Browsing by Author "Taylor, John E."
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- Aggregated responses of human mobility to severe winter storms: An empirical studyWang, Yan; Wang, Qi; Taylor, John E. (PLOS, 2017-12-07)Increasing frequency of extreme winter storms has resulted in costly damages and a disruptive impact on the northeastern United States. It is important to understand human mobility patterns during such storms for disaster preparation and relief operations. We investigated the effects of severe winter storms on human mobility during a 2015 blizzard using 2.69 million Twitter geolocations. We found that displacements of different trip distances and radii of gyration of individuals' mobility were perturbed significantly. We further explored the characteristics of perturbed mobility during the storm, and demonstrated that individuals' recurrent mobility does not have a higher degree of similarity with their perturbed mobility, when comparing with its similarity to non-perturbed mobility. These empirical findings on human mobility impacted by severe winter storms have potential long-term implications on emergency response planning and the development of strategies to improve resilience in severe winter storms.
- A Bio-inspired Solution to Mitigate Urban Heat Island EffectsHan, Yilong (Virginia Tech, 2014-06-18)Over the last decade, rapidly growing world energy consumption is leading to supply difficulties, exhaustion of fossil energy resources, and global environmental deterioration. More than one-third of energy expenditure is attributable to buildings. Urbanization is intensifying these trends with tighter spatial interrelationships among buildings. This is escalating building energy consumption due to the mutual impact of buildings on each other and, as a result, exacerbating Urban Heat Island (UHI) effects. I sought solutions to this significant engineering issue from nature, and discovered a similar heat island effect in flowers, namely the micro-greenhouse effect. However, a special cooling effect has been observed in a peculiar temperate flower, Galanthus nivalis, which generates cooler intrafloral temperatures. In this research, I studied the special retro-reflectance of the flower petals, which has been suggested as a possible contributor to this cooling effect, and implemented a bio-inspired retro-reflective pattern for building envelopes. I conducted cross-regional energy simulation of building networks in a dynamic simulation environment in order to examine its thermal-energy impact. I found that building surface temperatures dropped considerably when neighboring buildings were retrofitted with my bio-inspired retro-reflective facade. I concluded that my bio-inspired retro-reflective pattern for building envelopes; (1) lessens the reflected heat of solar radiation in spatially-proximal buildings leading to reduced UHI, and (2) reduces the energy required for cooling and, therefore, energy consumption. The research has further implications and contributions on building design, urban planning, development of retro-reflective technology, and environmental conservation.
- Closing the Road Infrastructure Gap: Analysis of Expenditure Dynamics and Public-Private Partnership Shaping ChallengesGuevara Maldonado, Jose Alberto (Virginia Tech, 2017-06-26)The global infrastructure gap has continually widened over the last few decades. Industry reports and academic publications suggest that, in terms of road infrastructure, both advanced and developing economies have not paid sufficient attention to modernize their infrastructure assets. A wider road infrastructure gap signifies that highway conditions have declined because governments have not had enough resources for maintenance and rehabilitation. In the same way, it also indicates that congestion levels have grown and the level of service in most road networks has dropped because public agencies have not had sufficient funds to generate new highways and expand existing corridors. This dissertation, therefore, provided insights into the difficulties associated with improving the existing highway assets and the barriers related to expanding the current roadway capacity through public-private partnerships (PPPs). The research involved three interdependent studies. In the first study, I examined the continuous deterioration of the US highway system through a system dynamics model, which focused on the dynamics of capital investments and maintenance expenditures in the US road infrastructure. The results confirmed that the American highway system is currently stuck in a capability trap. This makes it difficult for the system to improve at the rates required by the country's economic growth. In my second investigation, my attention shifted toward the governance challenges related to building new roads and expanding highway capacity through PPPs. I developed a systems map of governance variables informed by past-published evidence from actual projects. By specifically examining the shaping phase of public-private initiatives, the work uncovered the effects of feedback relationships and interdependencies on PPP feasibility. This offered insights about the relationship between governance mechanisms and successful PPP development. In the third study, I utilized variables and relationships identified in my second investigation to develop a management flight simulator in order to better explain governance difficulties in the procurement phase of PPP projects. The simulator was implemented during an educational exercise with graduate students of civil engineering. By doing so, I confirmed that the simulator has the potential to increase our understanding of PPP procurement processes. Results indicated that the simulation tool was a suitable instrument to explain how government capacity, project uncertainty, and technical complexity influence PPP tendering. Overall, my findings across the three studies illustrate different means to understand why closing the global road infrastructure gap is challenging. Together, the three inquiries indicate that examining the road infrastructure sector as a socio-technical system contributes to improve our understanding of the expenditure dynamics related to existing assets and to enhance our comprehension of the governance challenges associated with developing new roads.
- Comparison of Occupant Behavior in a Traditional, Green Featured, and LEED Certified Building CaseHill, Adrienne Marie (Virginia Tech, 2017-02-08)In developed nations, 20-40% of greenhouse gas emissions and more than one-third of energy consumption are attributable to buildings. Among various available strategies, the building sector has the greatest potential for carbon emission reduction. Leadership in Energy and Environmental Design (LEED) took early action to promote sustainable designs in buildings and has become the most well-known rating system in the field of building sustainability. However, little research has evaluated the effects of LEED on occupant pro-environmental behavior. To examine this, a Post-Occupancy Evaluation (POE) was conducted in a traditional, green featured, and LEED certified building case to compare the similarities and differences in environmental awareness, perceptions, and perceived ease or difficulty of pro-environmental behaviors, as well as to assess the degree to which pro-environmental behaviors were exhibited by occupants. This was used to determine if the aforementioned factors influence occupant behavior in different building cases. Ease or difficulty of pro-environmental behaviors and environmental awareness were found to be significant factors in influencing pro-environmental behavior in the LEED certified and green featured building cases. In addition, being in a LEED building appears to influence occupant pro-environmental behavior in a positive way. Also, there is evidence to suggest that being in a green featured building appears to influence occupants to exhibit pro-environmental behavior as well. These findings are valuable for owners and designers that want occupants in their buildings to exhibit pro-environmental behavior.
- Deploying Best Practices in Unfamiliar CountriesHorsey, Sara E. (Virginia Tech, 2013-09-06)This research developed a process to improve the systematic deployment of best practices in unfamiliar countries in response to rapid globalization in the engineering and construction industry. The engineering and construction industry needs processes, metrics and tools to improve the deployment of best practices in unfamiliar countries to help facilitate project success, as new challenges are encountered. The research identified issues that are commonly encountered when deploying best practices in unfamiliar countries. The issues were identified using content analysis and verified by experts using the Delphi Method. The Analytic Hierarchy Process was used to establish weightings for the importance of each issue. The weightings were then used to create a scoring metric for companies to measure their readiness for projects. In order to overcome the issues identified in the research, a series of processes and mitigation strategies to overcome the issues were developed, through a series of interviews and focus groups. The International Readiness Passport (IRP) is a tool created to support the use of the metric and the mitigation strategies. This tool utilizes a self-scoring section which is applied to the metric. The tool then generates a report with the relevant mitigation strategies related to each issue, based on the score. To ensure that the IRP provides a meaningful benefit to the systematic deployment of best practices in unfamiliar countries, it was validated through a series of retrospective tests. These tests have confirmed the accuracy and relevance of the process, metric, and tool, as well as the tool\'s capabilities.
- Diffusion Dynamics of Energy Saving Practices in Large Heterogeneous Online NetworksMohammadi, Neda; Wang, Qi; Taylor, John E. (PLOS, 2016-10-13)Online social networks are today's fastest growing communications channel and a popular source of information for many, so understanding their contribution to building awareness and shaping public perceptions of climate change is of utmost importance. Today's online social networks are composed of complex combinations of entities and communication channels and it is not clear which communicators are the most influential, what the patterns of communication flow are, or even whether the widely accepted two-step flow of communication model applies in this new arena. This study examines the diffusion of energy saving practices in a large online social network across organizations, opinion leaders, and the public by tracking 108,771 communications on energy saving practices among 1,084 communicators, then analyzing the flow of information and influence over a 28 day period. Our findings suggest that diffusion networks of messages advocating energy saving practices are predominantly led by the activities of dedicated organizations but their attempts do not result in substantial public awareness, as most of these communications are effectively trapped in organizational loops in which messages are simply shared between organizations. Despite their comparably significant influential values, opinion leaders played a weak role in diffusing energy saving practices to a wider audience. Thus, the two-step flow of communication model does not appear to describe the sharing of energy conservation practices in large online heterogeneous networks. These results shed new light on the underlying mechanisms driving the diffusion of important societal issues such as energy efficiency, particularly in the context of large online social media outlets.
- Establishing the Need for Tailored Energy Feedback Programs in BuildingsKhosrowpour, Ardalan (Virginia Tech, 2016-10-06)Buildings account for 40% of energy consumption in the US. Despite all improvements in buildings shell, equipment, and design, CO2 emissions from buildings are increasing as a result of increased energy consumption. Since occupants spend more than 90% of their time indoors, they are inseparable and significant elements of building system dynamics. Hence, there is a great potential for energy efficiency in buildings using a wide range of programs such as education, intervention, energy feedback, etc. Due to advancement of technology and accessibility of high resolution energy consumption data, utility companies are enabled to focus on implementing energy feedback programs to induce energy efficiency and reduce the peak energy load in the commercial and residential sector. In order to better understand various aspects of energy feedback programs, in the first chapter of this dissertation, I conduct a comprehensive literature review on the state-of-the-art energy feedback study methods and identify gaps of knowledge and challenges faced by researchers in the field. Accordingly, the future research vision is laid out at the intersection of methods and gaps of knowledge used in energy feedback studies and future research opportunities and questions are provided. One of the major gaps of knowledge I identified in the literature review is the lack of quantitative analyses used to investigate the variability of occupant responses to commercial buildings energy feedback programs to evaluate the need for targeted and tailored energy feedback programs. In the second chapter, I conducted a comprehensive analysis on occupant energy-use responses under the influence of a uniform energy feedback program. Furthermore, I investigated the effectiveness of notifications on increasing the level of engagement of the occupants in these studies. The results supported the existence of a variability in responses and engagement level in a uniform energy feedback program which may be due to intra-class variability of occupant behavior. In the third chapter, based on the established need for a targeted energy feedback program, I investigate the predictability of occupant energy consumption behavior and its correlation with energy consumption. The results report that 46% of occupants may be good candidates for targeted energy feedback programs due to their combination of higher levels of energy-use and predictability of their energy consumption behavior.
- Examining the Impact of Facilitation on the Performance of Global Project Networks Collaborating in Virtual WorkspacesComu, Semra (Virginia Tech, 2012-12-14)Globalization impacts the Architecture, Engineering and Construction (AEC) industry; customers in the AEC industry are seeking lower costs, faster construction schedules and higher quality services. In order to keep up with the changing demand and to stay competitive in the global AEC industry, firms are forming joint ventures and outsourcing design and services work. As a result, these new trends in the AEC industry require the collaboration of widely dispersed and diverse project workers and companies. Accordingly, it becomes increasingly important to understand the impact of diversity on performance. In this sense, the initial aim of this study was to find empirical evidence on how differences in national culture and language may affect performance in Global Project Networks (GPNs). According to the results of the first experiment comparing the performance of multi-cultural versus mono-cultural simulated project networks over time, I found cultural and linguistic diversity to have a negative impact on initial performance. However, culturally and linguistically diverse project networks studied achieved better adaptation performance that has long term advantages. Even though GPNs have long term performance benefits, bringing the widely dispersed project participants together is costly. Therefore, firms are seeking ways to employ collaboration technologies to bring together the project participants. Little research exists to examine how to increase the efficiency of GPNs that collaborate using technologies such as virtual workspaces to perform design work. In order to examine collaboration in GPNs utilizing virtual workspaces, I conducted two experiments. In the first study, I investigated the formation and the maintenance of Transactive Memory Systems (TMSs) and cohesive subgroups as a proxy for performance in two facilitated and two non-facilitated global virtual project networks. I found a negative impact on collaboration effectiveness when process facilitators engaged in content facilitation in virtual project networks, which restricts the establishment of TMSs. The findings of the first study revealed inappropriate ways of facilitating GPNs collaborating in virtual workspaces, which motivated the second study. In the second experiment, I observed two global and two domestic virtual project networks that were appropriately facilitated. I examined the interactions between network members in order to identify whether significant differences between the collaboration approaches of global and domestic virtual project networks exist. Facilitators were utilized more frequently in global networks, particularly in the early stages of collaboration. Boundary spanning visualization technologies within the virtual workspace were also utilized more frequently by the global network members; however, this was due more to the spatial richness of the task than the maturity of the collaboration. The overall findings have significant implications in improving the effectiveness of global project network collaborations in virtual workspaces.
- Exploring the Role of Cultural Boundary Spanners at Complex Boundaries in Global Virtual AEC NetworksZelkowicz, Andres; Iorio, Josh; Taylor, John E. (2015)As the architecture, engineering and construction industry continues to globalize, project work is more often executed by geographically distributed, technologically mediated teams of knowledge specialists organized into global virtual project networks. These networks are characterized by a number of boundaries that must be spanned in order to develop effective project outcomes. Prior research has examined the efficacy of cultural boundary spanners and technical boundary spanners in these types of networks, but we lack an understanding of how spanners perform in complex boundary environments where boundaries co-occur. Our research aims to explore the efficacy of cultural boundary spanners who are positioned at technical and knowledge domain boundaries. The results of our preliminary research suggest that cultural boundary spanners may only be effective at facilitating efficient information transfer when they are positioned at a knowledge domain boundary in which they have specialization. We found that the interactional norms that develop within the network based on the efficacy of boundary spanners can also position them at inappropriate knowledge domain boundaries, which can lead to decreased efficiency of information transfer. Our research provides an initial contribution to our understanding of boundary complexity in global virtual projects networks with implications for improving network performance.
- The field of human building interaction for convergent research and innovation for intelligent built environmentsBecerik-Gerber, Burcin; Lucas, Gale; Aryal, Ashrant; Awada, Mohamad; Berges, Mario; Billington, Sarah; Boric-Lubecke, Olga; Ghahramani, Ali; Heydarian, Arsalan; Hoelscher, Christoph; Jazizadeh, Farrokh; Khan, Azam; Langevin, Jared; Liu, Ruying; Marks, Frederick; Mauriello, Matthew Louis; Murnane, Elizabeth; Noh, Haeyoung; Pritoni, Marco; Roll, Shawn; Schaumann, Davide; Seyedrezaei, Mirmahdi; Taylor, John E.; Zhao, Jie; Zhu, Runhe (Nature Portfolio, 2022-12-21)Human-Building Interaction (HBI) is a convergent field that represents the growing complexities of the dynamic interplay between human experience and intelligence within built environments. This paper provides core definitions, research dimensions, and an overall vision for the future of HBI as developed through consensus among 25 interdisciplinary experts in a series of facilitated workshops. Three primary areas contribute to and require attention in HBI research: humans (human experiences, performance, and well-being), buildings (building design and operations), and technologies (sensing, inference, and awareness). Three critical interdisciplinary research domains intersect these areas: control systems and decision making, trust and collaboration, and modeling and simulation. Finally, at the core, it is vital for HBI research to center on and support equity, privacy, and sustainability. Compelling research questions are posed for each primary area, research domain, and core principle. State-of-the-art methods used in HBI studies are discussed, and examples of original research are offered to illustrate opportunities for the advancement of HBI research.
- Foliage Echoes and Sensing in Natural EnvironmentsMing, Chen (Virginia Tech, 2017-09-07)Foliage is very common feature in the habitats of echolocation bats and thus its echoes constitute the major input of bats' sensory systems. Acquiring useful information from vegetation echoes facilitates the bats significantly in the navigation and foraging behaviors. To better understand the foliage echoes, in this dissertation, a computer model was constructed to simulate foliage echoes with following simplifications: approximating leaves as circular disks, leaving out shading effects between leaves, and distributing leaves uniformly in the space. Then one tree can be described with three parameters in the model, leaf radius, orientation, and leaf density, where the first two determine the beampattern of each leaf. Compared with echoes collected from real trees, the simulation echoes are qualitatively accurate, i.e., they match in waveforms and also first-order statistics. Since the ground truth is known in the model, the three parameters were estimated with lasso model by selecting 40 features from each echo. The results have shown that estimation of one parameter with the other two known is usually successful with coefficient of determination close to one, and the classification still has reasonable accuracy when the number of known parameter is reduced to one. Besides, the three simplifications were examined with both experimental and simulation approaches. To assess the acoustic impact of leaf geometry on individual leaves, experiments were carried out by ensonifying leaves from both a single and different species. How the leaves' impulse responses change according to their equivalent radii was investigated. The simulation model of disks fits the experiments done with real leaves within one species and across species reasonably well. Shading effect is found to exist locally when two disks were 25 cm apart and were both in pulse direction. In addition, the inhomogeneous distribution of leaves was introduced by using the branching patterns of L-system. The evaluation of inhomogeneity in echoes produced with two distributions shows that there is always inhomogeneity in echoes, and L-system model does bring more inhomogeneity but not to the same extent as changes in the relative orientation between sonar beam and foliage do.
- Generational Differences in Virtual Teaming in the United States: Culture, Time, and TechnologyFerrara, Samuel J.; Mohammadi, Neda; Taylor, John E.; Javernick-Will, Amy N. (2017)The globalization of the workplace has led to the extensive use of virtual teams. Virtual teams are groups of geographically distributed workers that use technology to collaborate and communicate. Due to their geographic distribution, these teams experience high levels of cultural diversity and time dispersion among team members. Millennials and Baby Boomers in the United States have been reported as having differing views in regards to cultural diversity, time, and technology in the workplace. These differing views could lead to conflict and poor performing virtual teams. However, there is a lack of research on generational differences in the context of virtual teams. This study sought to quantify these generational differences (or lack thereof) in virtual teams, focusing specifically on differences between Baby Boomers and Millennials working in the fields of engineering and construction. The results show that Millennials may have relative strengths related to handling cultural diversity, time-distributed team members, and technology use in the context of a virtual team when compared to Baby Boomers. These findings will help inform virtual team leaders by allowing them to better leverage their team members' strengths.
- The Generational Impact in Virtual TeamsFerrara, Samuel Joseph (Virginia Tech, 2016-04-20)The world of today allows groups of people who are geographically-distributed to communicate through information and communication technologies (ICTs). In the workplace, these geographically-distributed teams are referred to as virtual teams. Quantifying and understanding issues in virtual teams has been a focus of research for the past two decades. This thesis aims to quantify generational differences between the Millennials and the Baby Boomers in the context of virtual teams in the engineering and construction sectors. This thesis consists of two studies. The first study broadly focuses on generational differences in regards to cultural, temporal, and technological issues faced in virtual teams. The results from the first study show that Millennials may be better suited to deal with cultural and language differences as well as time-distributed team members when compared to the Baby Boomers. However, the results for the technology hypothesis were mixed and motivated further research. Therefore, the second study focused on generational differences in views on specific ICTs. This study found that Millennials favored some ICTs more than their Baby Boomer counterparts. However, these generations also had indistinguishable views for many of the ICTs examined. The second study shows that the digital divide between generations is true for certain technologies but is unobservable in others. This thesis indicates that Millennials have relative strengths when handling the difficulties of virtual teaming when compared to the Baby Boomers.
- Holistic Building Technology Selection for Sustainability: A Market Analysis and Multi-Attribute Decision Making Approach for Residential Water Heaters in U.S.Doshi, Pratik (Virginia Tech, 2015-08-31)Water heating in the United States has the largest energy consumption of any residential related use. It uses more energy than all other home appliances combined. They have also been implicated as the source of waterborne disease outbreaks. With such high stakes, it is recommended that a Decision Support Tool (DST) be used prior to selection of a water heater for new construction or replacement. Although there are numerous tools available, it is challenging to find a tool that takes into account all factors critical to the selection of water heaters, addresses gaps and barriers, provides adequate information to all stakeholders and finally, assists in rational decision making towards more sustainable choices. The purpose of this research is threefold: (a) to inventory, organize and characterize web-based existing water heater Decision Support Tools (eDSTs) to highlight gaps and/or shortcomings; (b) to develop a Decision Support Tool Skeleton (DSTS) containing a comprehensive list of sustainability capital, criteria and indicators based on Multi-Attribute Decision Making (MADM) approach; (c) to create a stakeholder map comprising supply chain, stakeholder system, decision making process during water heater selections as well as other market factors, using metasynthesis of collected documents. The findings of this research indicate that considerable gaps and shortcomings exist in the current pool of water heater DSTs. To address these barriers, information was captured from various documents in a process of qualitative data analysis called coding. The coding process generated attributes which were used to generate a comprehensive set of capital, criteria, subcriteria and indicators using MADM approach. This organizing structure developed on lines of sustainability assessment will serve as a starting point towards achieving global sustainability in real life. Importantly, information asymmetry between various stakeholders is evidence of the fact that the existing tools are not addressed in an equitable manner. This study will help determine the stakeholder system and the decision making process for selection of water heaters in the residential sector, so as to effectively implement new tools being created.
- Human Mobility Perturbation and Resilience in Natural DisastersWang, Qi (Virginia Tech, 2015-04-30)Natural disasters exert a profound impact on the world population. In 2012, natural disasters affected 106 million people, forcing over 31.7 million people to leave their homes. Climate change has intensified natural disasters, resulting in more catastrophic events and making extreme weather more difficult to predict. Understanding and predicting human movements plays a critical role in disaster evacuation, response and relief. Researchers have developed different methodologies and applied several models to study human mobility patterns, including random walks, Lévy flight, and Brownian walks. However, the extent to which these models may apply to perturbed human mobility patterns during disasters and the associated implications for improving disaster evacuation, response and relief efforts is lacking. My PhD research aims to address the limitation in human mobility research and gain a ground truth understanding of human mobility patterns under the influence of natural disasters. The research contains three interdependent projects. In the first project, I developed a novel data collecting system. The system can be used to collect large scale data of human mobility from large online social networking platforms. By analyzing both the general characteristics of the collected data and conducting a case study in NYC, I confirmed that the data collecting system is a viable venue to collect empirical data for human mobility research. My second project examined human mobility patterns in NYC under the influence of Hurricane Sandy. Using the data collecting system developed in the first project, I collected 12 days of human mobility data from NYC. The data set contains movements during and several days after the strike of Hurricane Sandy. The results showed that human mobility was strongly perturbed by Hurricane Sandy, but meanwhile inherent resilience was observed in human movements. In the third project, I extended my research to fifteen additional natural disasters from five categories. Using over 3.5 million data entries of human movement, I found that while human mobility still followed the Lévy flight model during these disaster events, extremely powerful natural disasters could break the correlation between human mobility in steady states and perturbation states and thus destroy the inherent resilience in human mobility. The overall findings have significant implications in improving understanding and predicting human mobility under the influence of natural disasters and extreme events.
- The Impact of Avatars, Social Norms and Copresence on the Collaboration Effectiveness of AEC Virtual TeamsAnderson, Anne; Dossick, Carrie Sturts; Iorio, Josh; Taylor, John E. (2017)A growing number of architecture, engineering, and construction (AEC) firms are outsourcing complex design and construction work to international vendors. Due to the significant geographic distances that can separate project team members in global design networks, much of this work is executed in virtual teams, defined as teams composed of geographically separated members who collaborate to accomplish organizational tasks mediated by technology. The challenges of working in geographically distributed networks have prompted the development of alternative, virtual workspaces. Questions remain on how these virtual workspaces support or hinder collaborative work. People are social beings that rely on body language and other non-verbal cues to communicate. What happens to team formation and collaborative effectiveness when non-verbal cues are mediated through avatar actions? In this paper, qualitative ethnographic data collected over four years from studies conducted in a 3D virtual world are used to examine collaboration effectiveness of global virtual engineering project teams. We found that avatar movement and position was effective at communicating nonverbal information, even when done so unintentionally. Avatar actions that map to established social norms in the physical world results in more efficient communication. Collaboration was also enhanced when gesture bubbles were used for backchannel communication and when text chat was used to avoid interrupting voice communication. We found collaboration was hindered when the learning curve was too steep for participants to adapt to tool use or avatar actions in the environment. These findings have important implications for the future of collaboration in virtual environments, particularly in the AEC industry where 3D models can be imported into the virtual environment and explored synchronously by a project team.
- Impact of Delivery Method on Stakeholder Issues and Involvement Practices in Mega Projects: Evidence from Fixed Crossing Case StudiesGhadimi, Behshad (Virginia Tech, 2017-03-20)As the scale and scope of infrastructure projects have increased, so too has the array of stakeholders either involved or impacted. Such projects often take years to come together and evolve with time through the actions of project sponsors and the engagement of various stakeholders. Stakeholders through engagement and input can help legitimize and improve large-scale project initiatives. Stakeholders can also marshal opposition that can delay or block these projects. Consequently, the significance of stakeholder involvement is critical in megaprojects. Governments have increasingly utilized public-private partnerships (PPPs) for megaproject delivery. This method introduces characteristics that distinguish PPP megaprojects from others such as: private control, profiteering, foreign profits, and long-term concessions. This study investigates whether differences exist between PPP and non-PPP megaprojects with respect to stakeholder involvement strategies and stakeholder issues raised in such projects. This research employed a longitudinal multiple case study approach that examined four tolled fixed crossing megaprojects; two of them were delivered as PPPs and two were delivered as design-build (i.e. non-PPP). The approach followed the design of prior studies in this area by De Schepper, Dooms, and Haezendonck (2014) and Winn (2001). Pre and post milestone event analysis captured trends and shifts in involvement strategies and stakeholder issues. Subsequently, stakeholder issue tables (organized by issue themes) and stakeholder mechanism tables (organized by mechanism type and information flow) were utilized for across case synthesis and comparison to identify similarities and differences. Analysis of stakeholder involvements across cases showed that NEPA establishes a baseline for involvement, but its requirements are not sufficient for megaprojects; a more comprehensive strategy is necessary. Further, although participatory involvements may be beneficial particularly in complex settings, these mechanisms must be carefully managed in terms of process and criteria for evaluating stakeholder input. Additionally, when private partners/contractors are involved in megaprojects, they become part of the project team and support a coordinated involvement approach. Examination of stakeholder issues indicated that issues that are common to non-PPP and PPP projects are more prevalent than PPP specific issues. In particular, issues related to tolling are dominant; moreover, toll affordability is extremely sensitive, and its severity is predictable based on affected area demographics and past toll escalation practices. The study provided insights about how megaprojects are shaped through actions of project sponsors as well as impacted and interested stakeholders. It also demonstrated how these projects become artifacts of aspiration for politically powerful figures. Lastly, it identified the main stakeholder issues and suggested a set of guidelines to assist future practitioners in developing better stakeholder involvement strategies, which should both enhance and legitimize megaprojects.
- The Impact of Water-Energy Feedback on Water Conservation at Residence HallsJeong, Seung Hyo (Virginia Tech, 2013-08-28)Demand for potable water and energy is increasing with growing populations and economies and many fear that scarcity of such resources will become a significant worldwide problem in the future. As such, promoting water and energy conservation in residential building environments has become an important focal area for research. Providing feedback of water or energy consumption to residential building occupants has been demonstrated to be effective in promoting water and energy conservation separately. However, although water and energy are inexorably connected, we lack research that investigates the bridge between water and energy in the representation of feedback to promote water conservation. In this paper, we describe a study that was designed to investigate the impact of two different representations of water consumption feedback on water conservation. Water consumption was represented to consumers in one of two different ways: 1) gallons and 2) gallons along with the estimated embodied energy of water consumption. The study was conducted in 18 residential halls at Virginia Tech and lasted approximately six weeks. The outcome of the study suggests that representing water consumption in terms of gallons together with the embodied energy associated with water consumption can lead to a statistically significant reduction in water conservation while representing water consumption only in terms of gallons may not. This has significant implications for future water feedback designed to promote water conservation and the study indicates that non-monetary approach can be taken.
- Improving Public-Private Partnership Contracts through Risk Characterization, Contract Mechanisms, and FlexibilityNguyen, Duc Anh (Virginia Tech, 2017-06-28)Public-private partnerships (PPPs) have become a significant global phenomenon and governments are utilizing them more frequently to deliver projects that satisfy increasing societal demands in infrastructure sectors such as highways. Compared to traditional project delivery approaches, PPPs are long-term contracts between the public and the private sectors, where the private sector is engaged in more project tasks and accepts more risks. However, due to their long-term and complex nature, PPP contracts face many issues. Consequently, each project's contract becomes vital to project success because it: allocates risks, governs project relationships, and can align parties' interests. This dissertation examined 21 project contracts in the US highway PPP market to investigate risk allocation; contract designs and risk sharing mechanisms; and revenue risk guarantees. Using a content analysis framework, the allocation of 31 risks associated with highway PPPs was determined. These risks were mostly transferred to the private sector or shared between public and private parties, and project context had a significant influence on risk allocation. Assessment of contract designs indicated that the public sector imposes extensive monitoring and retains a majority of the decision rights to preclude opportunistic actions by the private sector; further, risk sharing mechanisms were complex and largely dependent on resolution during project implementation, which likely increases ex post transaction costs. Finally, revenue guarantees, commonly structured as standard options to mitigate revenue risk, were redesigned to incorporate exotic option features; quantitative analysis revealed that exotic structures can better serve chief PPP stakeholders' interests through increased robustness and flexibility.
- Influence of Project-Level Characteristics and Factors on Innovation and Value Creation in US Highway Public-Private Partnership ProjectsGonzález Montalvo, Edwin E. (Virginia Tech, 2017-07-17)Innovation is a popular topic that receives significant attention from both organizations and academics. This attention includes scholars, executives, public entities, and private organizations in the construction and infrastructure fields. Scholars have examined innovation in both construction and public-private partnerships (P3s). Despite this work, gaps remain – particularly regarding the impact of project-level factors on technical innovation in P3s. Hence, this dissertation contributes to the areas of infrastructure innovation and P3s using a three pronged approach. First, exploration of the literature identified 348 factors that drive or inhibit innovation in infrastructure projects. These factors were synthesized into 33 aggregate factors such as client, integration, and risk. Subsequently, case interviews with practitioners revealed 110 factors that influence innovation in P3 projects; these were further grouped into six main categories. Literature and practitioner perspectives were strongly aligned around four predominant factors influencing innovation in P3 projects: i) risk, ii) client, iii) procurement, and iv) project type. Second, a framework to identify and classify project level innovation was derived and tested using deviations from project baselines submitted as alternative technical concepts (ATCs) in four infrastructure project procurements. The developed framework provides the infrastructure and construction community with a replicable approach to assess technical enhancements in projects to determine whether they are innovative or not and if so the type of innovation. Application of the framework classified only 7 of 53 ATCs from the four projects as innovative. However, the remainder added significant value through cost savings, improved safety or operational efficiency. Lastly, a case study of six contemporary US highway P3 projects: i) Elizabeth River Tunnels in Virginia; ii) East End Crossing in Indiana; iii) North Tarrant Expressway segments 3A&B in Texas; iv) I-4 Ultimate Improvement in Florida; v) I-77 HOT Lanes in North Carolina; and vi) SH 288 Toll Lanes in Texas was conducted to determine the types of innovation found and to assess the influence of key project characteristics on P3 technical innovation. Technical enhancements proposed by concessionaires were assessed using project documentation and semi-structured interviews with 23 experienced public and private sector project participants. Innovations were uncovered, albeit limited. Procurement, project type, and payment mechanism (demand risk/traffic risk) were the key project characteristics influencing innovation. Further, these same characteristics promoted added-value in the form of increased safety, reduced project durations, and decreased project costs. Together, the three studies advance our understanding of the effect of project attributes on technical innovation and value creation in infrastructure public-private arrangements.