Investigation Of Subjective Perception & Objective Metrics Of Acoustic Room Diffusion, Jay Michael Bliefnick

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

While a variety of assessment methodologies have been proposed to quantify acoustic diffusivity within rooms, a link between these and the perception of diffusion has not been fully established. This study investigated various ways of analyzing diffusion, through both human perception and objective metrics. Numerous impulse response measurements were collected from a physical acoustics testing facility designed for diffusion research. This space featured reversible absorptive/diffusive/reflective wall panels, which allowed numerous testing configurations. One such setup investigated how changing the diffusivity of an isolated wall surface impacted diffusive room conditions. Alternatively, the effects diffuser configurations had on diffusive room conditions were …

Power-Weighted Divergences For Relative Attenuation And Delay Estimation, Ruairí De Fréin, Scott T. Rickard Prof

Articles

Power-weighted estimators have recently been proposed for relative attenuation and delay estimation in blind source separation. Their provenance lies in the observation that speech is approximately windowed-disjoint orthogonal (WDO) in the time-frequency (TF) domain; it has been reported that using WDO, derived from TF representations of speech, improves mixing parameter estimation. We show that power-weighted relative attenuation and delay estimators can be derived from a particular case of a weighted Bregman divergence. We then propose a wider class of estimators, which we tune to give better parameter estimates for speech.

Image Text Search And Retrieval System, Wayne De Fremery, Sanghun Kim

Barowsky School of Business | Faculty Patents

An imaging device comprising a flexible sensor attached to a control case. The flexible sensor provides both a source of illumination to the image being captured and a method of capturing the image. The method of capture comprises a field of reactors disbursed across the facial area of the sensor, the output of which produces a dot-pattern capture of the intended image which is passed to a storage device.

Construction Professional Service Firm Management: A Longitudinal Study Of Strategic Planning In Irish Quantity Surveying Practices, Roisin Murphy

Conference papers

This paper reports on the ongoing investigation of strategic planning in Irish Quantity Surveying practices. The construction industry in Ireland has undergone a period of significant change in the last five years fuelling a shift in focus from tactical to strategic planning in professional service firms operating within the sector. A previous paper identified the type, scope and extent of strategic planning within Quantity Surveying (QS) practices in Ireland in the years up to and during the economic downturn. The current paper expands on the previous research by identifying changes in approach to strategic management within these professional service firms …

A Time For Change” An Evaluation Of The Ability Of The Quantity Surveyor To Measure Mechanical And Electrical Services Under The Irish Public Works Contracts (Designed By The Employer) Using The Agreed Rules Of Measurement., Charles Mitchell

Other Resources

Abstract

This dissertation seeks to examine the ability of the quantity surveyor to measure mechanical and electrical bills of quantities under the Irish Public Works Contracts using the Agreed Rules of Measurement 4. The study uses the opinions and perspectives of a broad range of industry stakeholders to identify barriers and drivers which will facilitate this change.

A mixed methodology research method incorporating both quantitative and qualitative research methods was used. A literature review covers relevant research in the field of the Public Works Contracts, the use of bills of quantities and specialist sub-contractors. The results of an unreported survey …

Designing And Building An Automatic Chamfer Grinder, William Johnson

Mahurin Honors College Capstone Experience/Thesis Projects

Modern day manufacturing is a demanding environment with a constant need for process improvement. As automation becomes more advanced, there are fewer jobs that must be completed by a human. In the case of Stupp Bridge Company, a local manufacturer of steel bridge girders, their workforce is highly skilled, so replacing mundane tasks with automation allow the skilled workers to focus on the difficult jobs. One such task is grinding a chamfer onto every leading edge of each girder flange, eight edges in total, ranging from 20 to 200 feet long. The purpose of this project was to design an …

Lifelong Housing Design: User Feedback Evaluation Of Smart Objects And Accessible Houses For Healthy Ageing, Matteo Zallio, Niccolò Casiddu

Conference Papers

According to the latest research by the European Community and ISTAT (Italian National Institute of Statistics) surveys, Europe has the highest average age for its population. According to those data, in the near future, it could be necessary to move from a welfare model based on the centralization of care systems, to a system based on the distribution of certain healthcare facilities [1]. This means that the ageing population is ever increasing, thanks to better lifestyles, innovative medical care and wider access to different services. This work seeks to observe and analyse key implications of architectural and interior design features …

Calcium Phosphate As A Key Material For Socially Responsible Tissue Engineering, Vuk Uskoković, Victoria M. Wu

Pharmacy Faculty Articles and Research

Socially responsible technologies are designed while taking into consideration the socioeconomic, geopolitical and environmental limitations of regions in which they will be implemented. In the medical context, this involves making therapeutic platforms more accessible and affordable to patients in poor regions of the world wherein a given disease is endemic. This often necessitates going against the reigning trend of making therapeutic nanoparticles ever more structurally complex and expensive. However, studies aimed at simplifying materials and formulations while maintaining the functionality and therapeutic response of their more complex counterparts seldom provoke a significant interest in the scientific community. In this review …

Toward Mining Massive And Multi-Dimensional Data For Extreme Hydrometeorological And Climate Event Analyses, Ling Qiu, Francisco Munoz-Arriola, Carlos M. Carrilo

UCARE Research Products

This poster presents the research on the main patterns of spatial distribution and temporal variability of precipitation and temperature in the Missouri River Basin (MRB). MRB has 117 million acres in cropland, produces of 46%, 22%, and 34% US's wheat, corn, and cattle, respectively. Also, MRB is known for intense weather and extreme climate variability. The approach is to identify different patterns of spatial distribution and temporal variability of precipitation and temperature through the use of a Principal Component Analysis. We have found that precipitation and temperature are the ideal meteorological variable to test spatiotemporal variability of extreme events using …

Engineering Outreach Education Through Social Media, Katie E. Meiergerd, Dagen Valentine, Jennifer R. Keshwani, Bradley Barker

UCARE Research Products

Familiarizing teachers and educators with Engineering and other related STEM fields is crucial in educating students, so ensuring teachers with access to these resources is important. The objective of this work is to identify ways to use social media to provide support to K – 12 educators interested in implementing engineering education with their students.

Thermal Mass Behaviour Of Concrete Panels Incorporating Phase Change Materials, Dervilla Niall, Roger West, Sarah Mccormack, Oliver Kinnane

Conference papers

Phase Change Materials (PCM) have been incorporated into a range of building envelope materials with varied success. This study investigates two different methods of combining concrete and phase change materials to form PCM/concrete composite panels. The first method involves adding microencapsulated paraffin to fresh concrete during the mixing process. The second method involves vacuum impregnating butyl stearate into lightweight aggregate which is then included in the concrete mix design. The primary aim of the study is to determine which method is the most effective way to improve the thermal mass characteristics of a concrete panel in the context of a …

Grange Stone Circle (B) – New Thoughts On An Old Monument, Frank Prendergast

Book/Book Chapter

No abstract provided.

What Do We Know About Eesd And How Do We Know It?, Eddie Conlon, Iacovos Nicolaou, Brian Bowe

Conference papers

Huckle (2004) has argued that critical realism (CR) can provide a philosophical framework for higher education for sustainability. This paper reflects on the process of researching EESD in the Irish context and the usefulness of our approach which used mixed methods and drew on CR as its guiding philosophy. We will argue that aspects of the CR approach: its emphasis on a depth ontology, the search for causal mechanisms, its model of agency/structure relations and its emphasis on the combination of extensive and intensive methods provide tools for exploring EESD as a system. CR requires us to focus on “deeper …

Dlvo Approximation Methods For Predicting The Attachment Of Silver Nanoparticles To Ceramic Membranes, Anne M. Mikelonis, Sungmin Youn, Desmond F. Lawler

All Engineering Faculty Research

This article examines the influence of three common stabilizing agents (citrate, poly(vinylpyrrolidone) (PVP), and branched poly(ethylenimine) (BPEI)) on the attachment affinity of silver nanoparticles to ceramic water filters. Citrate-stabilized silver nanoparticles were found to have the highest attachment affinity (under conditions in which the surface potential was of opposite sign to the filter). This work demonstrates that the interaction between the electrical double layers plays a critical role in the attachment of nanoparticles to flat surfaces and, in particular, that predictions of double-layer interactions are sensitive to boundary condition assumptions (constant charge vs constant potential). The experimental deposition results can …

Laser Micromachining Of Contactless Rf Antenna Modules For Payment And Cards And Wearable Objects, Matthias John

Conference papers

The use of contactless payment methods for consumer transactions is becoming increasingly popular - 1.1 billion contactless transactions were made by Visa cardholders across Europe in the 12 months to July 2015 (€12.6 billion total value). Typically the contactless payment process uses a Radio Frequency (RF) enabled smartcard or a Near Field Communication (NFC) enabled smartphone. In order to ensure continued market acceptance and repeat usage the contactless operation must be robust, quick and efficient. This paper describes the development of an inductively coupled contactless smartcard utilising UV DPSS laser micromachining to fabricate the novel antenna structures from copper laminated …

Book Reviews: Robert Hensey, First Light: The Origins Of Newgrange. Oxford: Oxbow Books, Series: Oxbow Insights In Archaeology, 2015, Frank Prendergast

Articles

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Student Absenteeism And The Comparisons Of Two Sampling Procedures For Culturable Bioaerosol Measurement In Classrooms With And Without Upper Room Ultraviolet Germicidal Irradiation Devices, Chunxiao Su, Josephine Lau, Shawn G. Gibbs

Durham School of Architectural Engineering and Construction: Faculty Publications

Upper room ultraviolet germicidal irradiance (UVGI) has been shown to reduce the concentration of bioaerosols in controlled chambers. However, there is a lack of experimental results on the reduction of bioaerosol concentrations by UVGI devices in actual uncontrolled buildings. This study was carried out in an American elementary school in the Midwest. Two sampling procedures were carried out in six selected classrooms with similar dimensions that were separated into two groups: (1) UVGI exposure group and (2) non-UVGI control group. Two-stage Tisch culturable impactors were utilized to collect airborne culturable bacteria and fungi. Monthly samples were collected during unoccupied period …

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 E. Waters, James A. Bovaird

Durham School of Architectural Engineering and Construction: Faculty Publications

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 …

Fault Detection And Diagnosis Process For Oversizing Design On Multiple Packaged Air-Conditioning Units, Denchai Woradechjumroen, Haorong Li, Thanapat Promwattanapakee

Durham School of Architectural Engineering and Construction: Faculty Publications

Heating, ventilation, air-conditioning and Refrigeration (HVAC&R) systems are seldom designed or commissioned properly. The situation leads to abrupt or degradation faults resulting in inefficient energy uses, excessive energy consumption and high service costs. To solve these aforementioned problems, fault detection and diagnosis (FDD) is utilized to firstly detect any abnormal conditions of a system and then diagnoses and determines their causes. In order to apply this concept in HVAC oversizing designs, this paper proposes the state-of-art procedure of a FDD procedure for analyzing the inherently faulty design (oversizing) of multiple packaged air-conditioning units used to supply cooling for an open …

Development Of Coordination Control For Multiple Rooftop Units, Denchai Woradechjumroen, Haorong Li, Akekachai Deesiri

Durham School of Architectural Engineering and Construction: Faculty Publications

Rooftop Units (RTUs) have been widely applied in providing space heating and cooling for commercial buildings. In total, they serve over 60% of the commercial building floor space in the U.S. Even through the current control approaches of a RTU can maintain the zone temperature corresponding to a set point temperature, it performs inefficiently due to several factors such as limited sensing capability, non- coordinated local control, inherent oversizing effects and so on. In addition to unnecessary power consumptions, the current control and operation technology on RTUs also lead to the space humidity problem, equipment efficiency degradation, and premature failure. …

Cognitive Radio For Smart Grid With Security Considerations, Khaled Shuaib, Ezedin Barka, Nedaa Al Hussien, Mohammed Abdel-Hafez, Mahmoud Alahmad

Durham School of Architectural Engineering and Construction: Faculty Publications

In this paper, we investigate how Cognitive Radio as a means of communication can be utilized to serve a smart grid deployment end to end, from a home area network to power generation. We show how Cognitive Radio can be mapped to integrate the possible different communication networks within a smart grid large scale deployment. In addition, various applications in smart grid are defined and discussed showing how Cognitive Radio can be used to fulfill their communication requirements. Moreover, information security issues pertained to the use of Cognitive Radio in a smart grid environment at different levels and layers are …

Compressor Having A Control And Dagnostic Module, Hung M. Pham, Fadi M. Alsaleem

Durham School of Architectural Engineering and Construction: Faculty Publications

An apparatus includes a Voltage sensor, a current sensor, and a controller. The Voltage sensor measures Voltage values of alternating current power Supplied to a capacitor. The capaci tor is electrically coupled to a compressor. The current sensor measures current values of the alternating current power. The controller is configured to receive the Voltage values and the current values. The controller is configured to determine a first power factor value based on at least one of the voltage values and at least one of the current values. The controller is configured to selectively detect a first capacitor fault in response …

A Prediction Method For Overall Economic Value Of Fault Detection And Diagnostic Tools For Rooftop And Split Systems, David Yuill, James Braun

Durham School of Architectural Engineering and Construction: Faculty Publications

Fault detection and diagnostics (FDD) tools for air-conditioning application may perform well or poorly, but it is difficult to characterize this performance in a meaningful way. Some recently proposed evaluation techniques have provided various statistics to characterize FDD performance, but these results can be difficult for a potential adopter of FDD to understand. A new method of characterizing FDD performance by predicting the overall economic value of the FDD tool is proposed in this paper. It is applicable to FDD tools intended for air-cooled unitary airconditioners, such as rooftop units (RTU) and split systems. The method gives an estimated dollar …

Normalized Effect Of Condenser Fouling And Refrigerant Charge On Performance Of Vapor Compression Air Conditioning Systems, Mehdi Mehrabi, David Yuill

Durham School of Architectural Engineering and Construction: Faculty Publications

Several laboratory experiments have studied the effect of faults on vapor compression cycle air-conditioning systems. There has been a particular focus on refrigerant charge variation, which is believed to be quite common in air conditioners, and a lesser focus on heat exchanger fouling. The majority of the published results evaluate the fault effects on particular system operating parameters in one unit. For example, the effect on capacity and efficiency are typically evaluated. The results differ from one study to the next. The current paper summarizes the effects for all of the results available in the literature for condenser fouling and …

Fault Diagnosis Of Refrigerant Charge Based On Pca And Decision Tree For Variable Refrigerant Flow Systems, Jiangyan Liu, Huanxin Chen, Jiangyu Wang, Guannan Li, Haorong Li, Wenju Hu

Durham School of Architectural Engineering and Construction: Faculty Publications

Variable refrigerant flow (VRF) systems are easily subjected to performance degradation due to refrigerant leakage, mechanical failure or improper maintenance after years of operation. Ideal VRF systems should equip with fault detection and diagnosis (FDD) program to sustain its normal operation. This paper presents the fault diagnosis method for refrigerant charge faults of variable refrigerant flow (VRF) systems. It is developed based on the classification and regression tree (CART) algorithm. Data of the experimental VRF system is used to test the advantages of the CART method. Results show that the decision tree can achieve desirable diagnosis efficiency on undercharge faults, …

Developing Equations For Estimating Reference Evapotranspiration In Australia, Matin Ahooghalandari, Mehdi Khiadani, Mina Esmi Jahromi

Research outputs 2014 to 2021

Quantifying reference evapotranspiration (ET₀) is essential in water resources management. Although, many methods have been developed with different level of accuracy, in this study, two new equations were developed and optimized for estimating ET₀ using Honey-Bee Mating Optimization (HBMO) algorithm. The firs eq. estimates ET₀ from extraterrestrial radiation (R_a), relative humidity (RH) and mean daily temperature (T_mean), while the second uses the same parameters except that mean daily temperatures is replaced with maximum daily air temperature (T_max). Both equations were developed using climatic data from eight weather stations in Western …