A. James Clark School of Engineering

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The collections in this community comprise faculty research works, as well as graduate theses and dissertations.

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Subject: search.filters.subject.Information technology

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Now showing 1 - 9 of 9
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    ADVANCED VISION INTELLIGENT METHODS FOR FOOD, AGRICULTURAL, AND HEALTHCARE APPLICATIONS
    (2021) Wang, Dongyi; Tao, Yang; Bioengineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    With fast software and hardware developments, vision intelligence models have attracted great attention and showed unprecedented performance on large-scale datasets. In practice, studies are still needed to design innovative intelligence models for niche applications with limited data accessibilities in uncertain real-world scenarios. This research casts light on cutting edge vision intelligent applications that enhance the essential areas of people’s livelihood, including food, agriculture, and healthcare. First, a 2D/3D imaging system was developed to facilitate the autonomous processing of Chesapeake Bay blue crabs, as an efficient solution to current hand-picking protocols. The system integrates a semantic segmentation model to understand crab 2D morphology. It can detect crab back-fin knuckles with R2 larger than 0.995, which guides movements of a two degree-of-freedom gantry station in removing crab legs and extracting crab body cores with 2mm accuracy. The customized active laser line scanning 3D range imaging system shows high imaging accuracy (0.15mm) and is able to assist a linear actuator in removing crab chamber cartilages. Second, computer aided vision intelligent methods were applied to an emerging ophthalmologic imaging modality known as, erythrocyte mediated angiography. A novel regression-based segmentation model and a Monte Carlo based tracking method were proposed to monitor the erythrocytes in stasis and in movements. Both models displayed comparable performance to human experts. Preliminary clinical results also manifest the potential relationships between paused erythrocyte densities and primary open-angle glaucoma. To better understand retinal vessel and erythrocyte distributions, a novel network architecture, the Hard Attention Net was proposed. This network has achieved state-of-art retinal vessel segmentation performance across different ophthalmologic imaging modalities. Finally, deep learning based qualitative and quantitative analyses were applied to spectral signals for monitoring high-level status and low-level chemical properties of agricultural bioproducts. Experiments include early-stage tomato spotted wilt virus detection as well as nutrition content estimation of plant and corn kernels. By using adversarial training and feature weighting ideas, the two proposed networks were effectively trained with a limited dataset. The results of these studies show great potential for vision intelligence models for promoting applications of advanced imaging modalities and vision-guided automations in food, agricultural, and healthcare fields.
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    INFORMATION TECHNOLOGY PROJECTS IN NONPROFIT UNIVERSITY: A PROJECT GOVERNANCE PERSPECTIVE
    (2016) Ghosh, Soumajit; Cui, Qingbin; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    The universities rely on the Information Technology (IT) projects to support and enhance their core strategic objectives of teaching, research, and administration. The researcher’s literature review found that the level of IT funding and resources in the universities is not adequate to meet the IT demands. The universities received more IT project requests than they could execute. As such, universities must selectively fund the IT projects. The objectives of the IT projects in the universities vary. An IT project which benefits the teaching functions may not benefit the administrative functions. As such, the selection of an IT project is challenging in the universities. To aid with the IT decision making, many universities in the United States of America (USA) have formed the IT Governance (ITG) processes. ITG is an IT decision making and accountability framework whose purpose is to align the IT efforts in an organization with its strategic objectives, realize the value of the IT investments, meet the expected performance criteria, and manage the risks and the resources (Weil & Ross, 2004). ITG in the universities is relatively new, and it is not well known how the ITG processes are aiding the nonprofit universities in selecting the right IT projects, and managing the performance of these IT projects. This research adds to the body of knowledge regarding the IT project selection under the governance structure, the maturity of the IT projects, and the IT project performance in the nonprofit universities. The case study research methodology was chosen for this exploratory research. The convenience sampling was done to choose the cases from two large, research universities with decentralized colleges, and two small, centralized universities. The data were collected on nine IT projects from these four universities using the interviews and the university documents. The multi-case analysis was complemented by the Qualitative Comparative Analysis (QCA) to systematically analyze how the IT conditions lead to an outcome. This research found that the IT projects were selected in the centralized universities in a more informed manner. ITG was more authoritative in the small centralized universities; the ITG committees were formed by including the key decision makers, the decision-making roles, and responsibilities were better defined, and the frequency of ITG communication was higher. In the centralized universities, the business units and colleges brought the IT requests to ITG committees; which in turn prioritized the IT requests and allocated the funds and the resources to the IT projects. ITG committee members in the centralized universities had a higher awareness of the university-wide IT needs, and the IT projects tended to align with the strategic objectives. On the other hand, the decentralized colleges and business units in the large universities were influential and often bypassed the ITG processes. The decentralized units often chose the “pet” IT projects, and executed them within a silo, without bringing them to the attention of the ITG committees. While these IT projects met the departmental objectives, they did not always align with the university’s strategic objectives. This research found that the IT project maturity in the university could be increased by following the project management methodologies. The IT project management maturity was found higher in the IT projects executed by the centralized university, where a full-time project manager was assigned to manage the project, and the project manager had a higher expertise in the project management. The IT project executed under the guidance of the Project Management Office (PMO) has exhibited a higher project management maturity, as the PMO set the standards and controls for the project. The IT projects managed by the decentralized colleges by a part-time project manager with lower project management expertise have exhibited a lower project management maturity. The IT projects in the decentralized colleges were often managed by the business, or technical leads, who often lacked the project management expertise. This research found that higher the IT project management maturity, the better is the project performance. The IT projects with a higher maturity had a lower project delay, lower number of missed requirements, and lower number of IT system errors. This research found that the quality of IT decision in the university could be improved by centralizing the IT decision-making processes. The IT project management maturity could be improved by following the project management methodologies. The stakeholder management and communication were found critical for the success of the IT projects in the university. It is hoped that the findings from this research would help the university leaders make the strategic IT decisions, and the university’s IT project managers make the IT project decisions.
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    Age of Information and Energy Efficiency in Communication Networks
    (2015) Dutra da Costa, Maice; Ephremides, Anthony; Electrical Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    This dissertation focuses on two important aspects of communication systems, namely energy efficiency and age of information. Both aspects have received much less attention than traditional performance metrics, such as throughput and delay. The need to improve the energy efficiency in communication networks is apparent, given the high demand for power consuming applications to be implemented in devices with limited energy supplies. Additionally, improvements in energy efficiency are encouraged by possible reductions in network operation costs, and by the increasing awareness of the environmental impact caused by the information and communication technologies. In this dissertation, energy efficiency is studied in the context of a cognitive wireless network, in which users have different priorities to access the network resources, possibly interfering and cooperating among themselves. A new parametrization is proposed to characterize performance trade-offs associated with energy efficiency for non-cooperative and cooperative network models. Additionally, a game theoretic model is proposed to study resource allocation in a cooperative cognitive network, accounting for energy efficiency in the utility functions. Age of information is a relatively new concept, which aims to characterize the timeliness of information. It is relevant to any system concerned with timeliness of information, and particularly relevant when information is used to make decisions, but the value of the information is degraded with time. This is the case in many applications of communications and control systems. In this dissertation, the age of information is first investigated for status update communication systems. The status updates are samples of a random process under observation, transmitted as packets, which also contain the time stamp to identify when the sample was generated. The age of information at the destination node is the time elapsed since the last received update was generated. The status update systems are modeled using queuing theory. We propose models for status update systems capable of managing the packets before transmission, aiming to avoid wasting network resources with the transmission of stale information. In addition to characterizing the average age, we propose a new metric, called peak age, which provides information about the maximum value of the age, achieved immediately before receiving an update. We also propose a new framework, based on the concept of age of information, to analyze the effect of outdated Channel State Information (CSI) on the performance of a communication link in which the source node acquires the CSI through periodic feedback from the destination node. The proposed framework is suitable to analyze the trade-off between performance and timeliness of the CSI, which is a fundamental step to design efficient adaptation functions and feedback protocols.
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    COMBINATORIAL INVESTIGATION OF RARE-EARTH FREE PERMANENT MAGNETS
    (2015) Fackler, Sean Wu; Takeuchi, Ichiro; Material Science and Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    The combinatorial high throughput method allows one to rapidly study a large number of samples with systematically changing parameters. We apply this method to study Fe-Co-V alloys as alternatives to rare-earth permanent magnets. Rare-earth permanent magnets derive their unmatched magnetic properties from the hybridization of Fe and Co with the f-orbitals of rare-earth elements, which have strong spin-orbit coupling. It is predicted that Fe and Co may also have strong hybridization with 4d and 5d refractory transition metals with strong spin-orbit coupling. Refractory transition metals like V also have the desirable property of high temperature stability, which is important for permanent magnet applications in traction motors. In this work, we focus on the role of crystal structure, composition, and secondary phases in the origin of competitive permanent magnetic properties of a particular Fe-Co-V alloy. Fe38Co52V10, compositions are known as Vicalloys. Fe-CoV composition spreads were sputtered onto three-inch silicon wafers and patterned into discrete sample pads forming a combinatorial library. We employed highthroughput screening methods using synchrotron X-rays, wavelength dispersive spectroscopy, and magneto-optical Kerr effect (MOKE) to rapidly screen crystal structure, composition, and magnetic properties, respectively. We found that in-plane magnetic coercive fields of our Vicalloy thin films agree with known bulk values (300 G), but found a remarkable eight times increase of the out-of-plane coercive fields (~2,500 G). To explain this, we measured the switching fields between in-plane and out-of-plane thin film directions which revealed that the Kondorsky model of 180° domain wall reversal was responsible for Vicalloy’s enhanced out-of-plane coercive field and possibly its permanent magnetic properties. The Kondorsky model suggests that domain-wall pinning is the origin of Vicalloy’s permanent magnetic properties, in contrast to strain, shape, or crystalline anisotropy mechanisms suggested in the literature. We also studied the thickness dependence of an Fe70Co30- V thin film library to consider the unique effects of our thin film libraries which are not found in bulk samples. We present results of data mining of synchrotron X-ray diffraction data using non-negative matrix factorization (NMF). NMF can automatically identify pure crystal phases that make up an unknown phase mixture. We found a strong correlation between magnetic properties and crystal phase quantity using this valuable visualization. In addition to the combinatorial study, this dissertation includes a study of strain controlled properties of magnetic thin films for future applications in random access memories. We investigated the local coupling between dense magnetic stripe domains in transcritical Permalloy (tPy) thin films and ferroelectric domains of BaTiO3 single crystals in a tPy/BaTiO3 heterostructure. Two distinct changes in the magnetic stripe domains of tPy were observed from the magnetic force microscopy images after cooling the heterostructure from above the ferroelectric Curie temperature of BaTiO3 (120°C) to room temperature. First, an abrupt break in the magnetic stripe domain direction was found at the ferroelectric a-c-domain boundaries due to an induced change in in-plane magnetic anisotropy. Second, the magnetic stripe domain period increased when coupled to a ferroelectric a-domain due to a change in out-of-plane magnetic anisotropy. Micromagnetic simulations reveal that local magnetic anisotropy energy from inverse magnetostriction is conserved between in-plane and out-of-plane components.
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    Analyzing Complex Events and Human Actions in "in-the-wild" Videos
    (2014) Lee, Hyungtae; Davis, Larry S; Electrical Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    We are living in a world where it is easy to acquire videos of events ranging from private picnics to public concerts, and to share them publicly via websites such as YouTube. The ability of smart-phones to create these videos and upload them to the internet has led to an explosion of video data, which in turn has led to interesting research directions involving the analysis of ``in-the-wild'' videos. To process these types of videos, various recognition tasks such as pose estimation, action recognition, and event recognition become important in computer vision. This thesis presents various recognition problems and proposes mid-level models to address them. First, a discriminative deformable part model is presented for the recovery of qualitative pose, inferring coarse pose labels (e:g: left, front-right, back), a task more robust to common confounding factors that hinder the inference of exact 2D or 3D joint locations. Our approach automatically selects parts that are predictive of qualitative pose and trains their appearance and deformation costs to best discriminate between qualitative poses. Unlike previous approaches, our parts are both selected and trained to improve qualitative pose discrimination and are shared by all the qualitative pose models. This leads to both increased accuracy and higher efficiency, since fewer parts models are evaluated for each image. In comparisons with two state-of-the-art approaches on a public dataset, our model shows superior performance. Second, the thesis proposes the use of a robust pose feature based on part based human detectors (Poselets) for the task of action recognition in relatively unconstrained videos, i.e., collected from the web. This feature, based on the original poselets activation vector, coarsely models pose and its transitions over time. Our main contributions are that we improve the original feature's compactness and discriminability by greedy set cover over subsets of joint configurations, and incorporate it into a unified video-based action recognition framework. Experiments shows that the pose feature alone is extremely informative, yielding performance that matches most state-of-the-art approaches but only using our proposed improvements to its compactness and discriminability. By combining our pose feature with motion and shape, the proposed method outperforms state-of-the-art approaches on two public datasets. Third, clauselets, sets of concurrent actions and their temporal relationships, are proposed and explored their application to video event analysis. Clauselets are trained in two stages. Initially, clauselet detectors that find a limited set of actions in particular qualitative temporal configurations based on Allen's interval relations is trained. In the second stage, the first level detectors are applied to training videos, and discriminatively learn temporal patterns between activations that involve more actions over longer durations and lead to improved second level clauselet models. The utility of clauselets is demonstrated by applying them to the task of ``in-the-wild'' video event recognition on the TRECVID MED 11 dataset. Not only do clauselets achieve state-of-the-art results on this task, but qualitative results suggest that they may also lead to semantically meaningful descriptions of videos in terms of detected actions and their temporal relationships. Finally, the thesis addresses the task of searching for videos given text queries that are not known at training time, which typically involves zero-shot learning, where detectors for a large set of concepts, attributes, or objects parts are learned under the assumption that, once the search query is known, they can be combined to detect novel complex visual categories. These detectors are typically trained on annotated training data that is time-consuming and expensive to obtain, and a successful system requires many of them to generalize well at test time. In addition, these detectors are so general that they are not well-tuned to the specific query or target data, since neither is known at training. Our approach addresses the annotation problem by searching the web to discover visual examples of short text phrases. Top ranked search results are used to learn general, potentially noisy, visual phrase detectors. Given a search query and a target dataset, the visual phrase detectors are adapted to both the query and unlabeled target data to remove the influence of incorrect training examples or correct examples that are irrelevant to the search query. Our adaptation process exploits the spatio-temporal coocurrence of visual phrases that are found in the target data and which are relevant to the search query by iteratively refining both the visual phrase detectors and spatio-temporally grouped phrase detections (`clauselets'). Our approach is demonstrated on to the challenging TRECVID MED13 EK0 dataset and show that, using visual features alone, our approach outperforms state-of-the-art approaches that use visual, audio, and text (OCR) features.
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    Exploring Linkages between Travel Behavior and Health with Person-Level Data from Smartphone Applications
    (2013) Vemulapati, Sapeksha Virinchi; Zhang, Lei; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    In the past, scholars have explored different variables and linked them with the individual's travel behavior. This study explores the linkages between an individual's health and his/her everyday travel behavior. In order to capture accurate and comprehensive travel behavior information, a smartphone application is developed that can track user location for long periods without the need of user intervention. Focus is placed on designing the application to have minimum respondent burden and long-standing battery life of the smart device. Subjects are recruited through a web survey designed to collect information about the individual's healthy living habits. Data from the application is regressed against the health measure data acquired from the survey. Results show that active modes of travel are positively associated with the person's general health measures. The feasibility of this platform as a data collection method is highlighted while explaining the limitations due to the sample distribution and size.
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    Study of real-time traffic state estimation and short-term prediction of signalized arterial network considering heterogeneous information sources
    (2013) Lu, Yang; Ali, Haghani; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Compared with a freeway network, real-time traffic state estimation and prediction of a signalized arterial network is a challenging yet under-studied field. Starting from discussing the arterial traffic flow dynamics, this study proposes a novel framework for real-time traffic state estimation and short-term prediction for signalized corridors. Particle filter techniques are used to integrate field measurements from different sources to improve the accuracy and robustness of the model. Several comprehensive numerical studies based on both real world and simulated datasets showed that the proposed model can generate reliable estimation and short-term prediction of different traffic states including queue length, flow density, speed and travel time with a high degree of accuracy. The proposed model can serve as the key component in both ATIS (Advanced Traveler's Information System) and proactive traffic control systems
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    GOVERNANCE STRATEGIES FOR ENTERPRISE APPLICATION SYSTEM IMPLEMENTATIONS
    (2013) Ghosh, Saumyendu N.; Skibniewski, Miroslaw J; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Enterprise application system implementations are highly complex implementations that automate several business functions, such as financials, accounting, supply chain, customer services management, human resources management and reporting among others. This study aims at providing an alternative view of organization's enterprise application system (EAS) acceptance. Despite the large body of literature, there are still empirical inquiries to investigate the EAS system implementation from adopters' perspectives and how to identify risks in a multi-stakeholder and dynamic environment. The thesis consists of three essays on various aspects of relationship between enterprise application implementation in a multi-stakeholder environment and project governance. Valid measurement scales for predicting organization's acceptance of enterprise systems are in short supply. The first essay develops and validates new scales for two specific variables, integration and inter-dependency risks. These variables are hypothesized as key determinant for organizational success of enterprise application implementations by mitigating risks involved in a multi-stakeholder environment. A model of organization acceptance of enterprise systems was developed using these two scales and then tested for reliability from a total of 365 users and nine application groups. The measures were validated using ten different direct measures with reliabilities between 0.72 and 0.96. Integration risk was significantly related with perceived ease of use, consultant's product knowledge and training provided to the end users. Inter-dependency risk was significantly correlated with perceived usefulness, consultant's industry and product knowledge. Both integration and inter-dependency risks are significantly related with success of the new enterprise application. This study would benefit project executives by offering valuable managerial insights that enable them to appreciate and improve integration and inter-dependency of stakeholders. Implications for theory and practice are discussed for two sub-groups: that less experienced resources treat risks differently than more experienced resources, and business applications compared to technical enterprise applications. Academic community has not addressed governance of enterprise application projects that involve dynamic environments and how to mitigate integration and inter-dependency risks. In the second essay it is argued that acceptance of the system from end users is not enough? Adopters of new enterprise wide information technology solutions get most benefit when the solution continues to be adaptable when business, environment or other organizational priorities change - therefore making an implementation sustainable. The second essay discussed characteristics of sustainability of enterprise application implementation from organizational perspective. A case study was used to validate the characteristics of sustainability. The thesis sought to demonstrate the causal relationship between the organization's preparedness for sustainability and the emergence of implementation problems. The study extracted insight into the criticality of certain factors and the type of problems making decisions under weak governance situation. The third essay develops determinants for project governance success of enterprise application implementations by mitigating risks in a multi-stakeholder environment. This essay develops and validates new scales for five specific variables. Definitions of five variables were used to develop a model that was presented for content validity and then tested for reliability from a total of 117 project executives globally. The measures were validated with reliabilities between 0.73 and 0.94. Relationships between five measures were broken down to meaningful components and a three tier project governance structure was proposed to mitigate integration and inter-dependency risks in a multi-stakeholder environment.
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    Measuring the Impact of Training in the Implementation of Project Management Information Systems
    (2012) McCarty, Andrew; Skibniewski, Miroslaw; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Organizations can use training to maximize the benefits realized through the implementation of project, program, and portfolio management software. However, the relationship between Project Management Information System (PMIS) training and the creation of organizational value is not well understood. The goal of the research is to create a better understanding of current industry project management software training practices and outcomes. This research investigates training utilization and outcomes in the PMIS industry, the prevalence, relative effectiveness and efficiency of several commonly used training delivery methods at increasing PMIS outcomes, and the relationships of individual and organizational characteristics on outcomes. An expansive multi-disciplinary review of existing scholarly literature was undertaken to develop a framework for the measurement of project management software training outcomes. Expert input from a panel of 9 practitioners averaging 16.7 years of professional experience related to PM, and 15.1 years of years of professional experience related to PM software usage was used to objectively select a small number of the best-scoring elements of the proposed framework for inclusion in a survey to be administered to practitioners. In total, 1,021 completed surveys were collected and analyzed using statistical methods. Research findings suggest statistically significant differences in consumption rates, effectiveness and efficiency among the examined training delivery methods. This research may contribute to training that is more effective and more efficient, based on the unique requirements of each individual and organization, at a reasonable cost. The methodologies and findings of this research have immediate implications in improving the planning, delivery, and measurement of PMIS training.