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Iowa Waste Reduction Center Newsletter, August 2025, University Of Northern Iowa. Iowa Waste Reduction Center.

Iowa Waste Reduction Center Newsletter

Contents:

--- Announcing the IWRC’s Painter Training Team
--- Are On-Site Visits the Answer to Easing the Stress Environmental Compliance?
--- Wrap Up: The Rural Compost Operations and Compost Use Training Project
--- ICAW 2026 Poster Contest
--- Partner Events
--- Industrial News

A Three-Stage Matheuristic For The Blood Stochastic Inventory Routing Problem, Vincent F. Yu, Nabila Salsabila, Aldy Gunawan, Aldy Gunawan, Nurhadi Siswanto

Research Collection School Of Computing and Information Systems

This research introduces a blood distribution system under vendor-managed inventory that considers uncertain supply and demand. We present it as the Blood Stochastic Inventory Routing Problem, formulating it as a two-stage stochastic programming model. To solve this problem, this study proposes a three-stage matheuristic that combines a perturbation heuristic, Adaptive Large Neighborhood Search, and an exact approach. From historical data of Surabaya Blood Center in Indonesia, six sets of new instances are generated under different settings. Computational results show that our proposed three-stage matheuristic outperforms CPLEX and a two-stage matheuristic by gaining optimal or better solutions within a significantly shorter …

Towards Context-Aware Traffic Classification Via Time-Wavelet Fusion Network, Ziming Zhao, Zhuoxue Song, Xiaofei Xie, Zhaoxuan Li, Jiongchi Yu, Fan Terry Zhang, Tingting Li

Research Collection School Of Computing and Information Systems

Encrypted traffic classification occupies a significant role in cybersecurity and network management. The existing encrypted traffic classification technology mostly relies on intra-flow semantics for extracting features. However, considering that some attack behaviors inherently have similar patterns to legitimate behaviors, and powerful adversaries could simulate benign users to conceal their attack intentions, intra-flow features may be similar between different categories. In this paper, we propose TrafficScope, a time-wavelet fusion network based on Transformer to enhance the performance of encrypted traffic classification. Specifically, in addition to using intra-flow semantics, TrafficScope also extracts contextual information to construct more comprehensive representations. Moreover, to cope …

Ai-Assisted Risk Assessment In Generative Ai Governance, Wu Jiaqi Young, Fiona Fui-Hoon Nah

Research Collection School Of Computing and Information Systems

Effective risk assessment is paramount for responsible generative AI (GenAI) deployment. Traditional governance approaches that rely on manual reviews are inadequate given the scale and velocity of GenAI outputs. A risk-based approach incorporating real-time monitoring and governance is paramount. In this research, we examine how the efficacy of suggestive versus supportive explanations for AI’s risk assessment of GenAI outputs is moderated by user domain expertise and AI’s risk assessment in determining user acceptance. We hypothesize that cognitive involvement increases with AI’s risk assessment, with higher risks triggering more critical evaluation. By drawing on the elaboration likelihood model, we hypothesize that …

Tetd: Trusted Execution In Trust Domains, Zhanbo Wang, Jiaxin Zhan, Xuhua Ding, Fengwei Zhang, Ning Hu

Research Collection School Of Computing and Information Systems

Intel TDX empowers cloud service providers to construct confidential virtual machines called trust domains (TDs) on x86 platforms. Similar to its counterparts from AMD and Arm, TDX's hardware based protection over integrity and secrecy of virtual machine memory and vCPU states inevitably hinders legitimate virtual machine management such as introspection. At the presence of compromised high-privileged software (e.g., the guest kernel), neither the cloud service provider nor the TD owner can securely carry out a task within the TD. To tackle this problem, we propose TETD, an in-TD trusted execution technique without trusting any TD system software. Our design does …

Oblivious Digital Tokens, Mihael Liskij, Xuhua Ding, Gene Tsudik, David A. Basin

Research Collection School Of Computing and Information Systems

A computing device typically identifies itself by exhibiting unique measurable behavior or by proving its knowledge of a secret. In both cases, the identifying device must reveal information to a verifier. Considerable research has focused on protecting identifying entities (provers) and reducing the amount of leaked data. However, little has been done to conceal the fact that the verification occurred.We show how this problem naturally arises in the context of digital emblems, which were recently proposed by the International Committee of the Red Cross to protect digital resources during cyber-conflicts. To address this new and important open problem, we define …

Life Cycle Assessment Of The Cultivation Of Lettuce In A Hydroponic System Using The Nutrient Film Technique, Raquel Jordan

All Theses

Hydroponic systems are an emerging method of soilless crop cultivation typically done inside a greenhouse where nutrients are delivered dissolved in water rather than being supplied from the soil. Potential benefits of hydroponic systems include reduced irrigation requirements, higher crop yield per area, and the ability to grow crops year-round in nontraditional areas such as urban settings, cold climates, and sites with contaminated soil. However, hydroponic systems tend to have high energy requirements for lighting and climate control, which can yield significant environmental impacts. To explore the environmental impacts of cultivating lettuce in a nutrient film technique (NFT) hydroponic system, …

Machine Learning Based Medical Ultrasound Image Classification And Grad-Cam Interpretation, Victoria C. Hemphill

All Theses

This work takes a step in creating a diagnostic tool for the classification decision process of Achilles tendinopathy using ultrasound images. An attention-based multiple instance learning model is developed to classify the images. Typically, doctors capture multiple ultrasound images of the Achilles tendon during a study to determine a complete diagnosis. Multiple instance models adopt this behavior by providing a single label for a set of instances (images). The images are grouped into ”bags” at the study level and passed into the model. The MIL model then uses its attention property to assign an importance score to each image to …

A Generalizable And Privacy-Preserving Framework For Anomaly Detection In Heterogeneous Iot Environments, Mahshid Rezakhani

All Theses

With the rapid growth of Internet of Things (IoT) devices across various sectors, detecting anomalies in such systems has become increasingly challenging. IoT environments produce diverse and evolving data streams, often lacking labeled examples, which limits the effectiveness of traditional machine learning models. These models typically require frequent retraining and struggle to adapt to new deployment conditions. This thesis proposes a flexible, privacy-aware framework for anomaly detection in multivariate time series data generated by heterogeneous IoT systems. The approach integrates a long short-term memory variational autoencoder (LSTM-VAE) with contrastive learning and adversarial adaptation, enabling the model to generalize across domains, …

Effects Of Variation In Altitude And Temperature On The Restraining Force And Internal Gauge Pressure Of Constrained Dunnage Airbags, Charles R. Weaver

All Theses

Dunnage airbags are an increasingly popular choice for securing cargo. During transit, changes in ambient temperature and pressure can cause airbags to expand generating damaging horizontal compressive forces in the trailer or container. Previous studies have developed numerical models for the behavior of Kraft paper and woven polypropylene fabric dunnage airbags under standard conditions but do not account for the behavior of airbags under varied altitudes and temperatures. This study provides empirical data on the internal gauge pressure and restraining force dynamics of 4-ply Kraft, woven polypropylene, and polyvinyl chloride airbags under simulated altitude and temperature conditions. Tensile testing characterizes …

Optimizing Park Locations While Considering Resident Behavior, Lu Liu

All Theses

Urban parks and green-spaces significantly enhance community well-being by improving physical health, mental wellness, and environmental quality. Given these extensive benefits, ensuring fair and widespread access to urban parks represents a critical priority in urban planning. Despite the advantages of parks, optimizing their location poses unique and complex challenges distinct from traditional facility location problems, such as those involving emergency services or schools. The core distinction arises from the decentralized nature of residents’ park selection behaviors. Unlike centralized allocations typically managed by public administrators, park usage decisions are driven by individual preferences and behaviors. This decentralized decision-making introduces two additional …

Direct Photopatterning Of Quantum Dots Via Thiol-Yne Click Chemistry, Nicholas Langer, Ofer Kedem

Chemistry Faculty Research and Publications

Functional nanomaterials are revolutionizing electronic devices such as displays and photovoltaics, yet existing semiconductor manufacturing methods struggle to adapt to the unique properties of nanoparticles. In particular, quantum dots (QDs) display density-dependent properties such as tunable energy transfer, yet current preferred methods of producing QD patterns lack control over the density of QDs deposited in specific locations on a surface. Here, we present a photochemical method to generate QD patterns directly from solution onto a functionalized surface, which enables density control. The overall dose of light used in the pattern (visible or UV) determines the surface density of deposited QDs …

Practical Keyword Private Information Retrieval From Key-To-Index Mappings, Meng Hao, Weiran Liu, Liqiang Peng, Cong Zhang, Pengfei Wu, Lei Zhang, Hongwei Li, Deng, Robert H.

Research Collection School Of Computing and Information Systems

This paper introduces practical schemes for keyword Private Information Retrieval (keyword PIR), enabling private queries on public databases using keywords. Unlike standard indexbased PIR, keyword PIR presents greater challenges, since the query’s position within the database is unknown and the domain of keywords is vast. Our key insight is to construct an efficient and compact key-to-index mapping, thereby reducing the keyword PIR problem to standard PIR. To achieve this, we propose three constructions incorporating several new techniques. The high-level approach involves (1) encoding the server’s key-value database into an indexable database with a key-to-index mapping and (2) invoking standard PIR …

Mpo: Multilingual Safety Alignment Via Reward Gap Optimization, Weixiang Zhao, Yulin Hu, Yang Deng, Tongtong Wu, Wenxuan Zhang, Jiahe Guo, An Zhang, Yanyan Zhao, Bing Qin, Tat-Seng Chua, Ting Liu

Research Collection School Of Computing and Information Systems

Large language models (LLMs) have become increasingly central to AI applications worldwide, necessitating robust multilingual safety alignment to ensure secure deployment across diverse linguistic contexts. Existing preference learning methods for safety alignment, such as RLHF and DPO, are primarily monolingual and struggle with noisy multilingual data. To address these limitations, we introduce Multilingual reward gaP Optimization (MPO), a novel approach that leverages the well-aligned safety capabilities of the dominant language (e.g., English) to improve safety alignment across multiple languages. MPO directly minimizes the reward gap difference between the dominant language and target languages, effectively transferring safety capabilities while preserving the …

Think Both Ways: Teacher-Student Bidirectional Reasoning Enhances Mcq Generation And Distractor Quality, Yimiao Qiu, Yang Deng, Quanming Yao, Zhimeng Zhang, Zhiang Dong, Chang Yao, Jingyuan Chen

Research Collection School Of Computing and Information Systems

Generating high-quality Multiple Choice Questions (MCQs) remains challenging for educational tools due to the need for contextual relevance and plausible distractors. Existing methods still struggle with these dual requirements, leading to questions that lack depth and distractors that are either too obvious or irrelevant. In this paper, we propose BiFlow, a novel framework that integrates bidirectional reasoning perspectives: teacher reasoning generates contextually relevant questions and plausible distractors, while student reasoning evaluates question clarity and the misleading nature of the distractors. To further enhance reasoning, we introduce PathFinder, a mechanism that employs breadth-first search and Chainof-Thought (CoT) strategies to explore diverse …

Pricing The Unknown: An Analysis Of Expected Value Of Young Horses And Price-Determining Factors, Rupasri Sura

Graduate Theses and Dissertations

From a seller’s point of view in a market, it is crucial to plan the pricing strategies based on perceptions of buyer preferences and their willingness to purchase to ensure market success in selling and pricing. Applying this to the equine industry, this paper studies the factors determining the price of young horses (age ≤ 2 years) in digital auction platforms. Using data from Professional Horse Services, LLC (2012–2023), a Heckman’s two-step approach was employed, which involves a probit model as the first step and a hedonic price model as the second, aiming to correct for sample selection bias in …

Optimal Distributed Energy Resource Control And Scheduling In A Microgrid Framework, Timothy M. Dodge

All Graduate Theses and Dissertations, Fall 2023 to Present

As we use more renewable energy, such as solar power, and add new devices, such as electric vehicle chargers and battery storage, to our buildings, the management of electricity becomes more complex. These local energy sources and devices can form small "microgrids" that need careful coordination to work efficiently with the main power grid. The system figures out the best times to use, store or charge different devices (such as batteries and EVs) to avoid costly, high electricity demand spikes and help stabilize the main power grid, especially when asked by the utility company. A major part of this work …

Factors Influencing Cognitive Load: Exploring Affective Elements, Motivational Constructs, And Regulatory Strategies In Learning, Rebecca B. Brockbank

All Graduate Theses and Dissertations, Fall 2023 to Present

There are three separate research papers within this dissertation, each looking at specific elements of learning. The process of learning is a complex phenomenon that includes not just cognitive aspects, but also emotional and motivational aspects. During learning there is an input of information into our cognitive system (i.e., minds). When too much information is given or the information is not presented effectively, this can overload our cognitive system and negatively impact our learning. Understanding how to learn within the parameters of our cognitive system is important. However, learning is more complex than just the simple input and output of …

Twisted Equivariant Matrix Factorizations, Jan-Luca Spellmann

All Graduate Theses and Dissertations, Fall 2023 to Present

We introduce and study categories of twisted equivariant matrix factorizations MF^α_G(R, w), which are categories of matrix factorizations of a potential w over the local ring R = C[x₁, . . . , x_n] together with an action by a finite group G that is twisted via a 2-cocycle α. These categories provide rich examples of Z/2Z-differentially graded categories in the context of non-commutative geometry and come up naturally in the study of boundary conditions of 3d Rozansky–Witten theories. We prove that under certain assumptions on (R, w …

Tree Rings And The Broader Ocean-Atmospheric Circulation In The Highland Himalayas, Sanjaya Bhandari

All-Inclusive List of Electronic Theses and Dissertations

Climate change has altered tree-growth patterns and resulted in higher sea-surface temperatures across the planet. The Himalayan biome is one of the most vulnerable areas in the world to climate change because it has caused changes in forests’ growth and glaciers’ retreat. Dendrochronology has been used to understand the impact of climate change on tree growth and for climate reconstruction. In this dissertation, I discuss the growth of trees in the highlands of the eastern, central, and western Himalayas for the last 500 years and relate these patterns to the present global warming scenario and broad-scale climate modes. I reconstructed …

Exploring The Relationship Between Adhd, Mood Disorders, And Motivation Among Women Studying For The Ged: A Preregistered Study, Amanda Dawn Kennedy

Graduate Theses and Dissertations

Adult women with Attention Deficit Hyperactivity Disorder (ADHD) and mood disorders, such as anxiety and depression, represent an understudied and underserved demographic within educational research, particularly among those pursuing nontraditional academic pathways, such as obtaining the high school equivalency diploma (i.e., GED). Despite the well-documented challenges associated with ADHD and mood disorders, including difficulties with motivation, executive functioning, and emotional regulation, little research has examined how these factors influence women’s persistence and success in adult education settings. Understanding the unique experiences of this population is essential for developing targeted support systems that enhance learning outcomes and academic achievement. This study …

Measuring The Impact Of Ged Preparation On Ged Testing Outcomes, Matthew Utz

Graduate Theses and Dissertations

This quantitative study investigates the relationship between participation in GED preparation programs and GED test outcomes among adult learners at a single Adult Basic Education (ABE) center located in an urban area of a south-central U.S. state. Recognizing the significance of the GED as an alternative credential to a traditional high school diploma, the research examines how instructional hours and structured preparation correlate with students’ final scores in mathematics, English language arts, social studies, and science. The study also describes the demographic characteristics of the learners, including gender, race, and age groups, and analyzes their performance on the Test of …

Utilizing The Horseshoe Prior In Exploratory Factor Analysis And Gaussian Graphical Networks, James Thomas Roddy

Graduate Theses and Dissertations

High-dimensional data analysis frequently involves extracting meaningful structure from noisy, sparse signals. In recent years, Bayesian shrinkage priors—particularly global-local shrinkage priors—have emerged as powerful tools for inducing sparsity while preserving signal fidelity. Among these, the Horseshoe prior has gained notable attention for its capacity to simultaneously shrink irrelevant parameters and retain substantial signals. This dissertation explores the Horseshoe prior as a unified framework for sparse Bayesian inference across theory, simulation, and real-world application. The first component develops new theoretical results establishing the asymptotic Bayes optimality of the Horseshoe prior in Gaussian graphical models (GGMs). We consider sparse precision matrix estimation …

Impact Of Three Professional Development Models (Online, Face-To-Face, And Hybrid) On Bhutanese Inservice Science Teachers' Conceptions Of Aspects Of Nature Of Science (Nos) With Reports Of Translation Of Nos Content Into Classroom Teaching Practices, Pabi Maya Das

Graduate Theses and Dissertations

Having a scientifically literate citizenry is an asset nationally and globally, and knowledge of the nature of science (NOS) is a crucial element in such literacy. Science teachers are a vital link if students are to understand key elements of the NOS, yet teachers themselves often lack knowledge of NOS and how to integrate NOS content into science lessons. Investigating the impact of a series of inservice professional development experiences using three distinct delivery modes (face-to-face, hybrid, online) for teachers in my home country of Bhutan is the overarching goal of the study reported here. The study used a mixed-methods …

Classifying Advanced Persistent Threat Stages And Techniques Via Graph-Enhanced Network Flow Representations, Md Taef Uddin Nadim

Graduate Theses and Dissertations

Advanced Persistent Threats (APTs) are complex, stealthy attacks that involve multiple stages and many attack techniques used in each stage, making them difficult to defend against. Although many solutions can detect APTs, most of them only detect the existence of attack, but cannot produce fine-grained classification over the stage of the APT and the specific attack technique used. Some existing solutions can classify the stages of APT, but few of them provide attack technique classification, and existing work do not provide interpretability for the classification or countermeasures for the attack. In this thesis work, we propose a solution named CAPTure, …

The Case Against Finean Essentialism, Miles Thibodeaux

Graduate Theses and Dissertations

In this thesis, I survey, critique, and add to recent arguments against Finean Essentialism: the view that all de re modal facts are metaphysically explained by essences. Arguments against Finean Essentialism generally fall into two categories: (a) Finean Essentialism risks contradicting commonly held views or suppositions, or (b) Finean Essentialism involves an explanatory gap, vicious circularity, or a vicious regress. While the details of the arguments within each category differ significantly, it is useful to group them in this way given the relevant implications they have for one another. I will argue that the proposed critiques from category (a) are …

Strain Induced Quantum Emitters In Monolayer Wse₂: Fabrication And Characterization Of Dimple Dot Devices, Garrett Maxwell Kitterman

Graduate Theses and Dissertations

Strain induced defects in monolayer tungsten diselenide (WSe₂) give rise to localized exciton funnels, offering a promising approach for the development of tunable quantum emitters. The quantum devices fabricated for this thesis used a modified dimple dot geometry, in which nano indentation creates a strain profile on the monolayer WSe₂. This allows for the funneling of excitons to a confined region. These strain induced funnels enable localized emission from single excitons in WSe₂. Device fabrication was carried out through mechanical exfoliation, dry transfer, and electron beam lithography of Cr/Au gates on a SiO₂ substrate. These devices were then characterized using …

Synthesis, Structural Characterization And Optical Studies Of Silver-Indium-(Zinc)-Chalcogenide Fluorescent Quantum Dots, Sujal Acharya

Graduate Theses and Dissertations

Developing a non-toxic, high-performance fluorescent nanomaterial is crucial for overcoming the environmental and health restrictions of current cadmium, and lead based quantum dots (QDs), which limit the application of quantum dots in optoelectronics and bioimaging. In this thesis, we synthesized environmentally friendly AgInS2 QDs by a colloidal method, systematically altering the In/Ag precursor ratio from 2 to 6 to study the impact on their optical and photophysical properties. Our goals were to find the optimal stoichiometry for maximum quantum efficiency and stability. We also investigated further improving optical and photophysical properties through shelling with ZnS. The emission spectra appeared broad, …

Structure, Thermodynamics, And Dynamics Of Acetonitrile In Titan-Like Conditions, Sagar Chandra Roy

Graduate Theses and Dissertations

Titan is one of the most interesting satellites in the solar system. It is the only other place in the solar system containing stable deposits of liquid and a hydrological cycle other than earth. The abundant existence of N2 and CH4 in Titan’s atmosphere makes nitrile formation highly likely both in the atmosphere and surface. Infrared spectrometer data from Voyager 1 expedition revealed the presence of acetonitrile (CH3CN) in the atmosphere along with several other nitriles such as hydrogen cyanide (HCN) and cyanoacetylene (HC3N). According to theoretical models nitrile formation is caused by photodisscociation of nitrogen in the tholin haze …

The Scintillator Surface Detector Of The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, K. Nguyen, D. Nitz, Et Al.

Michigan Tech Publications

Data collected so far by the Pierre Auger Observatory have enabled major advances in ultrahigh energy cosmic ray physics and demonstrated that improved determination of masses of primary cosmic-ray particles, preferably on an event-by-event basis, is necessary for understanding their origin and nature. Improvement in primary mass measurements was the main motivation for the upgrade of the Pierre Auger Observatory, called AugerPrime. As part of this upgrade, scintillator detectors are added to the existing water-Cherenkov surface detector stations. By making use of the differences in detector response to the electromagnetic particles and muons between scintillator and water-Cherenkov detectors, the electromagnetic …