The optimal allocation of buffers in serial production systems is one of the oldest and most researched problems in Industrial Engineering. In general, there are three main approaches to the buffer allocation problem when the objective is to maximize throughput. The first is basically a systematic trial and error procedure...
Facility location-allocation decisions and inventory stocking decisions are very important in spare parts logistics. Both sets of decisions affect total costs in the system and the service levels that can be achieved by establishing distances between customers and distribution centers (DCs) in facility location-allocation, and by determining the availability of...
Humanitarian logistics in the post-disaster phase of an earthquake requires detailed planning about the relief distribution network including assigning available distribution centers (DCs) to the affected areas, distribution of the relief commodities demanded by the affected population, and efficient allocation of the available vehicle fleet for the distribution in a...
Modern supply chains have grown to be far more complex than their predecessors, as global trade and accessibility have opened avenues of trade that were previously impossible. As such, the inherent risk of internal and/or external disruptions impacting the performance of a supply chain has also grown due to the...
After a mobile communication device (MCD), such as a smartphone or tablet, has been sold to the public, the customer may find that there is a defect. Each MCD is sold with a warranty that covers the repair of manufacturing defects and is supported by the MCD manufacturer. A third...
On a paced mixed-model assembly line various product variants are assembled in the same sequence of serially arranged workstations that make up the line. The goal is to assemble the products with the lowest cost possible while meeting demand requirements. Since the work content of product variants may differ at...
Small organizations may face several management challenges, such as developing non-centralized management structures, knowledge retention in rapid turnover environments, complex operations, and diverse stakeholder requirements. Many methodologies exist to address such management challenges, including viable system model, knowledge management, and Toyota production system, or lean manufacturing. Each of these methodologies...
Ecoroofs have become more prominent in recent years. However, there is currently no enforceable standard or building code for the design and construction of ecoroofs across the United States (Kraupa, 2014). Further research is needed to determine how ecoroofs respond to roof motion and to develop an appropriate design standard.The...
Moving mixed-model assembly lines are used by many companies to assemble multiple model types of a particular product. A moving assembly line consists of a material movement system that moves jobs at a constant velocity across a series of workstations. The variation in the work content of jobs at workstations...
Wildfires are a recurring disaster that threatens communities living close to forests and result in significant financial losses along with negative environmental effects, especially with the increase of wildfire season length and intensity due to climate change and increasing urbanization. Wildfire events can also have a significant impact on the...
High early strength concrete (HESC) allows for faster construction with less impact on traffic, thus reducing the indirect costs associated with a project. There are multiple methods for achieving early strength, such as alternative cements like calcium sulfoaluminate (CSA) or chemically accelerated portland cements. The standard criteria for an HESC...
The performance of transit networks must be measured on a regular basis to understand how well these complex systems fulfill their intended purpose and to identify potential opportunities for improvement. Measuring transit network performance is only achievable by defining a specific set of transit network performance indicators (TNPIs). Different schemes...
In the past two decades, the advancement in data collection and storage have led to the accumulation of complex datasets. Consequently, various industries have sought data-driven solutions to predict and detect anomalies. Temporal patterns have emerged as potential features in prediction models that could improve the performance of the identification...
Changes in the global climate and forest management practices have given rise to increasing numbers and severity of wildfires. More than five million acres burned in the United States in 2017, while in Canada 7.4 million acres burned. In particular, an increasing amount of dead woody biomass is a key...
The onset of the COVID-19 pandemic led to significant transformations in global mobility patterns, primarily driven by stay-at-home orders and economic shutdowns. These measures resulted in a substantial decline in travel activities worldwide. In the United States, there was a notable reduction in travel demand, with a corresponding decrease in...
This study focused on the potential water and energy savings from implementing a revised schedule of a recirculation pump connected to a condensing gas tankless water heater located in a study home in Portland, Oregon. The existing recirculation pump activation schedule was studied for its impact on the overall water...
Simulated Annealing and Threshold Accepting are two stochastic search algorithms that have been successfully used on a variety of complex and difficult problem sets. Due to their stochastic nature they are not guaranteed to produce the same result for each run. This means that these techniques actually produce a distribution...
To address several challenges faced in healthcare, the Triple Aim (3A) was targeted by institutions to improve health outcomes and patient experience while reducing the costs of health. Process improvement techniques in manufacturing, such as Lean systems, were applied as tools to achieve the 3A framework. Unfortunately, the high level...
Creating schedules for the job shop manufacturing system is an extremely difficult task. Although researchers have devoted a lot of attention to generating optimal solutions, these solutions are static, thus they do not update as random events occur that disrupt the system. As smart manufacturing has grown, researchers have been...
Highway work zones are extremely dangerous environments due to the presence of workers near high-speed traveling vehicles. This dynamic environment results in a disproportionate number of accidents that cause injury and casualty to both drivers and workers due primarily to vehicular intrusions into work zones. Several emerging work zone intrusion...
Small business energy analysts often specialize in one aspect of the business. This specialized focus is done by necessity due to scarcity of resources and to maintain a proprietary market niche. However, this specialized focus results in a growth inhibitor due to their lack of ability to address all the...
Air traffic flow management over the U.S. airpsace is a difficult problem. Current management approaches lead to hundreds of thousands of hours of delay, costing billions of dollars annually. Weather and airport conditions may instigate this delay, but routing decisions balancing delay with congestion contribute significantly to the propagation of...
In this research, the comparative performance of permutation and non-permutation schedules is investigated in an assembly flow shop (AFS) with shift production, where a limited buffer storage is available between two machines. Most of the traditional scheduling problems consider continuous production, i.e., production occurs for 24 hours (3 * 8-hour...
Variational programming supports efficiently executing many related programs at once by encoding all of the programs in one "variational program" that captures the differences among them statically and explicitly. An open problem in variational programming is how to handle side effects—if two program variants perform different side effects, we cannot...
Physical activity recognition using accelerometer data is a rapidly emerging field with many real-world applications. Much of the previous work in this area has assumed that the accelerometer data has already been segmented into pure activities, and the activity recognition task has been to classify these segments. In reality, activity...
As the growth in demand for sustainable manufacturing continues, companies must begin to make conscious design decisions with regard to the sustainability of their products. This means balancing economics of production with environmental and social performance. Thus, design and manufacturing engineers must consider economic, environmental, and social aspects simultaneously when...
In the face of a disruptive event or prolonged period of stress, resilient performance ischaracterized by preventative measures, effective response, and the integration of lessonslearned. In healthcare, resilience significantly affects patient safety. However, currentguidelines for healthcare performance assessment, such as the Triple Aim, do notconsider physician satisfaction and preventative measures...
Research has shown that emotional connections during lab activities increase learning in chemistry and physics courses. However, little research has examined the effects of emotion in engineering courses, and these studies have recognized a dearth of research examining the ability of students to apply engineering concepts in real-world applications based...
Considering the deadly impacts of commercial motor vehicle (CMV) crashes on road safety, many previous studies have put in efforts to find the determinants of CMV crash injury severities. However, studies examining the impact of the different number of lanes on CMV crash
injury severities are lacking. Besides, the importance...
Auctions are used to solve resource allocation problem between many agents and many items in real-world settings. Unfortunately, in most cases, it is possible for selfish agents to manipulate the system for their own interest at the expense of the social welfare. Such manipulation can be prevented using the Vickrey-Clarke-Groves...
When pavement markings on roadways are removed, scarring can occur leaving behind traces of where the marking used to be called ghost lines. These ghost lines can confuse drivers on the roadway and divert their attention from the correct lane markings leading them into the false lane. Previous research has...
An important impact of the genome technology revolution will be the elucidation of mechanisms of cancer pathogenesis, leading to improvements in the diagnosis of cancer and the selection of cancer treatment. Integrated with current well-studied massive knowledge and findings about the role of protein-coding mutations in cancer, demystifying the functional...
Organizations are constantly looking for innovative strategies to face more stringent competitive environments and the ever increasing market globalization. An alternative these organizations can pursue to respond to these challenges is to optimize their supply chain network (SCN). Important considerations when optimizing a SCN involve determining locations for plants and...
Healthcare access exhibits differing levels of complexity, often requiring multi-disciplinary approaches to study its barriers and enablers. Though Argentina has achieved nominal universal healthcare coverage through its public healthcare system, full effective coverage has not been achieved. The public system also has a parallel private care system, adding further complexity...
Distracted driving is an adverse driving behavior that is widely known to impair the safety of all roadway users and traffic flow. Despite the extensive research efforts on the prevalence and effects of distracted driving on roadway safety and performance, the number of vehicular crashes and fatalities resulting from distracted...
The use of fossil fuels and their related impact on the environment and global warming have encouraged societies to pursue more sustainable and renewable alternatives, e.g., forest-based bio-oil. Thus, a vital need to decrease the level of greenhouse gas emissions and the tendency of nations to reduce their dependency on...
The rapid advancement of manufacturing has led to the creation of a myriad of technologies that facilitate the analysis and simulation of manufacturing processes. These technologies have become a pivotal component in maintaining and improving processes in today’s complex manufacturing environments. Discrete Event Simulation (DES) is one such technology that...
Manuscript I: The removal of residual casting material from gating has traditionally been performed by abrasive grinding techniques. However, high amounts of belt wear can occur when working with high strength alloys, especially those typically seen in the aerospace industry. An alternative machining process called electrochemical machining (ECM) uses electrolysis...
Monte Carlo simulation is used to quantify and characterize uncertainty in a variety of applications such as financial/engineering economic analysis, and project management. The dependence or correlation between the random variables modeled can also be simulated to add more accuracy to simulations. However, there exists a difference between how correlation...
CPM-M4 tool steel is a commonly used knife blade material due to its high strength and wear resistance. The goal of this thesis is to understand how heat treatment parameters affect blade performance and microstructure.Five heat treatments were applied to CPM-M4 steel by varying austenitizing and tempering temperatures. The microstructures...
The development of a Marine Pollution Monitoring Program (MPMP), in any coastal area of the world, requires a precise knowledge of the functioning of the local ecosystem. Because of the differences found in every coastal ecosystem, it is important to recognize and characterize the reservoirs and significant environments that maintain...
The outbreak of the Coronavirus Disease 2019 (COVID-19) and the restrictions implemented in response to it (e.g., stay-at-home orders, social distancing mandates, business closures) had unprecedented effects on the trucking industry. The pandemic prompted the first significant overhaul of federal hours-of-service (HOS) regulations in over 15 years. Prior to the...
An ultra low power crystal oscillator that provides a frequency reference for battery
powered timekeeping applications is presented. An amplitude control circuit is employed to ensure that minimum current is consumed. A subthreshold voltage regulator provides a supply voltage for the oscillator with minimum current consumption. The oscillator and regulator...
In this paper, I will analyze the nature of these
problems and examine how recent approaches to SLRA have
dealt with them. In addition, a framework for assessing the
potential impacts of sea level rise is proposed, drawing
upon the ecological concept of resilience (Holling 1978,
1984).
Design and control of legged robots is a popular field in the pursuit of building robots that can be as mobile as humans. While much effort is put into understanding how to control the dynamics of these legs, less effort is focused on designing and controlling robot ankles. Ankles on...
The production of fuel ethanol from lignocellulosic biomass has the potential to replace a significant portion of non-renewable transport fuels. Woody feedstocks are composed of cellulose, hemicellulose, and lignin. Glucose, the monomer of cellulose, is readily utilized by wild-type S. cerevisiae, but xylose, which comprises 60% of the sugar in...
Understanding the effects of disturbance and restoration on a species’ habitat is essential for understanding the demographic rates and population trends observed in a species. Sufficient habitat provides the space and resources required for survival and successful reproduction, such as food availability, access to water, protection from predators, protection from...
This thesis presents a discussion of the main materialistic theories proposed to explain the process of development among the indigenous population of Latin America. Four theoretical approaches are presented and discussed. The first one deals with the social group referred to as peasants. The second one explains the process of...
Crested wheatgrass (Agropyron cristatum (L.) Gaertn.) is a nonindigenous perennial grass that was introduced to North America to improve the condition of degraded rangelands. It has proven to be a successful revegetation species due to its superior ease of establishment, strong competitive ability, and ability to tolerate grazing. However, crested...
This thesis consists of five chapters: a general introduction, two manuscripts, a collection of published lesson plans, and a general conclusion. The works collected herein are united by the common theme of practical applications in plant breeding. The first manuscript reports a study performed on five malting barley lines grown...
This paper focuses on Satan as a sympathetic figure in Paradise Lost, and it argues that readers' sympathy for Satan drives them to pursue God's grace in order to avoid falling into the same fate as Satan. It uses Reader Response theory to show how readers connect with Satan, and...
Wireless device classification techniques play a key role in promoting emerging wireless applications such as allowing spectrum regulatory agencies to enforce their access policies and enabling network administrators to control access and prevent impersonation attacks to their wireless networks. Leveraging spectrum distortions of transmitted RF signals, caused by transceiver hardware...
From the earliest English colonization to the present day, there
has been interest in astronomy in this country. The purpose of this
thesis is to show how the science of astronomy developed in America
from the earliest observations by educated colonists using imported
instruments and publishing in European journals, to...
In recent years, many studies have focused on the molecular and biochemical mechanisms regulating the development of wine grapes. The course of grape berry development is directed by genetic design and is mediated by phytohormones, which regulate grape berry growth and development by orchestrating a complex network of interacting genes,...
The present thesis chemically examined 174 industrial North Staffordshire pottery fragments from an archaeological context, using Instrumental Neutron Activation Analysis (INAA). In an integrated effort to combine an archaeometric approach with archival research and traditional analysis methods, the purpose of the thesis was to link industrial pottery manufacturers recipes to...
The Mixteco primarily reside in the Mexican State of Oaxaca in Southwestern Mexico. They have been arriving in larger numbers then ever before to this part of the North American continent in the last twenty years.Their experience is composed of different dynamics compared to those of their mainstream Mexican counterpart....
The Mixteco primarily reside in the Mexican State of Oaxaca in Southwestern Mexico. They have been arriving in larger numbers then ever before to this part of the North American continent in the last twenty years.Their experience is composed of different dynamics compared to those of their mainstream Mexican counterpart....
Human activities have altered Earth’s ecosystems. Most biomes have experienced a 20-50% conversion to human use. Loss of habitat has obvious effects on the persistence of species. Fragmentation, however, may also negatively affect biodiversity for those species that exhibit behavioral responses to changes in habitat configuration. Such behavioral changes include...
There is still scholarly debate on the impacts of large floods on the geomorphic evolution of mountain rivers. Understating the geomorphic effects of large flows in mountain rivers is challenging given the hydraulic complexity of these systems and the inherent unpredictability of large floods. Prior work has demonstrated that extreme...
Pleuropogon oregonus Chase is a rare wetland grass endemic to eastern Oregon. The species is composed of two widely separated populations, one in Lake County and one in Union County. In order to reduce the risk of extinction, the Oregon Department of Agriculture Native Plant Conservation Program initiated several reintroduction...
Understanding prey quality and prey selection by predators is critical for management efforts aimed at identification and protection of essential habitats and prey. Marine predators must make daily foraging choices in a heterogenous and dynamic environment in order to meet the high energetic demands of migration, reproduction and foraging. With...
Is it possible to determine whether a signal violates a formula in Signal Temporal Logic (STL), if the monitor only has access to a low-resolution version of the signal? We answer this question affirmatively by demonstrating that temporal logic has a multiresolution structure, which parallels the multiresolution structure of signals....
This project aims at implementing Indexing for Web 2.0 Applications. Ajax applications consist of a set of states which are generated by the user through actions such as click, focus, blur etc. events. By saving these DOM states we can index information obtained from dynamically generated web content. To prevent...
A procedural manual for sampling and analyzing sanitary landfill
leachate was designed to guide sanitarians and other public health
officials in monitoring mineral and organic material drainage from
landfill sources. The manual was constructed to allow flexibility of
conducting analytical tests in a field or laboratory environment.
Step-by-step procedures for...
Rare plant reintroductions are a critical conservation tool for the augmentation of diminishing populations, or re-establishment of extirpated populations. Analysis of reintroduction failures suggests that a sophisticated understanding of species biology, ecology, and habitat is essential for producing self-sustaining rare plant populations. This study sought to generate that background knowledge...
Hemlock dwarf mistletoe (Arceuthobium tsugense subsp. tsugense) is an arboreal, hemiparasitic plant that principally parasitizes western hemlock (Tsuga heterophylla). Hemlock dwarf mistletoe exerts a profound influence on infected trees that can drastically change the structure of the tree crown due to reduced growth, top dieback, branch deformation and death, resulting...
Mixed-initiative programming entails collaboration between a computer system, and a human to achieve some desired goal or set of goals. Often these goals change or are amended in real time during the course of program execution. As such, the plans these programs are based on must adapt and evolve to...
Drought is expected to increase in many parts of the world and has been shown to affect tree physiology and growth, with seedlings being particularly vulnerable. Seedling drought responses are often species dependent, and even within species different populations may demonstrate a spectrum of responses to drought, from susceptibility to...
Cannabis sativa L. is emerging as an economically important crop, particularly for its high levels of cannabinoid production. One of these cannabinoids, cannabigerolic acid (CBGA), is the precursor to many well-researched cannabinoids such as the psychotropic delta-9-trans-tetrahydrocannabinolic acid (Δ9-THCA i.e., THCA) and the medically relevant cannabidiolic acid (CBDA). CBGA has...
This thesis focuses on the identification of ecohydrological processes in nested system of catchments in a tropical alpine (the wet Andean páramo) ecosystem. We accomplish this by conducting a water stable isotopic characterization of water sources, an evaluation of the mean transit time (MTT) of streams waters, and the investigation...
Rates of germination and emergence of corn were measured as
influenced by soil physical parameters using blotter paper and a sandy
loam soil as growth media. The corn seeds used were a hybrid of
Funk's (DJ7xLH93).
Experimental conditions were soil temperature of 20°C, 25°C,
30°C, and 35°C, soil water potential...
Preservation of rare plant species often requires establishment of new populations. Survivorship surveys are the most common method of post-introduction monitoring. However, they provide an incomplete picture of establishment success. This study is an attempt to develop a model for determining establishment success by determining the factors affecting recruitment in...
Declines in glacier area and volume are widespread. These changes will have important hydrologic consequences since glaciers store tremendous amounts of fresh water and buffer seasonally low flows in many densely populated regions. In this thesis I focus on a region that is hydrologically vulnerable to glacier change, namely the...
A fully integrated CMOS latched comparator is presented for use as a wake-up circuit that is attached to an RF energy harvester in a battery free wireless sensor network. The system consumes less than 36nA static current at 20°C and dissipates 2pJ of energy per conversion. The comparator comprises of...
This paper is an exploratory study of the risk perceptions in the Oregon Hazelnut growing community. The study takes place at a time when the industry as a whole has begun to stabilize from the effects of Eastern Filbert Blight, a fungal pathogen that infects hazelnut trees which had devastated...
Despite the importance of tropical forest ecosystems in the global carbon cycle, there have been few studies of carbon dynamics in this biome. The magnitude of carbon stocks in the tropics and their changes over time are poorly known since ground-based observations are lacking. In this study, total carbon stocks...
As competing uses of our coastlines increase, natural resource agencies are employing marine spatial planning (MSP) to designate areas for different uses or activities in order to reduce conflicts while achieving ecological, economic and social objectives. A central challenge of implementing MSP is development of a rigorous approach for analyzing...
Both conflicts and new identities result when indigenous' traditional values of landscape and resource management are superimposed with federal governments' management of archaeological and forest resources in federally designated protected areas. This thesis examines the relationship and discourse between two Cuicatec towns in Oaxaca, Mexico and three Mexican government agencies...
Over the last two decades, archaeologists have documented the widespread ancient Maya practice of collecting cave formations (speleothems) from ritually important caves and transporting them to their settlements. Little is known about their specific uses within settlements, but it is hypothesized that these objects convey a degree of sanctity from...
The Valley of Oaxaca, Mexico was home to one of the most intensively-studied archaic states in the New World. Centered at the hilltop city of Monte Albán, the Zapotec State first arose around 500 BC and eventually encompassed much of the present-day state of Oaxaca. But by the Late Classic...
The coastal zone is the area where the land, sea, air meet.
It has a unique combination of characteristics which favor human
development, trade and industry.
"Coastal climates are more moderate and stable than those of
the interior of the continents, and are usually associated with
sufficient rainfall to sustain...
This paper discusses research concerning redware vessel sherds found in an archaeological excavation at Oregon's historic Champoeg State Park, and comparative artifacts from four known Oregon and Washington late nineteenth pottery production sites. Visual and Instrumental Nuclear Activation Analysis comparison studies were conducted on samples from each site. The New...
Building institutional and human capacity for integrated coastal zone management (ICZM) is
increasingly recognized as critical to the future of sustainable development in coastal states.
Agenda 21 of the UNCED conference has underscored the urgency of capacity building for
ICZM as have other international bodies such as the North American...
In the western United States, sagebrush (Artemisia spp L.) dominated rangelands are extensive, accounting for approximately 63 million ha. The Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young) alliance is found in more xeric environments, occupying the largest area of the big sagebrush complex in areas within...
Bi-weekly sampling of zooplankton and environmental parameters was conducted along a cross-shelf transect off the coast of Newport, OR, USA (44.65°N) from 1996 to present. Results have demonstrated the feasibility of using copepod community structure as an early indicator of ecosystem response to seasonal and large scale environmental changes in...
Severe wildfires are increasing in the western United States, impacting vegetation structure, and in turn, forest regeneration conditions. These wildfires are also raising a substantial amount of scientific and management concern regarding the resilience of forested ecosystems, or the ability of the ecosystem to return to a pre-fire condition. This...
The combined effects of habitat loss, degradation, and fragmentation pose a serious threat to Earth's biodiversity, imperiling even relatively common species. 'Habitat' is necessarily a species-specific concept, and investigations of bird diversity relationships and subsequent efforts to prioritize conservation areas, are challenged by the difficulty of estimating complex habitat gradients...
A large, damaging earthquake in 1944 on a blind thrust fault caused 60 cm of surface rupture on the subsidiary La Laja fault and additional unmeasured growth of an associated backlimb fold. Both the fold and fault are components of the La Laja Fault System (LLFS) located 25 km northeast...
Using the honey bee (Apis mellifera L.) this thesis shows that entomological information and material can be retrieved using current historical archaeological methods. Historical archaeology has the ability to uncover connections between arenas as varied, and seemingly isolated, as the honey bee, the environment, and human cultures. By focusing on...
Variations in heat treatments have significant effects on the microstructure of tool steels. For CPM-M4 tool steel, the changes in microstructure and mechanical properties were observed based off of variations in temperature. Five heat treatments with constant exposure time and variable austenitizing and tempering temperatures were performed on samples of...
Sediments of the central Chile margin record changes in ocean circulation and
continental erosion associated with large–scale climate change. Here Antarctic–
influenced Southern Ocean currents flow equatorward, forming a link between the high–
and low–latitude oceans. Part of this link, Antarctic Intermediate Water, is an important
conduit that ventilates South...
In the contemporary United States, the process of "coming out of the closet," or public disclosure of one's non-normative sexual orientation or gender identity, is ongoing and performative. Particularly within the context of dominant contemporary U.S. society, popular media favors a hegemonic set of defining characteristics, which thereby forces the...
Wilderness character monitoring (WCM) is an interagency strategy created in 2008 in collaboration between the four federal land management agencies that manage designated wilderness (Forest Service, National Park Service, Fish and Wildlife Service and Bureau of Land Management) and other contributors (Landres et al. 2008a). The reports created from this...