Digital Commons Network^™

On Analysing Student Resilience In Higher Education Programs Using A Data-Driven Approach, Audrey Tedja Widjaja, Ee Peng Lim, Aldy Gunawan

Research Collection School Of Computing and Information Systems

Analysing student resilience is important as research has shown that resilience is related to students’ academic performance and their persistence through academic setbacks. While questionnaires can be conducted to assess student resilience directly, they suffer from human recall errors and deliberate suppression of true responses. In this paper, we propose ACREA, ACademic REsilience Analytics framework which adopts a datadriven approach to analyse student resilient behavior with the use of student-course data. ACREA defines academic setbacks experienced by students and measures how well students overcome such setbacks using a quasi-experimental design. By applying ACREA on a real world student-course dataset, we …

Channel Integration Services In Online Healthcare Communities, Anqi Zhao, Qian Tang

Research Collection School Of Computing and Information Systems

In online healthcare communities, channel integration services have become the bridge between online and offline channels, enabling patients to easily migrate across channels. Different from pure online services, online-to-offline (On2Off) and offline-to-online (Off2On) channel integration services involve both channels. This study examines the interrelationships between pure online services and channel integration services. Using a panel dataset composed of data from an online healthcare community, we find that pure online services decrease patients’ demand for On2Off integration services but increase their use of Off2On integration services. Our findings suggest that providing healthcare services online can reduce online patients’ needs to visit …

Etherlearn: Decentralizing Learning Via Blockchain, Nguyen Binh Duong Ta, Tian Jun Joel Yang

Research Collection School Of Computing and Information Systems

In institutes of higher learning, most of the time course material development and delivery follow a centralized model which is fully lecturer-controlled. In this model, engaging students as partners in learning is a challenging problem as: 1) students are usually hesitant to contribute due to the fear of getting it wrong, 2) not much incentive for them to put in the extra effort, and 3) current online learning systems lack adequate facilities to support seamless and anonymous interactions between students. In this work, we propose EtherLearn, a blockchain based peer-learning system to distribute the control of how course material and …

Decentralized Deterministic Multi-Agent Reinforcement Learning, Antoine Grosnit, Desmond Cai, Laura Wynter

Research Collection School Of Computing and Information Systems

Recent work in multi-agent reinforcement learning (MARL) by [Zhang, ICML12018] provided the first decentralized actor-critic algorithm to offer convergence guarantees. In that work, policies are stochastic and are defined on finite action spaces. We extend those results to develop a provably-convergent decentralized actor-critic algorithm for learning deterministic policies on continuous action spaces. Deterministic policies are important in many real-world settings. To handle the lack of exploration inherent in deterministic policies we provide results for the off-policy setting as well as the on-policy setting. We provide the main ingredients needed for this problem: the expression of a local deterministic policy gradient, …

Hierarchical Control Of Multi-Agent Reinforcement Learning Team In Real-Time Strategy (Rts) Games, Weigui Jair Zhou, Budhitama Subagdja, Ah-Hwee Tan, Darren Wee Sze Ong

Research Collection School Of Computing and Information Systems

Coordinated control of multi-agent teams is an important task in many real-time strategy (RTS) games. In most prior work, micromanagement is the commonly used strategy whereby individual agents operate independently and make their own combat decisions. On the other extreme, some employ a macromanagement strategy whereby all agents are controlled by a single decision model. In this paper, we propose a hierarchical command and control architecture, consisting of a single high-level and multiple low-level reinforcement learning agents operating in a dynamic environment. This hierarchical model enables the low-level unit agents to make individual decisions while taking commands from the high-level …

Learning To Iteratively Solve Routing Problems With Dual-Aspect Collaborative Transformer, Yining Ma, Jingwen Li, Zhiguang Cao, Wen Song, Le Zhang, Zhenghua Chen, Jing Tang

Research Collection School Of Computing and Information Systems

Recently, Transformer has become a prevailing deep architecture for solving vehicle routing problems (VRPs). However, it is less effective in learning improvement models for VRP because its positional encoding (PE) method is not suitable in representing VRP solutions. This paper presents a novel Dual-Aspect Collaborative Transformer (DACT) to learn embeddings for the node and positional features separately, instead of fusing them together as done in existing ones, so as to avoid potential noises and incompatible correlations. Moreover, the positional features are embedded through a novel cyclic positional encoding (CPE) method to allow Transformer to effectively capture the circularity and symmetry …

Mitigating Emissions Associated With The Production Of Traded Goods, Dan André Quirapas, Brian Irvyn Chan, Albert E. Lamberte, Maria Zunally Rapada, Krista Danielle Yu

Angelo King Institute for Economic and Business Studies (AKI)

The environmental impact of international trade is a concerning issue in the fight against climate change. Trade liberalization—combined with globally fragmented environmental policies—is often associated with the formation of pollution havens. This is because trade enables emissions leakages, which is defined as the outsourcing of emissions-intensive production to countries with weaker environmental regulations. Therefore, literature on this subject has suggested that a globally coordinated policy response is necessary to mitigate the impact of trade on climate change (Aichele & Felbermayr, 2012; Ben-David et al., 2020; Felbmermayr & Peterson, 2020). However, some studies have found that unilateral policy actions have no …

Analysis Of Circulating Tumour Cells In Early-Stage Uveal Melanoma: Evaluation Of Tumour Marker Expression To Increase Capture, Aaron B. Beasley, Timothy W. Isaacs, Tersia Vermeulen, James Freeman, Jean-Louis De Sousa, Riyaz Bhikoo, Doireann Hennessy, Anna Reid, Fred K. Chen, Jacqueline Bentel, Daniel Mckay, R. Max Conway, Michelle R. Pereira, Bob Mirzai, Leslie Calapre, Wendy N. Erber, Melanie R. Ziman, Elin S. Gray

Research outputs 2014 to 2021

Background:

The stratification of uveal melanoma (UM) patients into prognostic groups is critical for patient management and for directing patients towards clinical trials. Current classification is based on clinicopathological and molecular features of the tumour. Analysis of circulating tumour cells (CTCs) has been proposed as a tool to avoid invasive biopsy of the primary tumour. However, the clinical utility of such liquid biopsy depends on the detection rate of CTCs.

Methods:

The expression of melanoma, melanocyte, and stem cell markers was tested in a primary tissue microarray (TMA) and UM cell lines. Markers found to be highly expressed in primary …

Multi-Marker Immunofluorescent Staining And Pd-L1 Detection On Circulating Tumour Cells From Ovarian Cancer Patients, Du-Bois Asante, Michael Morici, Ganendra R. K. A. Mohan, Emmanuel Acheampong, Isaac Spencer, Weitao Lin, Paula Van Miert, Samantha Gibson, Aaron B. Beasley, Melanie Ziman, Leslie Calapre, Tarek M. Meniawy, Elin S. Gray

Research outputs 2014 to 2021

Detection of ovarian cancer (OC) circulating tumour cells (CTCs) is primarily based on targeting epithelial markers, thus failing to detect mesenchymal tumour cells. More importantly, the immune checkpoint inhibitor marker PD-L1 has not been demonstrated on CTCs from OC patients. An antibody staining protocol was developed and tested using SKOV-3 and OVCA432 OC cell lines. We targeted epithelial (cytokeratin (CK) and EpCAM), mesenchymal (vimentin), and OC-specific (PAX8) markers for detection of CTCs, and CD45/16 and CD31 were used for the exclusion of white blood and vascular endothelial cells, respectively. PD-L1 was used for CTC characterisation. CTCs were enriched using the …

Duty To Address Climate Change Litigation Risks For Australian Energy Companies—Policy And Governance Issues, Prafula Pearce

Research outputs 2014 to 2021

The transition from fossil fuels to renewable energy requires cooperation from all, including corporations, shareholders, and institutional investors. The purpose of this paper is to explore climate change litigation risks for Australian energy companies and investors from a policy and governance perspective. Companies are increasingly reporting their climate policies to satisfy their shareholders and investor demands. In addition, the government and judiciary are making laws and decisions to support the Paris Agreement. This paper explores whether company directors can and, in some cases, should be considering the impact of climate change litigation risks on their business, or else risk breaching …

An Enabling Environment For Asset Management Through Public Policy: The Benefits Of Standardization And Application To The Water Sector, Tiffany Batac, Kerry Brown, Rita Salgado Brito, Iain Cranston, Tetsuya Mizutani

Research outputs 2014 to 2021

Water services—including urban water supply, wastewater, and stormwater services—are essential to society and critical for protecting human health and the well-being of communities. Goal 6 of the United Nations (UN) Sustainable Development Goals (SDGs) recognizes this importance and aims to “ensure availability and sustainable management of water and sanitation for all.” Despite progress, the UN reports billions of people still lack water and sanitation services. Many governments around the world face the challenge of balancing between investment in new assets, programs, and services and providing the required funding for repair and replacement of existing water assets. This paper argues infrastructure …

Emerging Barrios In Metro New Orleans, Rosa Gomez-Herrin

LSU New Orleans Theses and Dissertations

As the United States experiences a demographic shift that will turn it into a majority people of color nation, with Latinxs making up the largest ethnic minority group, urban planning policies and practices require adjustment to meet the cultural needs of this and other ethnic groups. This dissertation explores how Latinxs’ ethnic identity is socially constructed and intrinsically tied to cultural manifestations that are (re)shaping the nation’s-built environment. This project studies demographic changes and emerging patterns of spatial concentration of the Latinx community in the Greater New Orleans area during the last two decades. I am developing a concept of …

A Machine Learning Method For The Prediction Of Melt Pool Geometries Created By Laser Powder Bed Fusion, Jonathan Ciaccio

LSU New Orleans Theses and Dissertations

A machine learning model is created to predict melt pool geometries of Ti-6Al-4V alloy created by the laser powder bed fusion process. Data is collected through an extensive literature survey, using results from both experiments and CFD modeling. The model focuses on five key input parameters that influence melt pool geometries: laser power, scanning speed, spot size, powder density, and powder layer thickness. The two outputs of the model are melt pool width and melt pool depth. The model is trained and tested by using the k fold cross validation technique. Multiple regression models are then applied to find the …

Paint's Peeling, Nicholas A. Manning

LSU New Orleans Theses and Dissertations

No abstract provided.

Anisotropic Optical Responses Of Layered Thallium Arsenic Sulfosalt Gillulyite, Ravi P. N. Tripathi, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Multi-element two-dimensional (2D) materials hold great promise in the context of tailoring the physical and chemical properties of the materials via stoichiometric engineering. However, the rational and controllable synthesis of complex 2D materials remains a challenge. Herein, we demonstrate the preparation of large-area thin quaternary 2D material flakes via mechanical exfoliation from a naturally occurring bulk crystal named gillulyite. Furthermore, the anisotropic linear and nonlinear optical properties including anisotropic Raman scattering, linear dichroism, and anisotropic third-harmonic generation (THG) of the exfoliated gillulyite flakes are investigated. The observed highly anisotropic optical properties originate from the reduced in-plane crystal symmetry. Additionally, the …

Home Quartet, Oliver Bonie

LSU New Orleans Theses and Dissertations

No abstract provided.

Personality As A Predictor Of Patterns Of Substance Use, Cynthia Sergi

LSU New Orleans Theses and Dissertations

Substance use (SU) affects many people worldwide and is an important public health concern. Personality has been theorized to play a crucial role in the development and maintenance of SU. To test how personality is related to patterns of SU, a latent profile analysis was used to cluster individuals into SU classes with multinomial logistic regression used to test the relationship between personality and patterns of SU. Results suggested that polysubstance use was common, with variations in primary substance of choice among classes. As classes became more inclusive of more substances, they increased in psychopathological personality traits. Higher domains of …

Super-Adsorbent Hydrogels For Removal Of Methylene Blue From Aqueous Solution: Dye Adsorption Isotherms, Kinetics, And Thermodynamic Properties, Buddhabhushan Salunkhe, Thomas P. Schuman

Chemistry Faculty Research & Creative Works

Removal of dyes through adsorption from wastewater has gained substantial interest in recent years, especially in development of hydrogel-based adsorbents, owing to their easy use and economical nature. The aim of the present study was to design a super-adsorbent hydrogel based on sodium styrene sulfonate (NaSS) monomer for removal of dyes like methylene blue (MB). NaSS displays both an aromatic ring and strongly ionic group in its monomer structure that can enhance adsorption capacity. Poly (sodium styrene sulfonate-co-dimethylacrylamide) hydrogels were prepared by solution free radical polymerization using gelatin meth acryloyl (GelMA) as crosslinker, creating a highly porous, three-dimensionally crosslinked polymer …

Anisotropy In Impact Toughness Of Powder Bed Fused Aisi 304l Stainless Steel, Sreekar Karnati, Atoosa Khiabhani, Aaron Flood, Frank W. Liou, Joseph William Newkirk

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The current effort involved investigation into the anisotropy of AISI 304L fabricated through laser powder bed fusion. Charpy V‐notch specimens made from material fabricated at three different build orientations were tested and analyzed. A statistically significant difference among the toughness values indicates the presence of anisotropy within the additively manufactured material. While the lowest toughness was found in vertically built specimens, the horizontal specimens were found to exhibit the highest toughness. From the fracture surfaces, an atypical mode of failure was observed. Exclusive crack propagation along the interlayer track boundaries was observed. The toughness variation correlated with the ease of …

Temperature And Strain Sensing With Hybrid Interferometer, Lashari Ghulam Abbas, Zhou Ai, Farhan Mumtaz, Atta Muhammad, Yutang Dai, Rashda Parveen

Electrical and Computer Engineering Faculty Research & Creative Works

A hybrid interferometer for simultaneous measurement of strain and temperature is proposed and investigated experimentally. This hybrid design is composed of Fabry-Perot interferometer (FPI) and Michelson Interferometer (MI) cascaded with each other. It is developed by fusion splicing a single mode fiber (SMF), a multimode fiber (MMF), a dual side hole fiber (DSHF), a hollow core fiber (HCF) and a tapered-SMF. The tapered SMF was inserted into the HCF to form a reflection mirror for the FPI. The maximum temperature and strain sensitivity of the hybrid interferometer achieved through experiments is 11.6 pm/°C and 6.8 pm/mu varepsilon , respectively. The …

Orchestrating Performance Of Healthcare Networks Subjected To The Compound Events Of Natural Disasters And Pandemic, Emad M. Hassan, Hussam N. Mahmoud

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The current COVID-19 pandemic has demonstrated the vulnerability of healthcare systems worldwide. When combined with natural disasters, pandemics can further strain an already exhausted healthcare system. To date, frameworks for quantifying the collective effect of the two events on hospitals are nonexistent. Moreover, analytical methods for capturing the dynamic spatiotemporal variability in capacity and demand of the healthcare system posed by different stressors are lacking. Here, we investigate the combined impact of wildfire and pandemic on a network of hospitals. We combine wildfire data with varying courses of the spread of COVID-19 to evaluate the effectiveness of different strategies for …

Healthcare And Education Networks Interaction As An Indicator Of Social Services Stability Following Natural Disasters, Emad M. Hassan, Hussam Mahmoud

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Healthcare and education systems have been identified by various national and international organizations as the main pillars of communities' stability. Understanding the correlation between these main social services institutions is critical to determining the tipping point of communities following natural disasters. Despite being defined as social services stability indicators, to date, no studies have been conducted to determine the level of interdependence between schools and hospitals and their collective influence on their recoveries following extreme events. In this study, we devise an agent-based model to investigate the complex interaction between healthcare and education networks and their overall recovery, while considering …

Frequency Domain Measurements Of Melt Pool Recoil Force Using Modal Analysis, Tristan Cullom, Cody Lough, Nicholas Altese, Douglas A. Bristow, Robert G. Landers, Ben Brown, For Full List Of Authors, See Publisher's Website.

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Recoil pressure is a critical factor affecting the melt pool dynamics during Laser Powder Bed Fusion (LPBF) processes. Recoil pressure depresses the melt pool. When the recoil pressure is low, thermal conduction and capillary forces may be inadequate to provide proper fusion between layers. However, excessive recoil pressure can produce a keyhole inside the melt pool, which is associated with gas porosity. Direct recoil pressure measurements are challenging because it is localized over an area proportionate to the laser spot size producing a force in the mN range. This paper reports a vibration-based approach to quantify the recoil force exerted …

2d Layered Sip As Anisotropic Nonlinear Optical Material, Huseyin Sar, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Two-dimensional (2D) material of silicon phosphide (SiP) has recently been shown as a promising optical material with large band gap, fast photoresponse and strong anisotropy. However, the nonlinear optical properties of 2D SiP have not been investigated yet. Here, the thickness-dependent in-plane anisotropic third-harmonic generation (THG) from the mechanically exfoliated 2D layered SiP flakes is reported. The crystal orientation of the SiP flake is determined by the angle-resolved polarized Raman spectroscopy. The angular dependence of the THG emission with respect to the incident linear polarization is found to be strongly anisotropic with the two-fold polarization dependence pattern. Furthermore, the effect …

Naturally Occurring Layered Mineral Franckeite With Anisotropic Raman Scattering And Third-Harmonic Generation Responses, Ravi P. N. Tripathi, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Vertically stacked van der Waals (vdW) heterostructures have introduced a unique way to engineer optical and electronic responses in multifunctional photonic and quantum devices. However, the technical challenges associated with the artificially fabricated vertical heterostructures have emerged as a bottleneck to restrict their proficient utilization, which emphasizes the necessity of exploring naturally occurring vdW heterostructures. As one type of naturally occurring vdW heterostructures, franckeite has recently attracted significant interest in optoelectronic applications, but the understanding of light-matter interactions in such layered mineral is still very limited especially in the nonlinear optical regime. Herein, the anisotropic Raman scattering and third-harmonic generation …

Formation And Quench Of Homonuclear And Heteronuclear Quantum Droplets In One Dimension, Simeon I. Mistakidis, T. Mithun, P. G. Kevrekidis, H. R. Sadeghpour, P. Schmelcher

Physics Faculty Research & Creative Works

We Study The Impact Of Beyond Lee-Huang-Yang (LHY) Physics, Especially Due To Intercomponent Correlations, In The Ground State And The Quench Dynamics Of One-Dimensional Quantum Droplets With An Ab Initio Nonperturbative Approach. It Is Found That The Droplet Gaussian-Shaped Configuration Arising For Intercomponent Attractive Couplings Becomes Narrower For Stronger Intracomponent Repulsion And Transits Towards A Flat-Top Structure Either For Larger Particle Numbers Or Weaker Intercomponent Attraction. Additionally, A Harmonic Trap Prevents The Flat-Top Formation. At The Balance Point Where Mean-Field Interactions Cancel Out, We Show That A Correlation Hole Is Present In The Few-Particle Limit Of LHY Fluids As Well …

Impact Of Surface And Pore Characteristics On Fatigue Life Of Laser Powder Bed Fusion Ti–6al–4v Alloy Described By Neural Network Models, Seunghyun Moon, Ruimin Ma, Ross Attardo, Charles Tomonto, Mark Nordin, Paul Wheelock, Michael Glavicic, Maxwell Layman, Richard Billo, Tengfei Luo

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this study, the effects of surface roughness and pore characteristics on fatigue lives of laser powder bed fusion (LPBF) Ti–6Al–4V parts were investigated. The 197 fatigue bars were printed using the same laser power but with varied scanning speeds. These actions led to variations in the geometries of microscale pores, and such variations were characterized using micro-computed tomography. To generate differences in surface roughness in fatigue bars, half of the samples were grit-blasted and the other half were machined. Fatigue behaviors were analyzed with respect to surface roughness and statistics of the pores. For the grit-blasted samples, the contour …

Towards Automation Of Aluminum Cell Ramming Process, Maryam Salem Abdelfattah Mohamed Alkaabi

Theses

Newly installed cathode blocks in an aluminium reduction cell, expand due to a rapid increase of temperature when passing a high current at the start-up of the cell. High thermal stresses may result if cathode blocks are lined without gaps, and this can lead to cracking of the cathodes and failure of the cell. On the other hand, leaving gaps would cause failure due to molten metal infiltration in the gaps. To overcome these problems carbon-based ramming material is used to fill these gaps. Currently ‘Filling’ is carried out manually or partially automated, but this needs to be fully automated …

Immobilized Lipase On Zif For Enhanced Biofuel Production, Reem Mohammed Al Mansouri

Theses

Enzymatic transesterification of triglycerides to produce biodiesel has been gaining increasing attention owing to its advantages over chemical processes. Being catalysts, enzymes are not consumed during the processes in which they are used. Therefore, a successful technique to allow their repeated use can significantly enhance the economic feasibility of the process. The most common approach to allow easy separation of the enzymes and to eliminate their wastage is immobilization on a support matrix. Recently, Metal-Organic Frameworks (MOFs) have been suggested as preferable support for enzyme immobilization, owing to their high-order structure and high porosity and specific surface area. This thesis …

The Impact Of Wastewater Chemistry And Flow Characteristics On Hydrogen Sulfide Concentration, Mohsina Muhammed Sherief

Theses

Hydrogen sulfide (H₂S) is a naturally occurring, highly toxic gas that is formed from the decomposition of sulfur compounds. At low concentrations, H₂S is an irritant for the eyes, respiratory and gastrointestinal tract. At higher H₂S concentrations, it produces neurological impairment with dizziness, headache, and loss of consciousness. Mortality was reported to reach 6 percent following exposure to elevated concentrations. H₂S is generated in different industrial processes. In wastewater collection and treatment plants, H₂S is a common source of concrete and metal corrosion that has resulted in huge economic loss. …