Architectural Engineering Commons^™

Developing A Workflow To Integrate Tree Inventory Data Into Urban Energy Models, Farzad Hashemi, Breanna L. Marmur, Ulrike Passe, Janette R. Thompson

Farzad Hashemi

Building energy simulation is of considerable interest and benefit for architects, engineers, and urban planners. Only recently has it become possible to develop integrated energy models for clusters of buildings in urban areas. Simulating energy consumption of the built environment on a relatively large scale (e.g., such as a neighborhood) will be necessary to obtain more reliable results, since building energy parameters are influenced by characteristics of the nearby environment. Therefore, the construction of a 3-D model of urban built areas with detail of the near-building environment should enhance simulation approaches and provide more accurate results. This paper describes the …

The Impact Of Trees On Passive Survivability During Extreme Heat Events In Warm And Humid Regions, Ulrike Passe, Janette R. Thompson, Baskar Ganapathysubramanian, Boshun Gao, Breanna L. Marmur

Breanna L. Marmur

Communities are increasingly affected by excessive heat. The likelihood of extreme heat events is predicted to increase in the Midwest region of the United States. By mid-century (2036–2065), one year out of 10 is projected to have a 5-day period that is 13°F warmer than a comparable earlier period (1976–2005). The frequency of high humidity/dew point days (“extra moist tropical air mass days,” MT++ synoptic climate classification system) has also increased significantly during a similar period (1975–2010) and between 2010 and 2014 included 8 of 26 heat events. This impact is exacerbated by the fact that many residences in low-income …

Thermoelectric Materials In Exterior Walls: Experimental Study On Using Smart Facades For Heating And Cooling In High-Performance Buildings, Ajla Aksamija, Zlatan Aksamija, Christopher H. Counihan, Dylan Brown, Meenakshi Upadhyaya

Ajla Aksamija

Thermoelectric Materials In Exterior Walls: Experimental Study On Using Smart Facades For Heating And Cooling In High-Performance Buildings, Ajla Aksamija, Zlatan Aksamija, Christopher H. Counihan, Dylan Brown, Meenakshi Upadhyaya

Zlatan Aksamija

Effects Of Reverberation And Noise On Speech Comprehension By Native And Non-Native English-Speaking Listeners, Z. Ellen Peng, Lily M. Wang, Siu-Kit Lau, Adam M. Steinbach

Lily M Wang

Previous studies have demonstrated the negative impact of adverse signal-to-noise-ratios on non-native English-speaking listeners' performance on speech recognition using recall tasks, as well as implied that comprehension skills were more impaired than recognition skills under reverberation and noise. The authors have themselves previously conducted a pilot study on three native and three non-native Englishspeaking listeners to examine the effects of reverberation and noise using speech comprehension tasks. Those results suggested that speech comprehension performance is worse under longer reverberation times (RT), and that a longer RT is more detrimental to speech comprehension by non-native listeners than native listeners. This paper …

How Tonality And Loudness Of Noise Relate To Annoyance And Task Performance” Noise Control Eng. J. 65(2), 71-82., Joonhee Lee, Jennifer M. Francis, Lily M. Wang

Lily M Wang

Audible tones in noise generated by building mechanical equipment can be a leading cause of complaints from occupants. A number of metrics have been developed to quantify prominence of a tone, but previous work has shown that the impact of a certain tonality appears to vary with the level of the broadband noise signal. More work on how tonal signals of varying tonality, tone frequency and broadband noise levels relate to annoyance and task performance is needed. This paper investigates such relationships between current noise metrics, annoyance and task performance under assorted tonal noise conditions through subjective testing. Participants rated …

Acoustic Tweets And Blogs: Using Social Media In An Undergraduate Acoustics Course, Lily M. Wang

Lily M Wang

Each fall, the author teaches an undergraduate architectural acoustics course to around 40 third-year architectural engineering students at the University of Nebraska. Beginning in 2011, a social media component was introduced to explore the use of this technology and how it may supplement the students' learning experience. Students were given an opportunity to receive extra credit by using Twitter and/or blogging about course material using a set hashtag (#AE3300) or through the course website. Results were positive, and the author will discuss pros and cons that she has experienced in adding this social media component. Suggestions for future implementations and …

A Need For Evidence-Based And Multidisciplinary Research To Study The Effects Of The Interaction Of School Environmental Conditions On Student Achievement, Josephine Lau, Lily M. Wang, Clarence Waters, James A. Bovaird

Lily M Wang

With funding from the U.S. Environmental Protection Agency’s (EPA) Healthy Schools initiative, a research team from the University of Nebraska– Lincoln (UNL) is currently working on establishing how environmental conditions in K-12 school buildings impact student scholastic achievement. The objectives of the research project are: (1) to study comprehensively the impacts of a wide set of indoor environmental factors (including indoor air quality, thermal, lighting and acoustic conditions) on student achievement; (2) to investigate how these environmental conditions interact with each other to impact student achievement; (3) to rank order the environmental variables in terms of their relative impact on …

Effects Of Noise, Reverberation And Foreign Accent On Native And Non-Native Listeners’ Performance Of English Speech Comprehension, Zhao Ellen Peng, Lily M. Wang

Lily M Wang

A large number of non-native English speakers may be found in American classrooms, both as listeners and talkers. Little is known about how this population comprehends speech in realistic adverse acoustical conditions. A study was conducted to investigate the effects of background noise level (BNL), reverberation time (RT), and talker foreign accent on native and non-native listeners' speech comprehension, while controlling for English language abilities. A total of 115 adult listeners completed comprehension tasks under 15 acoustic conditions: three BNLs (RC-30, RC-40, and RC-50) and five RTs (from 0.4 to 1.2 s). Fifty-six listeners were tested with speech from native …

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

Lily M Wang

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 …

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

Lily M Wang

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

Lily M Wang

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 …

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

Lily M Wang

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 …

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

Lily M Wang

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 …

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

Lily M Wang

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

Lily M Wang

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 …

Umass Amherst Green Building Guidelines 2013, Ludmilla Pavlova-Gillham, Ted Mendoza, Ezra Small, Patricia O'Flaherty, Nariman Mostafavi, Mohamed Farzinmoghadam, Somayeh Tabatabaee Pozveh

Ludmilla D Pavlova

Facilities & Campus Services, Sustainable UMass and Campus Planning support sustainability and energy conservation initiatives by providing in-house resources to campus staff as well as designers and contractors working with the University. The UMass Amherst Green Building Guidelines provide a framework for approaching new construction and major renovation projects at UMass Amherst that are undergoing LEED certification by focusing the conversation on green building aspects that are most important to the campus. They are intended to be the beginning of a dynamic conversation between designers, environmental consultants and constructors, university stakeholders, and users of new high performance buildings.

No Admixture, Sustainable, Self-Consolidating Grout, Craig V. Baltimore Dr

Craig V. Baltimore

ABSTRACT: The consolidation of grout in concrete masonry unit (CMU) walls is labor-intensive. Also, the grout’s Portland cement content has a high embodied energy demand – a non-sustainable characteristic. For the labor-intensive issue, chemical admixture self-consolidating grouts have been used in walls 12.67 ft. (3.86 m) tall, however the chemical additive can impose new limitations on the grout (non-robust characteristics). No admixture self-consolidating grout with high percentage Portland cement replacement have potential for robust and sustainable application.

This paper reports on the consolidation of no admixture self-consolidating grout made by substituting high percentages of Portland cement with Type-F fly ash …

Validation Of A Fault-Modeling Equipped Vapor Compression System Model Using A Fault Detection And Diagnostics Evaluation Tool, David P. Yuill, Howard Cheung, James E. Braun

David Yuill

A methodology for evaluating the performance of fault detection and diagnostics (FDD) tools for unitary air- conditioners has been developed (Yuill and Braun 2013). The methodology uses laboratory measurements of systems with and without faults to test FDD tools’ effectiveness. A gray box modeling method capable of modeling systems with faults was developed by Cheung and Braun (2013a and 2013b) to provide input data, as an alternative to using laboratory data that had been collected. The simulation method was validated by direct comparison with experimental data, but a comparison of FDD evaluation results provides a more direct and useful validation …

Quantifying The Just Noticeable Difference Of Reverberation Time With Band-Limited Noise Centered Around 1000 Hz Using A Transformed Up-Down Adaptive Method, Matthew G. Blevins, Adam T. Buck, Zhao Peng, Lily M. Wang

Lily M Wang

This study seeks to quantify the just noticeable difference (JND) of reverberation time (RT) using band-limited noise. ISO 3382-1 lists the JND of reverberation metrics at 5% based on work by Seraphim (1958). However, others have found the JND of RT to be higher from 6% to 39%. Many of these studies utilized band-limited stimuli, e.g. speech, music motifs and bandlimited noise. A previous study by the authors conducted on 30 subjects using white noise demonstrated a JND of RT at 22%. To further verify these results and investigate potential upward frequency masking, the present study was conducted following the …

Rating Low Levels Of Ambient Noise In Performing Arts Facilities, Lily M. Wang, Brent A. Kraay

Lily M Wang

Previous studies have indicated that common indoor noise rating metrics, such as Noise Criteria NC and Room Criteria RC, do not best correlate to human perceptions of annoyance and distraction in typical office environments. Based on investigations conducted at the University of Nebraska using noise levels between 30 – 60 dBA, the author has proposed that an effective indoor noise rating method should begin with a rating of level (either dBA or sones), then an assessment of spectral quality, tones, and fluctuations. How well would such a system work at very low levels of ambient noise, though, as found in …

Effects Of Reverberation And Noise On Speech Comprehension By Native And Non-Native English-Speaking Listeners, Zhao Peng, Lily M. Wang, Siu Kit Lau, Adam M. Steinbach

Lily M Wang

Previous studies have demonstrated the negative impact of adverse signal-to-noise-ratios on non-native English-speaking listeners' performance on speech recognition using recall tasks, as well as implied that comprehension skills were more impaired than recognition skills under reverberation and noise. The authors have themselves previously conducted a pilot study on three native and three non-native Englishspeaking listeners to examine the effects of reverberation and noise using speech comprehension tasks. Those results suggested that speech comprehension performance is worse under longer reverberation times (RT), and that a longer RT is more detrimental to speech comprehension by non-native listeners than native listeners. This paper …

Comparison Of Radiated Power From Structurally Different Violins, Lily M. Wang, Courtney B. Burroughs

Lily M Wang

The acoustic power has been determined from intensity measurements on three structurally different violins: a Scherl and Roth student violin, Hutchins' SUS29S, and Hutchins' mezzo violin SUS 100. While each violin was bowed with an open-frame mechanical bowing machine, the intensity measurements were made by scanning each side of the bowing machine with an intensity probe. One-third octave band sound power levels of the acoustic radiation from each of the three instruments as each of the four open strings is bowed show that the structurally different mezzo violin produces greater power at low frequencies when the lowest (G) string is …

Effects Of Background Noise Alternating Between Two Levels At Varying Time Intervals On Human Perception And Performance, Andrew Hathaway, Lily M. Wang

Lily M Wang

This research experiment aims to better quantify human perception and performance under increased background noise levels of varying intervals. Twenty-seven participants were tested over five 30 minute sessions where they were subjected to RC-29(H) and RC-47(RV) conditions created by broadband noise fluctuating on different time intervals. These intervals varied from two minutes to ten minutes, simulating the conditions of a noisy HVAC system turning on and off. The performance results of an arithmetic test dealing with short-term memory and a subjective questionnaire will be presented and compared to a similar test using broadband noise bursts and correlated to noise metrics …

Scattered Responses From Suspended Reflector Panels With Rounded Edges, Jonathan Rathsam, Lily M. Wang

Lily M Wang

Sound reflections from most finite surfaces, such as overhead reflector panels, include a component known as edge diffraction. Edge diffraction is the scattered energy required to maintain a continuous sound field despite the discontinuity in acoustical impedance presented by the scatterer. Edge diffraction can interfere with primary scattered energy to produce comb filtering at receiver locations. Several decades ago, the effect of changing the edge profile of loudspeaker boxes was investigated with the goal of producing a smoother frequency response. By rounding the edges of loudspeaker boxes, the edge diffraction could be decreased noticeably [H. F. Olson, J. Aud. Eng. …

Effects Of Noise On Productivity: Does Performance Decrease Over Time?, Jessica Errett, Erica Eileen Bowden, Marc Choiniere, Lily M. Wang

Lily M Wang

Most people at one time or another have found themselves irritated or distracted by the background noise in a building. The irritation might have resulted in minor aggravation or may have been dramatic enough to hinder their work. This leads us to ask whether occupants are increasingly aggravated by noise the longer they are exposed to it, or if they naturally habituate to their acoustic environment. In an effort to answer this question, a study was completed in the “Indoor Environment Lab” at the University of Nebraska. This lab resembles a typical office and was specially constructed to be acoustically …

Ab-10-C037: Effects Of Noise From Building Mechanical Systems On Elementary School Student Achievement, Lauren M Ronsse, Lily M. Wang

Lily M Wang

This project seeks to determine what relationship, if any, exists betweenbackground noise levels in elementary classrooms due to the building mechanicalsystems and student performance on achievement tests. Previous research inclassroom acoustics has clearly identified that lower background noise levelsresult in higher speech intelligibility which is crucial for the learning process;however, there is a lack of data correlating lower noise levels to improved studentachievement scores. For this study, background noise level measurements were madein 14 elementary schools in a public school system in Council Bluffs, Iowa, USA.The measurements were made in unoccupied classrooms with the central buildingmechanical systems activated. Second and …

Effects Of Changing The Amount Of Absorption In A Computer Model Of Queen’S Hall, Copenhagen, Denmark, Michelle C Vigeant, Lily M. Wang, Jens Holger Rindel

Lily M Wang

Room acoustics modelling and auralizations are very useful tools in the design of acoustically sensitive spaces. One area of improvement for auralizations is the method of modelling the source directivity. A new method to incorporate source directivity is multi-channel auralizations. This study first evaluates the objective effects of using four and thirteen channel impulse responses in an ODEON model of Queen’s Hall, where the actual variable absorption is changed within the model. Analyses of the results reveal great differences in the objective parameters of reverberation time and sound pressure level across each channel’s impulse response. Subjective studies were then conducted …

Binaural Room Impulse Response Database Acquired From A Variable Acoustics Classroom, Zhao Peng, Siu Kit Lau, Lily M. Wang, Sean Browne, Kenneth P. Roy

Lily M Wang

Room measurements were conducted in a variable acoustics classroom mockup space (epod) at Armstrong World Industries in Lancaster, Pennsylvania, USA. Binaural room impulse responses were measured in the epod using a head and torso simulator. Five reverberation time (RT) scenarios were achieved with various combinations of absorptive wall panels and acoustical ceiling tile. These provided a range of mid-frequency RTs from 0.4 to 1.1 seconds. Three of the five RT scenarios were achieved using two different material configurations to also consider material location effects. For each of the eight material configurations, two student-teacher orientations were tested. One orientation had all …

Or-05-6-4: Relating Human Productivity And Annoyance To Indoor Noise Criteria Systems: A Low Frequency Analysis, Erica Eileen Bowden, Lily M. Wang

Lily M Wang

A number of indoor noise criteria systems are used to quantify the background noise in a built environment, including Noise Criteria (NC), Balanced Noise Criteria (NCB), Room Criteria (RC), Room Criteria Mark II (RC Mark II), A-weighted Equivalent Sound Pressure Level (LAeq), and others. An on-going debate exists in the acoustical community over which criterion is the most appropriate to use in the variety of ambient noise situations encountered. In an effort to quantitatively support the use of individual criterion, this project subjectively correlates these various criteria with human task performance and perception. Eleven subjects participated in a pilot study …