860 research outputs found

    Path selection system development and evaluation for a Martian roving vehicle

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    A path selection system evaluation test procedure has been developed to enhance the analysis capability of an existing digital computer simulation package. The procedure investigates the obstacle avoidance ability of a path selection system on a sequence of test terrains with and without random effects. Using the standard test procedure a proposed mid-range sensor system has been evaluated and recommendations directed at improving the performance of the system have been made. In addition, the initial development and evaluation of a short range sensor system has been undertaken

    The effect of extreme temperatures on the elastic properties and fracture behavior of graphite/polyimide composites

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    The influence of elevated and cryogenic temperatures on the elastic moduli and fracture strengths of several C6000/PMR-15 and C6000/NR-15082 laminates was measured. Tests were conducted at -157 C, 24 C, and 316 C (-250 F, 75 F, and 600 F). Both notched and unnotched laminates were tested. The average stress failure criterion was used to predict the fracture strength of quasi-isotropic notched laminates

    Lunar base launch and landing facilities conceptual design

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    The purpose of this study was to perform a first look at the requirements for launch and landing facilities for early lunar bases and to prepared conceptual designs for some of these facilities. The emphasis of the study is on the facilities needed from the first manned landing until permanent occupancy, the Phase 2 lunar base. Factors including surface characteristics, navigation system, engine blast effects, and expected surface operations are used to develop landing pad designs, and definitions fo various other elements of the launch and landing facilities. Finally, the dependence of the use of these elements and the evolution of the facilities are established

    Space transportation nodes assumptions and requirements: Lunar base systems study task 2.1

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    The Space Transportation Nodes Assumptions and Requirements task was performed as part of the Advanced Space Transportation Support Contract, a NASA Johnson Space Center (JSC) study intended to provide planning for a Lunar Base near the year 2000. The original task statement has been revised to satisfy the following queries: (1) What vehicles are to be processed at the transportation node; (2) What is the flow of activities involved in a vehicle passing through the node; and (3) What node support resources are necessary to support a lunar scenario traffic model composed of a mix of vehicles in an active flight schedule. The Lunar Base Systems Study is concentrating on the initial years of the Phase 2 Lunar Base Scenario. The study will develop the first five years of that phase in order to define the transportation and surface systems (including mass, volumes, power requirements, and designs)

    Speech Evaluation Assessment: An Analysis of Written Speech Feedback on Instructor Evaluation Forms in the Basic Communication Course

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    As a critical component of many general education programs, the basic communication course is at the forefront of many assessment efforts. Five years after conducting extensive program assessment using student portfolios, and after implementing revisions to the instructor training program, course directors at Illinois State University conducted another round of portfolio assessment. The present study reveals progress in the specific areas originally targeted for improvement. Additional areas for future revisions to the instructor training program are suggested. Implications for assessment efforts at other institutions are discussed

    Assessing Classroom Management Training for Basic Course Instructors

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    Extant research demonstrates that graduate teaching assistants (GTAs) experience student misbehaviors in the classroom and that basic course administrators should be proactive in preparing GTAs for classroom management issues (Meyer et al., 2007). Following the recommendation for the development of classroom management training (CMT) by Meyer et al. (2007), the present study sought to assess the implementation of CMT. Specifically, a group of GTAs completed the same survey instrument twice following the completion of CMT, once early in the semester and again at the end of the semester. Results of the present study indicate that GTA reports of student misbehavior were reduced, and GTA confidence in the ability to manage misbehaviors increased following CMT. Additionally, the results indicate that the frequency and severity of student misbehaviors were reduced for GTAs who received CMT compared to GTAs who did not receive CMT

    Designing Classroom Management Training for Basic Course Instructors

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    Since many basic course training programs fail to adequately address classroom management issues, most graduate teaching assistants (GTAs) enter the classroom unprepared to confront student misbehaviors. However, literature suggests that by incorporating classroom management issues into training pro­grams, GTAs will be better armed to establish the instructional climate of the classroom and confront stu­dent misbehaviors. In this study, GTAs who had not received classroom management training (CMT) were given a survey containing closed and open-ended questions regarding typical student misbehaviors, possible classroom responses to those behaviors, and preferences for classroom management information during training. The results of this study identify student misbehaviors that occur in the basic course and draw implications for the integration of CMT into future GTA training and research

    Comparisons of various configurations of the edge delamination test for interlaminar fracture toughness

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    Various configurations of Edge Delamination Tension (EDT) test specimens, of both brittle (T300/5208) and toughened-matrix (T300/BP907) graphite reinforced composite laminates, were manufactured and tested. The mixed-mode interlaminar fracture toughness, G sub C, was measured using (30/30 sub 2/30/90 sub N)sub s, n=1 or 2, (35/-35/0/90) sub s and (35/0/-35/90) sub s layups designed to delaminate at low tensile strains. Laminates were made without inserts so that delaminations would form naturally between the central 90 deg plies and the adjacent angle plies. Laminates were also made with Teflon inserts implanted between the 90 deg plies and the adjacent angle (theta) plies at the straight edge to obtain a planar fracture surface. In addition, interlaminar tension fracture toughness, GIc, was measured from laminates with the same layup but with inserts in the midplane, between the central 90 deg plies, at the straight edge. All of the EDT configurations were useful for ranking the delamination resistance of composites with different matrix resins. Furthermore, the variety of layups and configurations available yield interlaminar fracture toughness measurements needed to generate delamination failure criteria. The influence of insert thickness and location, and coupon size on G sub c values were evaluated

    Cadaveric Study for Intraoral Needle Access to the Infratemporal Fossa: Application to Posterior Superior Alveolar Nerve Block Technique.

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    The posterior superior alveolar (PSA) nerve block is, from an anatomical perspective, challenging because the mandibular ramus and the zygomatic process of the maxilla can interfere with the course of the needle. Dentists empirically know that shifting the patient\u27s mandible to the ipsilateral side can improve visibility and accessibility for such blocks. This cadaveric study aimed to establish anatomical evidence for the ipsilateral mandible shifting used in the PSA. The distance between the lateral most bulging point of the alveolar part of the maxilla and ipsilateral anterior border of the ramus of the mandible ranged from 1.4 to 6.9 mm with a mean of 4.3 ± 1.6 mm. This result supports the empirical technique of shifting the mandible ipsilaterally for PSA nerve block

    An appraisal of the sciaky 300 KVA projection/spot welding equipment

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    Using the Systems Design Procedure developed at Cranfield, an appraisal of the Sciaky Welding Equipment has been carried out. In particular, the interface on the electronic control cabinet has been redesigned, five solutions of varying engineering complexity and cost being presented
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