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Framing Complex Challenges
Get PDFInnovating to achieve impact at scale in ill-structured environments is a complex challenge, with numerous socio-techno-economic dimensions. Whether tailoring a product or service offering to meet the needs of a global customer base, forecasting the socio-economic implications of a new technology, or working to address a societal challenge in a low-to-middle income country, problems that encompass social, technical and/or economic uncertainty, significant variations in involved stakeholder characteristics, and even subtle differences across the focal environment, inevitably benefit from a holistic analysis that spans multiple levels of abstraction, encompasses a plurality of perspectives, and can be tailored to include contextual nuances. In addition, and perhaps most importantly, these types of problems require an accurate definition of the problem to be solved. To foster effective progress in this class of challenges, we herein introduce a novel problem analysis method, termed Comprehensive Success Factor Analysis (CSFA), that provides a rigorous and structured approach to attain holistic problem frames across an array of challenge types to inform decision making, innovation, and capacity building with the goal of achieving impact at scale
MakeYourStory: Showcasing Student Entrepreneurs
Get PDFThis presentation details the Purdue MakeYourStory podcast, highlighting stories of student entrepreneurs and various forms of making. Among many achievements, this podcast details use of the makerspace, student Soybean Competition innovations, and TikTok content creation
Exploring ChatGPT for Business Question/Assignments
Get PDFLightning Talk for the Midwest Business Librarians Summit on testing the ChatGPT AI service using academic business questions and scenarios. The brief presentation will show and comment on the results of a variety of questions posed to the Chat GPT service that reflect common types of questions from different business disciplines. It will conclude with an assessment of what this and other similar tools might mena for the future of Business Librarianshi
On a central problem of the Human Placenta Project
Get PDFThis brief technical note describes a design concept for a low-cost, painless, noninvasive monitor of total placental blood flow during the third trimester of pregnancy. The approach may offer an overlooked solution to a central problem of the human placenta project. A systems level biophysical analysis shows that jets of blood flow emerging from spiral arteries in the placenta generate characteristic 1/f or “pink noise” which is routinely audible, but typically ignored, during fetal phonocardiography. The amplitude of the 1/f noise, recorded at a standardized location in an individual patient, is a measure of total placental blood flow that is potentially useful for monitoring of placental function and better management of third trimester complications such as preeclampsia and maternal diabetes
Three-dimensional Fluorescence Microscopy Image Synthesis and Analysis Using Machine Learning
No full textRecent advances in fluorescence microscopy enable deeper cellular imaging in living tissues with near-infrared excitation light. High quality fluorescence microscopy images provide useful information for analyzing biological structures and diagnosing diseases. Nuclei detection and segmentation are two fundamental steps for quantitative analysis of microscopy images. However, existing machine learning-based approaches are hampered by three main challenges: (1) Hand annotated ground truth is difficult to obtain especially for 3D volumes, (2) Most of the object detection methods work only on 2D images and are difficult to extend to 3D volumes, (3) Segmentation-based approaches typically cannot distinguish different object instances without proper post-processing steps. In this thesis, we propose various new methods for microscopy image analysis including nuclei synthesis, detection, and segmentation. Due to the limitation of manually annotated ground truth masks, we first describe how we generate 2D/3D synthetic microscopy images using SpCycleGAN and use them as a data augmentation technique for our detection and segmentation networks. For nuclei detection, we describe our RCNN-SliceNet for nuclei counting and centroid detection using slice-and-cluster strategy. Then we introduce our 3D CentroidNet for nuclei centroid estimation using vector flow voting mechanism which does not require any post-processing steps. For nuclei segmentation, we first describe our EMR-CNN for nuclei instance segmentation using ensemble learning and slice fusion strategy. Then we present the 3D Nuclei Instance Segmentation Network (NISNet3D) for nuclei instance segmentation using gradient vector field array. Extensive experiments have been conducted on a variety of challenging microscopy volumes to demonstrate that our approach can accurately detect and segment the cell nuclei and outperforms other compared methods. Finally, we describe the Distributed and Networked Analysis of Volumetric Image Data (DINAVID) system we developed for biologists to remotely analyze large microscopy volumes using machine learning
Geometric Uncertainty Analysis of Aerodynamic Shapes Using Multifidelity Monte Carlo Estimation
No full textUncertainty analysis is of great use both for calculating outputs that are more akin to real flight, and for optimization to more robust shapes. However, implementation of uncertainty has been a longstanding challenge in the field of aerodynamics due to the computational cost of simulations. Geometric uncertainty in particular is often left unexplored in favor of uncertainties in freestream parameters, turbulence models, or computational error. Therefore, this work proposes a method of geometric uncertainty analysis for aerodynamic shapes that mitigates the barriers to its feasible computation. The process takes a two- or three-dimensional shape and utilizes a combination of multifidelity meshes and Gaussian process regression (GPR) surrogates in a multifidelity Monte Carlo (MFMC) algorithm. Multifidelity meshes allow for finer sampling with a given budget, making the surrogates more accurate. GPR surrogates are made practical to use by parameterizing major factors in geometric uncertainty with only four variables in 2-D and five in 3-D. In both cases, two parameters control the heights of steps that occur on the top and bottom of airfoils where leading and trailing edge devices are attached. Two more parameters control the height and length of waves that can occur in an ideally smooth shape during manufacturing. A fifth parameter controls the depth of span-wise skin buckling waves along a 3-D wing. Parameters are defined to be uniformly distributed with a maximum size of 0.4 mm and 0.15 mm for steps and waves to remain within common manufacturing tolerances. The analysis chain is demonstrated with two test cases. The first, the RAE2822 airfoil, uses transonic freestream parameters set by the ADODG Benchmark Case 2. The results show a mean drag of nearly 10 counts above the deterministic case with fixed lift, and a 2 count increase for a fixed angle of attack version of the case. Each case also has small variations in lift and angle of attack of about 0.5 counts and 0.08◦ , respectively. Variances for each of the three tracked outputs show that more variability is possible, and even likely. The ONERA M6 transonic wing, popular due to the extensive experimental data available for computational validation, is the second test case. Variation is found to be less substantial here, with a mean drag increase of 0.5 counts, and a mean lift increase of 0.1 counts. Furthermore, the MFMC algorithm enables accurate results with only a few hours of wall time in addition to GPR training
The Evolution of Leftism in Peruvian Literature from the 20th Century to the Contemporary Era: José Carlos Mariátegui, José María Arguedas, and Antonio Gálvez Ronceros
No full textMariátegui, Arguedas, and Gálvez Ronceros represent important leftist voices in Peruvian literature that used their writings as a tool for political and social change. With this scholarship it is my aim to present an in-depth analysis on the origins of leftism in the context of Peruvian literature and the changes it experienced over time. Given the pluralism in the way the concept of leftism is interpreted and understood today, this research also provides a guide on how it should be defined in Peru’s context, given that mere importation of European leftism does not fully explain the unique characteristics of Peruvian leftism. In chapter one, I argue that the José Carlos Mariátegui played a significant role in shaping Peruvian society by championing a form of socially engaged leftist literature that reflected the realities of life for the working class and marginalized communities of Peru. To this day, Mariátegui’s ideas continue to influence leftist writers in Peru and in all Latin America, as well. While his role as a leftist author must not be undermined, this research also addresses the need that exists today to reexamine his figure and highlight the shortcomings that are found in his writings; namely, the underrepresentation of women and racial stereotypes used against Asians and people of African descent. In chapter two, I study the life and work of José María Arguedas who played a significant role in shaping Peruvian literature by giving voice to the experiences of indigenous people and challenging the dominant literary and cultural norms of Peru’s Andean region. His works deal with themes such as identity, culture, and oppression while insisting on a uniquely Andean expression of leftist thought that highlights the importance of indigenous spirituality, customs, and traditions. The final chapter of the dissertation is one of the first works to present an in-depth analysis of the role and writings of a contemporary leftist Peruvian author, Antonio Gálvez Ronceros. Gálvez Ronceros has utilized his work to give a greater representation to Peru’s most marginalized groups, namely AfroPeruvians, and mestizo campesinosliving on Peru’s southern coast. Leftist literature in Peru has played an important role in shaping the country’s political and cultural landscape, and it continues to be an important means of political and social resistance and activism. By analyzing the works of these three authors, we are given a unique opportunity to not only study the origins of leftism in Peru, but to also highlight its evolution over time to better understand its continued influence on Peruvian society
Reproductive Competence in Female ICR Mice Following High Fat Diet and Constant Light Exposure
No full textIn modern society, continuous light exposure and obesity are increasingly prevalent, especially in women of childbearing age. Circadian, metabolic, and reproductive systems have a complex, inter-regulated relationship. Thus, the disruption of one system likely impedes another. Excessive adiposity and circadian disruption alter normal behavior and physiology and disrupt the endocrine milieu. The overall goal of the studies described in this thesis was to develop and test a model system that could tease apart the influence of prepregnancy obesity and circadian disruption, as well as study the combined effects on female reproductive competence.The first study focuses on the prepregnancy period and aims to determine the effect of high fat diet feeding on diurnal eating pattern, body weight over the four-week period, the body composition at the end of the four-week period, hair corticosterone levels, and circadian fecal corticosterone patterns on female ICR mice. Five-week-old female ICR mice were randomly assigned to control (CON; 10% fat) or high fat (HF; 60%) diets and fed for four weeks to achieve adequate adiposity. During this four-week time period, mice had routine light exposure of 12h light and 12h dark. Feed was weighed at 0600 and 1745 Monday-Friday to determine diurnal feed intake. The mice were weighed on a weekly basis. After four weeks on respective diets, mice were anesthetized with isoflurane to measure crown-rump length to calculate BMI and hair was shaved for corticosterone extraction. Once mice recovered from anesthesia, body composition was measured with EchoMRI. After 1 week on diets, HF mice consumed more (P\u3c0.05) during the day than CON mice, which is typically when mice are inactive. After two weeks on diets, HF mice weighed more (P\u3c0.05) than CON, as well as had higher BMI and percent body fat (P\u3c0.05) than CON after four weeks on diets. After four weeks on diets, HF mice had high hair corticosterone (P\u3c0.05). Sampling feces over a 48h period at the end of the four weeks demonstrated that HF mice had elevated basal corticosterone, attenuated circadian rhythms, and a shift in corticosterone amplitude. The prepregnancy period demonstrated that high fat diets alone alter circadian eating pattern and corticosterone rhythms.The remainder of the study continued the dietary treatments assigned during the prepregnancy period, as well as implemented light conditions to create a 2Χ3 factorial study design. There were three light conditions: 12h light and 12h dark (LD), 24h dim light (L5), or 24h bright light (L100). Mice were moved into experimental light conditions after the observation of a vaginal plug or after 5 days with males. This portion of the study aimed to determine the effect of diet (CON or HF) and light exposure (LD, L5, or L100) on gestation length, number of pups born, milk composition, litter weight on postnatal day 12, as well as dam feed intake, hair corticosterone levels, and plasma prolactin. Continuous light exposure increased gestation length, with L5 (19.1 d ± 0.23) and L100 (18.9 d ± 0.21) having longer gestation lengths (P\u3c0.05) than LD (18.1 d ± 0.25). Diet affected the number of pups born (P\u3c0.05), with HF dams having fewer pups (9.99 ± 0.4) than CON (11.4 ± 0.4)
Effect of Temperature on the Delamination and Performance of Monocrystalline Silicon Solar Cells
No full textThe solar cells degrade over time in the field due to various environmental conditions including temperature and humidity. Accelerated lifetime testing was used to test solar cells in a short period of time to obtain reliability and predict the lifetime. Accelerated lifetime testing was done on two 10-WATT ACOPOWER rigid mono crystalline silicon solar panel, 2 3-WATT semi-flexible monocrystalline silicon solar panel and 30 Sunyima Mini Monocrystalline Solar Cell to calculate the acceleration factor, mean reliable life through statistical analysis at certain working conditions. Two Damp heat tests were conducted on the samples to find the degradation and potential defects that occur in the solar cell and that data was used for the statistical analysis. Reliasoft ALTA software was used to statistically analyze the experimental data and to predict the lifetime and to find the probability of failure of the solar cells.Peeling tests were conducted to find the adhesion strength between layers of the untested solar cell samples and accelerated life testing (ALT) tested solar cell samples. Tensile tests were conducted to find out the Young’s Modulus, yield stress and yield strain of the peel arm from the peeling test. The data from the tests were used to calculate the energy release rate or the fracture energy. A multivariable Regression analysis was done to develop an analytical equation between the energy release rate (Gc) and Temperature & Humidity
Numerical Investigations on the Comparative Study of Headed Studs and Headed Reinforcement
No full textThe use of headed reinforcement in concrete has found an increasing interest in construction applications. From shear reinforcement in walls to longitudinal reinforcement in beams and columns, there is a growing need to understand the behavior of headed rebars. A headed rebar is a deformed bar with a head attached to its end and while similar anchorage devices such as headed studs and hooked rebars are well established in theory with design equations developed, headed reinforcement lack this level of knowledge and hence, their application in industry is limited.Current code provisions such as fib Model Code 2010 allow the design of headed rebars as (1) a hooked bar, (2) a headed stud, and (3) using experimental results. Moreover, ACI 318-19 only contains a design equation for the development length of headed rebars but not its capacity. While the literature has justified the approximation of the capacity of headed rebars with hooked bars through a multitude of studies comparing both anchorage devices. Such a justification is not well-founded for headed studs due to a scarcity of studies comparing headed rebars to headed studs. Moreover, there is a lack of design equations accurately predicting the behavior of headed rebars in several parameters. All these issues emanate from the complexity of headed rebars due to their joint mechanism of anchorage coming from both resistance along the rebar deformations and bearing on the head.This study aims to better understand the behavior of headed bars by numerically analyzing the influence of different parameters on their performance. Furthermore, direct comparisons are made between headed reinforcement, headed studs, and straight bars to segregate the effect of the bond along the shaft and the bearing at the head on the behavior of headed bars.The parameters included in this study are embedment depth, edge distance, and concrete compressive strength. The numerical models are verified using a 3D non-linear finite element software MASA (Macroscopic Space Analysis) which employs the microplane model with relaxed kinematic constraint as the constitutive laws of concrete. Two numerical approaches, which differ only in the interface properties between the head and concrete, are validated against experimental results before carrying out the parametric study. Several properties including head, concrete, and bond stresses, along with ultimate capacities and crack patterns are extracted from the models and analyzed. Moreover, the load-displacement graphs of headed rebars, studs, and straight rebars are compared and contrasted. Assessments and theories about the discrepancies between the behavior of headed studs and rebars are stipulated. Finally, potential methods for formulating design equations are proposed for future studies