Engineering Commons^™

Manifold Learning Based Spectral Unmixing Of Hyperspectral Remote Sensing Data, Jun-Hwa Chi

Open Access Dissertations

Nonlinear mixing effects inherent in hyperspectral data are not properly represented in linear spectral unmixing models. Although direct nonlinear unmixing models provide capability to capture nonlinear phenomena, they are difficult to formulate and the results are not always generalizable. Manifold learning based spectral unmixing accommodates nonlinearity in the data in the feature extraction stage followed by linear mixing, thereby incorporating some characteristics of nonlinearity while retaining advantages of linear unmixing approaches. Since endmember selection is critical to successful spectral unmixing, it is important to select proper endmembers from the manifold space. However, excessive computational burden hinders development of manifolds for …

Adaptive Targeting: Engaging Farmers To Assess Perceptions And Improve Watershed Modeling, Optimization, And Adoption Of Agricultural Conservation Practices, Margaret Mccahon Kalcic

Open Access Dissertations

Targeting agricultural conservation practices to farmland that has the greatest impact on surface water quality has received wide support from scientists and watershed managers. The targeting approach has, however, been politically contentious as many believe farmers will oppose the approach on grounds such as privacy invasion and unfair distribution of government incentives. Targeting conservation practices using complex optimization models has become common in the scientific community, and yet targeted results are underutilized in practice because of difficulties such as knowledge transfer and absence of a political framework for their use. For targeting to be successful, it must be politically supported …

Simulating Land Use Land Cover Change Using Data Mining And Machine Learning Algorithms, Amin Tayyebi

Open Access Dissertations

The objectives of this dissertation are to: (1) review the breadth and depth of land use land cover (LUCC) issues that are being addressed by the land change science community by discussing how an existing model, Purdue's Land Transformation Model (LTM), has been used to better understand these very important issues; (2) summarize the current state-of-the-art in LUCC modeling in an attempt to provide a context for the advances in LUCC modeling presented here; (3) use a variety of statistical, data mining and machine learning algorithms to model single LUCC transitions in diverse regions of the world (e.g. United States …

An Evaluation Of Spatial Variability Of Water Stress Index Across The United States: Implications Of Supply And Demand In The East Vs The West, Jennifer Ann Roath

Open Access Theses

In order to support both human and environmental needs, high quality fresh water must be available when and where it is required. As a metric for indicating unsustainable water usage, WSI is only useful when the values reflect accurate interactions between supply and demand; however, the complexity of temporal and spatial variability of available fresh water complicates the analysis of water stress.

The overall goal of this project was to investigate the spatial variability of water stress across the United States and the appropriate spatial scale for management decisions. To accomplish this, a national dataset describing spatial distribution and breakdown …

Product Characterization And Headspace Analysis Of Solar Irradiated Aqueous C60 Clusters, Dan Su

Open Access Theses

Buckminsterfullerene (C60) is an important fullerene material that has drawn much attention and is currently being applied in many different fields. It was discovered in 1985. As its production has largely increased to meet these industrial needs, it is obvious that its environmental occurrence, especially in aqueous systems, will occur. To further provide information for environmental toxicity studies and for its risk assessment, this thesis focuses on the photo transformation processes of aqueous C60 clusters (Aqu/nC60), with a particular interest in measuring any mineralization that occurs under different irradiation conditions. Two sets of experiments were conducted to test for CO2 …

Nutrient Recovery From Anaerobically-Digested Dairy Manure By Struvite Formation And Its Effect On Gas Releases, Zhong Qiao

Open Access Theses

Manure management practices such as anaerobic digestion and lagoon storage have become important issues for large dairy farms partially due to water quality and air quality concerns caused by excess nitrogen and phosphorus. Prior research efforts have proven that struvite formation is an effective method for nutrients recovery from both municipal and agricultural wastewaters. However, little is known about nutrient recovery through struvite formation from anaerobically-digested dairy manure effluents.The effects of struvite precipitation on the releases of gases such as NH3, H2S, and CO2 are also unclear.

In this thesis, both bench-scale tests and pilot-scale storage tests were conducted to …

Interactional Analysis Of Emergent Risks In Institutionally Diverse Construction Projects, Nader Naderpajouh

Open Access Dissertations

Naderpajouh, Nader Ph.D., Purdue University, December 2013. Interactional Analysis of Emergent Risks in Institutionally Diverse Construction Projects. Major Professor: Makarand Hastak.

Construction projects, as complex systems of systems (SOS), increasingly involve institutionally diverse actors that escalate complexity of the projects. Examples of these actors include the export credit agencies, international organizations such as the World Bank, non-governmental organizations (NGO), regulatory actors, transnational organizations, as well as public and community groups. The observed surge in complexity of the projects aim to enhance their robustness in: i) sustaining the increasing demand for service of these projects, and ii) sustaining the contextual fluctuation …