Engineering Commons^™

Applications Of Complex Network Analysis In Electric Power Systems, Mahmoud Saleh, Yusef Esa, Ahmed Mohamed

Publications and Research

This paper provides a review of the research conducted on complex network analysis (CNA) in electric power systems. Moreover, a new approach is presented to find optimal locations for microgrids (MGs) in electric distribution systems (EDS) utilizing complex network analysis. The optimal placement in this paper points to the location that will result in enhanced grid resilience, reduced power losses and line loading, better voltage stability, and a supply to critical loads during a blackout. The criteria used to point out the optimal placement of the MGs were predicated on the centrality analysis selected from the complex network theory, the …

Tolerance Sensitivity Analysis And Robust Optimal Design Method Of A Surface-Mounted Permanent Magnet Motor By Using A Hybrid Response Surface Method Considering Manufacturing Tolerances, Cha-Seung Jun, Byung-Il Kwon, Ohbong Kwon

Publications and Research

This paper presents a robust optimal design method using a hybrid response surface method (H-RSM) which directly finds an optimal point satisfying a target Z-value or a probability of failure. Through three steps, this paper achieves the goal that is to increase the open-circuit airgap flux (OCAF) in a surface-mounted permanent magnet motor and decrease its variation caused by variations of the airgap lengths including an additional one between permanent magnets and rotor back yoke. First, the OCAF equation is derived from the magnetic equivalent circuit (MEC) considering the additional airgap. Then, the equation is validated by comparing its results …

Solar And Rain Catching Canopy. Urban Oasis, Afolabi Ibitoye, Langston Clark, Elena Zimareva, Evan Banks, Alexander Aptekar

Publications and Research

The Urban Oasis is designed to work within existing “pocket parks” in New York City as a combined rainwater collector, personal electronics charging station and resting designation for New Yorkers. Intended to not only lessen the demand on the city power grid by using renewable energy to charge devices, the urban oasis is also intended to mitigate grey water overfill in New York’s combined sewer system and, in general, serve as a model for responsible environmental stewardship in urban areas.

The important technical aspects of the canopy specifically analyzed were:

a) how much rainwater could the canopy be expected to …

Using Augmented Reality In Engineering Education, Juan Estrella

Publications and Research

Augmented Reality is an interactive mixture between the real world and computerized images that capture the audience’s attention. Devices that support augmented reality improve the image of the real-world surroundings with simulated physical input such as sound, video, or graphics overlaid on top of the real-world view. In recent years, augmented reality has improved beyond expensive military applications and has now entered a wide variety of domains. In engineering education, AR technologies can serve as a learning aid as well as a basis for innovation. The technology provides 3-D visualizations that allow to: (i) observe flaws in designs before the …

Service Quality Assessment For Cloud-Based Distributed Data Services, Arun Adiththan

Dissertations, Theses, and Capstone Projects

The issue of less-than-100% reliability and trust-worthiness of third-party controlled cloud components (e.g., IaaS and SaaS components from different vendors) may lead to laxity in the QoS guarantees offered by a service-support system S to various applications. An example of S is a replicated data service to handle customer queries with fault-tolerance and performance goals. QoS laxity (i.e., SLA violations) may be inadvertent: say, due to the inability of system designers to model the impact of sub-system behaviors onto a deliverable QoS. Sometimes, QoS laxity may even be intentional: say, to reap revenue-oriented benefits by cheating on resource allocations and/or …

Correlated Network Of Networks Enhances Robustness Against Catastrophic Failures, Byungjoon Min, Muhua Zheng

Publications and Research

Networks in nature rarely function in isolation but instead interact with one another with a form of a network of networks (NoN). A network of networks with interdependency between distinct networks contains instability of abrupt collapse related to the global rule of activation. As a remedy of the collapse instability, here we investigate a model of correlated NoN. We find that the collapse instability can be removed when hubs provide the majority of interconnections and interconnections are convergent between hubs. Thus, our study identifies a stable structure of correlated NoN against catastrophic failures. Our result further suggests a plausible way …

Week 4 Lab: Counterlist, Michelle Shu, David Soon, Nyc Tech-In-Residence Corps

Open Educational Resources

Syllabus and materials for the course "CSC 59940: Front-End Web Application Development" delivered at the City College of New York in Spring 2018 by Michelle Shu and David Moon as part of the Tech-in-Residence Corps program.

Computer-Aided Design, Gary Benenson

Open Educational Resources

No abstract provided.

Engaging Biomedical Engineering In Health Disparities Challenges, Maribel Vazquez

Publications and Research

Health Disparities (HD) are community-based, biomedical challenges in need of innovative contributions from Science, Technology, Engineering and Math (STEM) fields. Surprisingly, STEM professionals demonstrate a persistent lack of HD awareness and/or engagement in both research and educational activities. This project introduced Health Disparities (HD) as technical challenges to incoming undergraduates in order to elevate engineering awareness of HD. The objective was to advance STEM-based, HD literacy and outreach to young cohorts of engineers. Engineering students were introduced to HD challenges in technical and societal contexts as part of Engineering 101 courses. Findings demonstrate that student comprehension of HD challenges increased …

Performance Control Of A Spray Passive Down-Draft Evaporative Cooling System, Daeho Kang, Richard K. Strand

Publications and Research

A spray passive down-draft evaporative cooling system has been regarded as a low-energy cooling system that leads significant energy savings in the cooling of buildings. While the energy saving capability of the system has been proven, the ability to control a comfortable indoor environment is still inadequate due to strong climatic dependency. This study seeks viable solutions to advance the control competence of the system by mitigating critical problems of the system to be a reliable cooling application in the cooling of buildings. It proposes potential control strategies for the system and alternative operations. It develops a control algorithm for …

Bathymetry Data For Lakes Azuei And Enriquillo, Michael Piasecki, Mahrokh Moknatian

Publications and Research

This data set supports and forms the basis for the development of Digital Bathymetry Models (DBM) for Lakes Azuei (Haiti) and Enriquillo (Dominican Republic). Bathymetric Data is typically acquired using Sonar devices that measure the depth at specific points along a boat track and for which the longitude and latitude is recorded. From the resulting point cloud one develop a seamless representation of the floor of the lake on either a raster set (which is what we have done) or try to use a contour (vector representation) model in which the depth contours appear as polygons or -lines. The raw …

Vision-Based Assistive Indoor Localization, Feng Hu

Dissertations, Theses, and Capstone Projects

An indoor localization system is of significant importance to the visually impaired in their daily lives by helping them localize themselves and further navigate an indoor environment. In this thesis, a vision-based indoor localization solution is proposed and studied with algorithms and their implementations by maximizing the usage of the visual information surrounding the users for an optimal localization from multiple stages. The contributions of the work include the following: (1) Novel combinations of a daily-used smart phone with a low-cost lens (GoPano) are used to provide an economic, portable, and robust indoor localization service for visually impaired people. (2) …

Collaborative Appearance-Based Place Recognition And Improving Place Recognition Using Detection Of Dynamic Objects, Juan Pablo Munoz

Dissertations, Theses, and Capstone Projects

This dissertation makes contributions to the problem of Long-Term Appearance-Based Place Recognition. We present a framework for place recognition in a collaborative scheme and a method to reduce the impact of dynamic objects on place representations. We demonstrate our findings using a state-of-the-art place recognition approach.

We begin in Part I by describing the general problem of place recognition and its importance in applications where accurate localization is crucial. We discuss feature detection and description and also explain the functioning of several place recognition frameworks.

In Part II, we present a novel framework for collaboration between agents from a pure …

Nanoporous Carbon-Based Co2 Reduction Catalysts: Exploring The Combined Effects Of Surface Chemistry And Porosity, Wanlu Li

Dissertations, Theses, and Capstone Projects

For the first-time sulfur-doped, nitrogen-doped and sulfur, nitrogen-codoped nanoporous carbons were systematically studied as catalysts for CO₂ electrochemical reduction reaction (CO₂ERR). The Faradaic efficiencies (FE) of CO and CH₄ formation were calculated to evaluate the performance of these carbons. The best catalysts showed the FE of CO and CH₄ formation of 29% and 0.76%, respectively. It was found that the overall performance in CO₂ERR dramatically increased upon the reduction pretreatment of the carbons in N₂-saturated electrolyte before the CO₂ reduction process. The pretreated carbon showed the maximum FE of CO …

Collective Adhesion And Displacement Of Retinal Progenitor Cells Upon Extracellular Matrix Substrates Of Transplantable Biomaterials, Ankush Thakur, Shawn Mishra, Juan Pena, Jing Zhou, Stephen Redenti, Robert Majeska, Maribel Vazquez

Publications and Research

Strategies to replace retinal photoreceptors lost to damage or disease rely upon the migration of replacement cells transplanted into sub-retinal spaces. A significant obstacle to the advancement of cell transplantation for retinal repair is the limited migration of transplanted cells into host retina. In this work, we examine the adhesion and displacement responses of retinal progenitor cells on extracellular matrix substrates found in retina as well as widely used in the design and preparation of transplantable scaffolds. The data illustrate that retinal progenitor cells exhibit unique adhesive and displacement dynamics in response to poly-l-lysine, fibronectin, laminin, hyaluronic acid, and Matrigel. …

Communication Based Control For Dc Microgrids, Mahmoud S. Saleh, Yusef Esa, Ahmed Mohamed

Publications and Research

Centralized communication-based control is one of the main methods that can be implemented to achieve autonomous advanced energy management capabilities in DC microgrids. However, its major limitation is the fact that communication bandwidth and computation resources are limited in practical applications. This can be often improved by avoiding redundant communications and complex computations. In this paper, an autonomous communication-based hybrid state/event driven control scheme is proposed. This control scheme is hierarchical and heuristic, such that on the primary control level, it encompasses state-driven local controllers, and on the secondary control level, an event-driven MG centralized controller (MGCC) is used. This …

On The Feasibility Of Utilizing Commercial 4g Lte Systems For Misson-Critical Iot Applications, Alfred Rezk

Dissertations and Theses

Emerging Internet of Things (IoT) applications and services including e-healthcare, intelligent transportation systems, smart grid, and smart homes to smart cities to smart workplace, are poised to become part of every aspect of our daily lives. The IoT will enable billions of sensors, actuators, and smart devices to be interconnected and managed remotely via the Internet. Cellular-based Machine-to-Machine (M2M) communications is one of the key IoT enabling technologies with huge market potential for cellular service providers deploying Long Term Evolution (LTE) networks. There is an emerging consensus that Fourth Generation (4G) and 5G cellular technologies will enable and support these …

Analysis Of The Benefits Of Regenerative Braking In Urban Railway Traction System, Khan M. Adnan

Dissertations and Theses

Increasing environmental awareness and the requirement for lower project costs is forcing transit system suppliers to think more innovatively and engineer more accurately to strengthen their competitive edge. Of late, clients more often desire a system that is optimized to minimize the energy consumed during operation; a requirement that is often imposed upon transit system suppliers through financially binding energy commitments.

Electric rail transit systems are large consumers of energy. In trains with regenerative braking capability, a fraction of the energy used to power a train is regenerated during braking. This regenerated energy, if recuperated and reused, can result in …

Inhibition Of Apoptosis Exacerbates Fatigue-Damage Tendon Injuries In An In Vivo Rat Model, R. Bell, M. A. Robles-Harris, M. Anderson, D. Laudier, M. B. Schaffler, E. L. Flatow, N. Andarawis-Puri

Publications and Research

Tendinopathy is a common and progressive musculoskeletal disease. Increased apoptosis is an end-stage tendinopathy manifestation, but its contribution to the pathology of the disease is unknown. A previously established in vivo model of fatigue-damage accumulation shows that increased apoptosis is correlated with the severity of induced tendon damage, even in early onset of the disease, supporting its implication in the pathogenesis of the disease. Consequently, this study aimed to determine: (1) whether apoptosis could be inhibited after fatigue damage and (2) whether its inhibition could lead to remodeling of the extracellular matrix (ECM) and pericellular matrix (PCM), to ultimately improve …

Computational Methods In Civil Engineering, Nir Krakauer

Open Educational Resources

No abstract provided.

A Quantification Analysis On Potential Use Of Recuperated Regenerative Braking Energy From Nyct Subways Into Charging Electric Buses, Ahmed S. Rahman

Dissertations and Theses

The New York Metropolitan Transportation Authority (MTA) is one of the biggest consumers of electricity in east coast of the United States. According to a report published by Dayton T. Brown in 2013, MTA consumes approximately 2150 GWh electrical energy per year for traction power, where the New York City Transit (NYCT) alone is a consumer of about 80% of the total annual MTA energy consumption. This continuous high demand for electricity from a single organization opens research opportunities to search for alternative ways to reduce the needs. NYCT Subways has an existing total rolling stock of 6,418 train cars …

Knockdown Of Heparan Sulfate Via Ndst1 Knockout Does Not Inhibit Mouse Aortic Endothelial Cell Alignment In-Vivo, John Diaz De Leon Iii

Dissertations and Theses

Atherosclerotic plaque localizes in predictable areas such as arches and bifurcations which are characterized by disturbed flow patterns and the resulting damage and dysfunction to the endothelium. Endothelial cells (ECs) under sustained laminar flow align in the direction of flow; however, under disturbed flow conditions, ECs sustain damage to their glycocalyx (GCX) which results in unaligned and rounder cells. An investigation into the role of NDST1 sulfation of heparan sulfate (HS), a key component of many proteoglycans which make up the GCX, was conducted. The descending aortas (DAs) of transgenic mice with conditional knockouts (KOs) of NDST1 in vascular ECs …

Thermoresponsive, Redox-Polymerized Cellulosic Hydrogels Undergo In Situ Gelation And Restore Intervertebral Disc Biomechanics Post Discectomy, Devika Varma, H. A. Lin, R. G. Long, G. T. Gold, A. C. Hecht, J. C. Iadridis, Steven B. Nicoll

Publications and Research

Back and neck pain are commonly associated with intervertebral disc (IVD) degeneration. Structural augmentation of diseased nucleus pulposus (NP) tissue with biomaterials could restore degeneration-related IVD height loss and degraded biomechanical behaviors; however, effective NP replacement biomaterials are not commercially available. This study developed a novel, crosslinked, dual-polymer network (DPN) hydrogel comprised of methacrylated carboxymethylcellulose (CMC) and methylcellulose (MC), and used in vitro, in situ and in vivo testing to assess its efficacy as an injectable, in situ gelling, biocompatible material that matches native NP properties and restores IVD biomechanical behaviors. Thermogelling MC was required to enable consistent and timely …

Senior Design I, Alessandra Carriero, Luis Cardoso

Open Educational Resources

No abstract provided.

Energy Management System Of Hybrid Wayside Storage In Urban Railway Traction, Anil Rajpatei

Dissertations and Theses

In a city that never sleeps, NYC, also called the big apple, there is the largest population in the United States with close to 9 million people. In addition, it is the second wealthiest city in the world according to ranking by gross domestic product (GDP). Being such a densely populated city, people cannot only rely on their vehicles as the only source of commute. The alternative is to use mass transit. New York City Transit (NYCT) is the largest mass transit system that offers commuting services via subway or buses. More than half of the population rely on mass …

Collective Chemotaxis Of Retinal Neural Cells From Drosophila Melanogaster In Controlled Microenvironments, Stephanie Zhang

Dissertations and Theses

More than 172 million people are influenced by a retinal disorder that stems from either age-related or developmental causes. Of those, 1.5 million people endure a developmental retinal disorder. In the developing retina, neural cells undergo a series of highly complicated differentiation and migration process. A main cause of these diseases is abnormal collective migration of neural progenitors hindering the retinogenesis process. However, our grasp of collective migration and signaling molecules, critical to the developing retina, is incompletely understood. Understanding the molecular mechanisms, such as the fibroblast growth factor pathway, that regulate glial and neuronal migration provides decisive insights in …

Developing A 3d In Vitro Model By Microfluidics, Hung-Ta Chien

Dissertations and Theses

In vitro tissue models play an important role in providing a platform that mimics the realistic tissue microenvironment for stimulating and characterizing the cellular behavior. In particular, the hydrogel-based 3D in vitro models allow the cells to grow and interact with their surroundings in all directions, thus better mimicking in vivo than their 2D counterparts. The objective of this thesis is to establish a 3D in vitro model that mimics the anatomical and functional complexity of the realistic cancer microenvironment for conveniently studying the transport coupling in porous tissue structures. We pack uniform-sized PEGDA-GelMA microgels in a microfluidic chip to …

Understanding Of Molecular Interactions And Reversibility In Silylamines, Josephine Chen

Dissertations and Theses

Modern Li-ion batteries employ flammable electrolytes that pose safety concerns. Battery safety has become important as several incidents involving Li-ion battery fires have been observed. This issue could be addressed through a switchable battery electrolyte. Reversible ionic liquids (RevILs) could be used in such an electrolyte that would cease operation in the event of rapid temperature elevation because they can switch between states of drastically different properties upon the application of an external stimulus, such as temperature or CO₂ addition. Silylamines, in particular, are a class of thermally responsive RevILs that are conducting in its ionic liquid (RevIL) state …

Smart Prismatic Louver Technology For Enhanced Daylighting And Management Of Thermal Loads In Green Buildings, Michael Alva

Dissertations and Theses

Abstract

Two significant design strategies for mitigating building energy consumption are daylight redirection and solar energy harvesting. Good daylighting implementation enhances the amount of useful natural light within a space, thereby offsetting the need for electric lighting. Solar energy harvesting systems can mitigate energy costs from mechanical systems by managing incoming thermal loads or capturing solar energy that can be used to supplement thermal systems in the building. While there are many available façade-based technologies that can perform daylighting or solar thermal energy harvesting, there remains a limitation in available systems that can perform both simultaneously. The proposed Liquid Filled …

A Case Study On Grid Impacts Of Electric Vehicles On New York City Power Grid, Amir Abbas Rizvi

Dissertations and Theses

The U.S. electric power industry is anticipating a huge increase in electricity demand in the future due to reformation of the transportation industry. In this work, we focus on electric cars and their impact on the transportation industry as well as the electric grid. The increase in number of electric cars over the years and their growing number indicates that in the future, transportation means are going to largely depend upon electricity to achieve cost and environmental benefits. In other words, in future, the transportation will be impacting the electric grid and vice versa.

The surge in electric vehicles on …