Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Purdue University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1 - 30 of 2736

Full-Text Articles in Physical Sciences and Mathematics

Improving Developers' Understanding Of Regex Denial Of Service Tools Through Anti-Patterns And Fix Strategies, Sk Adnan Hassan, Zainab Aamir, Dongyoon Lee, James C. Davis, Francisco Servant Jan 2023

Improving Developers' Understanding Of Regex Denial Of Service Tools Through Anti-Patterns And Fix Strategies, Sk Adnan Hassan, Zainab Aamir, Dongyoon Lee, James C. Davis, Francisco Servant

Department of Electrical and Computer Engineering Faculty Publications

Regular expressions are used for diverse purposes, including input validation and firewalls. Unfortunately, they can also lead to a security vulnerability called ReDoS (Regular Expression Denial of Service), caused by a super-linear worst-case execution time during regex matching. Due to the severity and prevalence of ReDoS, past work proposed automatic tools to detect and fix regexes. Although these tools were evaluated in automatic experiments, their usability has not yet been studied; usability has not been a focus of prior work. Our insight is that the usability of existing tools to detect and fix regexes will improve if we complement them …


Polarimetric Radar And Vhf Lightning Observations In A Significantly Tornadic Supercell, Jacob Bruss Nov 2022

Polarimetric Radar And Vhf Lightning Observations In A Significantly Tornadic Supercell, Jacob Bruss

The Journal of Purdue Undergraduate Research

No abstract provided.


Redefining Research In Nanotechnology Simulations: A New Approach To Data Caching And Analysis, Darin Tsai, Alan Zhang, Aloysius Rebeiro Nov 2022

Redefining Research In Nanotechnology Simulations: A New Approach To Data Caching And Analysis, Darin Tsai, Alan Zhang, Aloysius Rebeiro

The Journal of Purdue Undergraduate Research

No abstract provided.


Agricultural Aerosols: The Impact Of Farming Activity On Ice Nucleating Particles, Joseph Robinson Nov 2022

Agricultural Aerosols: The Impact Of Farming Activity On Ice Nucleating Particles, Joseph Robinson

The Journal of Purdue Undergraduate Research

Farming activities cause particles such as soil dust and plant material to be emitted into the air. Some of these aerosols can become ice nucleating particles (INPs), serving as seeds for ice and mixed-phase clouds. While there have been ground-based studies of these particles in the western Great Plains and a single air-based study in Indiana, there is a distinct lack of ground-based studies in the Midwest. In Indiana, over two-thirds of the state is farmland, with over 75% of land in Tippecanoe County used for agriculture. Despite farming being such an essential part of life in Indiana, the connection …


Processing Of Plastic Film From Potato Starch: Effect Of Drying Methods, Kourtney Collier, Samantha Goins, Austin Chirgwin, Isabelle Stanfield Nov 2022

Processing Of Plastic Film From Potato Starch: Effect Of Drying Methods, Kourtney Collier, Samantha Goins, Austin Chirgwin, Isabelle Stanfield

The Journal of Purdue Undergraduate Research

Starch-based plastics are biodegradable, compostable compounds made of starch and plasticizers from natural sources. Their fabrication involves the starch-plasticizer reaction at 70–100°C followed by cooling and drying. Th e most common drying method is air drying (natural convection), which is effective but slow. Th e objective of this work is to study the effect of fast drying (forced convection) on the quality of the plastic film. Th is work compares the effects of drying conditions and drying rate on warpage, shrinkage rate, and presence of bubbles. Five drying methods are studied: (1) natural convection with uncovered petri dish, (2) natural …


Supporting The Protect Initiative, Josh Lefton, Jackson Murray, Ahmed Thabet, Sriram Baireddy, Prakash Shukla, Mridul Gupta, Reagan Becker, Julie Ertle, Tony Doan, Aerin Yang Nov 2022

Supporting The Protect Initiative, Josh Lefton, Jackson Murray, Ahmed Thabet, Sriram Baireddy, Prakash Shukla, Mridul Gupta, Reagan Becker, Julie Ertle, Tony Doan, Aerin Yang

Purdue Journal of Service-Learning and International Engagement

Recently, medication dosage errors have received more political and media attention. Dosage errors are the most common medical errors, affecting about 1.5 million people annually.

Furthermore, U.S. poison-control centers reported more than 200,000 cases per year of medication errors. These cases result in medical costs of around $3.5 billion, and children under 6 years old constitute approximately 30% of these cases.

The PROTECT Initiative (Preventing Overdoses and Treatment Errors in Children Taskforce) was launched in 2008 as a collaborative effort between public health agencies and patient advocates to minimize dosage errors.

In alignment with the PROTECT Initiative effort, this project …


Understanding The Influence Of Perceptual Noise On Visual Flanker Effects Through Bayesian Model Fitting, Jordan Deakin, Dietmar Heinke May 2022

Understanding The Influence Of Perceptual Noise On Visual Flanker Effects Through Bayesian Model Fitting, Jordan Deakin, Dietmar Heinke

MODVIS Workshop

No abstract provided.


A Two-Layer Model Explains Higher-Order Feature Selectivity Of V2 Neurons, Timothy D. Oleskiw, Justin D. Lieber, J. Anthony Movshon, Eero P. Simoncelli May 2022

A Two-Layer Model Explains Higher-Order Feature Selectivity Of V2 Neurons, Timothy D. Oleskiw, Justin D. Lieber, J. Anthony Movshon, Eero P. Simoncelli

MODVIS Workshop

Neurons in cortical area V2 respond selectively to higher-order visual features, such as the quasi-periodic structure of natural texture. However, a functional account of how V2 neurons build selectivity for complex natural image features from their inputs – V1 neurons locally tuned for orientation and spatial frequency – remains elusive.

We made single-unit recordings in area V2 in two fixating rhesus macaques. We presented stimuli composed of multiple superimposed grating patches that localize contrast energy in space, orientation, and scale. V2 activity is modeled via a two-layer linear-nonlinear network, optimized to use a sparse combination of V1-like outputs to account …


Promoting Ecosystem Services By Implementing Agroforestry, Martin L. Emerson Apr 2022

Promoting Ecosystem Services By Implementing Agroforestry, Martin L. Emerson

Ideas: Exhibit Catalog for the Honors College Visiting Scholars Series

A recent proposal to enhance the sustainability of agriculture is agroforestry, the practice of integrating trees into farmland. This technique can be analyzed through the ecosystem services model, which describes the interrelatedness of natural land, managed land, producers, and consumers. Agroforestry could shelter crops from the adverse weather conditions as well as provide habitat for wildlife. On the other hand, implementing agroforestry would also entail the drawback of a substantial upfront cost. Environmental scientists propose that efforts to reinforce ecosystem services could play a significant role in mitigating the effects of global environmental change on agriculture.


Streamlining Project Development Through Planning & Environmental Linkages, Karen Hadley, Brett Lackey Mar 2022

Streamlining Project Development Through Planning & Environmental Linkages, Karen Hadley, Brett Lackey

Purdue Road School

As transportation agencies continue to explore ways to be more efficient in the project development process, they are embracing integrated methodologies like planning and environmental linkages. This tool is practical, yet highly effective and inclusive, and teams across the country are experiencing its value. This presentation will highlight a variety of use cases, discuss lessons learned and best practices, and specifically address how planning and environmental linkages can be applied in Indiana and the Midwest.


A Decade Later – Us 31 Mitigation, Summer R. Elmore Mar 2022

A Decade Later – Us 31 Mitigation, Summer R. Elmore

Purdue Road School

Significant transportation projects are designed and built, but that’s not the end of the story. Wetland and stream mitigation efforts, including monitoring and maintenance, may continue for a decade. This presentation will showcase INDOT mitigation sites—from their creation a decade ago to the awesome results—for projects like US-31. We’ll share timelines, photos, quality data, and challenges identified and addressed over the years.


Comparison Of The Performance Of The Observation-Based Hybrid Edmf And Edmf-Tke Pbl Schemes In 2020 Tropical Cyclone Forecasts From The Globalnested Hurricane Analysis And Forecast System, Andrew Hazelton, Jun A. Zhang, Sundararaman Gopalakrishnan Feb 2022

Comparison Of The Performance Of The Observation-Based Hybrid Edmf And Edmf-Tke Pbl Schemes In 2020 Tropical Cyclone Forecasts From The Globalnested Hurricane Analysis And Forecast System, Andrew Hazelton, Jun A. Zhang, Sundararaman Gopalakrishnan

Department of Earth, Atmospheric, and Planetary Sciences Faculty Publications

Better representation of the planetary boundary layer (PBL) in numerical models is one of the keys to improving forecasts of TC structure and intensity, including rapid intensification. To meet this goal, our recent work has used observations to improve the eddy-diffusivity mass flux with prognostic turbulent kinetic energy (EDMF-TKE) PBL scheme in the Hurricane Analysis and Forecast System (HAFS). This study builds on that work by comparing a modified version of EDMF-TKE (MEDMF-TKE) with the hybrid EDMF scheme based on a K-profile method (HEDMF-KP) in the 2020 HAFS-globalnest model. Verification statistics based on 101 cases in the 2020 season demonstrate …


Sok: Analysis Of Software Supply Chain Security By Establishing Secure Design Properties, Chinenye Okafor, Taylor R. Schorlemmer, Santiao Torres-Arias, James C. Davis Jan 2022

Sok: Analysis Of Software Supply Chain Security By Establishing Secure Design Properties, Chinenye Okafor, Taylor R. Schorlemmer, Santiao Torres-Arias, James C. Davis

Department of Electrical and Computer Engineering Faculty Publications

This paper systematizes knowledge about secure software supply chain patterns. It identifies four stages of a software supply chain attack and proposes three security properties crucial for a secured supply chain: transparency, validity, and separation. The paper describes current security approaches and maps them to the proposed security properties, including research ideas and case studies of supply chains in practice. It discusses the strengths and weaknesses of current approaches relative to known attacks and details the various security frameworks put out to ensure the security of the software supply chain. Finally, the paper highlights potential gaps in actor and operation-centered …


An Empirical Study On The Impact Of Deep Parameters On Mobile App Energy Usage, Qiang Xu, James C. Davis, Y Charlie Hu, Abhilash Jindal Jan 2022

An Empirical Study On The Impact Of Deep Parameters On Mobile App Energy Usage, Qiang Xu, James C. Davis, Y Charlie Hu, Abhilash Jindal

Department of Electrical and Computer Engineering Faculty Publications

Improving software performance through configuration parameter tuning is a common activity during software maintenance. Beyond traditional performance metrics like latency, mobile app developers are interested in reducing app energy usage. Some mobile apps have centralized locations for parameter tuning, similar to databases and operating systems, but it is common for mobile apps to have hundreds of parameters scattered around the source code. The correlation between these "deep" parameters and app energy usage is unclear. Researchers have studied the energy effects of deep parameters in specific modules, but we lack a systematic understanding of the energy impact of mobile deep parameters. …


Exploiting Input Sanitization For Regex Denial Of Service, Efe Barlas, Xin Du, James C. Davis Jan 2022

Exploiting Input Sanitization For Regex Denial Of Service, Efe Barlas, Xin Du, James C. Davis

Department of Electrical and Computer Engineering Faculty Publications

Web services use server-side input sanitization to guard against harmful input. Some web services publish their sanitization logic to make their client interface more usable, e.g., allowing clients to debug invalid requests locally. However, this usability practice poses a security risk. Specifically, services may share the regexes they use to sanitize input strings — and regex-based denial of service (ReDoS) is an emerging threat. Although prominent service outages caused by ReDoS have spurred interest in this topic, we know little about the degree to which live web services are vulnerable to ReDoS.

In this paper, we conduct the first black-box …


Reflecting On Recurring Failures In Iot Development, Dharun Anandayuvaraj, James C. Davis Jan 2022

Reflecting On Recurring Failures In Iot Development, Dharun Anandayuvaraj, James C. Davis

Department of Electrical and Computer Engineering Faculty Publications

As IoT systems are given more responsibility and autonomy, they offer greater benefits, but also carry greater risks. We believe this trend invigorates an old challenge of software engineering: how to develop high-risk software-intensive systems safely and securely under market pressures? As a first step, we conducted a systematic analysis of recent IoT failures to identify engineering challenges. We collected and analyzed 22 news reports and studied the sources, impacts, and repair strategies of failures in IoT systems. We observed failure trends both within and across application domains. We also observed that failure themes have persisted over time. To alleviate …


Discrepancies Among Pre-Trained Deep Neural Networks: A New Threat To Model Zoo Reliability, Diego Montes, Pongpatapee Peerapatanapokin, Jeff Schultz, Chengjun Guo, Wenxin Jiang, James C. Davis Jan 2022

Discrepancies Among Pre-Trained Deep Neural Networks: A New Threat To Model Zoo Reliability, Diego Montes, Pongpatapee Peerapatanapokin, Jeff Schultz, Chengjun Guo, Wenxin Jiang, James C. Davis

Department of Electrical and Computer Engineering Faculty Publications

Training deep neural networks (DNNs) takes significant time and resources. A practice for expedited deployment is to use pre-trained deep neural networks (PTNNs), often from model zoos.collections of PTNNs; yet, the reliability of model zoos remains unexamined. In the absence of an industry standard for the implementation and performance of PTNNs, engineers cannot confidently incorporate them into production systems. As a first step, discovering potential discrepancies between PTNNs across model zoos would reveal a threat to model zoo reliability. Prior works indicated existing variances in deep learning systems in terms of accuracy. However, broader measures of reliability for PTNNs from …


Reflections On Software Failure Analysis, Paschal C. Amusuo, Aishwarya Sharma, Siddharth R. Rao, Abbey Vincent, James C. Davis Jan 2022

Reflections On Software Failure Analysis, Paschal C. Amusuo, Aishwarya Sharma, Siddharth R. Rao, Abbey Vincent, James C. Davis

Department of Electrical and Computer Engineering Faculty Publications

Failure studies are important in revealing the root causes, behaviors, and life cycle of defects in software systems. These studies either focus on understanding the characteristics of defects in specific classes of systems or the characteristics of a specific type of defect in the systems it manifests in. Failure studies have influenced various software engineering research directions, especially in the area of software evolution, defect detection, and program repair.

In this paper, we reflect on the conduct of failure studies in software engineering. We reviewed a sample of 52 failure study papers. We identified several recurring problems in these studies, …


A Note From The Co-Editors, Fayth Schutter Dec 2021

A Note From The Co-Editors, Fayth Schutter

Ideas: Exhibit Catalog for the Honors College Visiting Scholars Series

An introduction to the fourth issue of the third volume of Ideas Magazine, concerning the career and thoughts of Col. Richard Covey.


A Note From The Co-Editors, Fayth Schutter Dec 2021

A Note From The Co-Editors, Fayth Schutter

Ideas: Exhibit Catalog for the Honors College Visiting Scholars Series

An introduction to the first issue of the third volume of Ideas Magazine, concerning the work and research of Dr. Shoshana Magnet.


Frames For Justice Consciousness, Colin M. Gray, Rua M. Williams, Paul Parsons, Austin L. Toombs, Abbee Westbrook Nov 2021

Frames For Justice Consciousness, Colin M. Gray, Rua M. Williams, Paul Parsons, Austin L. Toombs, Abbee Westbrook

Computer Graphics Technology Open Educational Resources

We describe how UX design students become aware of citizen-engaged design work, and indicate the extent to which a progression toward social justice-focused design work might be possible in a single project cycle. Our study site is a sophomore-level UX design studio at a large Midwestern US university—part of a five-semester sequence in which students engage in a range of projects that address competence in user research, prototyping, and evaluation. The project cycle we focus on directly challenges the apolitical framing in most foundational UX methods literature, explicitly asking students to engage with issues of power disparities. We analyzed …


Automated Detection And Characterization Of Mesocyclones In X-Band Radar Observations, Raychel E. Nelson Oct 2021

Automated Detection And Characterization Of Mesocyclones In X-Band Radar Observations, Raychel E. Nelson

The Journal of Purdue Undergraduate Research

No abstract provided.


Participatory Action Research: Undergraduate Researchers Engaging Secondary Students In Social Justice Mathematics, Isabelle Miller, Alexis Grimes, Camryn Adkison Oct 2021

Participatory Action Research: Undergraduate Researchers Engaging Secondary Students In Social Justice Mathematics, Isabelle Miller, Alexis Grimes, Camryn Adkison

The Journal of Purdue Undergraduate Research

No abstract provided.


The Effects Of Climate Change On The Vertical Structure Of Severe Weather Environments, Isaac Davis Oct 2021

The Effects Of Climate Change On The Vertical Structure Of Severe Weather Environments, Isaac Davis

The Journal of Purdue Undergraduate Research

No abstract provided.


The Effects Of Environmental Copper Exposure On The Behavior And Morphology Of Developing Zebrafish, Christina Kaucic Oct 2021

The Effects Of Environmental Copper Exposure On The Behavior And Morphology Of Developing Zebrafish, Christina Kaucic

The Journal of Purdue Undergraduate Research

No abstract provided.


Automated Data Processing: Making Community Indicators Possible For Lafayette, Indiana, Jace T. Newell, Eli W. Coltin, Eric D. Flaningam Oct 2021

Automated Data Processing: Making Community Indicators Possible For Lafayette, Indiana, Jace T. Newell, Eli W. Coltin, Eric D. Flaningam

The Journal of Purdue Undergraduate Research

No abstract provided.


Experience Doesn't Matter, But The Direction Does, Hailey Blythe Oct 2021

Experience Doesn't Matter, But The Direction Does, Hailey Blythe

The Journal of Purdue Undergraduate Research

No abstract provided.


A Nosy Neighbor: Purification And Functional Characterization Of Lpg2149, Ashley M. Holahan Oct 2021

A Nosy Neighbor: Purification And Functional Characterization Of Lpg2149, Ashley M. Holahan

The Journal of Purdue Undergraduate Research

Ubiquitination is a process that marks proteins for various cell-signaling pathways, namely protein degradation and other processes. Th ese pathways are essential in a wide array of cellular processes, including defense mechanisms against invading pathogens. Th e ubiquitination process is universally found in all eukaryotic organisms, including plants and animals, and thus plays a vital role in cellular homeostasis. Recently, more discoveries have been made on prokaryotic effector proteins that hijack the ubiquitination system even when they do not possess a ubiquitin system of their own. MavC, also known as lpg2147 (Gan, Nakayasu, Hollenbeck, & Luo, 2019; Puvar et al., …


National Chemistry Week: From Irl To The Web, Ilayda Kelley, Daniela Mesa Sanchez Oct 2021

National Chemistry Week: From Irl To The Web, Ilayda Kelley, Daniela Mesa Sanchez

Purdue Journal of Service-Learning and International Engagement

National Chemistry Week, an outreach program initiated by the American Chemical Society (ACS), encourages scientists to bring their love of chemistry to their community. Celebrated nationwide, ACS invites businesses, schools, and individuals to organize and participate in community events to promote the value of chemistry in everyday life. The Purdue graduate student chapter of Iota Sigma Pi, a national honor society for women in chemistry, annually organizes one such celebration. On a normal year, this event is a large logistical undertaking in which 100+ volunteers go directly to over 70 local elementary school classrooms and perform a series of activities …


Formation Of Microcages From A Collagen Mimetic Peptide Via Metal-Ligand Interactions, Jeremy Gleaton, Ryan W. Curtis, Jean Chmielewski Aug 2021

Formation Of Microcages From A Collagen Mimetic Peptide Via Metal-Ligand Interactions, Jeremy Gleaton, Ryan W. Curtis, Jean Chmielewski

Department of Chemistry Faculty Publications

Here, the hierarchical assembly of a collagen mimetic peptide (CMP) displaying four bipyridine moieties is described. The CMP was capable of forming triple helices followed by self-assembly into disks and domes. Treatment of these disks and domes with metal ions such as Fe(II), Cu(II), Zn(II), Co(II), and Ru(III) triggered the formation of microcages, and micron-sized cup-like structures. Mechanistic studies suggest that the formation of the microcages proceeds from the disks and domes in a metal-dependent fashion. Fluorescently-labeled dextrans were encapsulated within the cages and displayed a time-dependent release using thermal conditions.