Architecture Commons^™

Subjective Perception Of Varying Reflection Densities In Room Impulse Responses, Hyun Hong

Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research

Reverberation time (RT) is a metric commonly used to describe room acoustic conditions, but different rooms which have the same reverberation time can have different reflection densities. Much less is known about how humans perceive different reflection densities and how sensitive humans are to changes in reflection density. Previous investigations in the existing literature have studied the upper limit of distinguishable reflection density using artificial impulse responses, but not with more realistic impulse responses simulated in room acoustic software or measured from real rooms. The aim of this dissertation is to investigate methods for quantifying reflection density from measured impulse …

Discomfort Glare From Small, High Luminance Light Sources In Outdoor Nighttime Environments, Yulia I. Tyukhova

Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research

The overarching goal of this research was to examine humans’ subjective and physiological responses to small, high luminance light sources in outdoor nighttime environments. Currently, discomfort glare is rarely calculated in lighting practice (Remaking Cities Institute (RCI) 2011), partly, because it is not known which metric predicts glare most accurately in the given application.

This dissertation describes a parametric experiment evaluating the effects of three glare source luminances (20,000; 205,000; 750,000 cd/m²), two source positions (0°, 10°), two source sizes (10^-5, 10^-4 sr), and three background luminances (0.03; 0.3; 1 cd/m²) on the …

The Effect Of Classical Order On The Seismic Behavior Of Ancient Masonry Columns, Cody M. Buckley

Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research

The design and erection of columns in classical Greece and Rome was a deceptively complicated task. Ancient engineers were not guided by a set of building codes, resulting in several regional design variations. The writer Vitruvius condensed these variations into three archetypes or “orders” defined by proportions based on an arbitrary “module”.

The goal of this thesis is to better understand the effect of these proportions on the seismic response of ancient columns through the use of Equivalent Lateral Force Procedure and finite element analysis software. To this end, a parametric study of linearly elastic, free-standing columns with homogeneous material …

Quantification And Subjective Perception Of Varying Reflection Densities In Measured Room Impulsed Responses, Hyun Hong, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

This project focuses on quantifying and testing the subjective perception of reflection densities, or the number of reflections per second, from different room impulse responses. The widely used room acoustic metric, reverberation time, is linked to the perceived reverberation in a room. Two different rooms having the same reverberation time, though, can have different reflection densities in their room impulse responses, and this difference in reflection density may affect how listeners perceive spatial impression in rooms. To investigate how sensitive humans are to a change of reflection density, this paper first reviews assorted parameters for quantifying reflection density from measured …

Room Acoustic Effects On Speech Comprehension Of English-As-Second-Language Talkers And Listeners Versus Native-English-Speaking Talkers And Listeners, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

Approximately 21% of the children in the United States school system speak a language other than English at home, but are being taught in English at school. English is additionally being used more and more often as a common language in international settings, even though participants at these international events again are not native English speakers. How do adverse room acoustic environments, including higher background noise levels and longer reverberation times, impact English-as-a-Second-Language (ESL) talkers and listeners versus native English-speaking talkers and listeners? This presentation focuses on two recent studies at the University of Nebraska that investigate how assorted room …

Effect Of The Physical Environment On Teacher Satisfaction With Indoor Environmental Quality In Early Learning Schools, Stuart Shell

Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research

While the quantity and quality of teacher-child interactions plays a key role in emotional and cognitive development for children, there is scant evidence regarding the contribution of physical environment to child outcomes. This study seeks to understand better the relative importance of variables within the physical environment for occupants. The research design targets teachers’ satisfaction with the physical environment as the outcome variable, based on the assumption that teachers who are more satisfied with their classroom provide higher-quality interactions with children. Teachers from two early learning schools with a total of 31 classrooms completed a written survey that asked about …

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Aspen Art Museum, Rumiko Handa

Architecture Program: Faculty Scholarly and Creative Activity

'I hope when people come to the New Aspen Art Museum they will sense that this building is very much at home in Aspen and could only live here', Shigeru Ban states in a short essay to visitors included in the museum brochure. Indeed, the way in which Ban's design fits uniquely within its context is nothing less than extraordinary. A full appreciation of his accomplishment, however, requires a study of Aspen's history.

What strategies are available to the architect who intends to design a museum that fits well for a community with keen interests in arts but lacking in …

Ventilation Rates And Airflow Pathways In Patient Rooms: A Case Study Of Bioaerosol Containment And Removal, Ehsan S. Mousavi, Kevin R. Grosskopf

Durham School of Architectural Engineering and Construction: Faculty Publications

Most studies on the transmission of infectious airborne disease have focused on patient room air changes per hour (ACH) and how ACH provides pathogen dilution and removal. The logical but mostly unproven premise is that greater air change rates reduce the concentration of infectious particles and thus, the probability of airborne disease transmission. Recently, a growing body of research suggests pathways between pathogenic source (patient) and control (exhaust) may be the dominant environmental factor. While increases in airborne disease transmission have been associated with ventilation rates below 2 ACH, comparatively less data are available to quantify the benefits of higher …

Air Change Rate Vs Airflow Pathway: Bioaerosol Containment And Removal In Patient Rooms, Kevin R. Grosskopf

Durham School of Architectural Engineering and Construction: Faculty Publications

Recent studies have shown that higher air change rates may have the unintended consequence of creating turbulent airflows that entrain high concentrations of infectious particles within the breathing zone, and possibly, breakdown pressure relationships necessary to contain the spread of infectious particles to other clinical spaces.

Use Of Fiber-Reinforced Cements In Masonry Construction And Structural Rehabilitation, Ece Erdogmus

Durham School of Architectural Engineering and Construction: Faculty Publications

The use of fiber reinforcement in traditional concrete mixes has been extensively studied and has been slowly finding its regular use in practice. In contrast, opportunities for the use of fibers in masonry applications and structural rehabilitation projects (masonry and concrete structures) have not been as deeply investigated, where the base matrix may be a weaker cementitious mixture. This paper will summarize the findings of the author’s research over the past 10 years in these particular applications of fiber reinforced cements (FRC). For masonry, considering both mortar and mortar-unit bond characteristics, a 0.5% volume fraction of micro fibers in type …

A Review Of Approaches For Sensing, Understanding, And Improving Occupancy-Related Energy-Use Behaviors In Commercial Buildings, Hamed Nabizadeh Rafsanjani, Changbum R. Ahn, Mahmoud Alahmad

Durham School of Architectural Engineering and Construction: Faculty Publications

Buildings currently account for 30–40 percent of total global energy consumption. In particular, commercial buildings are responsible for about 12 percent of global energy use and 21 percent of the United States’ energy use, and the energy demand of this sector continues to grow faster than other sectors. This increasing rate therefore raises a critical concern about improving the energy performance of commercial buildings. Recently, researchers have investigated ways in which understanding and improving occupants’ energy-consuming behaviors could function as a cost-effective approach to decreasing commercial buildings’ energy demands. The objective of this paper is to present a detailed, up-to-date …

Adaptive Predictive Functional Controller, Fadi Alsaleem, Arvind Rao

Durham School of Architectural Engineering and Construction: Faculty Publications

A controller device and a method for controlling a system that utilizes an adaptive mechanism to self-learn the system char acteristics and incorporates this adaptive self-learning ability to predict a control parameter correctly to provide precise control of a system component.

An Adaptive Photovoltaic Topology To Overcome Shading Effect In Pv Systems, Mohamed Amer Chaaban, Lana El Chaar, Mahmoud Alahmad

Durham School of Architectural Engineering and Construction: Faculty Publications

Shading in photovoltaic systems can cause many undesired effects.When shading occurs, the power generated from the PV system is much less than nominal power, increasing the electrical mismatching losses between PV system components. Active research to address this power loss focuses on static and adaptive systems.This paper addresses an adaptive system solution and proposes a new method to adaptively overcome losses due to shading during low radiation conditions. In addition, a statistical analysis for choosing the most feasible and efficient configuration for the system size is presented. The proposed system has been validated under shade conditions in a simulation and …

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 out door ambient temperature and an indoor temperature, deter mines 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 …