11,338 research outputs found

    Some NASA contributions to human factors engineering: A survey

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    This survey presents the NASA contributions to the state of the art of human factors engineering, and indicates that these contributions have a variety of applications to nonaerospace activities. Emphasis is placed on contributions relative to man's sensory, motor, decisionmaking, and cognitive behavior and on applications that advance human factors technology

    Southwest Research Institute assistance to NASA in biomedical areas of the technology

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    Significant applications of aerospace technology were achieved. These applications include: a miniaturized, noninvasive system to telemeter electrocardiographic signals of heart transplant patients during their recuperative period as graded situations are introduced; and economical vital signs monitor for use in nursing homes and rehabilitation hospitals to indicate the onset of respiratory arrest; an implantable telemetry system to indicate the onset of the rejection phenomenon in animals undergoing cardiac transplants; an exceptionally accurate current proportional temperature controller for pollution studies; an automatic, atraumatic blood pressure measurement device; materials for protecting burned areas in contact with joint bender splints; a detector to signal the passage of animals by a given point during ecology studies; and special cushioning for use with below-knee amputees to protect the integrity of the skin at the stump/prosthesis interface

    Smart system for aircraft passenger neck support

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    Air travel is becoming increasingly more accessible to people due to the availability of low cost air travel. However, long distance air travel is not a normal activity for human. During air travel, people experience different levels of physiological and psychological discomfort. The discomfort may affect the passenger’s health and feeling. With the rapid development of technology, the comfort of service has become an important issue. Nowadays, comfort is an attribute which is highly demanded by aircraft passengers. The comfort of aircraft passengers depends on different features and the cabin environment during air travel. Seat is one of the important features for the passengers and in which a passenger spends almost all their time during air travel. Different seat aspects have to be seen and taken into account in the comfort model. The research has five goals. First goal, literature research starts with the study on the state of the art and recent development of vehicle seat design which is available in current literature and products. The literature review gives a general idea about the research and the measurement method related to seating comfort and discomfort. Second goal, four surveys were conducted to identify the comfort factor of economy class aircraft passenger, body discomfort for truck driver, body discomfort for economy class aircraft passenger and relationship between seat location and sitting posture. The first survey is to identify and investigate the comfort factors for economy class aircraft passenger seat. Subsequently, survey on the body back sitting discomfort over travel time was conducted for truck driver and economy class aircraft passenger. The third survey is to investigate the relationship of the seat location and sitting posture of passengers in the economy class aircraft cabin. The postures of subjects were observed and recorded based on seven predefined sitting postures. Third goal, we contributed to develop a smart neck support system for economy class aircraft passenger. Our system aims to support and reduce neck muscle stress. A functional and working prototype was built to demonstrate the design concept and to perform experimental validation. Forth goal, we developed a low cost aircraft cabin simulator and we utilized it to validate our developed smart neck support system. The aircraft cabin simulator was built with motion platform and it is able to simulate a broad range of flight procedures. Next, a calibration experiment was conducted to investigate SCM muscle stress in relation to different support conditions, time interval and head rotation angle. Fifth goal, a validation experiment was conducted in the aircraft cabin simulator to evaluate the smart neck support system. The objective and subjective results show that the smart neck support system is able to reduce SCM muscle stress adaptively in a fully automate manner

    Exercises in applied phonics for grade two

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    Thesis (Ed.M.)--Boston Universit

    Sit-to-Stand Phases Detection by Inertial Sensors

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    The Sit-to-Stand(STS) is defined as the transition from the sitting to standing position. It is commonly adopted in clinical practice because musculoskeletal or neurological degenerative disorders, as well as the natural process of ageing, deter-mine an increased difficulty in rising up from a seated position. This study aimed to detect the Sit To Stand phases using data from inertial sensors. Due to the high variability of this movement, and, consequently the difficulty to define events by thresholds, we used the machine learning. We collected data from 27 participants (13 females,24.37\ub13.32 years old). They wore 10 Inertial Sensors placed on: trunk,back(L4-L5),left and right thigh, tibia, and ankles. The par-ticipants were asked to stand from an height adjustable chair for 10 times. The STS exercises were recorded separately. The starting and ending points of each phase were identified by key events. The pre-processing included phases splitting in epochs. The features extracted were: mean, standard deviation, RMS, Max and min, COV and first derivative. The features were on the epochs for each sensor. To identify the most fitting classifier, two classifier algorithms,K-nearest Neighbours( KNN) and Support Vector Machine (SVM) were trained. From the data recorded, four dataset were created varying the epochs duration, the number of sensors. The validation model used to train the classifier. As validation model, we compared the results of classifiers trained using Kfold and Leave One Subject out (LOSO) models. The classifier performances were evaluated by confusion matrices and the F1 scores. The classifiers trained using LOSO technique as validation model showed higher values of predictive accuracy than the ones trained using Kfold. The predictive accuracy of KNN and SVM were reported below: \u2022 KFold \u2013 mean of overall predictive accuracy KNN: 0.75; F1 score: REST 0.86, TRUNK LEANING 0.35,STANDING 0.60,BALANCE 0.54, SITTING 0.55 \u2013 mean of overall predictive accuracy SVM: 0.75; F1 score: REST 0.89, TRUNK LEANING 0.48,STANDING 0.48,BALANCE 0.59, SITTING 0.62 \u2022 LOSO \u2013 mean of overall predictive accuracy KNN: 0.93; F1 score: REST 0.96, TRUNK LEANING 0.79,STANDING 0.89,BALANCE 0.95, SITTING 0.88 \u2013 mean of overall predictive accuracy SVM: 0.95; F1 score phases: REST 0.98, TRUNK LEANING 0.86,STANDING 0.91,BALANCE 0.98, SIT-TING 0.9

    Manufacturing, Evaluation and Field Implementation of Recycled GFRP-Composite Railroad Ties

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    Wood railroad crossties resistance to current higher axle loads, speeds and frequency, along with the durability under harsh environments has proven to be inadequate. Additionally, defects such as decay, holes, splits, checks etc may further impair the strength and durability characteristics of the wood crossties. In this project, recycled polymer and discarded wood were used to increase the performance characteristics of the RR tie including resistance to higher axle loads, minimization of defects, and better performance under harsh environmental conditions. The objective of this study is to enhance and assess the strength characteristics of the timber crossties by using the glass fiber reinforced polymer (GFRP) composite shell. This research involved two different techniques for manufacturing the recycled composite ties, followed by laboratory testing of wood ties and GFRP recycled composite shell with wood core ties (thermoplastic) in WVU-CFC. The previous research program at WVU-CFC consisted of strengthening and evaluating the wood crossties by wrapping only the 12 inches wide steel plate embedment location using glass fiber fabrics saturated with resorcinol formaldehyde resin (thermoset).;In this research, over 200 recycled composite components were manufactured in the CFC laboratory that were used to mold 24 full-scale recycled composite ties with wood as a core material and GFRP composite as a shell material. The GFRP composite shell was manufactured using glass fabric reinforcement and Acrylonitrile Butadiene Styrene (ABS) resin. Two different fiber configurations were used in the manufacturing process-I (composite ties manufactured using twelve composite parts). Recycled composite ties produced under manufacturing process-I were tested under three point bending to evaluate the flexural rigidity. Test results of recycled composite ties from manufacturing process-I having fabric configuration-I were compared with those having fabric configuration-II. Further, recycled composite tie from manufacturing process-II (composite ties manufactured using two composite parts) along with wood crossties were tested under three point bending to evaluate the flexural rigidity, modulus of rupture, and static bending strength. Recycled composite ties showed higher static bending strength by approximately sixty percent than wood ties. Recycled composite ties also showed higher spike insertion and pullout strengths than the wood ties.;In order to study the dynamic response, a full-scale recycled composite tie produced through manufacturing process-II was embedded in gravel ballast and tested under flexural fatigue. The measured maximum deflection and applied bending moment values were compared with the theoretical values based on the classical beams on elastic foundation theory. The theoretical values were found to correlate well with the experimental values (within 10%). The research also included field testing of seven recycled composite ties on the South Branch Valley Railroad (SBVR) in Moorefield, WV. After three months of service, three ties with low fiber/fabric content showed localized horizontal cracking or some transverse cracks and the remaining four ties showed good field performance. Additional ties manufactured under this project are planned to be field-tested at TTCI, Pueblo, Colorado, test facilities. Conclusions and recommendations from this research work are summarized at the end of this report
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