Architecture Commons^™

Assessment Of Noise-Induced Annoyance By Tones In Noise From Building Mechanical Systems, Joonhee Lee, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

Prominent tones in noise generated by mechanical equipment in buildings can cause complaints from occupants in buildings. The ISO 1996-2 and ANSI S1.13 standards describe methodologies and metrics to quantify tonality perception, but the influence of tones in noise on human annoyance and performance is not fully understood yet. This paper investigates annoyance responses of humans while exposed to background noise with tonal components. Twenty participants completed digit span tasks while exposed to noise signals with differing levels of tones and overall loudness. Subjects were also asked to rate their annoyance after completing tasks under each noise signal. The subjective …

Effects Of Room Acoustics On Comprehension Of Foreign-Accented Speech By Native And Non-Native English-Speaking Listeners, Zhao Peng, Kristin E. Hanna, Brenna N. Boyd, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

In a previous study by the authors, reverberation time (RT) and background noise level (BNL) were both found to have negative effects on native and non-native English-speaking listeners in comprehending English speech produced by native American-English-speaking talkers. Comprehension scores were adjusted for listeners’ baseline English proficiency levels. In the present study, instead of native English-speaking talkers, two native Mandarin Chinese talkers (one male, one female) with similar English spoken proficiency were recruited to produce the same speech materials used in the previous study. A similar methodology was adopted to conduct speech comprehension tests on three groups of listeners: 1) native …

The Impact Of Building Acoustics On Speech Comprehension And Student Achievement, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

The movement for improved classroom acoustics has primarily been grounded on studies that show how building acoustics (i.e. background noise levels and room reverberation) affect speech intelligibility, as determined by speech recognition tests. What about actual student learning, though? If students do not understand each spoken word in the classroom perfectly, can they still manage to achieve high scholastic success? This presentation will review two recent studies conducted at the University of Nebraska – Lincoln, linking classroom acoustic conditions to student learning outcomes and speech comprehension (rather than simply recognition). In the first, acoustic measurements in two public school districts …

Determining Annoyance Thresholds Of Tones In Noise, Jennifer M. Francis, Joonhee Lee, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

Building services equipment often produces noise signatures with significant tones in them that can lead to complaints in the built environment. Previous studies have investigated prominence levels of assorted tonal frequencies, but it is still unclear what prominence of the tones across varying tonal frequencies can lead to human annoyance. This project seeks to apply two different methods towards defining annoyance thresholds of tones in noise at two tonal frequencies: 125 Hz and 500 Hz. In the first, subjects are asked to perform a task, while exposed to ten minutes of a broadband noise spectrum with a specific level of …

Volunteered Geographical Information: An Alternative Solution For Overcoming The Chasm Between Stormwater Management And Community Participation, Yanfu Zhou

Community and Regional Planning Program: Theses and Student Projects

It is a dramatic challenge to promote public engagement in stormwater management and green infrastructure initiatives. When traditional outreach approaches made important influence on public engagement, their limitations are also obvious. With the development of Web 2.0 technology, Volunteered Geographic Information (VGI) has been emerging as one of the most important user-generated geographic contents. The crowdsourcing data that generated by volunteers through geo-web, smartphones, and other geo-devices provides invaluable mass data for decision-making. VGI can provide a better understanding of planning issues and other challenges. The research aims to develop a mobile information platform to allow citizens to report the …

Quantifying And Modeling Stream-Aquifer Interactions In The Elkhorn River Basin, Nebraska, Can Liu

School of Natural Resources: Dissertations, Theses, and Student Research

This study combined statistical analyses, field investigations and numerical groundwater flow modeling to quantify the connectivity between the Elkhorn River and its adjacent aquifers in Nebraska. The Mann-Kendall trend tests were conducted to detect increasing or decreasing tendencies on the time series data of streamflow, which were collected from eighteen gauging stations in the Elkhorn River and its tributaries. Decreasing trends were not found in the annual streamflow data.

Field investigation of streambed hydraulic properties was performed in the Elkhorn River near Winslow and Norfolk. Vertical hydraulic conductivities (K_v) of the shallow streambed sediments were obtained by …

Method And System For Optimal Coordination Control And Soft Repair Of Multiple Rooftop Heating And Cooling Units, Haorong Li

Durham School of Architectural Engineering and Construction: Faculty Publications

Techniques are described that may be implemented in an adaptive control device to regulate multiple zone environmental units based upon multiple temperature values and multiple airflow values, where each temperature value and each airflow value is related to the temperature and the airflow in a specific zone. In an implementation, the input interface of the adaptive control device is configured to receive multiple temperature values and multiple air flow values from multiple zone sensors. The adaptive control device may calculate multiple operational values based on the multiple temperature values and the multiple air flow values. An operational value indicates a …

Virtual Surface Temperature Sensor For Multi-Zone Commercial Buildings, Yuebin Yu, Denchai Woradechjumroen, Daihong Yu

Durham School of Architectural Engineering and Construction: Faculty Publications

Multi-zone structure is commonly used in small commercial office buildings, retail stores and supermarket. While there is no adjacent wall between the zones, the impact of a neighbor zone on the current zone can be approximated and analyzed through the application of virtual walls. It is critical to accurately estimate the virtual wall surface temperature in order to evaluate the model uncertainty and apply improved supervisory control on multiple rooftop air-conditioning units (RTUs). We propose an innovative virtual surface temperature sensor based on system-identification to solve this challenge. The validation of the virtual temperature model is processed by the three …

Hybrid Of Natural Element Method (Nem) With Genetic Algorithm (Ga) To Find Critical Slip Surface, Shahriar Shahrokhabadi, Vahid Khoshfahm, Hamed Nabizadeh Rafsanjani

Durham School of Architectural Engineering and Construction: Faculty Publications

One of the most important issues in geotechnical engineering is the slope stability analysis for determination of the factor of safety and the probable slip surface. Finite Element Method (FEM) is well suited for numerical study of advanced geotechnical problems. However, mesh requirements of FEM creates some difficulties for solution processing in certain problems. Recently, motivated by these limitations, several new Meshfree methods such as Natural Element Method (NEM) have been used to analyze engineering problems. This paper presents advantages of using NEM in 2D slope stability analysis and Genetic Algorithm (GA) optimization to determine the probable slip surface and …

The Influence Of National Culture On Effectiveness Of Safety Trainings During Postdisaster Reconstruction, Behzad Esmaeili, Kevin Grosskopf, Amy Javernick-Will

Durham School of Architectural Engineering and Construction: Faculty Publications

Non-English speaking workers constitute a disproportionately high number of workers involved in postdisaster reconstruction. Additionally, the rate of fatality among these workers is higher than the industry average. Research shows this population is more prone to unsafe behaviors in the working environment, conceivably because many of these workers are sent into the field prior to any formalized training. Recent studies show that the native culture of construction workers can impact risk-taking behavior. While numerous researchers have attempted to develop training materials for Hispanic workers, the number of studies that consider the impact of native culture on safety behavior is minimal. …

Shallow Flat Soffit Precast Concrete Floor System, George Morcous, Maher Tadros

Durham School of Architectural Engineering and Construction: Faculty Publications

A precast concrete floor system that eliminates the need for column corbels and beam ledges while being very shallow. The main advantages of the present system include a span to-depth ratio of 30, a flat soffit, economy, consistency with prevailing erection techniques, and fire and corrosion protection. The present system consists of continuous precast columns, prestressed rectangular beams, hollow-core planks, and cast-in-place composite topping. Testing results have indicated that a 12 inch deep flat soffit precast floor system has adequate capacity to carry gravity loads (including 100 psf live load) in a 30 ft x 30 ft bay size. Testing …