Architecture Commons^™

Mechanical Connection For Concrete Structures, George Morcous, Raed Tawadrous

Durham School of Architectural Engineering and Construction: Faculty Publications

A system and method for connecting precast concrete structures includes anchoring a sleeve within a pocket formed in one of the concrete structures , and placing the concrete structures in contact with one another such that the pocket is diposed around a protruding end of a shear connector embedded in the other concrete structure . A bridge is inserted around the protruding end of the shear connector and a fastener is installed onto the protruding end of the shear connector to engage the bridge and urge the bridge in abutting relation with a lip of the sleeve . The pocket …

The Relationship Between Separated Bicycle Lanes And Bicycle Crashes In Denver, Colorado., Wonsun Chang

Community and Regional Planning Program: Theses and Student Projects

Cyclists feel more comfortable when they ride in a bike facility separated from traffic. Therefore, cyclists tend to prefer separated bicycle lanes over other lanes. It follows that cities are increasing the installation of separated bicycle lanes for bicycle utilization and bicycle safety. However, previous research has proven that separated bicycle lanes cause more crashes. Through empirical study, this paper examined the impact of both separated bicycle facilities and shared roads on bicycle crashes and which is safer or dangerous among methods of the separation. This study deals with bicycle accidents in Denver from 2013 to 2019. This research creates …

Workforce Development Through Online Experiential Learning For Stem Education, Arefeh Mohammadi, Kevin Grosskopf, John Killingsworth

Durham School of Architectural Engineering and Construction: Faculty Publications

The U.S. workforce is increasingly comprised of older adults, women, and minorities who lack basic skills and are unable to acquire these skills through traditional educational and training programs. New approaches are needed to provide effective training to the adult learner and flexible support for nontraditional students who must balance work-life demands with limited educational opportunities. Contextualized teaching and learning (CTL) is a form of experiential learning that blends both basic skills and occupational training together in environments that allow students to relate subject matter to real-world situations. Virtual CTL environments can be created to better engage students, provide immediate …

Combating Zombie Subdivisions In Teton Valley, Idaho, Taylor Cook

Community and Regional Planning Program: Theses and Student Projects

This research examined the history, background, and viable solutions to deal with zombie subdivisions in the Teton Valley area (Teton County, Idaho). Overdevelopment, lack of responsible zoning code enforcement and the 2008 economic recession are just some of the key factors that contributed to the ongoing dilemma of zombie subdivisions in the Teton Valley. The current and past long-range plan for Teton County, Idaho was reviewed and analyzed to understand the workings and planning mechanisms that were and are currently set in place. Zoning code, Idaho state statutes and development agreements between Teton County officials and developers, were closely reviewed …

Automated Generation Of Daily Evacuation Paths In 4d Bim, Kyungki Kim, Yong-Cheol Lee

Durham School of Architectural Engineering and Construction: Faculty Publications

Spatial movements of workers and equipment should be carefully planned according to project plans. In particular, it is crucial for workers’ safety to prepare emergency evacuation paths according to changing construction site configurations and construction progress. However, creating evacuation paths for all crews for each day can be an extremely labor-intensive task if it is done manually. Consequently, in most construction projects, evacuation plans are not provided to managers and crews throughout the entire construction. Even state-of-the-art technologies do not suggest ways to generate evacuation paths according to changing progresses presented in 4-Dimensional Building Information Model (4D BIM). This research …

Efficient Excitation Of Micro/Nano Resonators And Their Higher Order Modes, N. Jaber, M. A. A. Hafiz, S. N. R. Kazmi, M. H. Hasan, F. Alsaleem, S. Ilyas, M. I. Younis

Durham School of Architectural Engineering and Construction: Faculty Publications

We demonstrate a simple and flexible technique to efficiently activate micro/nano-electromechanical systems (MEMS/NEMS) resonators at their fundamental and higher order vibration modes. The method is based on the utilization of the amplified voltage across an inductor, L, of an LC tank resonant circuit to actuate the MEMS/NEMS resonator. By matching the electrical and mechanical resonances, significant amplitude amplification is reported across the resonators terminals. We show experimentally amplitude amplification up to twelve times, which is demonstrated to efficiently excite several vibration modes of a microplate MEMS resonator and the fundamental mode of a NEMS resonator.

Voltage And Deflection Amplification Via Double Resonance Excitation In A Cantilever Microstructure, Mohammad H. Hasan, Fadi Alsaleem, Abdallah Ramini

Durham School of Architectural Engineering and Construction: Faculty Publications

Cantilever electrostatically-actuated resonators show great promise in sensing and actuating applications. However, the electrostatic actuation suffers from high-voltage actuation requirements and high noise low-amplitude signal-outputs which limit its applications. Here, we introduce a mixed-frequency signal for a cantilever-based resonator that triggers its mechanical and electrical resonances simultaneously, to overcome these limitations. A single linear RLC circuit cannot completely capture the response of the resonator under double resonance excitation. Therefore, we develop a coupled mechanical and electrical mathematical linearized model at different operation frequencies and validate this model experimentally. The double-resonance excitation results in a 21 times amplification of the voltage …

Experiencing Extreme Height For The First Time: The Influence Of Height, Self-Judgment Of Fear And A Moving Structural Beam On The Heart Rate And Postural Sway During The Quiet Stance, Mahmoud Habibnezhad, Jay Puckett, M. S. Fardhosseini, Houtan Jebelli, Terry Stentz, L. A. Pratama

Durham School of Architectural Engineering and Construction: Faculty Publications

Falling from elevated surfaces is the main cause of death and injury at construction sites. Based on the Bureau of Labor Statistics (BLS) reports, an average of nearly three workers per day suffer fatal injuries from falling. Studies show that postural instability is the foremost cause of this disproportional falling rate. To study what affects the postural stability of construction workers, we conducted a series of experiments in the virtual reality (VR). Twelve healthy adults—all students at the University of Nebraska-Lincoln—were recruited for this study. During each trial, participants’ heart rates and postural sways were measured as the dependent factors. …

Skip This Chore: Cleaning Your Air Conditioner Condenser Probably Won't Make It Work Better, David Yuill

Durham School of Architectural Engineering and Construction: Faculty Publications

I asked my neighbor who hoses off his air conditioner condenser every spring why he does it. “Because my dad always told me I had to,” he said.

Conventional wisdom like what my neighbor’s dad imparted may always seem right. But through my HVAC scholarship – the study of heating, ventilation and air-conditioning systems – I’ve learned that this particular presumption is probably wrong.

Need For Aeromedical Evacuation High-Level Containment Transport Guidelines, Shawn G. Gibbs, Jocelyn J. Herstein, Aurora B. Le, Elizabeth L. Beam, Theodore J. Cieslak, James V. Lawler, Joshua L. Santarpia, Terry L. Stentz, Kelli R. Kopocis-Herstein, Chandran Achutan, Gary W. Carter, John J. Lowe

Durham School of Architectural Engineering and Construction: Faculty Publications

Circumstances exist that call for the aeromedical evacuation high-level containment transport (AE-HLCT) of patients with highly hazardous communicable diseases. A small number of organizations maintain AE-HLCT capabilities, and little is publicly available regarding the practices. The time is ripe for the development of standards and consensus guidelines involving AE-HLCT.

Prediction Of Stress Increase At Ultimate In Unbonded Tendons Using Sparse Principal Component Analysis, Eric Mckinney, Minwoo Chang, Marc Maguire, Yan Sun

Durham School of Architectural Engineering and Construction: Faculty Publications

While internal and external unbonded tendons are widely utilized in concrete structures, an analytical solution for the increase in unbonded tendon stress at ultimate strength, ∆f_ps, is challenging due to the lack of bond between strand and concrete. Moreover, most analysis methods do not provide high correlation due to the limited available test data. The aim of this paper is to use advanced statistical techniques to develop a solution to the unbonded strand stress increase problem, which phenomenological models by themselves have done poorly. In this paper, Principal Component Analysis (PCA), and Sparse Principal Component Analysis (SPCA) …

Benchmarking Image Processing Algorithms For Unmanned Aerial System-Assisted Crack Detection In Concrete Structures, Sattar Dorafshan, Robert J. Thomas, Marc Maguire

Durham School of Architectural Engineering and Construction: Faculty Publications

This paper summarizes the results of traditional image processing algorithms for detection of defects in concrete using images taken by Unmanned Aerial Systems (UASs). Such algorithms are useful for improving the accuracy of crack detection during autonomous inspection of bridges and other structures, and they have yet to be compared and evaluated on a dataset of concrete images taken by UAS. The authors created a generic image processing algorithm for crack detection, which included the major steps of filter design, edge detection, image enhancement, and segmentation, designed to uniformly compare dierent edge detectors. Edge detection was carried out by six …

A Practitioner’S Guide To Small Unmanned Aerial Systems For Bridge Inspection, Sattar Dorafshan, Robert J. Thomas, Calvin Coopmans, Marc Maguire

Durham School of Architectural Engineering and Construction: Faculty Publications

Small unmanned aerial system(s) (sUAS) are rapidly emerging as a practical means of performing bridge inspections. Under the right condition, sUAS assisted inspections can be safer, faster, and less costly than manned inspections. Many Departments of Transportation in the United States are in the early stages of adopting this emerging technology. However, definitive guidelines for the selection of equipment for various types of bridge inspections or for the possible challenges during sUAS assisted inspections are absent. Given the large investments of time and capital associated with deploying a sUAS assisted bridge inspection program, a synthesis of authors experiences will be …

Remotely Testing Whether A Climate Control System Controller Is Correctly Installed, Fadi M. Alsaleem

Durham School of Architectural Engineering and Construction: Faculty Publications

Disclosed are exemplary embodiments of apparatus and methods for remote testing of controllers such as thermostats, to detect incorrect climate control system configuration parameters . In an exemplary embodiment, a computer wirelessly connects with a remote thermostat and sends signal (s) to the thermostat instructing the thermostat to perform climate control function (s) in predefined sequence (s). The computer receives signal (s) from the thermostat indicating whether the thermostat is performing the climate control function (s) in accordance with the sent signal (s). Based on the signal (s) received from the thermostat, the computer determines whether the thermostat is configured …

Hvac System Remote Monitoring And Diagnosis, Jeffrey N. Arensmeier, Gregg M. Hemmelgarn, Fadi M. Alsaleem, Priotomo Abiprojo

Durham School of Architectural Engineering and Construction: Faculty Publications

A monitoring system for an HVAC system of a building includes a monitoring server located remotely from the building. The monitoring server receives, from a device installed at the building, (i) time-domain current data based on a measured aggregate current supplied to a plurality of components of the HVAC system, and (ii) data based on frequency-domain current data of the measured aggregate current. Based on the received data, the monitoring server accesses (i) whether a failure has occurred in a first com ponent of the plurality of components and (ii) generates a preliminary advisory in response to determining that the …

Heat Pump And Air Conditioning Grading Systems And Methods, Fadi Mohammad Alsaleem

Durham School of Architectural Engineering and Construction: Faculty Publications

An expectation module determines an expected average power consumption of a heat pump for a predetermined period as a function of indoor and outdoor temperatures of the building during the predetermined period. A difference module determines a power difference between an average power consumption of the heat pump during the predeter mined period and the expected average power consumption of the heat pump for the predetermined period. A grade determination module determines a grade of the heat pump for the predetermined period based on the power difference of the predetermined period. A reporting module generates a displayable report including the …

Method Of Monitoring Charge Condition Of Heat Pump System, Fadi M. Alsaleem, Gregg M. Hemmelgarn

Durham School of Architectural Engineering and Construction: Faculty Publications

A heat-pump circuit may include an indoor heat exchanger, an outdoor heat exchanger, a compressor adapted to circulate a working fluid between the indoor and outdoor heat exchangers, and an expansion device disposed between the indoor and outdoor heat exchangers. A monitor for the heat-pump system may include a return-air temperature sensor, a supply-air temperature sensor, and a processor. The return-air temperature sensor may be adapted to measure a first air temperature of air upstream of the indoor heat exchanger. The supply-air temperature sensor may be adapted to measure a second air temperature of air down stream of the indoor …

Building Envelope And Interior Grading Systems And Methods, Fadi Mohammad Alsaleem

Durham School of Architectural Engineering and Construction: Faculty Publications

A difference module determines differences between an outdoor ambient temperature and an indoor temperature, determines a first average of the differences , and determines a second average of the differences. A storing module stores a first data point, the first data point including the first average and a first total run time of a heating, ventilation, and/or air conditioning (HVAC) system, and stores a second data point, the second data point including the second average and a second total run time of the HVAC system. A fitting module fits a line to the first and second data points. An envelope …

Hvac System Air Filter Diagnostics And Monitoring, Priotomo Abiprojo, Fadi M. Alsaleem

Durham School of Architectural Engineering and Construction: Faculty Publications

A system and method for monitoring a heating, ventilation, or air conditioning (HVAC) system of a building is provided. A monitoring server, located remotely from the building, receives operating parameter data from a monitoring device at the building that measures an operating parameter of the HVAC system. The monitoring server generates a plurality of data clusters from the operating parameter data, each data cluster corresponding to operating parameter data generated during steady-state operation of the HVAC system. The monitoring server calculates an average operating parameter value for each data cluster. The monitoring server calculates normalized operating parameter values based on …