College of Science and Engineering
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Item 30-day mortality prediction of patients with congestive heart failure (CHF)(Institute of Industrial and Systems Engineer (IISE) Annual Conference and Expo 2016, 2016-05-21) Khuriekar, N.; Aladeemy, M.; Chou, C. A.; Shan, Xiaojun; Poranki, S.; Khasawneh, M. T.; Srihari, K.Abstract not available.Item 30-Day Mortality Prediction of Patients With Congestive Heart Failure (CHF)(2016-05-21) Khuriekar, N.; Aladeemy, M.; Chou, C. A.; Shan, Xiaojun; Poranki, S.; Khasawneh, M. T.; Srihari, K.The paper builds a prediction model of 30-day mortality risk in patients with CHF. Least absolute shrinkage and selection operator (LASSO) was applied to select the significant features. Three data mining techniques, namely, decision tree, logistic regression, and AdaBoost.M1 algorithms were used to predict mortality risk in patients with CHF. A case study was conducted using data (January 2012 to December 2014) from a community hospital in Upstate New York and a comparison among the three predictive algorithms was performed. The primary measure for comparing the performance of the prediction algorithms were area under the receiver operating characteristic curve (AUC), specificity, sensitivity, and accuracy. The results show that logistic regression model resulted in an accuracy of 84.85% with the specificity, sensitivity and AUC of 1, 0.44 and 0.72, respectively. On the other hand, the decision tree algorithm resulted in an accuracy of 75.76% with specificity, sensitivity and AUC of 0.83, 0.56 and 0.69, respectively, whereas the AdaBoost.M1 algorithm resulted in 81.82% accuracy with specificity, sensitivity and AUC of 0.56, 0.54 and 0.55, respectively. This research concludes that the logistic regression model fitted with LASSO outperforms AdaBoost.M1 and decision tree in terms of both AUC score as well as predictive accuracy. Accurate prediction of 30-day mortality based on this research can be useful in risk stratification, individualized treatment, and patient management.Item A Framework for Improving Performance Testing in Agile Software Development(2020-11-20) Whiting, Erik; Datta, Soma; Helm, James; Dabney, JamesThe subdiscipline of software quality assurance concerned with non-functional requirements (NFRs) and hardware metrics is known as performance testing. Conducting effective performance testing is complicated, time consuming, and expensive. These attributes put performance testing at odds with agile software development methodologies, which incrementally build software systems in quick cycles while being supported by exhaustive unit and integration test coverage. Due to a variety of challenges, performance testing often cannot keep up with an agile release cadence, and there is a growing body of research that catalogues and describes these challenges and proposes solutions to some of them. This study presents a software testing framework which implements several of the proposed solutions. The framework, called Lulu Performance Test (LPT), aims to confront many of the challenges noted in recent research, with the goal of making effective performance testing more palatable to agile software development methodologies.Item A Framework for Planetary Resource Classifications to Further Sustainability in Space Exploration Missions(2020-12-21) Alvi, Arjumand; Dabney, James P; Bozkurt, Ipek; Sun, Dongmin; Helm, JamesThe long-term impacts and overall sustainability of space exploration missions in the space environment were often unknown in past space missions. Historically, the space exploration vision of various space-faring agents refers to "planetary sustainability" as a synonym for mission assurance, rather than as an evaluation of long-term viability or as a means to ensure the sanctity of the space environment. Moreover, past missions have treated the space environment as an infinite frontier and not as a finite resource. NASA's Artemis program aims to return to the moon and achieve sustainable presence in lunarspace by 2028. Many planned future endeavors require resource extraction or in-situ resource utilization efforts. Resource prospecting is considered the first step in accessing resources in the lunarscape. Prospecting is a term utilized most in the mining and extractive industries and, by definition, is a means of experimental drilling and excavation. Prospecting, however, is not the same as classifying. Resource prospecting is more invasive than resource classification, although resource prospecting can advance resource classification efforts. When terrestrial (Earth-based) resources are evaluated on various measures – including availability, recoverability, accessibility – quantifying resource reserve estimates are a part of the evaluation; however, there is no framework established to characterize planetary resources on the basis of mission resource metrics. This investigation develops a framework to classify resources on the lunar surface, in response to the current, heightened interest in resource recovery and utilization in planetary resource-focused missions. Resource and risk classification methods established by the Society of Petroleum Engineers and General Electric will guide framework development. In the process, the investigation considers existing research proposals to establish resource limits and discusses how resource restrictions and risk thresholds are implemented in the final proposed framework. A novel resource classification framework is the final deliverable and is applied to geologic data from lunar fly-by and surface missions, thereby increasing the yield of existing mission data. Additionally, the framework integrates availability, recoverability, and accessibility metrics, while also addressing a composite sustainability metric. These four metrics are established as essential resource classification benchmarks to ensure that sustainable mission design is implemented early in the space systems engineering lifecycle by space systems engineers and mission designers in multidisciplinary teams.Item A Mixed-Method Study of the Impact of Covid-19 Pandemic on U.S. Students’ Educational Attainment(2021-07-27) Beheshti, Mohammadali 1988-; Shan, Xiaojun "Gene"; Jeong, Ki-Young; Bozkurt, IpekIn this case study, we implemented a quantitative and sentiment analysis of the effects of the COVID-19 pandemic on the education, physical, and mental health of college students in the United States. As students are the future workforce of society and play a significant role in the future prosperity of a country, appropriate measures should be taken to minimize the impacts of adverse events on their education and health. As compared to natural disasters, health disasters could have more psychological impacts leading to stress and anxiety, as reflected in their educational performance. This study is based on survey data from students at the University of Houston at Clear Lake. The survey consists of twenty-three questions that ask the students about their experiences during the pandemic of COVID-19. Based on the analyzed data, UHCL students’ attainment is impacted by the COVID-19 pandemic. The average GPAs of participants show a decreasing trend from Fall 2019 to Fall 2020 and mental health issues might lead to such problems as lacking behind the study. Increased levels of anxiety and nervousness are the most significant influencers on student achievement during the pandemic of COVID-19.Item A scalable image/video FPGA processing platform with approximate design(2018-12-04) Zhang, Yunxiang; Yang, Xiaokun; Wu, Lei; Lu, JiangThis dissertation presents a scalable image/video platform with approximate computing design on Field-Programmable Gate Array (FPGA). The platform is able to capture images in real time with a low-cost OV7670 camera and display the original, in-process and final results of images on a VGA-interfaced monitor. To make the platform reusable and expandable, the design with Verilog Hardware Description Language (HDL) and the verification environment including six Open Verification Components (OVCs) are provided. Compared to prior works, our proposed work achieves the least FPGA resource cost (753 Look Up Tables (LUTs) and 277 Registers) on the design of a Camera-FPGA-VGA platform. Furthermore, we present a novel approximate design library with FPGA and provide several slice-energy cost solutions corresponding to different application constrains. Specifically three approximations of multipliers and two approximations of adders, along with the exact designs, are presented and integrated as twelve benchmarks to implement RGB to grayscale conversion as a case study. Experimental results show that the minimum slice-energy cost, integrated with approximate\#2 adder and approximate\#3 multiplier, achieves 25.17% slice-energy saving compared with the exact design by sacrificing the quality of results as 5.69% error for multiplier and 2.85% for adder.Item A Sliding Window Based Voting Classifier for Activity Sensor Based User Identification(2021-04-30) Vallam Sudhakar, Sai Ram; Sha, Kewei; Wei, Wei; Yue, Kwok-BunIdentification is the core of any authentication protocol design as the purpose of the authentication is to verify the user’s identity. The efficient establishment and verification of identity remain a big challenge. Recently, biometrics-based identification algorithms gained popularity as a means of identifying individuals using their unique biological characteristics. In this thesis, we propose a novel and efficient identification framework, ActID, which can identify a user based on his/her hand motion while walking. ActID not only selects a set of high-quality features based on Optimal Feature Evaluation and Selection and Correlation-based Feature Selection algorithms but also includes a novel sliding window based voting classifier. Therefore, it achieves several important design goals for gait authentication based on resource-constrained devices, including lightweight and real-time classification, high identification accuracy, a minimum number of sensors, and a minimum amount of data collected. Performance evaluation shows that ActID is cost-effective and easily deployable, selects only a minimum number of 10 high-quality features, uses only accelerometer sensor and increases the cost efficiency of user identification, collects only a small amount of 10 seconds of activity data, satisfies real-time requirements, and achieves a high identification accuracy of 100% when applied to a 30 user dataset.Item A Systems Engineering Approach to Staff Scheduling Problems, as Applied to Flight Controller Scheduling at NASA’S Mission Control Center(2019-05-17) Honey, Benjamin; Dabney, James B; Harman, Thomas; Helm, James C; Bozkurt, IpekThe flight controllers of NASA’s Flight Operations Directorate (FOD) have become experts at human spaceflight operations over the past six decades. Despite this expertise, flight controllers and their managers are still struggling with the challenges of building effective console schedules in a 24/7 operations environment. By studying the lessons learned from the operational research field, NASA FOD can improve their staff scheduling practices, which have been largely home-grown. Likewise, the field of staff scheduling research itself suffers from an insular focus on finding more and more optimal mathematical techniques for solving schedules, ignoring important factors such as operator preferences and the health effectives of shift work. By adopting a systems engineering framework, these optimized solutions can become even more useful. These concepts are developed and then applied in a case study of the Attitude Determination and Control Officer (ADCO) flight controller group within FOD, demonstrating the effectiveness of systems engineering thinking when applied to new fields. As a result, the ADCO flight controller group has adopted the new framework into their standard scheduling practices, which has improved measured outcomes.Item Absolute Configuration and Polymorphism of 2-phenylbutyramide and a-methyl -a-phenylsuccinimide(Crystal Growth & Designs, 2014) Krivoshein, ArcadiusCrystal structures of racemic and homochiral forms of 2-phenylbutyramide (1) and 3-methyl-3-phenylpyrrolidine-2,5-dione (2) were investigated in detail by a single crystal X-ray diffraction study. Absolute configurations of the homochiral forms of 1 and 2, obtained by chromatographic separation of racemates, were determined. It was revealed that racemate and homochiral forms of 1 are very similar in terms of supramolecular organization (H-bonded ribbons) in crystal, infrared (IR) spectral characteristics, and melting points. The presence of two different molecular conformations in homochiral forms of 1 allowed mimicking of crystal packing of the H-bonded ribbons in racemate 1. Two polymorph modifications (monoclinic and orthorhombic) comprising very similar H-bonded zigzag-like chains were found for the homochiral forms of compound 2 that were significantly different in terms of crystal structure, IR spectra, and melting points from the racemic form of 2. Unlike compound 1, homochiral forms of compound 2 have a higher density than the corresponding racemate which contradicts the Wallach rule and indicates that, in this case, homochiral forms are more stable than racemate forms.Item Accurate Characterization of Moisture Absorption in Polymeric Materials(SPE Plastics Research Online, 2017) Hamidi, YoussefThe importance of using the exact solution of the hindered diffusion model is demonstrated on experimental data from a nanoclay/epoxy composite.Item Acoustic Flame Suppression Mechanics in a Microgravity Environment(Microgravity Science and Technology, 2015) Yue, Kwok-BunThe following paper deals with acoustic flame suppression mechanics in a microgravity environment with measurements taken from an Arduino-based sensor system and validation of the technique. A Zippo lighter is ignited in microgravity and then displaced from the base of the flame and suppressed using surface interactions with single tone acoustic waves to extinguished the flame. The analysis of data collected shows that the acoustic flame suppression measurementtechniques are effective to finding qualitative differences in extinguishing in microgravity and normal gravity. Further, the results suggest that the suppression may be more effective in a microgravity environment than in a normal (1g) environment and may be a viable method of extinguishing fires during space flight.Item An Ada Solution to the General Mutual Exclusion Problem(Ada Letters, 1993) Yue, Kwok-BunAlthough some specific mutual exclusion problems have been studied extensively, automatic solutions to synchronize general mutual exclusion problems with arbitrary mutual exclusion constraints have not been fully explored. This paper discusses an Ada 83 solution that can be applied to any general mutual exclusion problem. This solution is based on strong binary semaphores. A generic package is used to generate the solution for an given mutual exclusion problem. An Ada program for the simulation of the classical Dining Philosophers Problem is presented as an example to demostrate how the solution can be used.Item Adaptive filtering applications to real-time laser spectroscopy(Optical Society of America Annual Meeting, 2000-10) Harman, Thomas L.; Leleux, DarrinAbstract not available.Item Adaptive Privacy-Preserving Authentication in Vehicular Networks(Journal of Computer Science and Technology, 2008) Kewei, ShaVehicular networks have attracted extensive attention in recent years for their promises in improving safety and enabling other value-added services. Most previous work focuses on designing the media access and physical layer protocols. Privacy issues in vehicular networks have not been well addressed. We argue that privacy is a user-specific concept and a good privacy protection mechanism should allow users to select the degree of privacy they wish to have. To address this requirement, we propose an adaptive privacy-preserving authentication mechanism that can trade off the privacy degree with computational and communication overheads (resource usage). This mechanism, to our knowledge, is the first effort on adaptive privacy-preserving authentication. We present analytical and preliminary results to show that the proposed protocol is nt only adaptive but scalable.Item An Advanced Bus Architecture for AES-Encrypted High-Performance Embedded Systems(2017-10-19) Yang, XiaokunMethods and systems of AES-centric bus architectures and AES-centric state transfer modes are provided. The bus architecture may be implemented on system-on-chip (SoC) devices in conjunction with existing intellectual property (IP) cores. The bus architecture can include a control-bus with a single master, such as a microprocessor, and a data-bus with a single slave, such as DMA.Item Advanced Engineering Mathematics with MATLAB(Brooks/Cole, 2000) Harman, Thomas L.Advanced Engineering Mathematics with MATLAB, Second Edition, is written for engineers and engineering students who want to use MATLAB to solve practical engineering problems." "The authors emphasize mathematical principles, not computations. The second edition features new chapters on Laplace Transforms, Discrete Systems, and Z-Transforms. MATLAB is used as an analysis tool to define and solve engineering problems. MATLAB is integrated throughout, with abundant engineering problems drawn from the daily challenges of working engineers.Item Aerobic Biodegradation Kinetics of Four Anionic and Nonionic Surfactants at Sub and Supra Critical Micelle Concentrations(Water Resarch, 1999) Zhang, CarlAerobic biodegradation of four representative commercial surfactants under a range of concentrations (i.e., sub- and supra-critical micelle concentrations, CMCs) beyond those ordinarily used in biodegradation studies was investigated. Of the four surfactants tested, sodium dodecylbenzene sulfonate (SDBS) showed no biodegradation and foam degradation. At a sub-CMC (500 mg/l), primary biodegradation, as measured by methylene blue active substances (MBAS) for an anionic surfactant sodium dodecyl sulphate (SDS) and by cobalt thiocyanate active substances (CTAS) for a nonionic surfactant Witconol, followed Monod kinetics, substrate depletion being a function of both microbial growth and substrate concentrations. However, primary biodegradation at supra-CMCs (500 for Tergitol and 2500 mg/l for SDS and Witconol) and ultimate biodegradation (mineralization) at both sub- and supra-CMCs were best described by first-order kinetics, the degradation rate being a sole function of substrate concentrations. Parameters for the kinetic models (Ks, Y, μmax, and k) were estimated using non-linear least squares methods. Increasing surfactant concentrations from sub- to supra-CMCs significantly decreased primary biodegradation, ultimate biodegradation, and foam degradation. This decrease may be attributed to the limited bioavailability of surfactants in the micellar phase as compared to the monomeric surfactants. The results are of significance for surfactant-based remediation, since the concentrations of surfactants employed in remediation are typically much higher than CMCs, while surfactant concentrations of primary interest in biodegradation work are in the neighborhood of and below 10 mg/l, which is usually 10–100 times lower than CMCs.Item An Algorithm for Combining Graphs Based on Shared Knowledge(International Conference on Bioinformatics and Computational Biology, 2012) Bettayeb, SaidWe propose an algorithm for connecting nodes from multiple disconnected graphs based on a given tuple set representing shared knowledge. The set of tuples is used to create bridgeedges for combining two graphs. The path from a node in a graph to a node in the other graph passes through a bridgeedge. This method of combining two graphs will enable more comprehensive understanding and exploring of the relatedness of the knowledge entities (the nodes) in two graphs based on a given domain knowledge represented in the set of tuples. This approach has useful applications in various domains and in particular in bioinformatics. In bioinformatics, for example, we can explore the functional relationship between two gene products given their Gene Ontology annotation terms from the molecular function MF and biological process BP graphs of GO. Moreover, the proposed algorithm can be applied to WordNet to enable exploring the relative degree of relatedness of words from multiple lexical hierarchies, like nouns and verbs, within the WordNet.Item Alternation by Gerbils and Rats during Practice(Animal Behavior Society Annual Meeting, 2004-05) Mercado III, E.; Ruch, M. C.; Liu, H. M.; Shan, Xiaojun; Sidaras, S. K.; Bogdan, M. L.Abstract not available.Item Amino acid biosynthesis in chloroplasts(Balaban International Science Service, 1981) Mills, Ronald