration of flooding, and nutrient dynamics. Catahoula Lake is a floodplain lake that has existed with seasonally fluctuating water levels for at least 4,000 years. The herbaceous vegetation that attracts these waterfowl is slowly being outcompeted by woody vegetation, most notably water-elm (Planera aquatica). Our general goal is to understand the processes that cause this shift, focusing on the role of sediments. Our first objective was to use historical aerial imagery to detect historical changes in plant communities …

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Legacy Phosphorus Implications In The Lake Pontchartrain Estuary Sediment Due To The 2011 Bonnet Carre Spillway Opening, Nhan Thanh Nguyen Jan 2014

Legacy Phosphorus Implications In The Lake Pontchartrain Estuary Sediment Due To The 2011 Bonnet Carre Spillway Opening, Nhan Thanh Nguyen

LSU Master's Theses

Phosphorus (P) is an essential nutrient for life and excess P in aquatic systems can trigger algal blooms. Nutrient-rich Mississippi River water is diverted into the Lake Pontchartrain estuary (LPE) periodically through the Bonnet Carré Spillway (BCS) to avoid downstream flooding to the city of New Orleans, Louisiana and can significantly increase the internal P load in the sediment. A sequential P fractionation procedure was performed on sediments collected before the opening and after the closing of the 2011 BCS operation to understand the role of these large river diversions on P dynamics. Before the 2011 BCS opening, 10,368 Mt …

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Oxygen Isotope Composition Of Phosphate Along Vertical Weathering Profiles That Developed On Igneous Rocks: Testing Modern Analogues For Identifying Terrestrial Life In Ancient Paleosols, Dustin Warn Boyd Jan 2014

Oxygen Isotope Composition Of Phosphate Along Vertical Weathering Profiles That Developed On Igneous Rocks: Testing Modern Analogues For Identifying Terrestrial Life In Ancient Paleosols, Dustin Warn Boyd

LSU Master's Theses

Life on Earth began in its early oceans before moving on to land. Determining the exact timing of an established biosphere on land, however, has been elusive, due largely to the lack of either fossil or chemical evidence on land deposits. Here I test a hypothesis that the activity of land biota can be recorded in the oxygen isotope composition of phosphate in weathering profiles developed on igneous parent rocks. Igneous rock contains phosphate (PO43-), which is readily utilized for biological activities during soil development. The oxygen in PO43- does not readily exchange its oxygen …

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A Toolkit For Tracking And Mediating Parametric Objects Upon Commodity Mobile Devices, Shantanu Thatte Jan 2014

A Toolkit For Tracking And Mediating Parametric Objects Upon Commodity Mobile Devices, Shantanu Thatte

LSU Master's Theses

The large number of mobile devices introduced in the market in recent years provide numerous interaction opportunities. We used commercially available products to create an interface for interaction with diverse datasets. We extended this scenario to include multiple physical instances, realizing a real-time multi-party interaction session. Tangibles act as tools and containers, in a fashion that requires their physical location and orientation to be evaluated continuously during a session. We present a technique to detect an object using only the touchscreen of a mobile device as an input, by means of touch patterns created on the screen. This helps avoid …

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Parallel Phase Modulation Scheme For Interferometric Gravitational-Wave Detectors, M. T. Hartman, V. Quetschke, D. B. Tanner, D. H. Reitze, G. Mueller Jan 2014

Parallel Phase Modulation Scheme For Interferometric Gravitational-Wave Detectors, M. T. Hartman, V. Quetschke, D. B. Tanner, D. H. Reitze, G. Mueller

Physics and Astronomy Faculty Publications and Presentations

Advanced LIGO (aLIGO) requires multiple frequency sidebands to disentangle all of the main interferometer's length signals. This paper presents the results of a risk reduction experiment to produce two sets of frequency sidebands in parallel, avoiding mixed 'sidebands on sidebands'. Two phase modulation frequencies are applied to separate Electro-Optic Modulators (EOMs), with one EOM in each of the two arms of a Mach-Zehnder interferometer. In this system the Mach-Zehnder's arm lengths are stabilized to reduce relative intensity noise in the recombined carrier beam by feeding a corrective control signal back to the Rubidium Titanyl Phosphate (RTP) EOM crystals to drive …

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Palynology Of The Upper Cretaceous Ferron-Notom Sandstone, Utah, Isil Akyuz Jan 2014

Palynology Of The Upper Cretaceous Ferron-Notom Sandstone, Utah, Isil Akyuz

LSU Master's Theses

ABSTRACT The Late Cretaceous Ferron-Notom Sandstone Member of the Mancos Shale Formation plays a dominant role in oil production in Utah. Although numerous sedimentological and sequence stratigraphic studies have been conducted in recent years on this sequence, palynological analyses had not yet been undertaken. Here we present palynological data from one hundred twenty eight samples collected in the Ferron-Noton Sandstone Member outcroping in south-central Utah. The purpose of this study is to refine our understanding of climatic and depositional environments and to build a biostratigraphic palynological framework. The dominance of terrestrial palynomorphs, especially the high yield in moisture-loving cryptogam spores …

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The Study Of The Degradation Rates Of The Hexabromocyclododecane Isomers With Polysulfides At 25 Oc And Ph 9 In 80% Water / 20% Methanol, John H. Wilson Jan 2014

The Study Of The Degradation Rates Of The Hexabromocyclododecane Isomers With Polysulfides At 25 Oc And Ph 9 In 80% Water / 20% Methanol, John H. Wilson

Dissertations and Theses

No abstract provided.

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Neuroevolution And An Application Of An Agent Based Model For Financial Market, Anil Yaman Jan 2014

Neuroevolution And An Application Of An Agent Based Model For Financial Market, Anil Yaman

Dissertations and Theses

Market prediction is one of the most difficult problems for the machine learning community. Even though, successful trading strategies can be found for the training data using various optimization methods, these strategies usually do not perform well on the test data as expected. Therefore, selection of the correct strategy becomes problematic. In this study, we propose an evolutionary algorithm that produces a variation of trader agents ensuring that the trading strategies they use are different. We discuss that because the selection of the correct strategy is difficult, a variety of agents can be used simultaneously in order to reduce risk. …

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