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Seismic Performance and Cost Analysis of UHPC Tall Buildings in UAE with Ductile Coupled Shear Walls
No full textThe superior mechanical characteristics of ultra-high-performance concrete (UHPC) have attracted the interest of many researchers worldwide. Researchers have attempted to perform comparative analyses on the behavior of UHPC versus conventional and high-strength concrete, with their aim being to gain more insights into the difference between different types of concrete. However, the current state-of-the-art revealed no direct comprehensive comparisons between their behaviors in ductile coupled shear walls under seismic loading. This paper explores a comprehensive side-by-side comparison in terms of seismic behavior and cost analysis for four 60-story archetype buildings. The reference building was designed using high-strength concrete with a strength of 60 MPa. The other three archetype variations incorporated three different UHPC grades: 150 MPa, 185 MPa, and 220 MPa. The plan configuration and the lateral force-resisting system (LFRS) were chosen according to the most common practice in the UAE. The main objective is to report the effect of UHPC on the LFRS (ductile coupled shear walls). Moreover, a simplified initial cost analysis (materials and labor) design was performed. The findings of this paper indicate that the use of UHPC is capable of improving the seismic performance behavior of the lateral system as well as reducing the total initial costs.American University of Sharja
Automatic Video Summarization Using HEVC and CNN Features
No full textA Master of Science thesis in Computer Engineering by Obada Issa entitled, “Automatic Video Summarization Using HEVC and CNN Features”, submitted in November 2022. Thesis advisor is Dr. Tamer Shanableh. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).With the incredible surge of the internet and surveillance footage, there is a vast number of digital videos. The need to summarize these videos within databases is very crucial. This is where video summarization comes in handy. Video summarization can be achieved by a number of techniques. This study proposes a novel solution for the detection of key-frames for static video summarization. We preprocessed the well-known video datasets by coding them using the HEVC video coding standard. During coding, 64 proposed features were generated from the coder for each frame. Additionally, we extracted RGB frames from the original raw videos and fed them into pre-trained CNN networks for feature extraction. These include GoogleNet, AlexNet, Inception-ResNet-v2, and VGG16. The modified datasets are made publicly available to the research community. A subset of the proposed HEVC feature set was used to identify duplicate or similar frames and eliminate them from the video. We also propose an elimination solution based on the sum of the absolute differences between a frame and its motion-compensated predecessor. The proposed solutions are compared with existing works based on an SIFT flow algorithm that uses CNN features. Subsequently, an optional dimensionality reduction based on stepwise regression was applied to the feature vectors prior to detecting key-frames. The proposed solution is compared with existing studies that use sparse autoencoders with CNN features for dimensionality reduction. The accuracy of the proposed key-frame detection system was assessed using the Positive Predictive Values, Sensitivity, and F-score metrics. Combining the proposed solution with Multi-CNN features and using a Random Forests classifier, it was shown that the proposed solution achieved an average F-score of 0.98.College of EngineeringDepartment of Computer Science and EngineeringMaster of Science in Computer Engineering (MSCoE
Harmonic-Based Overcurrent Scheme for Optimal Protection Coordination of Islanded Microgrids
No full textA Master of Science thesis in Electrical Engineering by Abdelrahman M. A. Kamal Abdelaziz entitled, “Harmonic-Based Overcurrent Scheme for Optimal Protection Coordination of Islanded Microgrids”, submitted in December 2022. Thesis advisor is Dr. Mostafa Shaaban and thesis co-advisor is Dr. Maher Azzouz. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Protection of microgrids dominated by inverter-based distributed generators (IBDGs) is challenging as these IBDGs are characterized by their low contribution to fault currents. Therefore, their fault currents can be confused with the normal operating current, which imposes a major challenge for overcurrent protection relays to distinguish faulty conditions. Furthermore, the change in the microgrid's topology due to the intensive use of IBDGs imposes a major concern. The IBDG has an interfacing LC filter with relatively high impedance compared to the microgrid’s lines. This affects the sequence networks; hence, the three-phase fault is not the most severe. In this thesis, harmonic voltage generation methodology is deployed. Performing the protection coordination in a new harmonic layer formed during faults helps to avoid the problem of distinguishing faulty conditions. It is proposed to include the symmetrical as well as asymmetrical faults in the optimal protection coordination (OPC) problem formulation. The inclusion of asymmetrical faults ensures a more reliable operation of the proposed overcurrent protection scheme, as relying only on symmetrical faults can be deceptive. A comparison between current levels for different fault types and different transformer connections is presented to highlight the importance of asymmetrical faults inclusion in the OPC as well as provide evidence of symmetrical-based approaches failure. After modifying the OPC by including asymmetrical faults, the results are compared to a newly proposed fault type multi settings (MS)-based OPC. The OPC problem is formulated as a non-linear programming (NLP) that is developed in GAMS software. The results are validated using a test system which is a section of a Canadian distribution system, as well as the IEEE-33 bus system. Results confirm the proposed MS-based method’s ability to enhance the relays’ total operation time. 14% and 38% reduction in the total operating time are achieved for the 9 bus and 33 bus respectively. Several case studies are conducted to demonstrate the effectiveness of the proposed methodology in providing OPC considering symmetrical and asymmetrical faults with high fault resistances besides evaluating the proposed protection scheme capability to maintain precise coordination in case of expanding the IBDGs capacities.College of EngineeringDepartment of Electrical EngineeringMaster of Science in Electrical Engineering (MSEE
A Customer-Centered Smart Charging Strategy Considering Virtual Charging System
No full textElectric vehicle (EV) charging is considered as one of the main issues that face EV drivers. Thus, there should be a facility to suggest the best charging station based on the customer requirements. However, the routing process of EVs in most of the literature was generally implemented centrally based on the charging station/operator perspective. On contrary, this paper proposes a smart charging strategy that routes EVs drivers to the best charging station based on their priorities. In the proposed smart strategy, various charging stations will cooperate through a virtual charging system (VCS) to serve all EVs charging requests with a high satisfaction level. The drivers’ requirements are achieved through a new scoring criterion which ranks the participating charging stations based on EV driver’s perspective. Then, the EV driver will select individually the charging station based on his priorities. The data required for the scoring criterion are computed through two stages: offline (day-ahead) and online stages. The expected waiting time at each charging station within the VCS is computed during the offline stage based on the forecasted arrivals. The integration between offline and online stages aims to reduce the data flow, calculated data, and finally the communication bandwidth during the online stage. Different case studies are introduced to evaluate the significance of the proposed strategy. The results demonstrate the superiority of the proposed strategy in achieving EVs requirements.Advanced Power and Energy Center (APEC), Khalifa UniversityAmerican University of Sharja
The Importance of Protecting Cultural Capital in Community Development
No full textPresented at the 12th International Academy for Intercultural Research (IAIR) conference in Rapperswil-Jona, Switzerland on July 26, 2022.Community development, which aims to increase the agency and solidarity of community members in order to improve the well-being of communities as a whole as a well as the individual members of those communities. Community development practice occurs in many different forms, such as part of governmental agencies, non-governmental agencies, community-based participatory research, and service-learning programs at universities. The communities that receive support and aid via community development programs can be local to the practitioners or can be communities distantly removed from the practitioners – even communities in a different country. Unfortunately, too often international community development (as well as international aid) has characteristics uncomfortably similar to neo-colonialist practices and cultural imperialism. This is because receiving communities are sometimes expected (or even required) to adopt the cultural worldviews, beliefs, and traditions of the people providing the community development aid in order to continue qualifying for the support. Then, in a damaging cyclical fashion, the developmental support and aid is made necessary because of the manner in which previous support was provided, leading to a cycle of negative outcomes requiring even more support. Fortunately, there are more ethical and impactful ways of engaging in international and cross-cultural community development that avoids many (if not all) of the possible negative outcomes. In my presentation, I will use the Social Capitals Framework to discuss the ways in which communities share different types of capital (e.g., human capital, natural capital, etc.). I will then focus on the concept of cultural capital, which are the ways of living, traditions, values, beliefs, and worldviews that a community shares to make sense of the world. I will discuss how international and cross-cultural community development should be practices in such a way that cultural capital is at a minimum not damaged but ideally actively supported and even celebrated. I will utilize data collected via interviews with community members of a community (N = 8) in Guatemala that has received support from various international community development initiatives over the last several years. Based on a thematic analysis process, I will discuss the way in which the interviewees experience international community development efforts in the context of protecting and supporting cultural capital. I will conclude my presentation with specific suggestions for best practices and better engagement in international and cross-cultural community development
Engagement as a Dynamic but Perceivable Variable in Language Classroom Interactions
No full textA Master of Arts thesis in Teaching English to Speakers of Other Languages (TESOL) by Lydia Shepherd entitled, “Engagement as a Dynamic but Perceivable Variable in Language Classroom Interactions”, submitted in May 2022. Thesis advisor is Dr. Tammy Gregersen. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Engagement is understood as a multifaceted concept comprising behavioral engagement, emotional engagement, and cognitive engagement. These three dimensions are not always synchronized, and teachers may find students highly cognitively engaged, but not emotionally. Therefore, students can be engaged at varying degrees with some not engaged at all, and this disengagement can lead to decreased motivation and achievement. Keeping this in mind, it becomes critical that teachers understand what engages their students in the classroom. For this reason, the following study was conducted in order to find out whether or not teachers are aware of what engages their students, when their students are engaged, and if so, how? Over the span of a semester, researchers recorded two classrooms, over several lessons. Each video was displayed to the student represented in the video, and their respective teacher. The learners were then asked to self-rate their engagement as they watched themselves. Subsequently, the teacher was asked to watch the same video and, using the verbal and nonverbal cues of the learner, rank their judgment of the learner’s engagement. Upon completion of the learner’s and teacher’s idiodynamic responses, they underwent an interview to explain the dips and spikes from the response graphs produced by the software. After careful analysis of the graphs and verbal responses from both parties, the research revealed that the teachers were unable to identify if and when students were faking engagement, and on average assumed higher engagement throughout the class then the students had self-reported. In other words, teachers had a harder time perceiving the differences between engagement and disengagement in their students. Using the consistencies found in both the teacher and student responses, this paper aims to highlight the common patterns of learner engagement, disengagement, and fake engagement.College of Arts and SciencesDepartment of EnglishMaster of Arts in Teaching English to Speakers of Other Languages (MA TESOL
Improving Resilience in Water Distribution System
No full textA Master of Science thesis in Construction Management by Ahmed Farid Ismail entitled, “Improving Resilience in Water Distribution System”, submitted in December 2022. Thesis advisor is Dr. Md. Maruf Mortula. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).There has been an emerging realization that resilient water infrastructure is critical to ensuring sustainable urban water management. To improve the resilience of the buried water infrastructure, an evaluation of the inherent resilience of the water system is necessary. A water distribution system including the pipe network is considered one of the critical components of the water supply system and it ensures delivering adequate safe water to the end-users. A reliable distribution system should maintain water quality within the network and supply sufficient quantity and pressure to the users regularly even during maintenance or repair of any part of the system. Due to the events that may result in preventing the water distribution system from continuing its critical services, it is crucial to evaluate the system's resilience under extreme failure conditions. Therefore, this study aims to investigate the resilience of the water distribution system under exceptional failure conditions such as pipe failure, water contamination, and water excess demand, quantify the corresponding performance, and develop a resilience index using the global resilience analysis (GRA) approach. GRA can be applied to a hydraulic model under hypothetical failure scenarios to assess the system’s resilience. University City water distribution system was used as a case study. In this study, the resilience index is developed under five stress categories which are 20%, 40%, 60%, 80% and 99%. Furthermore, the resilience index provides a score from 0-100 which is an overview of the performance of the system under the failure scenarios. The developed resilience index for the existing system indicate that the water distribution system is categorized as low resilience for the first two stress categories and very low resilience for the last three stress categories with 58.0, 51.0, 44.0, 33.52 and 22.46 respectively.College of EngineeringMultidisciplinary ProgramsMaster of Science in Construction Management (MSCM
Cooling potential for hot climates by utilizing thermal management of compressed air energy storage systems
No full textThis work presents findings on utilizing the expansion stage of compressed air energy storage systems for air conditioning purposes. The proposed setup is an ancillary installation to an existing compressed air energy storage setup and is used to produce chilled water at temperatures as low as 5 °C. An experimental setup for the ancillary system has been built with appropriate telemetric devices to measure the temporal temperature variation, which consequently can be used to calculate the heat transfer and available cooling capacity. The system is compared to commercially available compression cooling air conditioners, and the potential of replacing them is promising, as one ton of conventional cooling can be replaced with a 500-L (0.5 mᵌ) air tank at 20 bar operating for an hour. More tanks can be added to extend the operational viability of the system, which is also serving the original purpose of storing energy from grid excess or from solar photovoltaic panels. The thermal management has had the added benefit of increasing the roundtrip efficiency of the storage system from 31.4 to 35.2%, along with handling a portion of the cooling load
Wireless Networks Physical Layer Security Analysis and Improvement
No full textA Master of Science thesis in Electrical Engineering by Youssef Mohamed Abdelfattah Eldokmak entitled, “Wireless Networks Physical Layer Security Analysis and Improvement”, submitted in November 2022. Thesis advisor is Dr. Mahmoud H. Ismail and thesis co-advisor is Dr. Mohamed Hassan. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).With the recent advancements in computational power, traditional security techniques are being challenged since it is now easier for an eavesdropper to decode messages previously deemed to be practically impossible to decode. That is why physical layer security is becoming an important research field that is gaining much attention among the research community. Studying the physical layer security for a wireless network enables us to find different important secrecy performance metrics such as the average secrecy capacity, the secrecy outage probability and the probability of non-zero secrecy capacity. These different metrics can be used to assess the network properly and to know what data rates could be transmitted to a legitimate receiver without an eavesdropper decoding it. As a consequence, studying secrecy performance over different fading channels and under various case scenarios depending on the application has been extensively addressed in the literature. In addition, as much as secrecy performance analysis is important, developing techniques to improve the secrecy performance is as important in order to ensure reliable and secure data transmission. In this thesis, we focus on analysing the secrecy performance over general fading/shadowing channels that have not yet been studied in the literature. Specifically, we focus on the analysis of two cases of the generalized gamma channels. In the first, the signal to noise ratio follows a composite generalized gamma log-normal distribution and in the second, the channels of the legitimate and eavesdropper receivers follow a correlated generalized gamma distribution. These fading models can be used to represent a wide range of channels that are encountered in many practical applications. We finally address how artificial noise could be used in secrecy performance improvement.College of EngineeringDepartment of Electrical EngineeringMaster of Science in Electrical Engineering (MSEE
Biomarker Discovery Utilizing Big Data: The Case of Diabetes in United Arab Emirates
No full textA Doctor of Philosophy Dissertation in Engineering Systems Management by Bayan Hassan Banimfreg entitled, “Biomarker Discovery Utilizing Big Data: The Case of Diabetes in United Arab Emirates”, submitted in May 2022. Dissertation advisor is Dr. Abdulrahim Shamayleh and dissertation co-advisor is Dr. Hussam Alshraideh. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Diabetes Mellitus (DM) received substantial attention for exploring its mechanism as expected to be the seventh primary reason for death worldwide by 2030. The hallmark of DM leads to damaging effects on many organ systems, mainly the cardiovascular, ophthalmic, and renal systems. The number of adults with DM to reach 95 million by 2030 and 136 million by 2045 in the Middle East and North Africa region. Type 2 diabetes (T2DM) is the most common type of DM, accounting for around 90% of diabetes cases. T2DM is a multifactorial chronic metabolic disease caused by genetic and non-genetic factors resulting from an imbalance between energy intake and output and other lifestyle-related factors. However, the detailed understanding of T2DM etiology is still limited. As the focus of this work is the metabolomic derived biomarker discovery, a non-targeted metabolomics experiment using liquid chromatography with tandem mass spectrometry (LC-MS/MS) is conducted to explore the metabolic profile of diabetic Emirati Citizens to uncover potential novel diabetes biomarkers through big data analytics. The study is twofold: in the first part, a comprehensive analysis is performed to reveal the profiling metabolites of diabetic Emirates compared to healthy ones. Blood samples of 50 diabetic Emiratis versus 42 healthy were utilized to investigate for differential metabolites. In the second part, a metabolomic study of patients with diabetic kidney disease against dialysis non-diabetics patients was conducted to uncover their distinct biomarkers. Blood samples of 11 dialysis diabetics and 25 dialysis non-diabetic were used to reveal potential biomarkers. A great panel of potential differential metabolites was identified among diabetic and non-diabetic Emirates. The identified metabolites were sorted into classes, including Tryptophan and Purines. Several potential biomarkers and their related pathways were pinpointed among dialysis patients, including Tyrosine metabolism-related metabolite and 3,4-Dihydroxymandelic acid. These studies provide detailed coverage of blood metabolic changes related to T2DM in the Emirati population. The results of this work are mainly consistent with similar international studies, with a few added biomarkers reflecting the region-specific health profile. The worldwide consensus on common metabolites encourages the clinical trials of novel biomarkers that could expedite the treatment process for diabetics. Monitoring and managing diseases might move medicine from a therapeutic model to a prevention model.College of EngineeringDepartment of Industrial EngineeringPhD in Engineering - Engineering Systems Management (PhD-ESM