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Architecture

University of Nebraska - Lincoln

Series

2015

Articles 1 - 13 of 13

Full-Text Articles in Engineering

Subjective Perception Of Varying Reflection Densities In Room Impulse Responses, Hyun Hong Dec 2015

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 …

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Quantification And Subjective Perception Of Varying Reflection Densities In Measured Room Impulsed Responses, Hyun Hong, Lily M. Wang Jul 2015

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 …

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Room Acoustic Effects On Speech Comprehension Of English-As-Second-Language Talkers And Listeners Versus Native-English-Speaking Talkers And Listeners, Lily M. Wang Jul 2015

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 …

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A Guide For Planning A Bike Share System At The University Of Nebraska-Lincoln, Wade M. Schuldt May 2015

A Guide For Planning A Bike Share System At The University Of Nebraska-Lincoln, Wade M. Schuldt

Community and Regional Planning Program: Theses and Student Projects

The purpose of this document is to serve as a framework for planning a bicycle share system at the University of Nebraska-Lincoln, with the possible inclusion of the City of Lincoln, Nebraska, in the system. This document provides a background review of the evolution of bike share systems and the recent rapid growth of these systems around the world. The document describes planning methodologies used in other locations and the lessons learned from the bike share systems around the world, as to what processes should be pursued to implement a successful bike share system. With the University of Nebraska-Lincoln move …

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Assessing Gait And Postural Stability Of Construction Workers Using Wearable Wireless Sensor Networks, Houtan Jebelli May 2015

Assessing Gait And Postural Stability Of Construction Workers Using Wearable Wireless Sensor Networks, Houtan Jebelli

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Falling accidents are a leading cause of fatal and nonfatal injuries in the construction industry. This fact demonstrates the need for a comprehensive fall-risk analysis that incorporates the effects of construction workers’ physiological characteristics. In this context, the objective of the thesis is to investigate and validate the usefulness of the gait- and postural-stability metrics in assessing construction workers’ fall risks. Diverse metrics that assess the capability to keep the body balanced and maintain coordination of body segments during locomotion (gait stability) and stationary postures (postural stability) have been introduced and used in clinical applications. However, their usefulness in the …

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Accounting For The Short Term Substitution Effects Of Walking And Cycling In Sustainable Transportation, Daniel P. Piatkowski, Kevin J. Krizek, Susan L. Handy Jan 2015

Accounting For The Short Term Substitution Effects Of Walking And Cycling In Sustainable Transportation, Daniel P. Piatkowski, Kevin J. Krizek, Susan L. Handy

Community and Regional Planning Program: Faculty Scholarly and Creative Activity

The environmental benefits of bicycling and walking depend on the degree to which their use substitutes for car driving. Assuming that every walking and bicycling trip replaces a driving trip is likely to produce overestimates of the potential for such modes to reduce vehicle travel and city-scale greenhouse gas emissions. Measuring this ‘‘substitution effect’’ is not straightforward. There are many dimensions of the substitution effect, including trip type, substituting mode, extent, time horizon, and activity patterns. Previously used approaches to measure substitution include indirect inference and direct questioning. This study piloted an intercept survey using the direct questioning approach at …

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Ventilation Rates And Airflow Pathways In Patient Rooms: A Case Study Of Bioaerosol Containment And Removal, Ehsan S. Mousavi, Kevin R. Grosskopf Jan 2015

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 …

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Use Of Fiber-Reinforced Cements In Masonry Construction And Structural Rehabilitation, Ece Erdogmus Jan 2015

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 …

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Adaptive Predictive Functional Controller, Fadi Alsaleem, Arvind Rao Jan 2015

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.

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An Adaptive Photovoltaic Topology To Overcome Shading Effect In Pv Systems, Mohamed Amer Chaaban, Lana El Chaar, Mahmoud Alahmad Jan 2015

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 …

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Building Envelope And Interior Grading Systems And Methods, Fadi Mohammad Alsaleem Jan 2015

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 …

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Air Change Rate Vs Airflow Pathway: Bioaerosol Containment And Removal In Patient Rooms, Kevin R. Grosskopf Jan 2015

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.

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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 Jan 2015

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 …

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