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Articles 10681 - 10710 of 302433

Full-Text Articles in Physical Sciences and Mathematics

Advances And Perspectives Of Using Stable Isotope Probing (Sip)-Based Technologies In Contaminant Biodegradation, Jinha Kim, Myung Hwangbo, Chih-Hsuan Shih, Kung-Hui Chu Sep 2023

Advances And Perspectives Of Using Stable Isotope Probing (Sip)-Based Technologies In Contaminant Biodegradation, Jinha Kim, Myung Hwangbo, Chih-Hsuan Shih, Kung-Hui Chu

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Highlights

  • Advances of SIP-based techniques/applications are comprehensively reviewed.

  • Varying stable isotopes types/numbers/ positions reinforce biodegradation studies.

  • SIP identifies microbes capable of co-metabolic degradation of contaminants.

  • Single-cell SIP.and qSIP are promising to overcome cross-feeding effects.

Abstract

Stable isotope probing (SIP) is a powerful tool to study microbial community structure and function in both nature and engineered environments. Coupling with advanced genomics and other techniques, SIP studies have generated substantial information to allow researchers to draw a clearer picture of what is occurring in complex microbial ecosystems. This review provides an overview of the advances of SIP-based technologies over time, summarizes the …


Impact Of Thermal Water On Environment: Case Study Of Mila And Guelma Region, Algeria, Rima Kifouche, Foued Bouaicha, Oualid Bouteraa Sep 2023

Impact Of Thermal Water On Environment: Case Study Of Mila And Guelma Region, Algeria, Rima Kifouche, Foued Bouaicha, Oualid Bouteraa

Bulletin of the Mineral Research and Exploration

A hydrochemical characterization of the waters of the study region (North-East Algeria) was carried out following samples taken at 36 thermal springs and their effluents during May 2022. The analysis of the waters allowed to establish the chemical facies and their classification according to the Stuyfzand’s method and to deduce the aptitude of these waters for irrigation and the risks of salinity. The results revealed physico-chemical characteristics, relatively, variable. Q-mode cluster analysis was applied to the thermal water, generated four (4) groups clusters. Group1 represent a group of waters with low salinity dominated by Na-HCO3; Stuyfzand’s classification indicated that the …


The Bactericidal Activity Of A Novel Aneurinibacillus Aneurinilyticus Isolate Effectively Controls Foodborne Pathogens Campylobacter Jejuni And Listeria Monocytogenes, Peter M. Rubinelli, Rohana Liyanage, Jackson Lay, Jennifer C. Acuff Sep 2023

The Bactericidal Activity Of A Novel Aneurinibacillus Aneurinilyticus Isolate Effectively Controls Foodborne Pathogens Campylobacter Jejuni And Listeria Monocytogenes, Peter M. Rubinelli, Rohana Liyanage, Jackson Lay, Jennifer C. Acuff

Chemistry & Biochemistry Faculty Publications and Presentations

Human zoonotic infection with Campylobacter is a major cause of gastroenteritis in the United States and worldwide. Listeria monocytogenes causes a potentially fatal infection in humans and is often attributed to contaminated food. Genetic typing has demonstrated that Campylobacter infection is often associated with the consumption of contaminated poultry products, with Campylobacter often colonizing the poultry gastrointestinal tract, while listeriosis is commonly associated with the consumption of contaminated ready-to-eat (RTE) foods. In this study, a strain of endospore-forming bacterium (strain NH) that is bactericidal towards the human food pathogens Campylobacter jejuni and Listeria monocytogenes was identified and characterized. Transwell experiments …


Greenhouse Gas Emissions And Fire Behavior Impacts Following California Fuel Treatments, Lindsay M. Senechal Sep 2023

Greenhouse Gas Emissions And Fire Behavior Impacts Following California Fuel Treatments, Lindsay M. Senechal

Master of Science in Environmental Sciences and Management Projects

Fuel treatments are being increasingly applied across California landscapes as communities struggle to recover from wildfire disasters nationwide. Increased funding for treatments stems from grants under CARB’s Greenhouse Gas Reduction Fund and funding requires reports accounting the yielded benefits from these fuel treatments. Using data from real-world local scale fuel treatments, I used the forest simulation model FVSFEE and fire behavior software IFTDSS to quantify GHG emission benefits and fire behavior impacts 70 years after treatment. Results suggest that fuel treatments do not yield significant GHG benefits, and fire behavior impacts (conditional flame length) are minimal but overall show slight …


Establishing A Monitoring Framework To Evaluate Impacts Of Grazing Exclusion And Inform Restoration At Santa Rita Ranch, Annie Booth, Annie Booth Sep 2023

Establishing A Monitoring Framework To Evaluate Impacts Of Grazing Exclusion And Inform Restoration At Santa Rita Ranch, Annie Booth, Annie Booth

Master of Science in Environmental Sciences and Management Projects

Santa Rita Ranch is a 1,750-acre cattle ranch in Templeton, California, that was privately owned and continuously grazed for the past 70 years. In 2021, The Land Conservancy of San Luis Obispo (LCSLO) acquired the property, and in the winter of 2022, they built a fence that bisects the ranch, excluding the cattle from 800 acres to preserve the riparian habitat. The LCSLO is currently defining the ecological baseline for the ranch to inform future management decisions. Given that cattle grazing has many environmental tradeoffs, they wanted to establish a long-term monitoring study to understand how relieving the pressures of …


Pumping-Induced Drawdown Of Streams In Proximity To Agricultural Wells, Sara Alina Sternberg Sep 2023

Pumping-Induced Drawdown Of Streams In Proximity To Agricultural Wells, Sara Alina Sternberg

Master of Science in Environmental Sciences and Management Projects

In the context of unprecedented drought and aquifer overdraft in California, understanding surface water and groundwater connectivity have become increasingly important. While there is a clear understanding of how wells induce drawdown in aquifers (Theis, 1935; Hantush, 1965), secondary effects on local streams have not fully been considered. Current mathematical models targeting aquifer drawdown do not address stream drawdown response in aquifer-stream systems with strong connectivity; instead, they assume the stream to be a constant head boundary. In the drought-stricken and summer-dry climate of California, streams often run dry for months out of the year, which is currently not reflected …


Ironnetinjector: Weaponizing .Net Dynamic Language Runtime Engines, Anthony J. Rose, Scott R. Graham, Jacob Krasnov Sep 2023

Ironnetinjector: Weaponizing .Net Dynamic Language Runtime Engines, Anthony J. Rose, Scott R. Graham, Jacob Krasnov

Faculty Publications

As adversaries evolve their Tactics, Techniques, and Procedures (TTPs) to stay ahead of defenders, Microsoft’s .NET Framework emerges as a common component found in the tradecraft of many contemporary Advanced Persistent Threats (APTs), whether through PowerShell or C#. Because of .NET’s ease of use and availability on every recent Windows system, it is at the forefront of modern TTPs and is a primary means of exploitation. This article considers the .NET Dynamic Language Runtime as an attack vector, and how APTs have utilized it for offensive purposes. The technique under scrutiny is Bring Your Own Interpreter (BYOI), which is the …


Area, Perimeter, Height, And Width Of Rectangle Visibility Graphs, John Caughman, Charles L. Dunn, Joshua Laison, Nancy Ann Neudauer, Colin L. Starr Sep 2023

Area, Perimeter, Height, And Width Of Rectangle Visibility Graphs, John Caughman, Charles L. Dunn, Joshua Laison, Nancy Ann Neudauer, Colin L. Starr

Mathematics and Statistics Faculty Publications and Presentations

A rectangle visibility graph (RVG) is represented by assigning to each vertex a rectangle in the plane with horizontal and vertical sides in such a way that edges in the graph correspond to unobstructed horizontal and vertical lines of sight between their corresponding rectangles. To discretize, we consider only rectangles whose corners have integer coordinates. For any given RVG, we seek a representation with smallest bounding box as measured by its area, perimeter, height, or width (height is assumed not to exceed width).


Climate Stories: South Carolina, Volume 1, Kaelyn Emon, Emily Arnold, Samantha Carter, Hayden Jones, Sarah Owens, Noel A. Tufts, Tiana White, Laura Barbas Rhoden, Christine S. Dinkins Sep 2023

Climate Stories: South Carolina, Volume 1, Kaelyn Emon, Emily Arnold, Samantha Carter, Hayden Jones, Sarah Owens, Noel A. Tufts, Tiana White, Laura Barbas Rhoden, Christine S. Dinkins

Community Based Research

In this volume, you will hear from South Carolina residents about how they have been sensing climate change throughout their lifetimes. All stories have been anonymized with the use of pseudonyms, except where participants asked for their story to be associated with their name.


Uncertainties In Retrieval Of Remote Sensing Reflectance From Ocean Color Satellite Observations, Eder I. Herrera Estrella Sep 2023

Uncertainties In Retrieval Of Remote Sensing Reflectance From Ocean Color Satellite Observations, Eder I. Herrera Estrella

Dissertations, Theses, and Capstone Projects

Ocean Color radiometry uses remote sensing to interpret ocean dynamics by retrieving remote sensing reflectance (𝑅𝑟𝑠) from satellite imagery at different scales and over different time periods. 𝑅𝑟𝑠 spectrum characterizes the ocean color that we observe, and from which we can discern concentrations of chlorophyll, organic and inorganic particles, and carbon fluxes in the ocean and atmosphere. 𝑅𝑟𝑠 is derived from the total radiance at the top of the atmosphere (TOA). However, it only represents up to ten percent of the total signal. Hence, the retrieval of 𝑅𝑟𝑠 from the total radiance at TOA involves the application of atmospheric correction …


Optimization And Application Of Graph Neural Networks, Shuo Zhang Sep 2023

Optimization And Application Of Graph Neural Networks, Shuo Zhang

Dissertations, Theses, and Capstone Projects

Graph Neural Networks (GNNs) are widely recognized for their potential in learning from graph-structured data and solving complex problems. However, optimal performance and applicability of GNNs have been an open-ended challenge. This dissertation presents a series of substantial advances addressing this problem. First, we investigate attention-based GNNs, revealing a critical shortcoming: their ignorance of cardinality information that impacts their discriminative power. To rectify this, we propose Cardinality Preserved Attention (CPA) models that can be applied to any attention-based GNNs, which exhibit a marked improvement in performance. Next, we introduce the Directional Node Pair (DNP) descriptor and the Robust Molecular Graph …


Rotation Period Distributions And Light Curve Morphologies Of Low Mass Stars And Young Associations, Mark Popinchalk Sep 2023

Rotation Period Distributions And Light Curve Morphologies Of Low Mass Stars And Young Associations, Mark Popinchalk

Dissertations, Theses, and Capstone Projects

This dissertation is centered around the rotation periods of low-mass stars and association of young stars. Rotation periods are a link to the age of the star, as they lose angular momentum over time. To understand how this angular momentum evolves requires understanding the rotation period distributions of a range of stellar types and ages. Traditionally, M dwarf stars and young stars were challenging to describe due to their intrinsic faintness and dispersed sky positions respectively. I approached this subject from several directions.


Binding Of ΒL-Crystallin With Models Of Animal And Human Eye Lens-Lipid Membrane, Preston Hazen, Geraline Trossi-Torres, Nawal K. Khadka, Raju Timsina, Laxman Mainali Sep 2023

Binding Of ΒL-Crystallin With Models Of Animal And Human Eye Lens-Lipid Membrane, Preston Hazen, Geraline Trossi-Torres, Nawal K. Khadka, Raju Timsina, Laxman Mainali

Physics Faculty Publications and Presentations

Several discoveries show that with age and cataract formation, β-crystallin binds with the lens membrane or associates with other lens proteins, which bind with the fiber cell plasma membrane, accompanied by light scattering and cataract formation. However, how lipids (phospholipids and sphingolipids) and cholesterol (Chol) influence β-crystallin binding to the membrane is unclear. This research aims to elucidate the role of lipids and Chol in the binding of β-crystallin to the membrane and the membrane’s physical properties (mobility, order, and hydrophobicity) with β-crystallin binding. We used electron paramagnetic resonance (EPR) spin-labeling methods to investigate the binding of βL-crystallin …


Final Butte Reduction Works (Brw) Phase Iii Quality Assurance Project Plan (Qapp) Request For Change Brw-2023-03, Josh Bryson Sep 2023

Final Butte Reduction Works (Brw) Phase Iii Quality Assurance Project Plan (Qapp) Request For Change Brw-2023-03, Josh Bryson

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Evaluation And Description Of Nature-Based Engineering Stream Restoration Through Dutton Shadyside Park, Julie Wildschut, Andrea Lubberts, David P. Warners, Haley Weesies Sep 2023

Evaluation And Description Of Nature-Based Engineering Stream Restoration Through Dutton Shadyside Park, Julie Wildschut, Andrea Lubberts, David P. Warners, Haley Weesies

Faculty and Professional Research

As land uses change over time, from wetlands and forests to agricultural fields, suburban neighborhoods, and commercial areas, stormwater runoff increases in volume and moves more rapidly into nearby streams. This altered hydrology conveys pollutants directly to local waterways and increases erosion, resulting in deeply entrenched channels with steep banks lacking vegetation. Plaster Creek, located near Grand Rapids, MI, is an example of such an impaired stream, having become channelized and separated from adjacent floodplain habitat along much of its 26-mile length. As part of a Michigan EGLE 319 grant, Plaster Creek Stewards, an initiative of Calvin University, used nature-based …


Endwatch: A Practical Method For Detecting Non-Termination In Real-World Software, Yao Zhang, Xiaofei Xie, Yi Li, Sen Chen, Cen Zhang, Xiaohong Li Sep 2023

Endwatch: A Practical Method For Detecting Non-Termination In Real-World Software, Yao Zhang, Xiaofei Xie, Yi Li, Sen Chen, Cen Zhang, Xiaohong Li

Research Collection School Of Computing and Information Systems

Detecting non-termination is crucial for ensuring program correctness and security, such as preventing denial-of-service attacks. While termination analysis has been studied for many years, existing methods have limited scalability and are only effective on small programs. To address this issue, we propose a practical termination checking technique, called EndWatch, for detecting non-termination through testing. Specifically, we introduce two methods to generate non-termination oracles based on checking state revisits, i.e., if the program returns to a previously visited state at the same program location, it does not terminate. The non-termination oracles can be incorporated into testing tools (e.g., AFL used in …


Advances And Perspectives Of Using Stable Isotope Probing (Sip)-Based Technologies In Contaminant Biodegradation, Jinha Kim, Myung Hwangbo, Chih-Hsuan Shih, Kung-Hui Chu Sep 2023

Advances And Perspectives Of Using Stable Isotope Probing (Sip)-Based Technologies In Contaminant Biodegradation, Jinha Kim, Myung Hwangbo, Chih-Hsuan Shih, Kung-Hui Chu

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Stable isotope probing (SIP) is a powerful tool to study microbial community structure and function in both nature and engineered environments. Coupling with advanced genomics and other techniques, SIP studies have generated substantial information to allow researchers to draw a clearer picture of what is occurring in complex microbial ecosystems. This review provides an overview of the advances of SIP-based technologies over time, summarizes the status of SIP applications to contaminant biodegradation, provides critical perspectives on ecological interactions within the community, and important factors (controllable and non-controllable) to be considered in SIP experimental designs and data interpretation. Current trend and …


Chloeia Rozbaczyloi, A New Species Of Polychaete (Archinominae: Amphinomidae) And First Record Of The Family For The Nazca Ridge, Southeastern Pacific Ocean, Juan I. Cañete, María S. Romero, Erin E. Easton, Ariadna Mecho, Javier Sellanes Sep 2023

Chloeia Rozbaczyloi, A New Species Of Polychaete (Archinominae: Amphinomidae) And First Record Of The Family For The Nazca Ridge, Southeastern Pacific Ocean, Juan I. Cañete, María S. Romero, Erin E. Easton, Ariadna Mecho, Javier Sellanes

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Highlights

  • A new species of amphinomid polychaete, Chloeia rozbaczyloi sp. nov. is described.

  • The new species inhabits poorly explored seamounts of the remote Nazca Ridge off Chile.

  • This finding constitutes the first report of the genus Chloeia for Chilean waters.

  • Genetic data for Chloeia rozbaczyloi sp. nov is provided.

  • The new species is reported for seamounts lying within the recently created Nazca Desventuradas Marine Park.

Abstract

The amphinomid polychaete Chloeia rozbaczyloi sp. nov., collected from seamounts of the Nazca Ridge (NR), northwest of Desventuradas islands, southeastern Pacific Ocean, is described. The new species was observed on only two of seven …


U.S. Parents’ Intentions To Use Anti-Bullying Apps: Insights From A Comprehensive Model, Brittany Wheeler, Katie Baumel, Deborah Hall, Yasin N. Silva Sep 2023

U.S. Parents’ Intentions To Use Anti-Bullying Apps: Insights From A Comprehensive Model, Brittany Wheeler, Katie Baumel, Deborah Hall, Yasin N. Silva

Computer Science: Faculty Publications and Other Works

Cyberbullying has become a prominent risk for youth and an increasing concern for parents. To help parents reduce their child’s cyberbullying risk, anti-bullying apps (ABAs)—mobile applications for identifying and preventing instances of cyberbullying—have been developed in recent years. Given that ABAs are an emerging technology, limited research has been conducted to understand the factors predicting parents’ intentions to use them. Drawing on three interdisciplinary theoretical frameworks, a sample of parents in the U.S. recruited through Amazon Mechanical Turk completed an online survey to assess parents’ knowledge of, attitudes about, and intentions to use ABAs. Participants also rated the importance of …


Iowa Waste Reduction Center Newsletter, September 2023, University Of Northern Iowa. Iowa Waste Reduction Center. Sep 2023

Iowa Waste Reduction Center Newsletter, September 2023, University Of Northern Iowa. Iowa Waste Reduction Center.

Iowa Waste Reduction Center Newsletter

In This Issue:

--- Representative Hinson Visits STAR4D
--- Cultivating Change: Community Gardens and Farmer Market Compost and Donation Project Wrap Up
--- IWRC Keeping Tabs on PFAS
--- The New Fashion Police: Fasion as Waste
--- Emerging Professionals Networking Opportunity
--- Iowa Recycling and Solid Waste Management Conference
--- Industry News


Centrality Effects On Heavy-Flavor Quark Production And Invariant Yield In Phenix Proton–Gold Collisions At Center-Of-Mass Energy 200 Gev, And Assembly, Testing, Calibration, And Installation Of The Sphenix Hadronic Calorimeters, Daniel Richford Sep 2023

Centrality Effects On Heavy-Flavor Quark Production And Invariant Yield In Phenix Proton–Gold Collisions At Center-Of-Mass Energy 200 Gev, And Assembly, Testing, Calibration, And Installation Of The Sphenix Hadronic Calorimeters, Daniel Richford

Dissertations, Theses, and Capstone Projects

Hadrons created in heavy-ion collisions interact with the open color-charge of the quark-gluon plasma through their constituent quarks. The medium imparts substantial modifications to heavy-flavor hadrons' momentum spectra. For collisions of small systems, the centrality of those collisions affects both the production of heavy-quarks and the medium modifications that the heavy-quarks experience. This analysis uses the PHENIX detector at the Relativistic Heavy Ion Collider, which collected data from proton--gold collisions in 2015, with a trigger to preference the collection of the five-percent most-central collisions. This analysis uses the distance-of-closest-approach of electron tracks to study semileptonic decays from charm and bottom …


Stereospecific Cross-Coupling Reactions With Enantioenriched Electrophiles, Iv Kraja Sep 2023

Stereospecific Cross-Coupling Reactions With Enantioenriched Electrophiles, Iv Kraja

Dissertations, Theses, and Capstone Projects

We have developed a novel palladium-catalyzed stereospecific C(sp3)–C(sp3) Stille cross-coupling reaction between carbastannatrane nucleophiles and α-(trifluoromethyl) benzylic tosylates. This constitutes the first example of a stereospecific C(sp3)–C(sp3) cross-coupling reaction using an enantioenriched electrophile and an alkyltin nucleophile. This system has the potential to be extended to cross-coupling reactions using configurationally stable enantioenriched nucleophiles, thus enabling stereochemical control of two newly formed contiguous stereocenters. Generating enantioenriched α-(trifluoromethyl) benzylic compounds also has importance in pharmaceutical and agrochemical industries.

Through the development of this reaction, our findings show that the addition …


Constrained Quantization For A Uniform Distribution With Respect To A Family Of Constraints, Megha Pandey, Mrinal Kanti Roychowdhury Sep 2023

Constrained Quantization For A Uniform Distribution With Respect To A Family Of Constraints, Megha Pandey, Mrinal Kanti Roychowdhury

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In this paper, with respect to a family of constraints for a uniform probability distribution we determine the optimal sets of n-points and the nth constrained quantization errors for all positive integers n. We also calculate the constrained quantization dimension and the constrained quantization coefficient. The work in this paper shows that the constrained quantization dimension of an absolutely continuous probability measure depends on the family of constraints and is not always equal to the Euclidean dimension of the underlying space where the support of the probability measure is defined.


Carbon-Aware Mine Planning With A Novel Multi-Objective Framework, Nurul Asyikeen Binte Azhar, Aldy Gunawan, Shih-Fen Cheng, Erwin Leonardi Sep 2023

Carbon-Aware Mine Planning With A Novel Multi-Objective Framework, Nurul Asyikeen Binte Azhar, Aldy Gunawan, Shih-Fen Cheng, Erwin Leonardi

Research Collection School Of Computing and Information Systems

The logistical complication of long-term mine planning involves deciding the sequential extraction of materials from the mine pit and their subsequent processing steps based on geological, geometrical, and resource constraints. The net present value (NPV) of profit over the mine's lifespan usually forms the sole objective for this problem, which is considered as the NP-hard precedence-constrained production scheduling problem (PCPSP) as well. However, increased pressure for more sustainable and carbon-aware industries also calls for environmental indicators to be considered. In this paper, we enhance the generic PCPSP formulation into a multi-objective optimization (MOO) problem whereby carbon cost forms an additional …


Testsgd: Interpretable Testing Of Neural Networks Against Subtle Group Discrimination, Mengdi Zhang, Jun Sun, Jingyi Wang, Bing Sun Sep 2023

Testsgd: Interpretable Testing Of Neural Networks Against Subtle Group Discrimination, Mengdi Zhang, Jun Sun, Jingyi Wang, Bing Sun

Research Collection School Of Computing and Information Systems

Discrimination has been shown in many machine learning applications, which calls for sufficient fairness testing before their deployment in ethic-relevant domains. One widely concerning type of discrimination, testing against group discrimination, mostly hidden, is much less studied, compared with identifying individual discrimination. In this work, we propose TestSGD, an interpretable testing approach which systematically identifies and measures hidden (which we call ‘subtle’) group discrimination of a neural network characterized by conditions over combinations of the sensitive attributes. Specifically, given a neural network, TestSGD first automatically generates an interpretable rule set which categorizes the input space into two groups. Alongside, TestSGD …


K-St: A Formal Executable Semantics Of The Structured Text Language For Plcs, Kun Wang, Jingyi Wang, Christopher M. Poskitt, Xiangxiang Chen, Jun Sun, Peng Cheng Sep 2023

K-St: A Formal Executable Semantics Of The Structured Text Language For Plcs, Kun Wang, Jingyi Wang, Christopher M. Poskitt, Xiangxiang Chen, Jun Sun, Peng Cheng

Research Collection School Of Computing and Information Systems

Programmable Logic Controllers (PLCs) are responsible for automating process control in many industrial systems (e.g. in manufacturing and public infrastructure), and thus it is critical to ensure that they operate correctly and safely. The majority of PLCs are programmed in languages such as Structured Text (ST). However, a lack of formal semantics makes it difficult to ascertain the correctness of their translators and compilers, which vary from vendor-to-vendor. In this work, we develop K-ST, a formal executable semantics for ST in the K framework. Defined with respect to the IEC 61131-3 standard and PLC vendor manuals, K-ST is a high-level …


Rosas: Deep Semi-Supervised Anomaly Detection With Contamination-Resilient Continuous Supervision, Hongzuo Xu, Yijie Wang, Guansong Pang, Songlei Jian, Ning Liu, Yongjun Wang Sep 2023

Rosas: Deep Semi-Supervised Anomaly Detection With Contamination-Resilient Continuous Supervision, Hongzuo Xu, Yijie Wang, Guansong Pang, Songlei Jian, Ning Liu, Yongjun Wang

Research Collection School Of Computing and Information Systems

Semi-supervised anomaly detection methods leverage a few anomaly examples to yield drastically improved performance compared to unsupervised models. However, they still suffer from two limitations: 1) unlabeled anomalies (i.e., anomaly contamination) may mislead the learning process when all the unlabeled data are employed as inliers for model training; 2) only discrete supervision information (such as binary or ordinal data labels) is exploited, which leads to suboptimal learning of anomaly scores that essentially take on a continuous distribution. Therefore, this paper proposes a novel semi-supervised anomaly detection method, which devises contamination-resilient continuous supervisory signals. Specifically, we propose a mass interpolation method …


Generative Model-Based Testing On Decision-Making Policies, Zhuo Li, Xiongfei Wu, Derui Zhu, Mingfei Cheng, Siyuan Chen, Fuyuan Zhang, Xiaofei Xie, Lei Ma, Jianjun Zhao Sep 2023

Generative Model-Based Testing On Decision-Making Policies, Zhuo Li, Xiongfei Wu, Derui Zhu, Mingfei Cheng, Siyuan Chen, Fuyuan Zhang, Xiaofei Xie, Lei Ma, Jianjun Zhao

Research Collection School Of Computing and Information Systems

The reliability of decision-making policies is urgently important today as they have established the fundamentals of many critical applications, such as autonomous driving and robotics. To ensure reliability, there have been a number of research efforts on testing decision-making policies that solve Markov decision processes (MDPs). However, due to the deep neural network (DNN)-based inherit and infinite state space, developing scalable and effective testing frameworks for decision-making policies still remains open and challenging.In this paper, we present an effective testing framework for decision-making policies. The framework adopts a generative diffusion model-based test case generator that can easily adapt to different …


When Routing Meets Recommendation: Solving Dynamic Order Recommendations Problem In Peer-To-Peer Logistics Platforms, Zhiqin Zhang, Waldy Joe, Yuyang Er, Hoong Chuin Lau Sep 2023

When Routing Meets Recommendation: Solving Dynamic Order Recommendations Problem In Peer-To-Peer Logistics Platforms, Zhiqin Zhang, Waldy Joe, Yuyang Er, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

Peer-to-Peer (P2P) logistics platforms, unlike traditional last-mile logistics providers, do not have dedicated delivery resources (both vehicles and drivers). Thus, the efficiency of such operating model lies in the successful matching of demand and supply, i.e., how to match the delivery tasks with suitable drivers that will result in successful assignment and completion of the tasks. We consider a Same-Day Delivery Problem (SDDP) involving a P2P logistics platform where new orders arrive dynamically and the platform operator needs to generate a list of recommended orders to the crowdsourced drivers. We formulate this problem as a Dynamic Order Recommendations Problem (DORP). …


Autoconf: Automated Configuration Of Unsupervised Learning Systems Using Metamorphic Testing And Bayesian Optimization, Lwin Khin Shar, Goknil Arda, Erik Johannes Husom, Sagar Sen Sen, Naing Tun Yan, Kisub Kim Sep 2023

Autoconf: Automated Configuration Of Unsupervised Learning Systems Using Metamorphic Testing And Bayesian Optimization, Lwin Khin Shar, Goknil Arda, Erik Johannes Husom, Sagar Sen Sen, Naing Tun Yan, Kisub Kim

Research Collection School Of Computing and Information Systems

Unsupervised learning systems using clustering have gained significant attention for numerous applications due to their unique ability to discover patterns and structures in large unlabeled datasets. However, their effectiveness highly depends on their configuration, which requires domain-specific expertise and often involves numerous manual trials. Specifically, selecting appropriate algorithms and hyperparameters adds to the com- plexity of the configuration process. In this paper, we propose, apply, and assess an automated approach (AutoConf) for config- uring unsupervised learning systems using clustering, leveraging metamorphic testing and Bayesian optimization. Metamorphic testing is utilized to verify the configurations of unsupervised learning systems by applying a …