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2022

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Articles 6421 - 6450 of 9377

Full-Text Articles in Engineering

Differential Game-Based Defensive Architecture Study Employing Ground-Based Interceptors, Stephen T. Zittrouer Mar 2022

Differential Game-Based Defensive Architecture Study Employing Ground-Based Interceptors, Stephen T. Zittrouer

Theses and Dissertations

A study of defensive architectures for combating hypersonic glide vehicles (HGVs) via interception with a ground-based interceptor (GBI) is presented. Pursuit-evasion differential games are formulated for numerical simulation of the interception engagements. A one-sided optimal control problem wherein the evader HGV is optimized and the pursuer GBI employs a suboptimal proportional navigation control strategy is solved. The solution space is characterized by varying the pursuer initial velocity advantage relative to the evader. A two-sided optimal control problem in which both players behave optimally is solved via the semi-direct collocation with nonlinear programming (semiDCNLP) method. The resulting state and control trajectories …

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Aeroelasticity Of Six Degree-Of-Freedom Satellite Bus Configurations During Terminal Reentry, Jinhee F. Byun Mar 2022

Aeroelasticity Of Six Degree-Of-Freedom Satellite Bus Configurations During Terminal Reentry, Jinhee F. Byun

Theses and Dissertations

With disposable equipment on board, the emphasis on structural strength and robust thermal protection system (TPS) pales for a conventional satellite in comparison to reentry capsules, which are specifically designed to withstand the intense aerothermodynamic effects experienced during reentry. In this research, six degree-of-freedom (6DOF) analyses of three distinct non-aerodynamic satellite bus configurations were performed with emphasis on the investigation of their terminal reentry characteristics, and thermal and deceleration loading on the satellite body. Aeroelastic effects on their respective solar panel structures were also analyzed focusing on characterizing bending stress at their attachment/deployment mechanism. It was found that the Terra …

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A Proposed Mission Assurance Framework For University Cubesat Programs, Mitchell R. Thomas Mar 2022

A Proposed Mission Assurance Framework For University Cubesat Programs, Mitchell R. Thomas

Theses and Dissertations

The low cost, small form factor, and use of Commercial-Off-The-Shelf components make CubeSats an ideal platform for university use given their unique constraints. Since 2000, roughly 55% of CubeSats developed by universities fail to meet mission goals. Mission assurance, which is used to increase confidence in mission success, is based around traditional government programs, and does not provide an adequate road map for universities. Leaving them without specific guidance in tailoring mission assurance activities to operate within their constraints. This paper adapts these traditional practices to develop a baseline mission assurance framework for university CubeSat programs.

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Considerations Using Iterative Closest Point In Presence Of Occlusions In Automated Aerial Refueling, Joel M. Miller Mar 2022

Considerations Using Iterative Closest Point In Presence Of Occlusions In Automated Aerial Refueling, Joel M. Miller

Theses and Dissertations

The United States Air Force is researching vision-based AAR and different methods for this actualization. Previous work has established a computer vision based pipeline with ICP. This work focuses on how ICP can become resilient to boom occlusion by minimizing errors and discusses the limitations of ICP in the face of occlusions. Specifically, we look at various filtering techniques to remove non-salient points. To register point clouds while maintaining real time interactivity, this work also presents a method for downsampling high resolution camera calibrations to preserve real-time processing and significantly decrease the vision pipeline latency.

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Monocular Pose Estimation For Automated Aerial Refueling Via Perspective-N-Point, James C. Lynch Mar 2022

Monocular Pose Estimation For Automated Aerial Refueling Via Perspective-N-Point, James C. Lynch

Theses and Dissertations

Any Automated Aerial Refueling (AAR) solution requires the quick and precise estimation of the relative position and rotation of the two aircraft involved. This is currently accomplished using stereo vision techniques augmented by Iterative Closest Point (ICP), but requires post-processing to account for environmental factors such as boom occlusion. This paper proposes a monocular solution, combining a custom-trained single-shot object detection Convolutional Neural Network (CNN) and Perspective-n-Point (PnP) estimation to calculate a pose estimate with a single image. This solution is capable of pose estimation at contact point (22m) within 7cm of error and a rate of 10Hz, regardless of …

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Towards The Integration Of Ferroelectric Negative Capacitance With Gallium Oxide Semiconductors For High Power Applications, Guillermo A. Salcedo Mar 2022

Towards The Integration Of Ferroelectric Negative Capacitance With Gallium Oxide Semiconductors For High Power Applications, Guillermo A. Salcedo

Theses and Dissertations

Gallium oxide is a relatively new semiconductor material with characteristics auspicious for high frequency and high-voltage applications. Although several research groups have already demonstrated radio-frequency (RF) devices on Ga2O3 with remarkable features, there is still room for improvement. For instance, the operating frequency of RF field-effect transistors (FET) decreases with the parasitic capacitance, which can be counteracted by higher gate capacitance. Implementing ferroelectric dielectrics with suitable parameters in Ga2O3 FET promises to enhance the gate capacitance and therefore increase operating frequency. This work investigated the effect of various factors (film composition, film thickness, TiN …

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Investigation Of Mechanical Properties Of Parts Fabricated With Gas- And Water-Atomized 304l Stainless Steel Powder In The Laser Powder Bed Fusion Process, M. Hossein Sehhat, Austin T. Sutton, Chia Hung Hung, Joseph William Newkirk, Ming-Chuan Leu Mar 2022

Investigation Of Mechanical Properties Of Parts Fabricated With Gas- And Water-Atomized 304l Stainless Steel Powder In The Laser Powder Bed Fusion Process, M. Hossein Sehhat, Austin T. Sutton, Chia Hung Hung, Joseph William Newkirk, Ming-Chuan Leu

Materials Science and Engineering Faculty Research & Creative Works

The use of gas-atomized powder as the feedstock material for the laser powder bed fusion (LPBF) process is common in the additive manufacturing (AM) community. Although gas-atomization produces powder with high sphericity, its relatively expensive production cost is a downside for application in AM processes. Water atomization of powder may overcome this limitation due to its low-cost relative to the gas-atomization process. In this work, gas- and water-atomized 304L stainless steel powders were morphologically characterized through scanning electron microscopy (SEM). The water-atomized powder had a wider particle size distribution and exhibited less sphericity. Measuring powder flowability using the Revolution Powder …

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Water Chemistry, Exposure Routes, And Metal Forms Determine The Bioaccumulation Dynamics Of Silver (Ionic And Nanoparticulate) In Daphnia Magna, Emma Lesser, Fatima Noor Sheikh, Mithun Sikder, Marie Noële Croteau, Natasha Franklin, Mohammed Baalousha, Niveen S. Ismail Mar 2022

Water Chemistry, Exposure Routes, And Metal Forms Determine The Bioaccumulation Dynamics Of Silver (Ionic And Nanoparticulate) In Daphnia Magna, Emma Lesser, Fatima Noor Sheikh, Mithun Sikder, Marie Noële Croteau, Natasha Franklin, Mohammed Baalousha, Niveen S. Ismail

Engineering: Faculty Publications

Treatment wetlands utilize various physical and biological processes to reduce levels of organic contaminants, metals, bacteria, and suspended solids. Silver nanoparticles (AgNPs) are one type of contaminant that can enter treatment wetlands and impact the overall treatment efficacy. Grazing by filter-feeding zooplankton, such as Daphnia magna, is critical to treatment wetland functioning; but the effects of AgNPs on zooplankton are not fully understood, especially at environmentally relevant concentrations. We characterized the bioaccumulation kinetics of dissolved and nanoparticulate (citrate-coated) 109Ag in D. magna exposed to environmentally relevant 109Ag concentrations (i.e., 0.2–23 nmol L−1 Ag) using a stable isotope as a tracer …

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Delaunay Walk For Fast Nearest Neighbor: Accelerating Correspondence Matching For Icp, James D. Anderson, Ryan M. Raettig, Josh Larson, Scott L. Nykl, Clark N. Taylor, Thomas Wischgoll Mar 2022

Delaunay Walk For Fast Nearest Neighbor: Accelerating Correspondence Matching For Icp, James D. Anderson, Ryan M. Raettig, Josh Larson, Scott L. Nykl, Clark N. Taylor, Thomas Wischgoll

Computer Science and Engineering Faculty Publications

Point set registration algorithms such as Iterative Closest Point (ICP) are commonly utilized in time-constrained environments like robotics. Finding the nearest neighbor of a point in a reference 3D point set is a common operation in ICP and frequently consumes at least 90% of the computation time. We introduce a novel approach to performing the distance-based nearest neighbor step based on Delaunay triangulation. This greedy algorithm finds the nearest neighbor of a query point by traversing the edges of the Delaunay triangulation created from a reference 3D point set. Our work integrates the Delaunay traversal into the correspondences search of …

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Solving The Negative Earnings Dilemma Of Multistage Bidding In Public Construction And Infrastructure Projects: A Game Theory-Based Approach, Muaz O. Ahmed, Islam H. El-Adaway, Kalyn T. Coatney Mar 2022

Solving The Negative Earnings Dilemma Of Multistage Bidding In Public Construction And Infrastructure Projects: A Game Theory-Based Approach, Muaz O. Ahmed, Islam H. El-Adaway, Kalyn T. Coatney

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

With the tremendous increase in spending on public projects, contractors need to employ efficient and effective bidding strategies to cope with the competitive bidding environment. Usually, general contractors carry a portion of the work and subcontract other parts to eventually submit a holistic joint bid. This bidding setting is referred to as multistage bidding where subcontractors submit their quotations/bids to the general contractor, after which the general contractor submits a final joint bid for the whole project. In a multistage bidding environment, general contractors may be faced with an increase in the probability of negative or below normal profits. Despite …

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Field Retrofit And Testing Of A Corroded Metal Culvert Using Gfrp, Mahmoud Reda Taha, Susan Bogus, Mohammed Abdellatef, Daniel Heras Murcia Mar 2022

Field Retrofit And Testing Of A Corroded Metal Culvert Using Gfrp, Mahmoud Reda Taha, Susan Bogus, Mohammed Abdellatef, Daniel Heras Murcia

Data

One of the current pressing problem for all DOTs is the corrosion-oriented deterioration of the existing metal culverts. These metal culverts typically are designed for a life of 50 years. However, corrosion is making them last no longer than 30years. Here we propose use of Glass Fiber Reinforced Polymers (GFRP) pipe section as a fit-in GFRP profile liner for complete repair and rehabilitation of the corroded metal culvert with an expected life of 75 years. This is mainly because of the corrosion free nature of the GFRP material. In the current study, the design method for using glass fiber-reinforced polymer …

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Increasing Versatility And Recyclability Of Additive Manufacturing By Utilizing Epdm/Pp Thermoplastic Vulcanizates, Nathan Zeringue Mar 2022

Increasing Versatility And Recyclability Of Additive Manufacturing By Utilizing Epdm/Pp Thermoplastic Vulcanizates, Nathan Zeringue

Honors Capstones

No abstract provided.

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Bone And Cartilage Compression Simulator, Karoline M. Wucherer, Benjamin A. Parmentier, Thomasina E. Hinkle Mar 2022

Bone And Cartilage Compression Simulator, Karoline M. Wucherer, Benjamin A. Parmentier, Thomasina E. Hinkle

Biomedical Engineering

A device was developed that delivers mechanical loads to bone and soft tissue samples under physiological conditions to aid in the research of tissue engineering bone and cartilage. To begin the design process, a Network Diagram and Gantt Chart were produced to create a general timeline for the project to follow. This allowed us to measure our progress and determine what effects (if any) delays could have on our project.

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Molecular Simulation Of Steady-State Evaporation And Condensation Of Water In Air, Eric Bird, Jesus Gutierrez Plascencia, Pawel Keblinski, Zhi Liang Mar 2022

Molecular Simulation Of Steady-State Evaporation And Condensation Of Water In Air, Eric Bird, Jesus Gutierrez Plascencia, Pawel Keblinski, Zhi Liang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

It Was Shown in Recent Experiments and Molecular Dynamics (MD) Simulations that Schrage Equation Predicts Evaporation and Condensation Rates of Water in the Absence of a Non-Condensable Gas with Good Accuracy. However, It is Not Clear Whether Schrage Equation is Still Accurate or Even Valid for Quantifying Water Evaporation and Condensation Rates in Air. in This Work, We Carry Out MD Simulations to Study Steady-State Evaporation and Condensation of Water at a Planar Water-Air Interface. the Simulation Results Show that the Evaporation and Condensation Fluxes of Water in the Presence of Air Are Still in a Good Agreement with the …

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Understanding Effects Of Permafrost Degradation And Coastal Erosion On Civil Infrastructure In Arctic Coastal Villages: A Community Survey And Knowledge Co-Production, Min Liew, Ming Xiao, Louise Farquharson, Dmitry Nicolsky, Anne Jensen, Vladimir Romanovsky, Jana Peirce, Lilian Alessa, Christopher Mccomb, Xiong Zhang, Benjamin Jones Mar 2022

Understanding Effects Of Permafrost Degradation And Coastal Erosion On Civil Infrastructure In Arctic Coastal Villages: A Community Survey And Knowledge Co-Production, Min Liew, Ming Xiao, Louise Farquharson, Dmitry Nicolsky, Anne Jensen, Vladimir Romanovsky, Jana Peirce, Lilian Alessa, Christopher Mccomb, Xiong Zhang, Benjamin Jones

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the results of a community survey that was designed to better under-stand the effects of permafrost degradation and coastal erosion on civil infrastructure. Observations were collected from residents in four Arctic coastal communities: Point Lay, Wainwright, Utqiaġvik, and Kaktovik. All four communities are underlain by continuous ice-rich permafrost with varying degrees of degradation and coastal erosion. The types, locations, and periods of observed permafrost thaw and coastal erosion were elicited. Survey participants also reported the types of civil infrastructure being affected by permafrost degradation and coastal erosion and any damage to residential buildings. Most survey participants reported …

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Microwave Hyperthermia Application With Bioimplant Single Slot Coaxial Antennadesign For Mouse Breast Cancer Treatment, Ahmet Ri̇fat Görgün, Cem Baytöre, Selçuk Çömlekçi̇, Mehmet İbrahi̇m Tuğlu, Adnan Kaya Mar 2022

Microwave Hyperthermia Application With Bioimplant Single Slot Coaxial Antennadesign For Mouse Breast Cancer Treatment, Ahmet Ri̇fat Görgün, Cem Baytöre, Selçuk Çömlekçi̇, Mehmet İbrahi̇m Tuğlu, Adnan Kaya

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a novel animal model for the breast cancer treatment which contains hyperthermia is proposed. For this main purpose a low cost, interstitial, bioimplant antenna by short ended single slot design is proposed to heat the cancerous tissues. Both the theoretical background of the proposed system and the simulation and measurement results of antenna design are presented. An artificial tissue phantom model has been created under laboratory conditions and then the utility of the proposed antenna has been tested on this model. Artificial tissues have been heated by 25W to (41-44 ? C) in a short time like …

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Identification And Mitigation Of Non-Line-Of-Sight Path Effect Using Repeater Forhybrid Ultra-Wideband Positioning And Networking System, Gwo Chin Chung, Mohd. Aqmal Syafiq Kamarudin, It Ee Lee, Soo Fun Tan Mar 2022

Identification And Mitigation Of Non-Line-Of-Sight Path Effect Using Repeater Forhybrid Ultra-Wideband Positioning And Networking System, Gwo Chin Chung, Mohd. Aqmal Syafiq Kamarudin, It Ee Lee, Soo Fun Tan

Turkish Journal of Electrical Engineering and Computer Sciences

At least two decades ago, various applications have been proposed for the implementation of ultra-wideband (UWB) technology, but only a few of them are being realised such as radar detection, home networking, and indoor positioning. Although UWB positioning offers precise locality tracking, the accuracy of the estimation is greatly affected by the non-line-of-sight (NLOS) path effect. In this paper, we propose a hybrid indoor UWB positioning and networking system that utilises the existing repeater of the data network to eliminate the NLOS paths. A switching algorithm is written to identify the existence of NLOS paths based on received signal strength …

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A Factor Graph Optimization Mapping Based On Normaldistributions Transform, Kedi Zhong, Yuansheng Liu, Jiansuo Yang, Ming Lu, Jun Zhang Mar 2022

A Factor Graph Optimization Mapping Based On Normaldistributions Transform, Kedi Zhong, Yuansheng Liu, Jiansuo Yang, Ming Lu, Jun Zhang

Turkish Journal of Electrical Engineering and Computer Sciences

This paper aims to achieve highly accurate mapping results and real time pose estimation of autonomous vehicle by using the normal distribution transform (NDT) algoritm. A factor graph optimization algorithm (FGO-NDT) is proposed to address the poor real-time performance and pose drift errors of the NDT algorithm. Smooth point cloud data are obtained by multisensor calibration and data preprocessing. NDT registration is then used for lidar odometry and feature matching. The global navigation satellite system (GNSS) data and loop detection results are added to the factor graph framework as the pose constraint factors to optimize the pose trajectory and eliminate …

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Fill Materials At Integral End Bents, Charlie Sun, Tony Beckham Mar 2022

Fill Materials At Integral End Bents, Charlie Sun, Tony Beckham

Kentucky Transportation Center Research Report

Jointless bridge designs have become increasingly popular due to their low construction and maintenance costs. But this design carries risks. Most notably, integral end bents can be displaced and undergo settlement due to soil movement in embankments and loads carried by the superstructure. In response, the Kentucky Transportation Cabinet (KYTC) devised a novel treatment for end bent and abutment backfills on low- and middle-span concrete bridges in which elasticized geofoam is placed between geosynthetically confined soil and an integral end bent (GCS-IEB). However, this design requires modification where the elasticized geofoam and overlying pavement meet. Using elasticized geofoam is also …

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Electric Vehicles: Analysis Of Revenue Issues And Charging Station Implementation Plans, Chris Van Dyke, Bryan Gibson, Ryan Griffith, Andrew Martin, Jeeyen Koo, Doug Kreis Mar 2022

Electric Vehicles: Analysis Of Revenue Issues And Charging Station Implementation Plans, Chris Van Dyke, Bryan Gibson, Ryan Griffith, Andrew Martin, Jeeyen Koo, Doug Kreis

Kentucky Transportation Center Research Report

No abstract provided.

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Fourth-Order Adjoint Sensitivity And Uncertainty Analysis Of An Oecd/Nea Reactor Physics Benchmark: Ii. Computed Response Uncertainties, Ruixian Fang, Dan Gabriel Cacuci Mar 2022

Fourth-Order Adjoint Sensitivity And Uncertainty Analysis Of An Oecd/Nea Reactor Physics Benchmark: Ii. Computed Response Uncertainties, Ruixian Fang, Dan Gabriel Cacuci

Faculty Publications

This work quantifies the impact of the most important 4th-order sensitivities of the leakage response of a polyethylene-reflected plutonium (PERP) reactor physics benchmark with respect to the benchmark’s 180 group-averaged microscopic total cross sections, on the expected value, variance and skewness of the benchmark’s leakage response. This work shows that, as the standard deviations of the cross sections increase, the contributions of the 4th-order sensitivities to the response’s expected value and variance become significantly larger than the corresponding contributions stemming from the 1st-, 2nd- and 3rd-order sensitivities. Considering a uniform 5% relative standard deviation for all microscopic total cross sections, …

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Decoupling And Matching Network For Dual-Band Mimo Antennas, Min Li, Yujie Zhang, Di Wu, Kwan Lawrence Yeung, Lijun Jiang, Ross Murch Mar 2022

Decoupling And Matching Network For Dual-Band Mimo Antennas, Min Li, Yujie Zhang, Di Wu, Kwan Lawrence Yeung, Lijun Jiang, Ross Murch

Electrical and Computer Engineering Faculty Research & Creative Works

This article presents a novel method to design the decoupling and matching network (DMN) for dual-band multi-input-multioutput (MIMO) antennas. The DMN consists of a grid of metallic microstrip stubs, some of which are connected while others are not. The connecting condition in the DMN is the only unknown variable for realizing high antenna isolation. It is determined by rigorous design formulas upon scattering matrix and optimized by the binary optimization algorithm, e.g., genetic algorithm (GA). Thus, high isolation among antennas can be achieved without requiring the optimization process in the electromagnetic simulation tool. Three decoupling examples of two two-element symmetric …

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Heuristic-Based Automatic Pruning Of Deep Neural Networks, Tejalal Choudhary, Vipul Mishra, Anurag Goswami, Jagannathan Sarangapani Mar 2022

Heuristic-Based Automatic Pruning Of Deep Neural Networks, Tejalal Choudhary, Vipul Mishra, Anurag Goswami, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

The performance of a deep neural network (deep NN) is dependent upon a significant number of weight parameters that need to be trained which is a computational bottleneck. The growing trend of deeper architectures poses a restriction on the training and inference scheme on resource-constrained devices. Pruning is an important method for removing the deep NN's unimportant parameters and making their deployment easier on resource-constrained devices for practical applications. In this paper, we proposed a heuristics-based novel filter pruning method to automatically identify and prune the unimportant filters and make the inference process faster on devices with limited resource availability. …

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Computational Based Investigation Of Lattice Cell Optimization Under Uniaxial Compression Load, Derek G. Spear, Jeremiah S. Lane, Anthony N. Palazotto, Ryan A. Kemnitz Mar 2022

Computational Based Investigation Of Lattice Cell Optimization Under Uniaxial Compression Load, Derek G. Spear, Jeremiah S. Lane, Anthony N. Palazotto, Ryan A. Kemnitz

Faculty Publications

Structural optimization is a methodology used to generate novel structures within a design space by finding a maximum or minimum point within a set of constraints. Topology optimization, as a subset of structural optimization, is often used as a means for light-weighting a structure while maintaining mechanical performance. This article presents the mathematical basis for topology optimization, focused primarily on the Bi-directional Evolutionary Structural Optimization (BESO) and Solid Isotropic Material with Penalization (SIMP) methodologies, then applying the SIMP methodology to a case study of additively manufactured lattice cells. Three lattice designs were used: the Diamond, I-WP, and Primitive cells. These …

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The Impact Of Ride-Hail Surge Factors On Taxi Bookings, Sumit Agarwal, Ben Charoenwong, Shih-Fen Cheng, Jussi Keppo Mar 2022

The Impact Of Ride-Hail Surge Factors On Taxi Bookings, Sumit Agarwal, Ben Charoenwong, Shih-Fen Cheng, Jussi Keppo

Research Collection School Of Computing and Information Systems

We study the role of ride-hailing surge factors on the allocative efficiency of taxis by combining a reduced-form estimation with structural analyses using machine-learning-based demand predictions. Where other research study the effect of entry on incumbent taxis, we use higher frequency granular data to study how location-time-specific surge factors affect taxi bookings to bound the effect of customer decisions while accounting for various confounding variables. We find that even in a unique market like Singapore, where incumbent taxi companies have app-based booking systems similar to those from ride-hailing companies like Uber, the estimated upper bound on the cross-platform substitution between …

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Hybrid Tabu Search Algorithm For Unrelated Parallel Machine Scheduling In Semiconductor Fabs With Setup Times, Job Release, And Expired Times, Changyu Chen, Madhi Fathi, Marzieh Khakifirooz, Kan Wu Mar 2022

Hybrid Tabu Search Algorithm For Unrelated Parallel Machine Scheduling In Semiconductor Fabs With Setup Times, Job Release, And Expired Times, Changyu Chen, Madhi Fathi, Marzieh Khakifirooz, Kan Wu

Research Collection School Of Computing and Information Systems

This research is motivated by a scheduling problem arising in the ion implantation process of wafer fabrication. The ion implementation scheduling problem is modeled as an unrelated parallel machine scheduling (UPMS) problem with sequence-dependent setup times that are subject to job release time and expiration time of allowing a job to be processed on a specific machine, defined as: R|rj,eij,STsd|Cmax. The objective is first to maximize the number of processed jobs, then minimize the maximum completion time (makespan), and finally minimize the maximum completion times of the non-bottleneck machines. A mixed-integer programming (MIP) model is proposed as a solution approach …

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Coordinated Delivery To Shopping Malls With Limited Docking Capacity, Ruidian Song, Hoong Chuin Lau, Xue Luo, Lei Zhao Mar 2022

Coordinated Delivery To Shopping Malls With Limited Docking Capacity, Ruidian Song, Hoong Chuin Lau, Xue Luo, Lei Zhao

Research Collection School Of Computing and Information Systems

Shopping malls are densely located in major cities such as Singapore and Hong Kong. Tenants in these shopping malls generate a large number of freight orders to their contracted logistics service providers, who independently plan their own delivery schedules. These uncoordinated deliveries and limited docking capacity jointly cause congestion at the shopping malls. A delivery coordination platform centrally plans the vehicle routes for the logistics service providers and simultaneously schedules the dock time slots at the shopping malls for the delivery orders. Vehicle routing and dock scheduling decisions need to be made jointly against the backdrop of travel time and …

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Efficient Certificateless Multi-Copy Integrity Auditing Scheme Supporting Data Dynamics, Lei Zhou, Anmin Fu, Guomin Yang, Huaqun Wang, Yuqing Zhang Mar 2022

Efficient Certificateless Multi-Copy Integrity Auditing Scheme Supporting Data Dynamics, Lei Zhou, Anmin Fu, Guomin Yang, Huaqun Wang, Yuqing Zhang

Research Collection School Of Computing and Information Systems

To improve data availability and durability, cloud users would like to store multiple copies of their original files at servers. The multi-copy auditing technique is proposed to provide users with the assurance that multiple copies are actually stored in the cloud. However, most multi-replica solutions rely on Public Key Infrastructure (PKI), which entails massive overhead of certificate computation and management. In this article, we propose an efficient multi-copy dynamic integrity auditing scheme by employing certificateless signatures (named MDSS), which gets rid of expensive certificate management overhead and avoids the key escrow problem in identity-based signatures. Specifically, we improve the classic …

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Analyzing Offline Social Engagements: An Empirical Study Of Meetup Events Related To Software Development, Abhishek Sharma, Gede Artha Azriadi Prana, Anamika Sawhney, Nachiappan Nagappan, David Lo Mar 2022

Analyzing Offline Social Engagements: An Empirical Study Of Meetup Events Related To Software Development, Abhishek Sharma, Gede Artha Azriadi Prana, Anamika Sawhney, Nachiappan Nagappan, David Lo

Research Collection School Of Computing and Information Systems

Software developers use a variety of social mediachannels and tools in order to keep themselves up to date,collaborate with other developers, and find projects to contributeto. Meetup is one of such social media used by softwaredevelopers to organize community gatherings. We in this work,investigate the dynamics of Meetup groups and events relatedto software development. Our work is different from previouswork as we focus on the actual event and group data that wascollected using Meetup API.In this work, we performed an empirical study of eventsand groups present on Meetup which are related to softwaredevelopment. First, we identified 6,327 Meetup groups related …

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Batchlens: A Visualization Approach For Analyzing Batch Jobs In Cloud Systems, Shaolun Ruan, Yong Wang, Hailong Jiang, Weijia Xu, Qiang. Guan Mar 2022

Batchlens: A Visualization Approach For Analyzing Batch Jobs In Cloud Systems, Shaolun Ruan, Yong Wang, Hailong Jiang, Weijia Xu, Qiang. Guan

Research Collection School Of Computing and Information Systems

Cloud systems are becoming increasingly powerful and complex. It is highly challenging to identify anomalous execution behaviors and pinpoint problems by examining the overwhelming intermediate results/states in complex application workflows. Domain scientists urgently need a friendly and functional interface to understand the quality of the computing services and the performance of their applications in real time. To meet these needs, we explore data generated by job schedulers and investigate general performance metrics (e.g., utilization of CPU, memory and disk I/O). Specifically, we propose an interactive visual analytics approach, BatchLens, to provide both providers and users of cloud service with an …

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