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Title: Advances in oscillometric blood pressure measurement
Creator: Chandrasekhar, Anand
Date: 2019
Collection: Electronic Theses & Dissertations
Description: High blood pressure (BP) is a major cardiovascular risk factor that is treatable, yet hypertensionawareness and control rates are low. Ubiquitous BP monitoring technology could improve hypertensionmanagement, but existing devices require an inflatable cuff and are not compatible withsuch anytime, anywhere measurement of BP. Oscillometry is the blood pressure (BP) measurementprinciple of most automatic cuff devices. We extended the oscillometric principle, which is usedby most automatic cuff...
Show moreHigh blood pressure (BP) is a major cardiovascular risk factor that is treatable, yet hypertensionawareness and control rates are low. Ubiquitous BP monitoring technology could improve hypertensionmanagement, but existing devices require an inflatable cuff and are not compatible withsuch anytime, anywhere measurement of BP. Oscillometry is the blood pressure (BP) measurementprinciple of most automatic cuff devices. We extended the oscillometric principle, which is usedby most automatic cuff devices, to develop a couple of instruments to measure cuff-less BP usinga smartphone-based device and standalone iPhone application. As the user presses her/his fingeragainst the smartphone, the external pressure of the underlying artery is steadily increased while thephone measures the applied pressure and resulting variable amplitude blood volume oscillations.A smartphone application provides visual feedback to guide the amount of pressure applied overtime via the finger pressing and computes systolic and diastolic BP from the measurements.We prospectively tested the smartphone-based device for real-time BP monitoring in humansubjects to evaluate usability (n = 30) and accuracy against a standard automatic cuff-based device(n = 32). We likewise tested a finger cuff device, which uses the volume-clamp method of BPdetection. About 90% of the users learned the finger actuation required by the smartphone-baseddevice after one or two practice trials. The device yielded bias and precision errors of 3.3 and 8.8mmHg for systolic BP and [Special character(s) omitted]5:6 and 7:7 mmHg for diastolic BP over a 40 to 50 mmHg range of BP.These errors were comparable to the finger cuff device. Cuff-less and calibration-free monitoringof systolic and diastolic BP may be feasible via a smartphone. In addition, we tested the iPhoneapplication. The application yielded bias and precision errors of -4.0 and 11.4 mmHg for systolicBP and -9.4 and 9.7 mmHg for diastolic BP (n = 18). These errors were near the finger cuff deviceerrors. This proof-of-concept study surprisingly indicates that cuff-less and calibration-free BPmonitoring may be feasible with many existing and forthcoming smartphones.These devices use empirical algorithms, already descried in the literature, to estimate bloodpressure. Hence, the next objective was to establish formulas to explain three popular empiricalalgorithms- the maximum amplitude, derivative, and fixed ratio algorithms. A mathematicalmodel of the oscillogram was developed and analyzed to derive parametric formulas for explainingeach algorithm. Exemplary parameter values were obtained by fitting the model to measuredoscillograms. The model and formulas were validated by showing that their predictions correspondto measurements. The formula for the maximum amplitude algorithm indicates that it yields aweighted average of systolic and diastolic BP (0.45 and 0.55 weighting) instead of commonlyassumed mean BP. The formulas for the derivative algorithm indicate that it can accurately estimatesystolic and diastolic BP (<1.5 mmHg error), if oscillogram measurement noise can be obviated.The formulas for the fixed ratio algorithm indicate that it can yield inaccurate BP estimates, becausethe ratios change substantially (over a 0.5-0.6 range) with arterial compliance and pulse pressureand error in the assumed ratio translates to BP error via large amplification (>40). The establishedformulas allow for easy and complete interpretation of perhaps the three most popular oscillometricBP estimation algorithms in the literature while providing new insights. The model and formulasmay also be of some value towards improving the accuracy of automatic cuff BP measurementdevices.
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Title: Integration of planning, design, and construction to train 21st century urban professionals
Creator: Dalton, Robert
Date: 2016
Collection: Electronic Theses & Dissertations
Description: The built environment professions are struggling as budgets decrease and scope and importance increase. Attempting to save money, clients are turning to multidisciplinary offices for all-in-one service. Higher education can respond to these shifting trends by preparing the students for a growth mindset and openness to the ideas constructed by a team rather than an individual. Integrative learning may foster such minds. Integrative learning concerns the building of cognitive connections from...
Show moreThe built environment professions are struggling as budgets decrease and scope and importance increase. Attempting to save money, clients are turning to multidisciplinary offices for all-in-one service. Higher education can respond to these shifting trends by preparing the students for a growth mindset and openness to the ideas constructed by a team rather than an individual. Integrative learning may foster such minds. Integrative learning concerns the building of cognitive connections from one skill or piece of knowledge to the next. This study found cultural areas shared among professions as well as those distinct to one profession. These cultural attributes group into four categories: axiology, epistemology, methodology, and ontology. All professions rate learning (epistemology) the required skills best while they work in offices, rather than their time in higher education. Methodologies include the tasks accomplished to plan, design, and build a project and the tools used to do so. Each profession brings their own contributions to problem solving and uses varied software to accomplish their means. These contributions are highly related to the corresponding values (axiology), though mean ratings indicate a high value for a task even if it is not one’s own. The study concludes by assessing the products (ontology) that may be created by the professions most likely to work together. The teams coming together most often represent the professions of the exterior spaces, building and interior spaces, and the legal and real estate professions. Employers and educators alike may use this information to understand the differences among the professional cultures and how bridging these divides or allowing gaps to remain can impact the project delivery.
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Title: Enhancing item pool utilization when designing multistage computerized adaptive tests
Creator: Yang, Lihong
Date: 2016
Collection: Electronic Theses & Dissertations
Description: In recent years, the multistage adaptive test (MST) has gained increasing popularity in the field of educational measurement and operational testing. MST refers to a test in which pre-constructed sets of items are administered adaptively and are scored as a unit (Hendrickson, 2007). As a special case of Computerized Adaptive Testing (CAT), a MST program needs the following components: an item response theory (IRT) model or non-IRT-based alternatives; an item pool design; module assembly;...
Show moreIn recent years, the multistage adaptive test (MST) has gained increasing popularity in the field of educational measurement and operational testing. MST refers to a test in which pre-constructed sets of items are administered adaptively and are scored as a unit (Hendrickson, 2007). As a special case of Computerized Adaptive Testing (CAT), a MST program needs the following components: an item response theory (IRT) model or non-IRT-based alternatives; an item pool design; module assembly; ability estimation; routing algorithm; and scoring (Yan et al., 2014). A significant amount of research has been conducted on components like module assembly, ability estimation, routing and scoring, but few studies have addressed the component of item pool design. An item pool is defined as consisting of a maximal number of combinations of items that meet all content specifications for a test and provide sufficient item information for estimation at a series of ability levels (van der Linden et al., 2006). An item pool design is very important because any successful MST assembly is inseparable from an optimal item pool that provides sufficient and high-quality items (Luecht & Nungester, 1998). Reckase (2003, 2010) developed the p-optimality method to design optimal item pools using the unidimensional Rasch model in CAT, and it has been proved to be efficient for different item types and IRT models. The present study extended this method to MST context in supporting and developing different MST panel designs under different test configurations. The study compared the performance of the MST assembled under the most popularly studied panel designs in the literature, such as 1-2, 1-3, 1-2-2, and 1-2-3. A combination of short, medium and long tests with different routing test proportions were used to build up different tests. Using one of the most popularly investigated IRT models, the Rasch model, simulated optimal item pools were generated with and without practical constraints of exposure control. A total number of 72 optimal items pools were generated and the measurement accuracy was evaluated by an overall sample and conditional sample using various statistical measures. The p-optimality method was also applied in an operational MST licensure test to see if it is feasible in supporting test assembly and achieving sufficient measurement accuracy in practice. Results showed that the different MST panel designs achieved sufficient measurement accuracy by using the items from the optimal item pools built with the p-optimality method. The same was true with the operational item pool. Measurement accuracy was related to test length, but not so much to the routing test proportions. Exposure control affected the item pool size, but the distributions of the item parameters and item pool characteristics for all the MST panel designs were similar under the two conditions. The item pool sizes under the exposure control conditions were several times larger than those under no exposure control, depending on the types of MST panel designs and routing test proportions. The results from this study provide information for how to enhance item pool utilization when designing multistage computerized adaptive tests, facilitating the MST assembly process, and improving the scoring accuracy.
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Title: Evaluation and validation of soft robotic end effectors for produce harvesting
Creator: Dutcher, Zachary F.
Date: 2018
Collection: Electronic Theses & Dissertations
Description: Global population is expected to exceed 9 billion people by 2050 which will require a 70% increase in net global food production. 75% of global farm holdings are considered small at 2.5 acres or less. While contemporary industrial farming gains efficiency through increased mechanization, it comes with significant environmental costs. Industrial farming practices such as frequent tillage, monocropping and use of synthetic fertilizers, pesticides and herbicides are unsustainable practices that...
Show moreGlobal population is expected to exceed 9 billion people by 2050 which will require a 70% increase in net global food production. 75% of global farm holdings are considered small at 2.5 acres or less. While contemporary industrial farming gains efficiency through increased mechanization, it comes with significant environmental costs. Industrial farming practices such as frequent tillage, monocropping and use of synthetic fertilizers, pesticides and herbicides are unsustainable practices that will continue to degrade the surrounding ecosystem. Small scale farms present an opportunity to utilize regenerative farming practices; however, they are potentially challenging to scale up and expensive to automate with conventional automation solutions. In this thesis, soft robotic end effectors are explored as a potential means of harvesting on regenerative (as well as conventional) farms. Three end effector designs are testing for parameters including grasp variability, grasp effectiveness and real-world simulation on apple orchards at Michigan State University. Apple harvesting metrics including detachment force, diameter and weight have been collected for one hundred early harvest Spartan-Macintosh variety apples. Results of this evaluation show promise for the application of these low-cost technologies; however, much work is needed before a complete and viable soft robotic harvesting system is available.
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Title: The design and organisation features of two online courses : a case study of their emergence and evolution
Creator: Richards, Kari
Date: 2017
Collection: Electronic Theses & Dissertations
Description: This study reports the findings of a qualitative case study that examined how elements of design and organization were conceptualized and enacted in two graduate level online courses, and, how these conceptualizations and enactments evolved. Data was collected through interviews and ‘think-alouds’ with the course instructors and through screen captures of the course home pages. The Community of Inquiry Framework (CoI) (Garrison, Anderson, & Archer, 2000) was used as a lens to analyze the data...
Show moreThis study reports the findings of a qualitative case study that examined how elements of design and organization were conceptualized and enacted in two graduate level online courses, and, how these conceptualizations and enactments evolved. Data was collected through interviews and ‘think-alouds’ with the course instructors and through screen captures of the course home pages. The Community of Inquiry Framework (CoI) (Garrison, Anderson, & Archer, 2000) was used as a lens to analyze the data for the Design & Organization element of the framework’s concept of Teaching Presence. The analysis identified patterns in the five features of the Design & Organization element: Setting Curriculum, Designing Methods, Establishing Time Parameters, Utilizing the Medium, and Establishing Netiquette. The data shows variation in the way most of the features are conceptualized and enacted in the online courses, with some exceptions. These variations reflect the different experiences, expectations, and logic of the two instructors, while the exceptions reflect the influence of external norming agents such as the Learning Management System or institutional guidelines. The results indicate a wider range of possibilities in course design and organization than the CoI framework has been conceptualized to account for, which has implications for the various programs and institutions using the framework as an instrument for their evaluation of online courses.
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Title: Design patterns for developing dynamically adaptive systems
Creator: Ramirez, Andres J.
Date: 2008
Collection: Electronic Theses & Dissertations

Title: Design and engineering of novel starch-based foam and film products
Creator: Nabar, Yogaraj Umesh
Date: 2004
Collection: Electronic Theses & Dissertations

Title: System identification and control design for internal combustion engine variable valve timing systems
Creator: Ren, Zhen
Date: 2011
Collection: Electronic Theses & Dissertations
Description: Variable Valve Timing (VVT) systems are used on internal combustion engines so that they can meet stringent emission requirements, reduce fuel consumption, and increase output. Also, VVT plays a critical role in order for the engine to smoothly transit between spark ignition (SI) and homogeneous charge compression ignition (HCCI) combustion modes. In order to achieve these performance benefits and SI/HCCI transition, it is required that the VVT system be controlled accurately using a model...
Show moreVariable Valve Timing (VVT) systems are used on internal combustion engines so that they can meet stringent emission requirements, reduce fuel consumption, and increase output. Also, VVT plays a critical role in order for the engine to smoothly transit between spark ignition (SI) and homogeneous charge compression ignition (HCCI) combustion modes. In order to achieve these performance benefits and SI/HCCI transition, it is required that the VVT system be controlled accurately using a model based controller. This work studies hydraulic and electric VVT system modeling and controller design. The VVT system consists of electric, mechanical, and fluid dynamics components. Without knowledge of every component, obtaining physical-based models is not feasible. In this research, the VVT system models were obtained using system identification method. Limited by the sample rate of the crank-based camshaft position sensor, a function of engine speed, the actuator control sample rate is different from that of cam position sensor. Multi-rate system identification is a necessity for this application. On the other hand, it is also difficult to maintain the desired actuator operational condition with an open-loop control. Therefore, system identification in a closed-loop is required. In this study, Pseudo Random Binary Sequence (PRBS) q-Markov Cover identification is used to obtain the closed-loop model. The open-loop system model is calculated based on information of the closed-loop controller and identified closed-loop system model. Both open and closed-loop identifications are performed in a Hardware-In-the-Loop (HIL) simulation environment with a given reference model as a validation process. A hydraulic VVT actuator system test bench and an engine dynamometer (dyno) are used to conduct the proposed multi-rate system identification using PRBS as excitation signals. Output covariance constraint (OCC) controllers were designed based upon the identified models. Performance of the designed OCC controller was compared with those of the baseline proportional integral (PI) controller. Results show that the OCC controller uses less control effort and has less overshoot than those of PI ones. An electric VVT (EVVT) system with planetary gear system and local speed controller was modeled based on system dynamics. Simulation results of the EVVT system model provided a controller framework for the bench test. The EVVT system test bench was modified from the hydraulic VVT bench. Multi-rate closed-loop system identification was conducted on the EVVT system bench and a model based OCC controller was designed. The bench test results show that the OCC controller has a lower phase delay and lower overshoot than a tuned proportional controller, while having the same or faster response time. It is also observed that engine oil viscosity has a profound impact on the EVVT response time. The maximum response speed is saturated at a slow level if the viscosity is too high. From the bench and dyno tests, it is concluded that multi-rate closed-loop identification is a very effective way to retrieve controller design orientated VVT models. It is possible to use an OCC controller to achieve lower energy consumption, lower overshoot, and better tracking compared to PI and proportional controllers on both hydraulic and electric VVT systems.
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Title: Design and evaluation of a health care needs assessment tool for adults with cerebral palsy and mental retardation
Creator: Clark, Nuala Catherine
Date: 1991
Collection: Electronic Theses & Dissertations

Title: The relationship of instructional method and occupational interests to the perception of proportion in the environment
Creator: Smith, Ruth Ann
Date: 1973
Collection: Electronic Theses & Dissertations

Title: Wide-band antenna design for use in minimal-scan, microwave tomographic imaging
Creator: Klaser, Jacob
Date: 2013
Collection: Electronic Theses & Dissertations
Description: Microwave tomography is widely used in biomedical imaging and nondestructive evaluation of dielectric materials. A novel microwave tomography system that uses an electrically-conformable mirror to steer the incident energy for producing multi-view projection data is being developed in the Non-Destructive Evaluation Laboratory (NDEL). Such a system will have a significant advantage over existing tomography systems in terms of simplicity of design and operation, particularly when there is...
Show moreMicrowave tomography is widely used in biomedical imaging and nondestructive evaluation of dielectric materials. A novel microwave tomography system that uses an electrically-conformable mirror to steer the incident energy for producing multi-view projection data is being developed in the Non-Destructive Evaluation Laboratory (NDEL). Such a system will have a significant advantage over existing tomography systems in terms of simplicity of design and operation, particularly when there is limited-access of the structure that is being imaged. The major components of a mirror-based tomography system are the source mirror assembly, and a receiver array for capturing the multi-view projection data. This thesis addresses the design and development of the receiver array. This imaging array features balanced, anti-podal Vivaldi antennas, which offer large bandwidth, high gain and a compact size. From the simulations, as well as the experimental results for the antenna, the return loss (S11) is below -10dB for the range from 2.2GHz to 8.2GHz, and the gain is measured to be near 6dB. The data gathered from the receiver array is then run through MATLAB code for tomographic reconstruction using the Filtered Back-Propagation algorithm from limited-view projections. Initial results of reconstruction from the measured data shows the feasibility of the approach, but a significant challenge remains in interpolating the data for a limited number of receiving antenna elements and removing noise from the reconstructed image.
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Title: Assessing bikeway design alternatives : DALMAC route centeral Michigan case study
Creator: Li, Yinliang
Date: 2018
Collection: Electronic Theses & Dissertations
Description: The objective of this thesis is to explore the differences and possibilities of bikeway design implemented with different treatments by examining the DALMAC bicycle camping tour. In the following steps, the thesis conducted series of analysis to select the final route by assessing three segments (Site A, Site B, and Site C) as study sites from DALMAC (b = 3). The investigation studied treatment including: 1) Existing Treatment, 2) Balance Treatment, 3) Extremely Safe Treatment, 4) Extremely...
Show moreThe objective of this thesis is to explore the differences and possibilities of bikeway design implemented with different treatments by examining the DALMAC bicycle camping tour. In the following steps, the thesis conducted series of analysis to select the final route by assessing three segments (Site A, Site B, and Site C) as study sites from DALMAC (b = 3). The investigation studied treatment including: 1) Existing Treatment, 2) Balance Treatment, 3) Extremely Safe Treatment, 4) Extremely Enjoyable Treatment, and 5) Extremely Environmental Treatment (k = 5). In order to test the differences among treatments statistically through Freidman Test of variances, there is a scoring criteria consisting of 30 questions. As a result, this data indicated that at least one treatment yield different values among all treatments (p ≤ 0.005 or p ≤ 0.001). Furthermore, among all treatments across 3 sites, the Extremely Enjoyable Treatment statistically performed best (p ≤ 0.05). In conclusion, this thesis investigated the potential values of bicycle enjoyment for a specific segment of DALMAC route.
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Title: Impact of color on children's play behaviors
Creator: Safferman, Bridget Nicole
Date: 2015
Collection: Electronic Theses & Dissertations
Description: IMPACT OF COLOR ON CHILDREN’S PLAY BEHVIORSByBridget Nicole SaffermanThis research examines the effects of differently colored playground balls on the play behaviors of children between the ages of three and four. Color vision in human beings triggers certain physical and psychological responses that can influence behavioral changes; the goal of this observational study is to determine if these responses are strong enough to influence the type and durations of children’s play. This...
Show moreIMPACT OF COLOR ON CHILDREN’S PLAY BEHVIORSByBridget Nicole SaffermanThis research examines the effects of differently colored playground balls on the play behaviors of children between the ages of three and four. Color vision in human beings triggers certain physical and psychological responses that can influence behavioral changes; the goal of this observational study is to determine if these responses are strong enough to influence the type and durations of children’s play. This observational study was conducted on children between the ages of 36 and 60 months old who were enrolled in a children’s daycare and child development research facility. Results of this study produced trends that indicate that certain colors do have an impact on the level of activity in which children play, namely, that children exhibit a greater number of play behaviors on traditional playgrounds, but play longer on nature playgrounds. Additionally, trends suggested that red and yellow, warm colors, increase the number of active and low active play behaviors observed and blue, a cool color, increases the durations of play behaviors. This knowledge suggest that color could be a viable tool in designing play spaces to meet specific needs and promoting different play behaviors in childrenKeywords: Color, Children’s Play Behaviors, Children’s Play Durations, Level of Activity
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Title: Targeting metabolic vulnerabilities in breast cancer subtypes
Creator: Ogrodzinski, Martin Peter
Date: 2020
Collection: Electronic Theses & Dissertations
Description: Breast cancer is a highly prevalent and deadly disease. Globally, it is the most diagnosed cancer in women and is responsible for the most cancer-related deaths among women. Breast cancer is also a remarkably heterogeneous disease, with clear variability in clinical parameters including histological presentation, receptor status, and gene expression patterns that differ between patients. A significant amount of effort has been spent characterizing breast cancer into subtypes, with the main...
Show moreBreast cancer is a highly prevalent and deadly disease. Globally, it is the most diagnosed cancer in women and is responsible for the most cancer-related deaths among women. Breast cancer is also a remarkably heterogeneous disease, with clear variability in clinical parameters including histological presentation, receptor status, and gene expression patterns that differ between patients. A significant amount of effort has been spent characterizing breast cancer into subtypes, with the main goal of improving patient outcomes by: 1) designing targeted therapies, and 2) improving our ability to determine patient prognosis. While scientists have made significant strides in meeting these goals, we still lack targeted therapies for some subtypes of breast cancer, and current therapies often fail to provide a lasting cure. Thus, additional research is needed to improve patient care. One promising area in breast cancer research is cancer metabolism. Using metabolism as a therapeutic target is rapidly gaining traction, as it is now widely appreciated that cancer cells exhibit significant differences in metabolism compared to normal cells. The primary goal of this dissertation is to study the metabolism of distinct subtypes of breast cancer and identify metabolic vulnerabilities that can be used to effectively treat each subtype.This thesis will begin with a review of current classification strategies for breast cancer subtypes and knowledge regarding subtype-specific metabolism. It will also consider modern techniques for targeting breast cancer metabolism for therapeutic benefit. Breast cancer heterogeneity and metabolism are investigated using cell lines and tumors derived from the MMTV-Myc mouse model, which mimics the complexity observed in human disease. Cell lines derived from two histologically defined subtypes, epithelial-mesenchymal transition (EMT) and papillary, are used to establish clear metabolic profiles for each subtype. Metabolic vulnerabilities are identified in glutathione biosynthesis and the tricarboxylic acid cycle in the EMT subtype and nucleotide biosynthesis is determined to be a metabolic weakness in the papillary subtype. It is further shown that pharmacologically targeting each of these metabolic pathways has the greatest effect on reducing proliferation when used against the vulnerable subtype. These in vitro findings are then expanded upon by integrating genomic and metabolomic data acquired from in vivo tumors. In vivo experiments reveal that the EMT and papillary tumors prefer parallel pathways to generate nucleotides, with the EMT subtype preferring to salvage nucleotides while the papillary subtype prefers to produce nucleotides de novo. CRISPR/Cas9 gene editing is used to functionally characterize the metabolic effects of targeting nucleotide salvage and de novo biosynthesis in the EMT and papillary subtypes, and determine that targeting the preferred pathway of each subtype is most effective at slowing tumor growth.Overall, this work demonstrates the power of using metabolism as a therapeutic target of breast cancer, and further shows that metabolic vulnerabilities specific to individual subtypes can be used effectively to guide personalized medicine.
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Title: Natural landscaping, a comparison of design treatments in a surface mine setting
Creator: Wang, Lishuang
Date: 2013
Collection: Electronic Theses & Dissertations
Description: Planners, designers, scientists, and citizens are interested in rehabilitation, reclamation and protection of the post-mining environment. Consequently, a fair amount of research from scholars is focused on the technical aspects concerning the revegetation of the landscape and the science of reclamation; while only a small portion of the literature concerns planning and design. In this thesis, a case study in the Upper Peninsula of Michigan is used to explore post-ming treatments: abandoned...
Show morePlanners, designers, scientists, and citizens are interested in rehabilitation, reclamation and protection of the post-mining environment. Consequently, a fair amount of research from scholars is focused on the technical aspects concerning the revegetation of the landscape and the science of reclamation; while only a small portion of the literature concerns planning and design. In this thesis, a case study in the Upper Peninsula of Michigan is used to explore post-ming treatments: abandoned mine, resort development. a super hotel resot, and natural vegetation communities. The treatments (k=4) were evaluated with an environmental quality measure upon 10 images from each treatment (b=10). The results indicated that the resort and the natural community were best treatments, significantly better than the abandoned mine treatment (p<0.05). The super hotel was ranked as the third, which is less preferred than the two best treatments, but much better than the abandoned mine treatment (p<0.05). By identifying difference between each treatment, the results shows people have preference for natural environment and natural landscape is beautiful in their views.
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Title: BTAudio (Bluetooth Audio Program) and quite talk profile
Creator: Chen, Jun
Date: 2003
Collection: Electronic Theses & Dissertations

Title: Analysis and design of reliable and stable link-layer protocols for wireless communication
Creator: Soltani, Sohraab
Date: 2009
Collection: Electronic Theses & Dissertations

Title: A unique approach to frequency-modulated continuous-wave radar design
Creator: Charvat, Gregory Louis
Date: 2003
Collection: Electronic Theses & Dissertations

Title: On the evolution of mutation bias in digital organisms
Creator: Rupp, Matthew
Date: 2011
Collection: Electronic Theses & Dissertations
Description: Mutation is one of the primary drivers of genetic change. In this work I study mutation biases, which are sets of different genetic-state inflow probabilities. Mutation biases have the potential to change the composition of genomes over time, leading to divergent short- and long-term evolutionary outcomes. I use digital organisms, self-replicating computer programs, to explore whether or not mutation biases are capable of altering the long-term adaptive behavior of populations; whether...
Show moreMutation is one of the primary drivers of genetic change. In this work I study mutation biases, which are sets of different genetic-state inflow probabilities. Mutation biases have the potential to change the composition of genomes over time, leading to divergent short- and long-term evolutionary outcomes. I use digital organisms, self-replicating computer programs, to explore whether or not mutation biases are capable of altering the long-term adaptive behavior of populations; whether mutation biases can be competitive traits; and whether mutation biases can evolve. I find that mutation biases can alter the long-term adaptive behavior of mutation bias-obligate populations in terms of both mean fitness and complex trait evolution. I also find that mutation biases can compete against one another under a variety of conditions, meaning mutation bias can selectable over relatively-short periods of time. The competitive success of a mutation bias does not always depend upon the presence of beneficial mutations, implicating an increase in the probability of neutral mutations as a sufficient mechanism for bias selection. Finally, I demonstrate that by giving organisms a mutable mutation bias allele, populations preferentially evolve to possess specific biases over others. Overall, this work shows that mutation bias can act as a selectable trait, influencing the evolution of populations with regard to both their internal-genetic and external environments.
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Title: A study of Pakistani decorative textile design motifs adapted for use in western-style contemporary homes
Creator: Wasi, Surraya
Date: 1962
Collection: Electronic Theses & Dissertations

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