1,817 research outputs found

    Logistic Knowledge Tracing: A Constrained Framework for Learner Modeling

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    Adaptive learning technology solutions often use a learner model to trace learning and make pedagogical decisions. The present research introduces a formalized methodology for specifying learner models, Logistic Knowledge Tracing (LKT), that consolidates many extant learner modeling methods. The strength of LKT is the specification of a symbolic notation system for alternative logistic regression models that is powerful enough to specify many extant models in the literature and many new models. To demonstrate the generality of LKT, we fit 12 models, some variants of well-known models and some newly devised, to 6 learning technology datasets. The results indicated that no single learner model was best in all cases, further justifying a broad approach that considers multiple learner model features and the learning context. The models presented here avoid student-level fixed parameters to increase generalizability. We also introduce features to stand in for these intercepts. We argue that to be maximally applicable, a learner model needs to adapt to student differences, rather than needing to be pre-parameterized with the level of each student's ability

    Reduction and Summarization of Forage Production Data from Pasture and Range Lands

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    In an attempt to control and properly manage our vast pasture and range lands there have been many problems that the scientist has been confronted with. Among these has been the problem of reducing the great quantity of collected data from the ranges and pasture lands into a form suitable for scientific analysis. In the past this reduction process has been accomplished by slow, painstaking hand calculation methods, thus making it virtually impossible for the scientist to analyze and propose corrective measures at the time they are needed. However, with the advent of high speed computing equipment this need no longer be a major factor of concern to the research worker today. It has been the purpose of this study to develop a program utilizing computers to solve one of these many problems. The problem that has been specifically dealt with in this report is that of the summarization of forage weight production data

    13.4.18. Chufa Biology and Management

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    Chufa (Cyperus esculentus) is an emergent perennial sedge that is common in seasonally flooded wetlands. Although chufa is common in many States, it is most abundant in the Southeast, including the Mississippi alluvial valley (Fig. 1). Belowground biomass of chufa, especially the tubers, serves as a valuable food source for waterfowl and cranes. Chufa tubers rank tenth among the most important waterfowl foods in the United States

    13.4.18. Chufa Biology and Management

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    Chufa (Cyperus esculentus) is an emergent perennial sedge that is common in seasonally flooded wetlands. Although chufa is common in many States, it is most abundant in the Southeast, including the Mississippi alluvial valley (Fig. 1). Belowground biomass of chufa, especially the tubers, serves as a valuable food source for waterfowl and cranes. Chufa tubers rank tenth among the most important waterfowl foods in the United States

    TB18: Mensuration Methods for Site Classification of Shade Tolerant Tree Species

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    All of the climax tree species in Maine are shade tolerant. This means that they have the capacity of surviving and growing slowly in the seedling, sapling and pole-size stages. As a result none of the established methods employing total age are applicable. In searching for a way to overcome this problem an entirely new approach to quantitative site evaluation was conceived. This study evaluates this new mensurational approach to site evaluation for shade-tolerant trees.https://digitalcommons.library.umaine.edu/aes_techbulletin/1178/thumbnail.jp

    Increases in efficiency and enhancements to the Mars Observer non-stored commanding process

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    The Mars Observer team was, until the untimely loss of the spacecraft on August 21, 1993, performing flight operations with greater efficiency and speed than any previous JPL mission of its size. This level of through-put was made possible by a mission operations system which was composed of skilled personnel using sophisticated sequencing and commanding tools. During cruise flight operations, however, it was realized by the project that this commanding level was not going to be sufficient to support the activities planned for mapping operations. The project had committed to providing the science instrument principle investigators with a much higher level of commanding during mapping. Thus, the project began taking steps to enhance the capabilities of the flight team. One mechanism used by project management was a tool available from total quality management (TQM). This tool is known as a process action team (PAT). The Mars Observer PAT was tasked to increase the capacity of the flight team's nonstored commanding process by fifty percent with no increase in staffing and a minimal increase in risk. The outcome of this effort was, in fact, to increase the capacity by a factor of 2.5 rather than the desired fifty percent and actually reduce risk. The majority of these improvements came from the automation of the existing command process. These results required very few changes to the existing mission operations system. Rather, the PAT was able to take advantage of automation capabilities inherent in the existing system and make changes to the existing flight team procedures

    Critical Issues: Defining and Debunking Misconceptions in Health, Education, Criminal Justice, and Social Work/Social Services

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    The University of Houston Downtown Committee for the Journal of Family Strengths introduces Volume 18, Issue 1: Critical Issues: Defining and Debunking Misconceptions in Health, Education, Criminal Justice, and Social Work/Social Services

    Effect of In-Plane Voiding on the Fracture Behavior of Laser Sintered Polyamide

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    The primary contributors to poor mechanical properties in polyamide materials used during Selective Laser Sintering® are qualified. Methods to quantify the decreased mechanical properties, including Scanning Electron Microscopy (SEM) of fracture surfaces, are compared against each other and against mechanical properties of components fabricated using multiple process parameters. Of primary interest are Ultimate Tensile Strength (UTS) and Elongation at Break (EOB) of tensile specimens fabricated under conditions that produce varying degrees of ductile and brittle fracture.Mechanical Engineerin

    Examining the reliability of a retinal recognition device as database size and the number of enrollment scans are varied for application in Command, Control and Communications (C³)

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    As the amount of sensitive information stored in databases increases due to the current trend to automate Command, Control and Communication (C³) systems, the impact of unauthorized access could be very detrimental to our nation's security. Access control hardware that uses retinal blood vessel pattern recognition may be the solution to the problem. This thesis looks at one retinal pattern recognition device and attempts to determine it's reliability as a function of the data base size stored in memory and the number of enrollment scans averaged together to form the reference template. The database sizes used consisted of 300, 600 or 1200 templates, and the reference templates tested were comprised of 3. 5 or 7 enrollment scans. The applicability of this technology for protecting C³ systems is discussed. This study employed the Eye Dentify 7.5 system developed by Eye Dentify Inc. of Beaverton. Oregon, which performed extremely well by producing a low TYPE I error rate and no TYPE II errors in over 1000 trials. This technology has potential for the protection of C³ systems.http://archive.org/details/examiningreliabi00leigLieutenant, United States NavyApproved for public release; distribution is unlimited
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