Tenneson, Karis; Patterson, Matthew S.; Mellin, Thomas; Nigrelli, Mark; Joria, Peter; Mitchell, Brent. (2018). Development of a Regional Lidar-Derived Above-Ground Biomass Model with Bayesian Model Averaging for Use in Ponderosa Pine and Mixed Conifer Forests in Arizona and New Mexico, USA. Remote Sensing, 10(3).
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Abstract
Historical forest management practices in the southwestern US have left forests prone to high-severity, stand-replacement fires. Reducing the cost of forest-fire management and reintroducing fire to the landscape without negative impact depends on detailed knowledge of stand composition, in particular, above-ground biomass (AGB). Lidar-based modeling techniques provide opportunities to increase ability of managers to monitor AGB and other forest metrics at reduced cost. We developed a regional lidar-based statistical model to estimate AGB for Ponderosa pine and mixed conifer forest systems of the southwestern USA, using previously collected field data. Model selection was performed using Bayesian model averaging (BMA) to reduce researcher bias, fully explore the model space, and avoid overfitting. The selected model includes measures of canopy height, canopy density, and height distribution. The model selected with BMA explains 71% of the variability in field-estimates of AGB, and the RMSE of the two independent validation data sets are 23.25 and 32.82 Mg/ha. The regional model is structured in accordance with previously described local models, and performs equivalently to these smaller scale models. We have demonstrated the effectiveness of lidar for developing cost-effective, robust regional AGB models for monitoring and planning adaptively at the landscape scale.
Keywords
Laser Scanner Data; Landscape Restoration Program; Canopy Fuel Parameters; Discrete-return Lidar; Western United-states; Wave-form Lidar; Airborne Laser; Tropical Forest; Climate-change; Adaptive Management; Forest Biomass; Aboveground Biomass; Airborne Lidar; Monitoring; Regional Forest Inventory; Variable Selection; Bayesian Model Averaging; Multiple Linear Regression
Kim, Yong-Woo; Rhee, Byong-Duk. (2020). The Impact of Empowering Front-Line Managers on Planning Reliability and Project Schedule Performance. Journal Of Management In Engineering, 36(3).
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Abstract
This study applies empowerment theory to production planning at the level of frontline managers in a construction project. Using structural equation modeling, we investigate how empowering frontline managers impacts their planning performance. In contrast to prior studies, we find that although psychological empowerment of frontline managers has no direct effect on their production planning reliability or scheduling performance, it has an indirect effect on planning reliability and scheduling performance, as long as the organization supports the empowerment structurally during production planning. This implies that a project manager should provide frontline managers at the operational level with proper formal and informal authority over workflow development, shielding, and resource allocation when planning production in order to enhance job performance through psychological empowerment. This study contributes to the body of knowledge on construction management by exploring the impact of psychological and structural empowerment of frontline managers on their performance of production planning reliability and scheduling performance.
Keywords
Psychological Empowerment; Work; Model; Variables; System; Job; Planning Reliability; Production Planning; Scheduling Performance; Structural Empowerment; Structural Equation Modeling
Parsaee, Mojtaba; Demers, Claude M. H.; Potvin, Andre; Lalonde, Jean-Francois; Inanici, Mehlika; Hebert, Marc. (2021). Biophilic Photobiological Adaptive Envelopes for Sub-Arctic Buildings: Exploring Impacts of Window Sizes and Shading Panels’ Color, Reflectance, and Configuration. Solar Energy, 220, 802 – 827.
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Abstract
Northern building envelopes must provide efficient indoor-outdoor connections based on photobiologicalpsychological needs of occupants for positive relationships with the sub-Arctic nature, particularly daylighting and day/night cycles. Envelope configurations of Northern Canada's buildings have not yet considered such requirements. Potentials of adaptive systems are also still limited. This research develops a fundamental model of adaptive multi-skin envelopes for sub-Arctic buildings based on main biophilic and photobiological indicators which characterize efficient indoor-outdoor connections. Biophilic indicators characterize the state of connections among occupants and outdoors which could stimulate biological-psychological responses. Photobiological indicators determine human-centric lighting adaptation scenarios for hourly lighting qualities and sufficient darkness in relation to local day/night cycles and daylighting. Biophilic performance of the proposed envelope was evaluated through 18 numerical models in terms of impacts of window and shading sizes on occupants' field of views. Photobiological lighting performance was evaluated by experimental methods using 23 physical models at 1:10 scale. Surface characteristics of dynamic shading panels, including color, reflectance, orientation, and inclination, were studied for potential photobiological impacts in terms of melanopic/photopic ratios and color temperatures. Results show that the proposed envelope could (i) offer acceptable direct visual connections with the outdoor nature through efficient window sizes for biophilia, and (ii) modify daylighting qualities to address hourly/seasonal photobiological needs of sub-Arctic occupants. Challenges of the proposed envelope to implement under sub-Arctic climatic conditions are underlined especially in terms of energy issues. The research outcomes help architects and decision-makers to improve occupants' wellbeing and healthy buildings in subArctic climates.
Keywords
Window Shades; Building Envelopes; Reflectance; Color Temperature; Daylighting; Building-integrated Photovoltaic Systems; Daylight; Outdoor Living Spaces; Canada; Adaptive Envelope; Arctic Climate; Biophilic Design; Healthy Building; Photobiological Lighting; Light; Exposure; Stress; Design; Architecture; Sensitivity; Illuminance; Environment; Melatonin; Recovery; Surface Properties; Performance Evaluation; Indicators; Polar Environments; Lighting; Shading; Darkness; Decision Making; Envelopes; Configurations; Buildings; Color; Adaptive Systems; Climatic Conditions; Numerical Models; Mathematical Models; Panels; Night; Climate; Orientation; Arctic Region
Neff, Gina; Fiore-Silfvast, Brittany; Dossick, Carrie Sturts. (2010). A Case Study of the Failure of Digital Communication to Cross Knowledge Boundaries in Virtual Construction. Information Communication & Society, 13(4), 556 – 573.
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Abstract
When can digital artefacts serve to bridge knowledge barriers across epistemic communities? There have been many studies of the roles new information and communication technologies play within organizations. In our study, we compare digital and non-digital methods of inter-organizational collaboration. Based on ethnographic fieldwork on three construction projects and interviews with 65 architects, engineers, and builders across the USA, we find that IT tools designed to increase collaboration in this setting instead solidify and make explicit organizational and cultural differences between project participants. Our study suggests that deeply embedded disciplinary thinking is not easily overcome by digital representations of knowledge and that collaboration may be hindered through the exposure of previously implicit distinctions among the team members' skills and organizational status. The tool that we study, building information modelling, reflects and amplifies disciplinary representations of the building by architects, engineers, and builders instead of supporting increased collaboration among them. We argue that people sometimes have a difficult time overcoming the lack of interpretive flexibility in digital coordinating tools, even when those tools are built to encourage interdisciplinary collaboration.
Keywords
Digital Communications; Data Transmission Systems; Communication & Technology; Digital Electronics; System Analysis; Building Information Modelling; Collaboration; Qualitative Methods; Teams; Civil Engineering Computing; Digital Communication; Groupware; Knowledge Representation; Organisational Aspects; Virtual Reality; Case Study; Virtual Construction; Knowledge Barriers; Epistemic Community; Interorganizational Collaboration; Ethnographic Fieldwork; Interpretive Flexibility; Digital Coordinating Tool; Digital Collaboration; Technology; Objects; Design; Representations; Organizations
Hoofnagle, Chris Jay; Whittington, Jan. (2014). Free: Accounting for the Costs of the Internet’s Most Popular Price. UCLA Law Review, 61(3), 606 – 670.
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Abstract
Offers of free services abound on the Internet. But the focus on the price rather than on the cost of free services has led consumers into a position of vulnerability. For example, even though internet users typically exchange personal information for the opportunity to use these purportedly free services, one court has found that users of free services are not consumers for purposes of California consumer protection law. This holding reflects the common misconception that the costs of free online transactions are negligible when in fact true costs may be quite significant. To elucidate the true costs of these allegedly free services, we apply a transaction cost economics (TCE) approach. Unlike orthodox economic theory, TCE provides a framework for analyzing exchanges in which the price of the product seems to be zero. Under a TCE analysis, we argue that information-intensive companies misuse the term free to promote products and services that involve numerous nonpecuniary costs. In so doing, firms generate contractual hazards for consumers, ignore consumer preferences for privacy, and mislead consumers by creating the impression that a given transaction will be free. While psychological research and behavioral economics may support an outright ban of free offers because of their biasing effects, TCE suggests reforming governance structures to place the business risks associated with free transactions more firmly in the hands of businesses. We suggest alterations to governance structures such as the Federal Trade Commission's Guide Concerning Use of the Word Free (FTC Guide) to curb the incentives of firms to raise transaction costs for consumers. The FTC Guide provides support for two of the consumer protection measures we propose: first, a requirement that free service providers clearly disclose that such providers seek users' personal information in exchange for those services, and, second, the establishment of a regular price before providers can market a service as free. We further argue that the recognition of users of free services as consumers for purposes of consumer protection law would better align incentives and ensure users access to legal redress against some of the most popular services on the Internet. Lastly, we suggest the adoption of alternative governance structures designed to reduce the cost of transacting by curbing the collection of personal information from consumers of free services and by enhancing the rights of consumers to govern the dispersal of personal information from free online services to third parties.
Keywords
Free Internet Service Providers; Internet Usage Monitoring; Transaction Cost Theory Of The Firm; Internet Privacy -- Law & Legislation; Law; United States. Federal Trade Commission; Vertical Integration; Privacy
Inanici, Mehlika; Hashemloo, Alireza. (2017). An Investigation of the Daylighting Simulation Techniques and Sky Modeling Practices for Occupant Centric Evaluations. Building And Environment, 113, 220 – 231.
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Abstract
Occupant centric performance approaches in daylighting studies promote design decisions that support human visual comfort, productivity, and visual preferences, along with more conventional energy efficiency criteria. Simulating per-pixel luminance values and luminance distribution patterns for the entire scene allows us to analyze the occupant centric metrics and performance criteria. However, there are a number of different sky models, complex fenestration models, and simulation techniques that produce either conventional point in time images or annual luminance maps. This paper discusses the similarities and differences between different techniques; and a comparison analyses provides insight about their impact on occupant centric lighting measures. The comparisons for sky modeling include the conventional CIE skies (Clear, Intermediate, and Overcast), measurement based CIE models, Perez all-weather skies, and high dynamic range image based skies. The comparison of simulation techniques include point in time simulations, image based lighting simulations, and annual luminance simulations (threephase and five-phase methods). Results demonstrate that measurement based sky models match real world conditions with reasonable proximity, and generic CIE skies consistently underestimate the indoor lighting conditions. Annual simulation methods provide a large database of temporal luminance variations, where individual instances are comparable to point in time simulations. Long term luminance simulations provide opportunities to evaluate the percentage of the year that a given luminance based criteria is met or violated. (C)2016 Elsevier Ltd. All rights reserved.
Keywords
Complex Fenestration Systems; Scattering Distribution-functions; Discomfort Glare; Visual Comfort; Daylit Spaces; Validation; Radiance; Performance; Offices; Design; Sky Models; Daylight Simulations; Point In Time Simulations; Image Based Lighting; Annual Lighting Simulations; Annual Luminance Maps
Wentz, Elizabeth A.; York, Abigail M.; Alberti, Marina; Conrow, Lindsey; Fischer, Heather; Inostroza, Luis; Jantz, Claire; Pickett, Steward T. A.; Seto, Karen C.; Taubenboeck, Hannes. (2018). Six Fundamental Aspects for Conceptualizing Multidimensional Urban Form: A Spatial Mapping Perspective. Landscape And Urban Planning, 179, 55 – 62.
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Abstract
Urbanization is currently one of the most profound transformations taking place across the globe influencing the flows of people, energy, and matter. The urban form influences and is influenced by these flows and is therefore critical in understanding and how urban areas affect and are affected by form. Nevertheless, there is a lack of uniformity in how urban form is analyzed. Urban form analyzed from a continuum of a simple urban versus non-urban classification to highly detailed representations of land use and land cover. Either end of the representation spectrum limits the ability to analyze within-urban dynamics, to make cross-city comparisons, and to produce generalizable results. In the framework of remote sensing and geospatial analysis, we identify and define six fundamental aspects of urban form, which are organized within three overarching components. Materials, or the physical elements of the urban landscape, consists of three aspects (1) human constructed elements, (2) the soil-plant continuum, and (3) water elements. The second component is configuration, which includes the (4) two- and three-dimensional space and (5) spatial pattern of urban areas. Lastly, because of the dynamics of human activities and biophysical processes, an important final component is the change of urban form over (6) time. We discuss how a this urban form framework integrates into a broader discussion of urbanization.
Keywords
Ecosystem Services; Land-use; Reconceptualizing Land; Cellular-automata; Heterogeneity; Framework; Model; Emissions; Dynamics; Cities; Gis; Remote Sensing; Land Use; Land Cover; Urban Form; Urban Materials; Energy; Humans; Land Use And Land Cover Maps; Landscapes; Urban Areas; Urbanization
Lee, Yong-Cheol; Shariatfar, Moeid; Rashidi, Abbas; Lee, Hyun Woo. (2020). Evidence-Driven Sound Detection for Prenotification and Identification Of Construction Safety Hazards and Accidents. Automation In Construction, 113.
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Abstract
As the construction industry experiences a high rate of casualties and significant economic loss associated with accidents, safety has always been a primary concern. In response, several studies have attempted to develop new approaches and state-of-the-art technology for conducting autonomous safety surveillance of construction work zones such as vision-based monitoring. The current and proposed methods including human inspection, however, are limited to consistent and real-time monitoring and rapid event recognition of construction safety issues. In addition, the health and safety risks inherent in construction projects make it challenging for construction workers to be aware of possible safety risks and hazards according to daily planned work activities. To address the urgent demand of the industry to improve worker safety, this study involves the development of an audio-based event detection system to provide daily safety issues to laborers and through the rapid identification of construction accidents. As an evidence-driven approach, the proposed framework incorporates the occupational injury and illness manual data, consisting of historical construction accident data classified by types of sources and events, into an audio-based safety event detection framework. This evidence-driven framework integrated with a daily project schedule can automatically provide construction workers with prenotifications regarding safety hazards at a pertinent work zone as well as consistently contribute to enhanced construction safety monitoring by audio-based event detection. By using a machine learning algorithm, the framework can clearly categorize the narrowed-down sound training data according to a daily project schedule and dynamically restrict sound classification types in advance. The proposed framework is expected to contribute to an emerging knowledge base for integrating an automated safety surveillance system into occupational accident data, significantly improving the accuracy of audio-based event detection.
Keywords
Construction Projects; Occupational Hazards; Construction Workers; Construction; System Safety; Video Surveillance; Work-related Injuries; Audio-based Accident Recognition; Autonomous Safety Surveillance; Construction Safety; Evidence-driven Sound Event Detection; Accident Prevention; Accidents; Audio Acoustics; Classification (of Information); Construction Industry; Health Hazards; Health Risks; Knowledge Based Systems; Learning Algorithms; Losses; Machine Learning; Monitoring; Motion Compensation; Occupational Diseases; Steel Beams And Girders; Audio-based; Construction Accidents; Construction Work Zones; Historical Construction; Sound Event Detection; State-of-the-art Technology; Vision Based Monitoring; Algorithm; System
Shen, Qing; Wang, Yiyuan; Gifford, Casey. (2021). Exploring Partnership Between Transit Agency And Shared Mobility Company: An Incentive Program For App-based Carpooling. Transportation, 48(5), 2585 – 2603.
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Abstract
How should public transit agencies deliver mobility services in the era of shared mobility? Previous literature recommends that transit agencies actively build partnerships with mobility service companies from the private sector, yet public transit agencies are still in search of a solid empirical basis to help envision the consequences of doing so. This paper presents an effort to fill this gap by studying a recent experiment of shared mobility public-private partnership, the carpool incentive fund program launched by King County Metro in the Seattle region. This program offers monetary incentives for participants who commute using a dynamic app-based carpooling service. Through descriptive analysis and a series of logistic regression models, we find that the monetary incentive to encourage the use of app-based carpooling generates some promising outcomes while having distinctive limitations. In particular, it facilitates the growth of carpooling by making carpooling a competitive commuting option for long-distance commuters. Moreover, our evidence suggests that the newly generated carpooling trips mostly substitute single-occupancy vehicles, thus contributing to a reduction of regional VMT. The empirical results of this research will not only help King County Metro devise its future policies but also highlight an appealing alternative for other transit agencies in designing an integrated urban transportation system in the era of shared mobility.
Keywords
Shared Mobility; Public-Private Partnership; App-based Carpooling; Incentive Fund; Transit Agencies; Incentives; Commuting; Public Transportation; Mobility; Regression Analysis; Regression Models; Partnerships; Vehicles; Car Pools; Private Sector; Occupancy; Transportation Systems; Mass Transit; Transportation Planning; Empirical Analysis; Urban Transportation
Van Den Wymelenberg, Kevin; Inanici, Mehlika; Johnson, Peter. (2010). The Effect of Luminance Distribution Patterns on Occupant Preference in a Daylit Office Environment. Leukos, 7(2), 103 – 122.
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Abstract
New research in daylighting metrics and developments in validated digital High Dynamic Range (HDR) photography techniques suggest that luminance based lighting controls have the potential to provide occupant satisfaction and energy saving improvements over traditional illuminance based lighting controls. This paper studies occupant preference and acceptance of patterns of luminance using HDR imaging and a repeated measures design methodology in a daylit office environment. Three existing luminance threshold analysis methods [method1: predetermined absolute luminance threshold (for example, 2000 cd/m(2)), method2: scene based mean luminance threshold, and method3: task based mean luminance threshold] were studied along with additional candidate metrics for their ability to explain luminance variability of 18 participant assessments of 'preferred' and 'just disturbing' scenes under daylighting conditions. Per-pixel luminance data from each scene were used to calculate Daylighting Glare Probability (DGP), Daylight Glare Index (DGI), and other candidate metrics using these three luminance threshold analysis methods. Of the established methods, the most consistent and effective metrics to explain variability in subjective responses were found to be; mean luminance of the task (using method3; (adj)r(2) = 0.59), mean luminance of the entire scene (using method2; (adj)r(2) = 0.44), and DGP using 2000 cd/m(2) as a glare source identifier (using method1; (adj)r(2) = 0.41). Of the 150 candidate metrics tested, the most effective was the 'mean luminance of the glare sources', where the glare sources were identified as 7* the mean luminance of the task position ((adj)r(2) = 0.64). Furthermore, DGP consistently performed better than DGI, confirming previous findings. 'Preferred' scenes never had more than similar to 10 percent of the field of view (FOV) that exceeded 2000 cd/m(2). Standard deviation of the entire scene luminance also proved to be a good predictor of satisfaction with general visual appearance.
Keywords
Glare; Daylight Metrics; Luminance Based Lighting Controls; Discomfort Glare; Occupant Preference; High Dynamic Range